Rosca, I.; Barbulescu, A.
In certain lepidopterous insects partially gamma-ray-sterilized males mated with normal females produce progeny which are more sterile than their male parents. Inherited sterility has been observed in numerous pests including the European corn borer, Ostrinia nubilalis Hb. The most important discoveries contributing the development of this techniques are reviewed. The studies on the European corn borer have revealed a dramatic inherited sterility effect when pupae have been irradiated with a low dose of 100 or 150 Gy. Data on the growth, development and behaviour of F 1 individuals indicate that the treated insects are highly competitive with the normal insects. Field tests of the inherited sterility technique in isolated O. nubilalis infestations have indicated that this method is effective and a small eradication has been done. These studies are continuing. (author)
Suverkropp, B.P.; Dutton, A.; Bigler, F.; Lenteren, van J.C.
Oviposition behaviour and egg distribution of Ostrinia nubilalis is reviewed based on published information and new research. The position of egg masses of O. nubilalis on maize plants and leaves were sampled in the field. Most egg masses were found on the lower leaf side, on the middle part of the
Skopik, S D; Takeda, M; Holyoke, C W
Beck's dual system theory (DST) is examined theoretically and experimentally by investigating the oviposition rhythm of Ostrinia nubilalis and its entrainment by light cycles. Several well-known circadian phenomena are not accounted for by the DST. 1) It does not generate transient cycles when light pulses fall during the advance portion of the circadian cycle. This is also reflected in DST-predicted phase-response curves (PRC's) for both Drosophila pseudoobscura and O. nubilalis. Steady-state phase advances are predicted to occur on day 1 after the light pulses by the DST, not several cycles later as has been observed in many cases. 2) It does not account for the observation that the magnitude of a phase shift (delta phi) is often a function of pulse duration of both delays and advances. The DST predicts the same + delta phi, for example, for a 0.5-h and a 6.0-h light pulse beginning 5.0 h after dusk. 3) The DST does not accurately predict steady-state phase relationships between the light cycle and the gating oscillation (P-system) in non-24-h light cycles. 4) The driver (S-system) is given the property of being temperature sensitive whereas the driven rhythm (P-system) is temperature compensated. This is contrary to accumulated data suggesting that the circadian pacemaker is temperature compensated.
Harrison Richard G
Full Text Available Abstract Background Moth pheromone mating systems have been characterized at the molecular level, allowing evolutionary biologists to study how changes in protein sequence or gene expression affect pheromone phenotype, patterns of mating, and ultimately, the formation of barriers to gene exchange. Recent studies of Ostrinia pheromones have focused on the diversity of sex pheromone desaturases and their role in the specificity of pheromone production. Here we produce a Δ11 desaturase genealogy within Ostrinia nubilalis. We ask what has been the history of this gene, and whether this history suggests that changes in Δ11 desaturase have been involved in the divergence of the E and Z O. nubilalis pheromone strains. Results The Δ11 desaturase gene genealogy does not differentiate O. nubilalis pheromone strains. However, we find two distinct clades, separated by 2.9% sequence divergence, that do not sort with pheromone strain, geographic origin, or emergence time. We demonstrate that these clades do not represent gene duplicates, but rather allelic variation at a single gene locus. Conclusions Analyses of patterns of variation at the Δ11 desaturase gene in ECB suggest that this enzyme does not contribute to reproductive isolation between pheromone strains (E and Z. However, our genealogy reveals two deeply divergent allelic classes. Standing variation at loci that contribute to mate choice phenotypes may permit novel pheromone mating systems to arise in the presence of strong stabilizing selection.
Full Text Available European Corn Borer (ECB - (Ostrinia nubilalis Hübner is one of the most important pest on corn in Croatia. In the last decade corn production was on over 400 000 ha, in Eastern Croatia. Although ECB is present every year, with no such a low intensity, their control is not implemented. Corn is grown in monoculture, at 40% of cornfields, which also has influence on spreading of ECB. In the last ten years average attack of ECB was 51.5%; been done three different kinds of trials for controlling ECB. First trials were carried out in DeKalb hybrids, and ECB was controlled by Biobit XL, on the base of Bacillus thuringiensis Berliner. Intensity of attack was decreased for 46%. Second trial was carried out in ten hybrids, in order to determine the tolerance of hybrids against ECB. It was identified that several domestic hybrids (OSSK 382, OSSK 664 and BC 462 are tolerant to ECB. The third trial was carried out with GM hybrids. Experiments included Pioneer hybrids Evelina Bt, and Landia Bt. Intensity of attack at Evelina standard was 52%, while in Evelina Bt, ECB wasn't present at all. At Landia standard ECB was present on 98%, while in Landia Bt, intensity of attack was 21%. At both Bt hybrids, number of larvae and tunnels was lower comparing to standard hybrids. Length of damage in Landia check was 20.66 cm, while in Landia Bt it was 0.45 cm. The yield was increased for 10.27% at Evelina Bt, and for 26.67% in Landia Bt comparing to their standards. This kind of experiments will be continued in the future, not only because of its agronomic importance, but also because of its ecological relevance.
Charles Linn Jr.
Full Text Available The response of male moths from two pheromone races of the European corn borer, Ostrinia nubilalis, was measured in a flight tunnel assay to different ratios of structurally different compounds that comprise the sex pheromone of the Asian corn borer, Ostrinia furnacalis. For both O. nubilalis races, between 1 and 5% of the males completed upwind flights to two different blends of the O. furnacalis pheromone components (the 2:1 Z/E12-14:OAc female-produced blend, and a 97:3 Z/E mix, confirming that rare males exist in the O. nubilalis populations that can detect and respond to mixtures of the O. furnacalis pheromone components. Rare males that responded to the O. furnacalis blends also responded to their own O. nubilalis blends (97:3 or 1:99 Z/E11-14:OAc, indicating that rare O. nubilalis males are not preferentially sensitive to mixtures of the O. furnacalis compounds, but rather that they have a broad range of response specificity, which includes recognition of a wide range of conspecific female-produced ratios, and also recognition of heterospecific mixtures. The results support the hypothesis that saltational shifts in pheromone blend composition (Roelofs et al., 2002 can lead to the evolution of a new species-specific communication system, in part because the broad response specificity of some males includes the ability to respond in an agonistic manner to novel mixtures of compounds.
Full Text Available BACKGROUND: Tuning of the olfactory system of male moths to conspecific female sex pheromones is crucial for correct species recognition; however, little is known about the genetic changes that drive speciation in this system. Moths of the genus Ostrinia are good models to elucidate this question, since significant differences in pheromone blends are observed within and among species. Odorant receptors (ORs play a critical role in recognition of female sex pheromones; eight types of OR genes expressed in male antennae were previously reported in Ostrinia moths. METHODOLOGY/PRINCIPAL FINDINGS: We screened an O. nubilalis bacterial artificial chromosome (BAC library by PCR, and constructed three contigs from isolated clones containing the reported OR genes. Fluorescence in situ hybridization (FISH analysis using these clones as probes demonstrated that the largest contig, which contained eight OR genes, was located on the Z chromosome; two others harboring two and one OR genes were found on two autosomes. Sequence determination of BAC clones revealed the Z-linked OR genes were closely related and tandemly arrayed; moreover, four of them shared 181-bp direct repeats spanning exon 7 and intron 7. CONCLUSIONS/SIGNIFICANCE: This is the first report of tandemly arrayed sex pheromone receptor genes in Lepidoptera. The localization of an OR gene cluster on the Z chromosome agrees with previous findings for a Z-linked locus responsible for O. nubilalis male behavioral response to sex pheromone. The 181-bp direct repeats might enhance gene duplications by unequal crossovers. An autosomal locus responsible for male response to sex pheromone in Heliothis virescens and H. subflexa was recently reported to contain at least four OR genes. Taken together, these findings support the hypothesis that generation of additional copies of OR genes can increase the potential for male moths to acquire altered specificity for pheromone components, and accordingly
Huseth, Anders S; Groves, Russell L; Chapman, Scott A; Nault, Brian A
Multiple applications of pyrethroid insecticides are used to manage European corn borer, Ostrinia nubilalis Hübner, in snap bean, but new diamide insecticides may reduce application frequency. In a 2 year small-plot study, O. nubilalis control was evaluated by applying cyantraniliprole (diamide) and bifenthrin (pyrethroid) insecticides at one of three phenological stages (bud, bloom and pod formation) of snap bean development. Co-application of these insecticides with either herbicides or fungicides was also examined as a way to reduce the total number of sprays during a season. Cyantraniliprole applications timed either during bloom or during pod formation controlled O. nubilalis better than similar timings of bifenthrin. Co-applications of insecticides with fungicides controlled O. nubilalis as well as insecticide applications alone. Insecticides applied either alone or with herbicides during bud stage did not control this pest. Diamides are an alternative to pyrethroids for the management of O. nubilalis in snap bean. Adoption of diamides by snap bean growers could improve the efficiency of production by reducing the number of sprays required each season. © 2015 Society of Chemical Industry.
Full Text Available European corn borer (Ostrinia nubilalis Hubner is one of the major corn pest in the world and in Croatia. Former investigations of corn borer in Croatia covered mostly its Eastern region. In trials conducted in 1998 and 1999 the research was extended to the North Western part of Croatia too. Macro trials were carried out with corn hybrids of FAO groups 200-600 at three localities: Križevci, Agricultural institute Osijek and at «Belje» PIK Karanac. In 1998 the intensity of the corn borer attack at the locality of «Belje» PIK Karanac was about 37.92% and in Agricultural institute Osijek 80.83%. In 1999 it varied between 37.08% at the locality of Agricultural Institute Osijek and 71.20% at the locality in Križevci. The estimated number of holes per plant in all three localities in both years was higher than the number of caterpillars. Length of damage per plant was between 0.38 and 18.80 cm. The data showed significant differences in the intensity of damaging effects on different localities while no significant differences concerning various hybrids were found. The statistical data concerning yield in both years showed significant differences among hybrids, localities and their interactions.
Vuković, S; Indić, D; Grahovac, M; Franeta, F
O. nubilalis and H. armigera regularly occur and cause significant damages in corn crops in Serbia, particularly under global warming conditions. Several measures are applied against these pests (crop rotation, tolerant and resistant hybrids, monitoring, forecast, chemical measures). Larvae damage stem, panicle and ear, which favour development of saprophytes and secondary infections by mycotoxin producing, pathogenic fungi. The aim of the paper was to test the efficacy of the insecticides azadirachtin and indoxacarb in sweet corn protection against the mentioned pests. The trials were conducted in 2014 at two localities (Becej B. and PoIjanice P.) on sweet corn, hybrid Enterprise according to standard OEPP methods (PP1/13; 1/152; 1/135). Products on the basis of azadirachtin (10 g a.i./I of product) at a rate of 0.4 and 0.5% and indoxacarb (150 g a.i./I of product) at a rate of 0.25 I/ha, were applied. Treatments were conducted on the 5th of August with tractor sprayers (high clearance). The plot size was 5000 m². Three assessments were made. The first one prior to treatment, on 25 randomly selected plants per replicate, and the number of O. nubilalis and H. armigera egg masses and larvae on silk was registered. In the second assessment (18th of August), on 20 randomly selected plants per replicate, the number of damaged plants and the number of vital larvae was registered. In the third assessment, immediately before harvest (28th of August, i.e. 12th of September) on 20 randomly selected plants per replicate, the number of plants broken below ear (fallen on the ground), damaged ears and vital larvae, was determined. Results are presented as means, efficacy (E%) according to Abbott and significance of differences by LSD test (5%). At B locality egg masses of O. nubilalis were registered on ear silk on 13-19% of plants and larvae on 3-7%, and larvae of H. armigera on 2-4%. At P locality egg masses of O. nubilalis were present on 34-40.8% of plants. After 13 days
Full Text Available European corn borer (Ostrinia nubilalis (ECB is an important maize pest in central and northern Europe. Presently it is controlled by insecticides or biological agents such as Trichogramma brassicae in several European countries, excluding Slovenia, where the pest’s pressure is highly variable and no appropriate mechanization is available. Lessening the dependence on chemical pesticides is an integral part of the European Union’s agenda for agriculture. Mass release of Trichogramma spp. could be seen as a promising alternative for ECB control in countries with a highly fluctuating ECB pressure and no mechanization for insecticide applications. However, no records of naturally occurring hymenopteran parasitoids of ECB exist in Slovenia. To address this important under-researched topic and provide the expert basis for potential introduction of ECB egg parasitoids in Slovene maize production, a systematic inventarisation programme of ECB parasitoids was launched in 2010. Additionally, ECB flight was monitored in 2011 and 2012 at two locations in Slovenia: Jablje and Rakičan. In both locations two ECB generations were observed. ECB was fist observed at the end of May in Rakičan. During the five years of the systematic survey we discovered two ECB parasitoid species. ECB egg masses were parasitized by Trichogramma brassicae, whereas ECB pupae were parasitized by Tycherus nigridens, with 6 or 7 % parasitation rate, respectively. T. nigridens represents a new taxon report for Slovenia. We conclude that there is a strong need for undertaking systematic surveys of natural enemies of agricultural pests.
Full Text Available The influence of different doses of ultraviolet (UV light on the pathogenicity of entomopathogenic fungus Beauveria bassiana (Balsamo Vuillemin to the European corn borer, Ostrinia nubilalis Hbn., and radial growth of fungus was studied in laboratory conditions. The suspensions of B. bassiana isolate SK99 were exposed to UV light. Four different doses of UV light were used in the experiment. The distance between exposed suspensions and UV light source was 0.3 m. Exposure duration was 15, 30, 45 and 60 minutes (as A, B, C and D variants. Control variant SK99 and obtained variants SK99A, SK99B, SK99C and SK99D were cultivated 21 days on Sabourard-dextrose agar. The larvae of O. nubilalis were infected with dry powder consisted of mycelia and spores from fungus cultures. During 10 days, the mortality of infected larvae was evaluated. It was ascertained that UV light exposition significantly influenced the mortality effect of B. bassiana isolates to O. nubilalis larvae. Variant SK99C showed the highest level of infectivity. Radial growth of UV variants was slower with rising time of exposure. The best ability to grow possessed non-irradiated isolate SK99 and the worse variant SK99D. The difference between these two variants was significant.
Crespo Andre LB
Full Text Available Abstract Background Lepidoptera represents more than 160,000 insect species which include some of the most devastating pests of crops, forests, and stored products. However, the genomic information on lepidopteran insects is very limited. Only a few studies have focused on developing expressed sequence tag (EST libraries from the guts of lepidopteran larvae. Knowledge of the genes that are expressed in the insect gut are crucial for understanding basic physiology of food digestion, their interactions with Bacillus thuringiensis (Bt toxins, and for discovering new targets for novel toxins for use in pest management. This study analyzed the ESTs generated from the larval gut of the European corn borer (ECB, Ostrinia nubilalis, one of the most destructive pests of corn in North America and the western world. Our goals were to establish an ECB larval gut-specific EST database as a genomic resource for future research and to explore candidate genes potentially involved in insect-Bt interactions and Bt resistance in ECB. Results We constructed two cDNA libraries from the guts of the fifth-instar larvae of ECB and sequenced a total of 15,000 ESTs from these libraries. A total of 12,519 ESTs (83.4% appeared to be high quality with an average length of 656 bp. These ESTs represented 2,895 unique sequences, including 1,738 singletons and 1,157 contigs. Among the unique sequences, 62.7% encoded putative proteins that shared significant sequence similarities (E-value ≤ 10-3with the sequences available in GenBank. Our EST analysis revealed 52 candidate genes that potentially have roles in Bt toxicity and resistance. These genes encode 18 trypsin-like proteases, 18 chymotrypsin-like proteases, 13 aminopeptidases, 2 alkaline phosphatases and 1 cadherin-like protein. Comparisons of expression profiles of 41 selected candidate genes between Cry1Ab-susceptible and resistant strains of ECB by RT-PCR showed apparently decreased expressions in 2 trypsin-like and 2
Droney, David C; Musto, Callie J; Mancuso, Katie; Roelofs, Wendell L; Linn, Charles E
Coordinated sexual communication systems, seen in many species of moths, are hypothesized to be under strong stabilizing natural selection. Stabilized communication systems should be resistant to change, but there are examples of species/populations that show great diversification. A possible solution is that it is directional sexual selection on variation in male response that drives evolution. We tested a component of this model by asking whether 'rare' males (ca. 5 % of all males in a population) of the European corn borer moth (ECB), Ostrinia nubilalis, that respond to the sex pheromones of both ECB and a different Ostrinia species (O. furnacalis, the Asian corn borer, ACB), might play an important role in diversification. We specifically tested, via artificial selection, whether this broad male response has an evolvable genetic component. We increased the frequency of broad male response from 5 to 70 % in 19 generations, showing that broad-responding males could be important for the evolution of novel communication systems in ECB. We did not find a broader range of mating acceptance of broad males by females of the base population, however, suggesting that broad response would be unlikely to increase in frequency without the involvement of other factors. However, we found that ECB selection-line females accepted a broader range of courting males, including those of ACB, than did females of the base population. Thus, a genetic correlation exists between broad, long-range response to female sex pheromone and the breadth of female acceptance of males at close range. These results are discussed in the context of evolution of novel communication systems in Ostrinia.
Toxity of Gedunin, Piperine and Crude Extracts of their Natural Products on Growth and Development of Ostrinia Nubilalis Hbner (Lepidoptera: Pyrarlidae). F K Ewete, J T Arnason, T Durst, S Mackinnon ...
Hernández-Rodríguez, Carmen Sara; Hernández-Martínez, Patricia; Van Rie, Jeroen; Escriche, Baltasar; Ferré, Juan
First generation of insect-protected transgenic corn (Bt-corn) was based on the expression of Cry1Ab or Cry1Fa proteins. Currently, the trend is the combination of two or more genes expressing proteins that bind to different targets. In addition to broadening the spectrum of action, this strategy helps to delay the evolution of resistance in exposed insect populations. One of such examples is the combination of Cry1A.105 with Cry1Fa and Cry2Ab to control O. nubilalis and S. frugiperda. Cry1A.105 is a chimeric protein with domains I and II and the C-terminal half of the protein from Cry1Ac, and domain III almost identical to Cry1Fa. The aim of the present study was to determine whether the chimeric Cry1A.105 has shared binding sites either with Cry1A proteins, with Cry1Fa, or with both, in O. nubilalis and in S. frugiperda. Brush-border membrane vesicles (BBMV) from last instar larval midguts were used in competition binding assays with 125I-labeled Cry1A.105, Cry1Ab, and Cry1Fa, and unlabeled Cry1A.105, Cry1Aa, Cry1Ab, Cry1Ac, Cry1Fa, Cry2Ab and Cry2Ae. The results showed that Cry1A.105, Cry1Ab, Cry1Ac and Cry1Fa competed with high affinity for the same binding sites in both insect species. However, Cry2Ab and Cry2Ae did not compete for the binding sites of Cry1 proteins. Therefore, according to our results, the development of cross-resistance among Cry1Ab/Ac, Cry1A.105, and Cry1Fa proteins is possible in these two insect species if the alteration of shared binding sites occurs. Conversely, cross-resistance between these proteins and Cry2A proteins is very unlikely in such case. PMID:23861865
Full Text Available Lepidopteran insects use sex pheromones for sexual communication. Pheromone receptors expressed on peripheral olfactory receptor neurons (ORNs are critical part to detect the sex pheromones. In genus Ostrinia, several pheromone receptors were functional analyzed in O. nubilalis and O. scapulalis but the knowledge in O. furnacalis was rare. In this study, seven pheromone receptors were deorphanized by heterologous expression system of Xenopus oocytes. Functional types of sensilla trichoidea were classified by single sensillum recordings to interpret the response pattern of olfactory sensory neurons to Ostrinia pheromone components. OfurOR4 and OfurOR6 responded to the major sex pheromone Z/E12-14:OAc. OfurOR4 is the main receptor for both Z/E12-14:OAc and OfurOR6 mainly responded to E12-14:OAc. Functional differentiation of gene duplication were found between OfurOR5a and OfurOR5b. OfurOR5b showed a broad response to most of the pheromone components in O. furnacalis, whereas OfurOR5a was found without ligands. OfurOR7 showed a specific response to Z9-14:OAc and OfurOR8 mainly responded to Z11-14:OAc and E11-14:OAc. OfurOR3 did not respond to any pheromone components. Our results improved the current knowledge of pheromone reception in Ostrinia species which may contribute to speciation.
Popović, Ž. D.; Subotić, A.; Nikolić, T. V.; Radojičić, R.; Blagojević, D. P.; Grubor-Lajšić, G.; Košťál, Vladimír
Roč. 186, AUG 1 (2015), s. 1-7 ISSN 1096-4959 R&D Projects: GA MŠk LH12103 Grant - others:Ministry of Education and Science of the Republic of Serbia(RS) 173014 Institutional support: RVO:60077344 Keywords : GST * redoxin * ferritin Subject RIV: ED - Physiology Impact factor: 1.651, year: 2015 http://www.sciencedirect.com/science/article/pii/S1096495915000627
Full Text Available Field experiments with natural population of European corn borer (ECB were conducted in three vegetation seasons (2012-2014 at Agricultural Institute in Osijek. The experiment was set up in a randomized block design as split-split plot method, with three repetitions. This plot has been constantly maize - soybean rotation for already 15 years. It was a 3x3x4 factorial experiment with three irrigation levels (A1- non-irrigated (only natural precipitation, A2-from 60% to 80% field water capacity - FWC and A3-from 80% to100% FWC, three nitrogen fertilizer levels (B1-0, B2-100 and B3-200 kg N/ha and four different genotypes (C1-0SSK 596; C2-0SSK 617; C3-0SSK 602 and C4-0SSK 552.The aim of this study was to determine the effect of different levels of irrigation, nitrogen fertilization and genotypes on occurrence and damage of maize plants by the European corn borer larvae and relation between leaf feeding larvae with nitrogen and silicon concentration as well as C/N ratio. At the end of each growing season, ten maize plants from each variant were cut. Ear weight for each specific plant (g, tunnel length (cm, number of larvae in stalk, number of larvae in the ear shank, ear shank damage (cm and total number of larvae in maize plantwere determined. In silking stage (middle of July ten leaves (below the ear, from 10 maize plants were sampled on each variant. Nitrogen, carbon and silicon concentrations were determined in maize leaf (% and C/N ratio calculated. In 2014, a significantly lower ECB attack was determined taking into account lower temperatures and higher amount of precipitate compared to the previous years. Dominance of Z-type European corn borer on pheromone traps in the area of eastern Slavonia was confirmed. Increasing the level of soil water content, damage from larvae was reduced and increasing the level of nitrogen fertilization feeding activity was increased. We have confirmed different hybrid resistance in regards to damage from larvae, so C4 (OSSK 552 genotype was the most resistant while C1 (OSSK 596 was the most susceptible. Concentration of nitrogen and silicon in a maize leaf was in negative correlation as well as nitrogen concentration and C/N ratio. Hybrid resistance didn't entirely depend on nitrogen and silicon concentrations, even though there was greater damage on most hybrids with higher concentration of nitrogen, while damage was reduced with higher concentration of silicon.
The sex determination system of Lepidoptera is comprised of heterogametic females (ZW) and homogametic males (ZZ), where voltinism (Volt) and the male pheromone response traits (Resp) are controlled by genes housed on the Z-chromosome. Volt and Resp determine traits that lead to ecotype differentia...
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Wang, H.S.; Liu, Q.R.; Lu, D.G.; Wang, E.D.; Kang, W.; Liu, X.H.; Li, Y.J.; He, Q.L.; Zhang, H.Q.
The mating competitiveness of Ostrinia furnacalis F 1 male moths (progeny of male parents irradiated with 200 Gy) was compared with the mating competitiveness of untreated moths. These studies revealed that F 1 male moths were involved in more than 50% of the matings with normal females. The flight ability and response towards sex pheromone was similar for F 1 and untreated moths, although the number of F 1 moths captured was slightly less than the number of untreated moths captured. The number of eupyrene sperm in the testes of P 1 moths treated with 200 Gy was similar to the number of eupyrene sperm in the testes of normal moths. However, the number of sperm bundles was significantly reduced in the testes of 200 Gy F 1 moths. Compared to normal moths, daily sperm descent into the duplex ejaculatorius was affected only at day 3 after eclosion of F 1 moths. Sperm transfer to spermatheca by 200 Gy F 1 male moths was less than that of their irradiated (200 Gy) parents and of normal moths. Successive releases of Trichogramma ostriniae in the egg stage of first and second generation Ostrinia furnacalis were combined with the release of F 1 moths from male parents treated with 200 Gy. The combination of the F 1 sterility technique with augmentative biological control suppressed the wild population of this pest in 500 hectares of field corn. (author)
Takanashi, Takuma; Nakano, Ryo; Surlykke, Annemarie
energy at 40 kHz, but distinctly different from the ultrasound produced by O. furnacalis, consisting of groups of pulses peaking at 50 kHz and with substantially more energy up to 80 kHz. Despite overall similarities, temporal features and patterns of amplitude modulation differed significantly among...... the geographic populations of O. nubilalis and O. scapulalis, which differed in pheromone type. In contrast, no significant difference in hearing was found among the three species with regard to the most sensitive frequencies and hearing threshold levels. The patterns of variations in the songs and pheromones...... well reflected those of the phylogenetic relationships, implying that ultrasound and pheromone communications have diverged concordantly. Our results suggest that concordant evolution in sexual signals such as courtship ultrasounds and sex pheromones occurs in moths....
Itji Diana Daud
Full Text Available Connection between Zea mays L., Ostrinia furnacalis (Lep.:Pyralidae and Beauveria bassiana Vuill. The entomopatogen fungus, Beauveria bassiana (Balsamo, is obtained in the tissue of corn plant through submersion of seed in cinidia 1010/ml. Tissue observation showed that hifa B. bassiana appears when the plant attain the age of three weeks and when it reaches six weeks B bassiana appears in all sample plants. Hifa obtained in parenchyma tissue passively without causing illness the mother plant. The appearance of B. bassiana is remained until the 12th weeks of plant. Bio test of plan which contain the endofit of B. bassiana showed the percentage of tested insect mortality is 64%. The observation showed that the corn plant can still produce the toxin of beauverisin.
Aye Kyawt Kyawt Ei
Full Text Available The larval susceptibility of the Asian corn borer, Ostrinia furnacalis (Guenee (Lepidoptera: Crambidae, to a Bacillus thuringiensis protein (Cry1Ac was evaluated using insect feeding bioassays. The founding population of O. furnacalis was originally collected from the experimental station of UGM at Kalitirto and had been reared in the laboratory for three generations using an artificial diet “InsectaLf”. The tested instars were exposed on diets treated with a series of concentrations of Cry1Ac for one week. The LC50 values on the seventh day after treatment for 1st, 2nd, 3rd and 4th instars were 7.79, 21.12, 113.66, and 123.17 ppm, respectively, showing that the higher the instars the lesser the susceptibility to Cry1Ac. When the neonates were exposed to sublethal concentrations of Cry1Ac (0.0583, 0.116, and 0.5830 ppm, growth and development of the surviving larvae were inhibited. The fecundity and viability of females produced from treated larvae decreased with increasing the concentrations. These findings indicate that Cry1Ac is toxic to larva of O. furnacalis and has chronic effects to larvae surviving from Cry1Ac ingestion. Kepekaan larva penggerek batang jagung Asia, Ostrinia furnacalis (Guenee (Lepidoptera: Crambidae, terhadap protein Bacillus thuringiensis Cry1Ac diuji dengan metode celup pakan. Larva berasal dari pertanaman jagung di KP-4, UGM di Kalitirto dan telah dikembangbiakkan di laboratorium menggunakan pakan buatan (InsectaLF selama tiga generasi sebelum digunakan untuk pengujian. Larva O. furnacalis yang diuji dipaparkan pada pakan buatan yang telah dicelupkan pada seri konsentrasi Cry1Ac. Nilai LC50 pada hari ketujuh setelah perlakukan untuk instar 1, 2, 3, dan 4 berturut-turut adalah 0,79; 21,12; 113,66; dan 123,17 ppm. Hal ini menunjukkan bahwa instar yang semakin tinggi tingkat kepekaannya terhadap Cry1Ac semakin menurun. Larva yang baru menetas dan diberi pakan yang telah dicelupkan pada konsentrasi sublethal Cry1Ac
Full Text Available Insect phenoloxidase (PO belongs to the type 3 copper protein family and possesses oxidoreductase activities. PO is typically synthesized as a zymogen called prophenoloxidase (PPO and requires the proteolytic activation to function. We here cloned full-length cDNA for 3 previously unidentified PPOs, which we named OfPPO1a, OfPPO1b, and OfPPO3, from Asian corn borer, Ostrinia furnacalis (Gunée, in addition to the previously known OfPPO2. These conceptual PPOs and OfPPO2 all contain two common copper-binding regions, two potential proteolytic activation sites, a plausible thiol-ester site, and a conserved C-terminal region but lack a secretion signal peptide sequence at the N-terminus. O. furnacalis PPOs were highly similar to other insect PPOs (42% to 79% identity and clustered well with other lepidopteran PPOs. RT-PCR assay showed the transcripts of the 4 OfPPOs were all detected at the highest level in hemocytes and at the increased amounts after exposure to infection by bacteria and fungi. Additionally, we established an Escherichia coli (E. coli expression system to produce recombinant O. furnacalis PPO proteins for future use in investigating their functions. These insights could provide valuable information for better understanding the activation and functioning mechanisms of O. furnacalis PPOs.
Full Text Available Development of an ideal marker system facilitates a better understanding of the genetic diversity in lepidopteran non-model organisms, which have abundant species, but relatively limited genomic resources. Single nucleotide polymorphisms (SNPs discovered within single-copy genes have proved to be desired markers, but SNP genotyping by current techniques remain laborious and expensive. High resolution melting (HRM curve analysis represents a simple, rapid and inexpensive genotyping method that is primarily confined to clinical and diagnostic studies. In this study, we evaluated the potential of HRM analysis for SNP genotyping in the lepidopteran non-model species Ostrinia furnacalis (Crambidae. Small amplicon and unlabeled probe assays were developed for the SNPs, which were identified in 30 females of O. furnacalis from 3 different populations by our direct sequencing. Both assays were then applied to genotype 90 unknown female DNA by prior mixing with known wild-type DNA. The genotyping results were compared with those that were obtained using bi-directional sequencing analysis. Our results demonstrated the efficiency and reliability of the HRM assays. HRM has the potential to provide simple, cost-effective genotyping assays and facilitates genotyping studies in any non-model lepidopteran species of interest.
Chen, Long; Chen, Peng-Yan; Xue, Xiao-Feng; Hua, Hai-Qing; Li, Yuan-Xi; Zhang, Fan; Wei, Shu-Jun
Animal mitochondrial genomes usually exhibit conserved gene arrangement across major lineages, while those in the Hymenoptera are known to possess frequent rearrangements, as are those of several other orders of insects. Here, we sequenced two complete mitochondrial genomes of Trichogramma japonicum and Trichogramma ostriniae (Hymenoptera: Chalcidoidea: Trichogrammatidae). In total, 37 mitochondrial genes were identified in both species. The same gene arrangement pattern was found in the two species, with extensive gene rearrangement compared with the ancestral insect mitochondrial genome. Most tRNA genes and all protein-coding genes were encoded on the minority strand. In total, 15 tRNA genes and seven protein-coding genes were rearranged. The rearrangements of cox1 and nad2 as well as most tRNA genes were novel. Phylogenetic analysis based on nucleotide sequences of protein-coding genes and on gene arrangement patterns produced identical topologies that support the relationship of (Agaonidae + Pteromalidae) + Trichogrammatidae in Chalcidoidea. CREx analysis revealed eight rearrangement operations occurred from presumed ancestral gene order of Chalcidoidea to form the derived gene order of Trichogramma. Our study shows that gene rearrangement information in Chalcidoidea can potentially contribute to the phylogeny of Chalcidoidea when more mitochondrial genome sequences are available.
Chen, Ri-Zhao; Jow, Chung-Kuang; Klein, Michael G; Jia, Yu-di; Zhang, Da-Yu; Li, Lan-Bing
Mating disruption of Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae) with its sex pheromone has not been commonly used in NE China due to a lack of information about optimal sex pheromone dosages and the density of release points required in the field. During 2014-2016, first, the two active pheromone ingredients were evaluated in the laboratory alone at ca. 2.5-5.0 mg, or in combination at 0.2-6.0 mg, to disrupt male O. furnacalis mating behaviors. Then, mating disruption areas, with radii of disruption treatments. Finally, 6.0 (F30) and 0.2 mg (Fs) dosages were used in fields at 20-640 and 200-6,400 release points/ha. We found that ≧6.0 mg of the binary pheromone mixture, or ca. 5.0 mg of either of the two single components, completely disrupted mating behaviors, and F30 of the binary mixture provided a 200-m2 disruption area, with at least 50% capture reductions. At a density of 60-640 and 600-6,400 points/ha in a corn field, F30 and Fs dosages provided >90% mating disruption, leaf protection, and ear protection. The dispenser densities and inverse male catches in traps tended to follow a noncompetitive mechanism of mating disruption. Since 85% disruption of mating with 200-400 0.02 mg release points/ha was obtained, that level is recommended as the choice in future NE China O. furnacalis IPM programs. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Full Text Available BACKGROUND: The Asian corn borer (Ostrinia furnacalis (Guenée is one of the most serious corn pests in Asia. Control of this pest with entomopathogenic fungus Beauveria bassiana has been proposed. However, the molecular mechanisms involved in the interactions between O. furnacalis and B. bassiana are unclear, especially under the conditions that the genomic information of O. furnacalis is currently unavailable. So we sequenced and characterized the transcriptome of O. furnacalis larvae infected by B. bassiana with special emphasis on immunity-related genes. METHODOLOGY/PRINCIPAL FINDINGS: Illumina Hiseq2000 was used to sequence 4.64 and 4.72 Gb of the transcriptome from water-injected and B. bassiana-injected O. furnacalis larvae, respectively. De novo assembly generated 62,382 unigenes with mean length of 729 nt. All unigenes were searched against Nt, Nr, Swiss-Prot, COG, and KEGG databases for annotations using BLASTN or BLASTX algorithm with an E-value cut-off of 10(-5. A total of 35,700 (57.2% unigenes were annotated to at least one database. Pairwise comparisons resulted in 13,890 differentially expressed genes, with 5,843 up-regulated and 8,047 down-regulated. Based on sequence similarity to homologs known to participate in immune responses, we totally identified 190 potential immunity-related unigenes. They encode 45 pattern recognition proteins, 33 modulation proteins involved in the prophenoloxidase activation cascade, 46 signal transduction molecules, and 66 immune responsive effectors, respectively. The obtained transcriptome contains putative orthologs for nearly all components of the Toll, Imd, and JAK/STAT pathways. We randomly selected 24 immunity-related unigenes and investigated their expression profiles using quantitative RT-PCR assay. The results revealed variant expression patterns in response to the infection of B. bassiana. CONCLUSIONS/SIGNIFICANCE: This study provides the comprehensive sequence resource and expression
Zhou, Fan; Wang, Guirong; An, Chunju
Background The Asian corn borer (Ostrinia furnacalis (Guenée)) is one of the most serious corn pests in Asia. Control of this pest with entomopathogenic fungus Beauveria bassiana has been proposed. However, the molecular mechanisms involved in the interactions between O. furnacalis and B. bassiana are unclear, especially under the conditions that the genomic information of O. furnacalis is currently unavailable. So we sequenced and characterized the transcriptome of O. furnacalis larvae infected by B. bassiana with special emphasis on immunity-related genes. Methodology/Principal Findings Illumina Hiseq2000 was used to sequence 4.64 and 4.72 Gb of the transcriptome from water-injected and B. bassiana-injected O. furnacalis larvae, respectively. De novo assembly generated 62,382 unigenes with mean length of 729 nt. All unigenes were searched against Nt, Nr, Swiss-Prot, COG, and KEGG databases for annotations using BLASTN or BLASTX algorithm with an E-value cut-off of 10−5. A total of 35,700 (57.2%) unigenes were annotated to at least one database. Pairwise comparisons resulted in 13,890 differentially expressed genes, with 5,843 up-regulated and 8,047 down-regulated. Based on sequence similarity to homologs known to participate in immune responses, we totally identified 190 potential immunity-related unigenes. They encode 45 pattern recognition proteins, 33 modulation proteins involved in the prophenoloxidase activation cascade, 46 signal transduction molecules, and 66 immune responsive effectors, respectively. The obtained transcriptome contains putative orthologs for nearly all components of the Toll, Imd, and JAK/STAT pathways. We randomly selected 24 immunity-related unigenes and investigated their expression profiles using quantitative RT-PCR assay. The results revealed variant expression patterns in response to the infection of B. bassiana. Conclusions/Significance This study provides the comprehensive sequence resource and expression profiles of the
Full Text Available A field study was conducted to determine the distribution of egg masses of Ostrinia furnacalis on corn leaves and within corn field. The corn field was divided into three regions: the inner edge closed to other crops and outer edge closed to main road and the middle region. The numbers of egg masses laid were recorded entirely in all corn plants existed (census method. Egg laying period lasted for 34 days, with 11 days from initiation of egg laying to the peak of oviposition and 23 days from the peak to termination of egg laying. The egg masses laid on corn leaves were distributed in aggregation pattern. During eight-opened-leaf to twelve-opened-leaf stages, there were 847 egg masses found, and 80.9% was laid on the sixth-to-ninth leaves. From tasseling to blister stages there were 491 egg masses found of which approximately 80.7% was laid on the seventh-to-11 32.8, and 29.8% of those were found in the inner edge, middle, and outer edge of corn field, respectively. leaves. Egg masses laid within corn field varied, in which 37.4, 32.8, and 29.8% of those were found in the inner edge, middle, and outer edge of corn field, respectively. Kajian lapang dilaksanakan untuk mengetahui pola sebaran peletakan kelompok telur ngengat Ostrinia furnacalis pada daun tanaman jagung dan penyebarannya pada lahan pertanaman jagung. Lahan penelitian dibagi menjadi tiga kelompok yaitu lahan pinggir dalam berdekatan dengan pertanaman lain, bagian tengah lahan, dan lahan pinggir luar berdekatan dengan jalan raya. Pengamatan kelompok telur dilakukan pada seluruh tanaman jagung (sensus. Periode peletakan telur berlangsung selama 34 hari, dengan periode inisiasi hingga puncak 11 hari dan periode setelah puncak hingga akhir peletakan telur 23 hari. Peletakan telur O. furnacalis pada daun tanaman jagung menyebar secara berkelompok. Pada fase 8 hingga 10 daun telah terbuka sempurna ditemukan sebanyak 847 kelompok telur, 80,9% diantaranya ditemukan pada daun ke 6–9
JiaHe; Zeng-guangYan; Zhi-shengJiang
Five new compounds were tested on the growth and antifeeding activity compared with toosendanin against fifth instar larvae Ostrinia furtuwalis. The activities of two proteases, a weak alkaline trypsine-like enzyme and a chymotrypsin-like enzyme, in the midgut of Ostriniafurnacalis larvae were also measured. Experimental restilts suggest that when incorporated into an artificial diet at the concentration of 500mg/kg, the antifeeding activities of toosendanin, C19 , C23 , C24 , C26 , C28 were 51.16%, 57.61%, 4.28%, 51.08%, 36.73% and 51.67%,respectively, C19, C24, C28 had no significant difference with toosendanin. At 20mg/kg, the larval growth were remarkably suppressed by CI9, C26, C28, the inhibition of C28 was close to toosendanin in 48 h. The two proteases were activated by toosendanin and C28 while they were inhibited in 48 h but activated in 24 h by C19, C24 and C26,In this paper, the related functions and mechanisms were discussed.
Full Text Available Development of resistance in target pests is a major threat to long-term use of transgenic crops expressing Bacillus thuringiensis (Bt Cry toxins. To manage and/or delay the evolution of resistance in target insects through the implementation of effective strategies, it is essential to understand the basis of resistance. One of the most important mechanisms of insect resistance to Bt crops is the alteration of the interactions between Cry toxins and their receptors in the midgut. A Cry1Ac-selected strain of Asian corn borer (ACB, Ostrinia furnacalis, a key pest of maize in China, evolved three mutant alleles of a cadherin-like protein (OfCAD (MPR-r1, MPR-r2 and MPR-r3, which mapped within the toxin-binding region (TBR. Each of the three mutant alleles possessed two or three amino acid substitutions in this region, especially Thr1457→Ser. In highly resistant larvae (ACB-Ac200, MPR-r2 had a 26-amino acid residue deletion in the TBR, which resulted in reduced binding of Cry1Ac compared to the MPR from the susceptible strain, suggesting that the number of amino acid deletions influences the level of resistance. Furthermore, downregulation of OfCAD gene (ofcad transcription was observed in the Cry1Ac resistant strain, ACB-Ac24, suggesting that Cry1Ac resistance in ACB is associated with the downregulation of the transcript levels of the cadherin-like protein gene. The OfCAD identified from ACB exhibited a high degree of similarity to other members of the cadherin super-family in lepidopteran species.
Chu, Yuan; Liu, Yang; Shen, Dongxu; Hong, Fang; Wang, Guirong; An, Chunju
Exposure to entomopathogenic fungi is one approach for insect pest control. Little is known about the immune interactions between fungus and its insect host. Melanization is a prominent immune response in insects in defending against pathogens such as bacteria and fungi. Clip domain serine proteases in insect plasma have been implicated in the activation of prophenoloxidase, a key enzyme in the melanization. The relationship between host melanization and the infection by a fungus needs to be established. We report here that the injection of entomopathogenic fungus Beauveria bassiana induced both melanin synthesis and phenoloxidase activity in its host insect, the Asian corn borer, Ostrinia furnacalis (Guenée). qRT-PCR analysis showed several distinct patterns of expression of 13 clip-domain serine proteases in response to the challenge of fungi, with seven increased, two decreased, and four unchanged. Of special interest among these clip-domain serine protease genes are SP1 and SP13, the orthologs of Manduca sexta HP6 and PAP1 which are involved in the prophenoloxidase activation pathway. Recombinant O. furnacalis SP1 was found to activate proSP13 and induce the phenoloxidase activity in corn borer plasma. Additionally, SP13 was determined to directly cleave prophenoloxidase and therefore act as the prophenoloxidase activating protease. Our work thus reveals a biochemical mechanism in the melanization in corn borer associated with the challenge by B. bassiana injection. These insights could provide valuable information for better understanding the immune responses of Asian corn borer against B. bassiana. Copyright © 2015 Elsevier Inc. All rights reserved.
Full Text Available Two colonies of Asian corn borer, Ostrinia furnacalis (Guenée, artificially selected from a Bt-susceptible colony (ACB-BtS for resistance to Cry1Ab (ACB-AbR and Cry1Ac (ACB-AcR toxins, were used to analyze inheritance patterns of resistance to Cry1 toxins. ACB-AbR and ACB-AcR evolved significant levels of resistance, with resistance ratios (RR of 39-fold and 78.8-fold to Cry1Ab and Cry1Ac, respectively. The susceptibility of ACB-AbR larvae to Cry1Ac and Cry1F toxins, which had not previously been exposed, were significantly reduced, being >113-fold and 48-fold, respectively. Similarly, susceptibility of ACB-AcR larvae to Cry1Ab and Cry1F were also significantly reduced (RR > nine-fold, RR > 18-fold, respectively, indicating cross-resistance among Cry1Ab, Cry1Ac, and Cry1F toxins. However, ACB-AbR and ACB-AcR larvae were equally susceptible to Cry1Ie as were ACB-BtS larvae, indicating no cross-resistance between Cry1Ie and Cry1Ab or Cry1Ac toxins; this may provide considerable benefits in preventing or delaying the evolution of resistance in ACB to Cry1Ab and Cry1Ac toxins. Backcrossing studies indicated that resistance to Cry1Ab toxin was polygenic in ACB-AbR, but monogenic in ACB-AcR, whilst resistance to Cry1Ac toxin was primarily monogenic in both ACB-AbR and ACB-AcR, but polygenic as resistance increased.
The European corn borer, Ostrinia nubilalis (Hubner), (Lepidoptera: Crambidae), is a quarantine pest for several fresh commodities, including corn-on-the-cob, bell peppers, and green beans. Methyl bromide fumigation is the usual phytosanitary treatment, but the chemical is under increasing regulat...
Bacillus thuringiensis (Bt) maize was developed primarily for North American pests such as European corn borer (Ostrinia nubilalis Hubner). However, most Bt maize products also are cultivated outside of North America, where the primary pests are different and often have lower susceptibility to Bt to...
The Asian corn borer, Ostrinia furnacalis, and European corn borer, O. nubilalis (Lepidoptera: Crambidae) cause damage to cultivated maize in spatially distinct geographies, and have evolved divergent hydrocarbons as the basis of sexual communication. The Yili area of Xinjiang Province China repres...
Ostrinia nubilalis. PLoS ONE 5, e8685. Wanner, K.W., Nichols, A.S.,Walden, K.K., Brockmann, A., Luetje, C.W., Robertson, H.M., 2007. A honey bee odorant...allosteric”. Protein Sci. 20, 1119e1124. Christopoulos, A., Kenakin, T., 2002. G protein -coupled receptor allosterism and complexing. Pharmacol. Rev. 54...Newcomb, R.D., Warr, C.G., 2008. Drosophila odorant receptors are novel seven transmembrane domain proteins that can signal independently of
Svobodová, Eva; Trnka, Miroslav; Žalud, Zdeněk; Semerádová, D.; Dubrovský, Martin; Eitzinger, Josef; Štěpánek, Petr
Roč. 15, SEP 2012 (2012), s. 54-57 ISSN 1335-258X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŠk(CZ) EE2.4.31.0056 Institutional support: RVO:67179843 Keywords : Cydia pomonella * Ostrinia nubilalis * Lobesia botrana * změna klimatu * CLIMEX * climate change * sensitive areas Subject RIV: DG - Athmosphere Sciences, Meteorology
Kjellsson, Gøsta; Sørensen, Jesper Givskov; Damgaard, Christian
"Den genmodificerede fire-stakkede majskrydsning adskiller sig fra konven-tionelle majs ved at have indsat gener der gør planterne tolerante over for herbiciderne glufosinat-ammonium og glyfosat. Desuden er majsen tolerant over for angreb af sommerfuglearter såsom kornboreren (Ostrinia nubilalis...... consequences. In case of accidental mixing and/or dispersal of GMO-seed, this will probably be detected by the procedures performed by the Danish NaturErhvervstyrelse....
Kjellsson, Gøsta; Sørensen, Jesper Givskov; Damgaard, Christian
"Den genmodificerede fem-stakkede majskrydsning adskiller sig fra konventionelle majs ved at have indsat gener der gør planterne tolerante over for herbiciderne glufosinat-ammonium og glyfosat. Desuden er majsen tolerant over for angreb af sommerfuglearter såsom kornboreren (Ostrinia nubilalis) og...... or no adverse environmental consequences. In case of accidental mixing and/or dispersal of GMO-seed, this will probably be detected by the procedures performed by the Danish NaturErhvervstyrelse. "...
Kjellsson, Gøsta; Damgaard, Christian
"Den genmodificerede fem-stakkede majskrydsning adskiller sig fra konventionelle majs ved at have indsat gener der gør planterne tolerante over for herbiciderne glufosinat-ammonium og glyfosat. Desuden er majsen tolerant over for angreb af sommerfuglearter såsom kornboreren (Ostrinia nubilalis) og...... or no adverse environmental consequences. In case of accidental mixing and/or dispersal of GMO-seed, this will probably be detected by the procedures performed by the Danish NaturErhvervstyrelse. "...
刘紫娟; 李萍; 宗毓铮; 董琦; 郝兴宇
Since industrial revolution, global atmospheric carbon dioxide (CO2) concentration ([CO2]) has risen from 280mmol·mol–1 to the current level of about 392mmol·mol–1. Foxtail millet (Setaria italica) is one of the most important C4 crops in the semiarid regions of North China, yet there is lack of sufficient information on how the crop responds to climate change in China. Here, we studied the effects of elevated atmospheric [CO2] on foxtail millet in order to understand the changes in foxtail millet production under future CO2 concentrations along with the response of C4 crops to climate change. An open top chamber (OTC) system was used to test the effect of elevated [CO2] on foxtail millet. One OTC was used as the control chamber, which maintained the ambient [CO2]. In another OTC, elevated [CO2] (ambient [CO2] + 200 mmol×mol–1) was constantly maintained from crop emergence to harvest. Foxtail millet was sown in 40 cm × 60 cm pots (28 cm depth). Ten plants were grown in each pot and 10 pots were put in every OTC. Leaf photosynthesis was measured using a portable gas exchange system. Chlorophyll fluorescence parameter was assessed using a miniaturized pulse-amplitude modulated fluorescence analyzer with a leaf clip holder. The changes in morphological parameters, biomass, yield and damage of Asian corn borer (Ostrinia furnacalis) in response to elevated [CO2] were also determined. The results showed that elevated [CO2] increased the net photosynthesis rate (Pn), stomatal conductance (gs), transpiration rate (Tr) and water use efficiency (WUE) of foxtail millet by 38.73%, 27.53%, 6.93% and 40.56%, respectively. The maximal photochemical quantum yield (Fv/Fm) and non-photochemical quenching coefficient (NPQ) of foxtail millet leaf photosystem Ⅱ significantly decreased under elevated [CO2]. Photosystem Ⅱ quantum yield (ΦPSII) and apparent electron transfer rate (ETR) increased, but the change in photochemical quenching destruction coefficient (qP) was
Fotini A Koutroumpa
Full Text Available Pheromone communication relies on highly specific signals sent and received between members of the same species. However, how pheromone specificity is determined in moth olfactory circuits remains unknown. Here we provide the first glimpse into the mechanism that generates this specificity in Ostrinia nubilalis. In Ostrinia nubilalis it was found that a single locus causes strain-specific, diametrically opposed preferences for a 2-component pheromone blend. Previously we found pheromone preference to be correlated with the strain and hybrid-specific relative antennal response to both pheromone components. This led to the current study, in which we detail the underlying mechanism of this differential response, through chemotopically mapping of the pheromone detection circuit in the antenna. We determined that both strains and their hybrids have swapped the neuronal identity of the pheromone-sensitive neurons co-housed within a single sensillum. Furthermore, neurons that mediate behavioral antagonism surprisingly co-express up to five pheromone receptors, mirroring the concordantly broad tuning to heterospecific pheromones. This appears as possible evolutionary adaptation that could prevent cross attraction to a range of heterospecific signals, while keeping the pheromone detection system to its simplest tripartite setup.
Vélez, Ana M; Vellichirammal, Neetha Nanoth; Jurat-Fuentes, Juan Luis; Siegfried, Blair D
The Cry1Fa protein from the bacterium Bacillus thuringiensis (Bt) is known for its potential to control lepidopteran pests, especially through transgenic expression in maize and cotton. The maize event TC1507 expressing the cry1Fa toxin gene became commercially available in the United States in 2003 for the management of key lepidopteran pests including the European corn borer, Ostrinia nubilalis, and the fall armyworm, Spodoptera frugiperda. A high-dose/refuge strategy has been widely adopted to delay evolution of resistance to event TC1507 and other transgenic Bt crops. Efficacy of this strategy depends on the crops expressing a high dose of the Bt toxin to targeted pests and adjacent refuges of non-Bt host plants serving as a source of abundant susceptible insects. While this strategy has proved effective in delaying O. nubilalis resistance, field-evolved resistance to event TC1507 has been reported in S. frugiperda populations in Puerto Rico, Brazil, and the southeastern United States. This paper examines available information on resistance to Cry1Fa in O. nubilalis and S. frugiperda and discusses how this information identifies opportunities to refine resistance management recommendations for Bt maize. Copyright © 2016 Elsevier Inc. All rights reserved.
Full Text Available The Rubin-7 maize hybrid belongs to the FAO 700 maturity group. It is characterized by high yield potential for kernels, which was proven during investigations by the Committee for Species. During the three year monitoring period, from 1999 to 2001, the average yield of kernel was 9.412 t/ha which is 5% above the ZP 704 standard, and was highly statistically significant. Resistance to disease was high for Ustilago maydis 0.49, Fusarium spp. 0.13, and Exerohilum turcicum 1.25. Tolerance against Ostrinia nubilalis is 3-33. All of the above parameters and the agreeable phenotype of this hybrid indicate the value of Rubin-7. .
Bernard, C B; Krishanmurty, H G; Chauret, D; Durst, T; Philogène, B J; Sánchez-Vindas, P; Hasbun, C; Poveda, L; San Román, L; Arnason, J T
Insecticidal and growth-reducing properties of extracts of 14 species of American neotropical Piperaceae were investigated by inclusion in diets of a polyphagous lepidopteran, the European corn borer,Ostrinia nubilalis. Nutritional indices suggested most extracts acted by postdigestive toxicity.Piper aduncum, P. tuberculatum, andP. decurrens were among the most active species and were subjected to bioassay-guided isolation of the active components. Dillapiol was isolated from the active fraction ofP. aduncum, piperlonguminine was isolated fromP. tuberculatum, and a novel neolignan fromP. decurrens. The results support other studies on Asian and AfricanPiper species, which suggest that lignans and isobutyl amides are the active defence compounds in this family.
Full Text Available Lepidoptera, butterflies and moths, is the second largest animal order and includes numerous agricultural pests. To facilitate comparative genomics in Lepidoptera, we isolated BAC clones containing conserved and putative single-copy genes from libraries of three pests, Heliothis virescens, Ostrinia nubilalis, and Plutella xylostella, harboring the haploid chromosome number, =31, which are not closely related with each other or with the silkworm, Bombyx mori, (=28, the sequenced model lepidopteran. A total of 108–184 clones representing 101–182 conserved genes were isolated for each species. For 79 genes, clones were isolated from more than two species, which will be useful as common markers for analysis using fluorescence in situ hybridization (FISH, as well as for comparison of genome sequence among multiple species. The PCR-based clone isolation method presented here is applicable to species which lack a sequenced genome but have a significant collection of cDNA or EST sequences.
Drury, Suzanne M; Reynolds, Tracey L; Ridley, William P; Bogdanova, Natalia; Riordan, Susan; Nemeth, Margaret A; Sorbet, Roy; Trujillo, William A; Breeze, Matthew L
Insect-protected corn hybrids containing Cry insecticidal proteins derived from Bacillus thuringiensis have protection from target pests and provide effective management of insect resistance. MON 89034 hybrids have been developed that produce both the Cry1A.105 and Cry2Ab2 proteins, which provide two independent modes of insecticidal action against the European corn borer ( Ostrinia nubilalis ) and other lepidopteran insect pests of corn. The composition of MON 89034 corn was compared to conventional corn by measuring proximates, fiber, and minerals in forage and by measuring proximates, fiber, amino acids, fatty acids, vitamins, minerals, antinutrients, and secondary metabolites in grain collected from 10 replicated field sites across the United States and Argentina during the 2004-2005 growing seasons. Analyses established that the forage and grain from MON 89034 are compositionally comparable to the control corn hybrid and conventional corn reference hybrids. These findings support the conclusion that MON 89034 is compositionally equivalent to conventional corn hybrids.
Full Text Available Over the past decade, the high-dose refuge (HDR strategy, aimed at delaying the evolution of pest resistance to Bacillus thuringiensis (Bt toxins produced by transgenic crops, became mandatory in the United States and is being discussed for Europe. However, precopulatory dispersal and the mating rate between resident and immigrant individuals, two features influencing the efficiency of this strategy, have seldom been quantified in pests targeted by these toxins. We combined mark-recapture and biogeochemical marking over three breeding seasons to quantify these features directly in natural populations of Ostrinia nubilalis, a major lepidopteran corn pest. At the local scale, resident females mated regardless of males having dispersed beforehand or not, as assumed in the HDR strategy. Accordingly, 0-67% of resident females mating before dispersal did so with resident males, this percentage depending on the local proportion of resident males (0% to 67.2%. However, resident males rarely mated with immigrant females (which mostly arrived mated, the fraction of females mating before dispersal was variable and sometimes substantial (4.8% to 56.8%, and there was no evidence for male premating dispersal being higher. Hence, O. nubilalis probably mates at a more restricted spatial scale than previously assumed, a feature that may decrease the efficiency of the HDR strategy under certain circumstances, depending for example on crop rotation practices.
Crespo, André L B; Spencer, Terence A; Nekl, Emily; Pusztai-Carey, Marianne; Moar, William J; Siegfried, Blair D
Standardization of toxin preparations derived from Bacillus thuringiensis (Berliner) used in laboratory bioassays is critical for accurately assessing possible changes in the susceptibility of field populations of target pests. Different methods were evaluated to quantify Cry1Ab, the toxin expressed by 80% of the commercially available transgenic maize that targets the European corn borer, Ostrinia nubilalis (Hübner). We compared three methods of quantification on three different toxin preparations from independent sources: enzyme-linked immunosorbent assay (ELISA), sodium dodecyl sulfate-polyacrylamide gel electrophoresis and densitometry (SDS-PAGE/densitometry), and the Bradford assay for total protein. The results were compared to those obtained by immunoblot analysis and with the results of toxin bioassays against susceptible laboratory colonies of O. nubilalis. The Bradford method resulted in statistically higher estimates than either ELISA or SDS-PAGE/densitometry but also provided the lowest coefficients of variation (CVs) for estimates of the Cry1Ab concentration (from 2.4 to 5.4%). The CV of estimates obtained by ELISA ranged from 12.8 to 26.5%, whereas the CV of estimates obtained by SDS-PAGE/densitometry ranged from 0.2 to 15.4%. We standardized toxin concentration by using SDS-PAGE/densitometry, which is the only method specific for the 65-kDa Cry1Ab protein and is not confounded by impurities detected by ELISA and Bradford assay for total protein. Bioassays with standardized Cry1Ab preparations based on SDS-PAGE/densitometry showed no significant differences in LC(50) values, although there were significant differences in growth inhibition for two of the three Cry1Ab preparations. However, the variation in larval weight caused by toxin source was only 4% of the total variation, and we conclude that standardization of Cry1Ab production and quantification by SDS-PAGE/densitometry may improve data consistency in monitoring efforts to identify changes in
Dively, Galen P; Venugopal, P Dilip; Bean, Dick; Whalen, Joanne; Holmstrom, Kristian; Kuhar, Thomas P; Doughty, Hélène B; Patton, Terry; Cissel, William; Hutchison, William D
Transgenic crops containing the bacterium Bacillus thuringiensis (Bt) genes reduce pests and insecticide usage, promote biocontrol services, and economically benefit growers. Area-wide Bt adoption suppresses pests regionally, with declines expanding beyond the planted Bt crops into other non-Bt crop fields. However, the offsite benefits to growers of other crops from such regional suppression remain uncertain. With data spanning 1976-2016, we demonstrate that vegetable growers benefit via decreased crop damage and insecticide applications in relation to pest suppression in the Mid-Atlantic United States. We provide evidence for the regional suppression of Ostrinia nubilalis (Hübner), European corn borer, and Helicoverpa zea (Boddie), corn earworm, populations in association with widespread Bt maize adoption (1996-2016) and decreased economic levels for injury in vegetable crops [peppers ( Capsicum annuum L.), green beans ( Phaseolus vulgaris L.), and sweet corn ( Zea mays L., convar. saccharata )] compared with the pre-Bt period (1976-1995). Moth populations of both species significantly declined in association with widespread Bt maize (field corn) adoption, even as increased temperatures buffered the population reduction. We show marked decreases in the number of recommended insecticidal applications, insecticides applied, and O. nubilalis damage in vegetable crops in association with widespread Bt maize adoption. These offsite benefits to vegetable growers in the agricultural landscape have not been previously documented, and the positive impacts identified here expand on the reported ecological effects of Bt adoption. Our results also underscore the need to account for offsite economic benefits of pest suppression, in addition to the direct economic benefits of Bt crops.
Crespo, Andre L B; Pan, Zaiqi; Crain, Philip R; Thompson, Stephen D; Pilcher, Clinton D; Sethi, Amit
Abstract In this review, we evaluate the intentional mixing or blending of insecticidal seed with refuge seed for managing resistance by insects to insecticidal corn (Zea mays). We first describe the pest biology and farming practices that will contribute to weighing trade-offs between using block refuges and blended refuges. Case studies are presented to demonstrate how the trade-offs will differ in different systems. We compare biological aspects of several abstract models to guide the reader through the history of modeling, which has played a key role in the promotion or denigration of blending in various scientific debates about insect resistance management for insecticidal crops. We conclude that the use of blended refuge should be considered on a case-by-case basis after evaluation of insect biology, environment, and farmer behavior. For Diabrotica virgifera virgifera, Ostrinia nubilalis, and Helicoverpa zea in the United States, blended refuge provides similar, if not longer, delays in the evolution of resistance compared to separate block refuges. PMID:29220481
Dorhout, David L; Rice, Marlin E
The effect of genetically modified corn (event MON810, YieldGard Corn Borer) expressing the Bacillus thuringiensis sp. kurstaki (Berliner) (Bt) endotoxin, Cry1Ab, on the survival of western bean cutworm, Striacosta albicosta (Smith), larvae was examined during intraguild competition studies with either European corn borer, Ostrinia nubilalis (Hübner), or corn earworm, Helicoverpa zea (Boddie), larvae. Competition scenarios were constructed by using either a laboratory or field competition arena containing one of five different diets and one of 13 different larval size-by-species scenarios. The survival of western bean cutworms competing with corn earworms in the laboratory arenas on either a meridic diet or isoline corn silk diet was significantly lower (P corn earworm on a Cry1Ab-MON810 corn silk diet was significant higher (P corn borers generally did not alter the outcomes observed in the western bean cutworm and corn earworm only two-way competitions. These data suggest that Cry1Ab-MON810 corn may confer a competitive advantage to western bean cutworm larvae during intraguild competition, particularly from corn earworms, and that western bean cutworms become equal competitors only when they are of equal or larger size and the diet is Cry1Ab-MON810 corn.
Binning, Rachel R; Coats, Joel; Kong, Xiaoxiao; Hellmich, Richard L
Bacillus thuringiensis (Bt) maize was developed primarily for North American pests such as European corn borer (Ostrinia nubilalis (Hübner)). However, most Bt maize products are also cultivated outside of North America, where the primary pests may be different and may have lower susceptibility to Bt toxins. Fall armyworm (Spodoptera frugiperda JE Smith) is an important pest and primary target of Bt maize in Central and South America. S. frugiperda susceptibility to Cry1F (expressed in event TC1507) is an example of a pest-by-toxin interaction that does not meet the high-dose definition. In this study, the behavioral and toxic response of S. frugiperda to Cry1F maize was investigated by measuring the percentage of time naive third instars spent feeding during a 3-min exposure. S. frugiperda also were exposed as third instars to Cry1F maize for 14 d to measure weight gain and survival. S. frugiperda demonstrated an initial, postingestive aversive response to Cry1F maize, and few larvae survived the 14 d exposure. The role of susceptibility and avoidance are discussed in the context of global IRM refuge strategy development for Bt products.
An investigation was conducted to examine the effects of microsporidiosis on an insect's response to insecticide intoxication. Healthy European corn borer, Ostrinia nubilalis, larvae and those heavily infected with the microsporidian pathogen, Nosema pyrausta, were bioassayed with ten insecticides. The compounds used were carbaryl, carbofuran, chlorophrifos, DDT, diazinon, fonofos, methomyl, parathion, permethrin, and terbufos. Third instar larvae were used for topical bioassays. The compounds carbaryl, carbofuran, chlorophrifos, methomyl and terbufos were found to be significantly more toxic to diseased insects than healthy insects at the 0.05 probability level. To examine the effect of Nosema pyrausta infection on the European corn borer's ability to detoxify insecticides, 14 C ring-labeled carbaryl, chlorophrifos, DDT, and parathion were topically applied to fourth instar larvae. Qualitative differences between healthy and diseased insects were found in the metabolic pathways of carbaryl, DDT, and parathion. The degradative fate of chlorophrifos was the same in both groups. Quantitatively, each insecticide penetrated diseased larvae faster. This resulted in larger amounts of the applied dose of parent compound and metabolites being found in the feces from diseased insects. Conversely, healthy insects had more of these materials present in the body and associated with the cuticle
Full Text Available One of the most destructive maize pest in Croatia is European corn borer (Ostrinia nubilalis Hübner (ECB. The aim of this study was to determine the influence of irrigation, nitrogen fertilization, different maize genotypes and nitrogen leaf content on ECB feeding activity. The experiment was set up in Osijek, Croatia under field conditions during 2012-2013 vegetation season. Experiment treatments were as follows: three irrigation levels (A1 - control, A2 from 60% to 80% field water capacity - FWC and A3 from 80% to100% FWC, three nitrogen fertilizer levels (B1 - 0, B2 - 100 and B3 - 200 kg N/ha and four different genotypes (C1 - OSSK 596; C2 - OSSK 617; C3 - OSSK 602 and C4 - OSSK 552. Ear weight, number of larvae in stem and shank, tunnel length and nitrogen leaf content were evaluated. Genotype C1 was the most susceptible for following the tested variables of ECB feeding: tunnel length (TL, larvae in stalk (LS and total number of larvae (TNL at P<0.05 probability level. By raising the level of irrigation, European corn borer feeding activity was reduced while by raising the level of nitrogen fertilization feeding activity was increased. These results suggest that good production practices can significantly affect the susceptibility of maize to European corn borer.
Full Text Available The aim of this study was to determine the effectiveness of a chemical treatment against larvae of the European corn borer (Ostrinia nubilalis Hubner. The experiment was set up in 2010 and 2011 in Čepin (eastern Croatia in two treatments: control treatment and insecticide treatment. The trial involved two hybrids of FAO group 400: PR37N01 and PR37F73. Biology of pests was monitored in order to determine population size and larvae development stage as well as the optimal time of insecticide application. After determination of thresholds, maize was treated with chemical formulations of active substance dimethoate. Towards the end of vegetation, length of stem damage, number of larvae in maize stalk and ear as well as grain yield were recorded by dissection of maize stalks. Statistical analysis shows that year, hybrid and chemical treatment significantly influenced the incidence of this pest and justified the use of chemical preparations with mandatory monitoring biology of this pest.
Swale, Daniel R; Carlier, Paul R; Hartsel, Joshua A; Ma, Ming; Bloomquist, Jeffrey R
Insecticide resistance in the malaria mosquito Anopheles gambiae is well documented, and widespread agricultural use of pyrethroids may exacerbate development of resistance when pyrethroids are used in vector control. We have developed carbamate anticholinesterases that possess a high degree of An. gambiae:human selectivity for enzyme inhibition. The purpose of this study was to assess the spectrum of activity of these carbamates against other mosquitoes and agricultural pests. Experimental carbamates were potent inhibitors of mosquito acetylcholinesterases, with IC50 values in the nanomolar range. Similar potencies were observed for Musca domestica and Drosophila melanogaster enzymes. Although meta-substituted carbamates were potent inhibitors, two ortho-substituted carbamates displayed poor enzyme inhibition (IC50 ≥ 10(-6) M) in honey bee (Apis mellifera), Asian citrus psyllid (Diaphorina citri) and lepidopteran agricultural pests (Plutella xylostella and Ostrinia nubilalis). Enzyme inhibition results were confirmed by toxicity studies in caterpillars, where the new carbamates were 2-3-fold less toxic than propoxur and up to tenfold less active than bendiocarb, indicating little utility of these compounds for crop protection. The experimental carbamates were broadly active against mosquito species but not agricultural pests, which should mitigate selection for mosquito insecticide resistance by reducing agricultural uses of these compounds. © 2014 Society of Chemical Industry. © 2014 Society of Chemical Industry.
Full Text Available The frequency and incidence of A. flavus and A. niger on barley, maize, soybean, sunflowerand wheat grain, the abundance of European corn borer (Ostrinia nubilalis mothsand their interaction depending on weather conditions in the 2008-2012 period were studied.Under the agroecological conditions of Serbia, the species A. niger is more frequentthan A. flavus, and concerning the crop species, its frequency is highest in kernels of sunflower,than soybean, maize, barley and wheat. A. flavus was extremely dominant on allplant species in 2012 regarding its frequency: 100% on soybean, 95.3% on maize, 65.2% onbarley, 57.1% on sunflower and 45.8% on wheat. Furthermore, the incidence of A. flavus washigher in 2012 than in previous years. The uncommonly high frequency and incidence of A.flavus infestation of maize grain in 2012 were caused by extremely stressful agrometeorologicalconditions, high temperatures and drought over the period from flowering to waxymaturity of maize. The precipitation factor (Pf = precipitation sum / average monthly temperatureshowed that 2012 was extremely arid in June (Pf = 0.57, July (Pf = 1.45, August (Pf= 0.15 and September (Pf = 1.42. European corn borer (ECB was a second factor causingintensive occurrence of A. flavus on maize grain in 2012. The maximum flight of ECB mothswas recorded as early as in July (5,149 and, as a result of this, high damage and numerousinjuries were detected at harvest. Those injuries were covered by visible olive-green powderycolonies typical of A. flavus. In the chronology of A. flavus occurrence, these are thefirst data on its very high frequency and incidence under the agroecological conditions ofSerbia. As intensive infections with A. flavus were rare in the past 50 years, the level of aflatoxinsin maize grain was low.
Yin, Chuanlin; Li, Meizhen; Hu, Jian; Lang, Kun; Chen, Qiming; Liu, Jinding; Guo, Dianhao; He, Kang; Dong, Yipei; Luo, Jiapeng; Song, Zhenkun; Walters, James R; Zhang, Wenqing; Li, Fei; Chen, Xuexin
Parasitoid wasps are well-known natural enemies of major agricultural pests and arthropod borne diseases. The parasitoid wasp Macrocentrus cingulum (Hymenoptera: Braconidae) has been widely used to control the notorious insect pests Ostrinia furnacalis (Asian Corn Borer) and O. nubilalis (European corn borer). One striking phenomenon exhibited by M. cingulum is polyembryony, the formation of multiple genetically identical offspring from a single zygote. Moreover, M. cingulum employs a passive parasitic strategy by preventing the host's immune system from recognizing the embryo as a foreign body. Thus, the embryos evade the host's immune system and are not encapsulated by host hemocytes. Unfortunately, the mechanism of both polyembryony and immune evasion remains largely unknown. We report the genome of the parasitoid wasp M. cingulum. Comparative genomics analysis of M. cingulum and other 11 insects were conducted, finding some gene families with apparent expansion or contraction which might be linked to the parasitic behaviors or polyembryony of M. cingulum. Moreover, we present the evidence that the microRNA miR-14b regulates the polyembryonic development of M. cingulum by targeting the c-Myc Promoter-binding Protein 1 (MBP-1), histone-lysine N-methyltransferase 2E (KMT2E) and segmentation protein Runt. In addition, Hemomucin, an O-glycosylated transmembrane protein, protects the endoparasitoid wasp larvae from being encapsulated by host hemocytes. Motif and domain analysis showed that only the hemomucin in two endoparasitoids, M. cingulum and Venturia canescens, possessing the ability of passive immune evasion has intact mucin domain and similar O-glycosylation patterns, indicating that the hemomucin is a key factor modulating the immune evasion. The microRNA miR-14b participates in the regulation of polyembryonic development, and the O-glycosylation of the mucin domain in the hemomucin confers the passive immune evasion in this wasp. These key findings provide
Manuwoto, S; Scriber, J M
The effects of differential leaf water, leaf nitrogen and cyclic hydroxamate (DIMBOA) concentrations in corn seedlings were analyzed for a polyphagous insect, the southern armyworm (Spodoptera eridania Cram.). Six different combinations of nutrients and allelochemicals [DIMBOA = 2,4-dihydroxy-7-methoxy(2H)-benzoxazin-3(4H)-one] were generated using two corn genotypes (WF9 and CI3IA) and three fertility regimes (complete nutrient, Fe-deficient, and N-deficient solutions) in the University Biotron. Poorest larval growth was observed in the low-nitrogen treatments (1.2% and 1.7% leaf N) and was the result of both low consumption rates and high metabolic costs (low efficiency of conversion of digested food, ECD). Fastest growth rates were observed forthe larvae fed leaves from the high-nitrogen treatments (4.6% and 4.4% leaf N). It is noteworthy that these treatments also contained the highest concentration of cyclic hydroxamates, which are generally believed to be the primary defensive chemicals mediating resistance against the European corn borer,Ostrinia nubilalis (Hubner). If these hydroxamates do have any deleterious or costly effects (perhaps accounting for a large portion of metabolic expenditures), the high digestibility of the leaf tissue and the increased consumption rates more than compensate, resulting in rapid growth (growth rate = consumption rate × approximate digestibility × efficiency of conversion of the digested food). These studies illustrate that variation in key nutrients and allelochemicals within a single plant species (Zea mays L.) may have significantly different effects upon various potential leaf-chewing caterpillars, such as these armyworms versus corn borers (which cannot handle the cyclic hydroxamates, even if provided with young nutritious leaf tissues).
Barbulescu, A.; Rosca, I.
Investigations were undertaken to develop the foundation for control in the future of the European corn borer, Ostrinia nubilalis (Huebner), with a pest management system based on sterility expressed to the greatest extent during the F 1 generation of progeny of moths irradiated with gamma rays. As a basis for the mass rearing of the pest, a diet was developed from locally available ingredients. The ingredients are bean meal, wheat bran, brewe's yeast, milk powder substitute for calves, salt mixture used in poultry production, sugar, ascorbic acid, sorbic acid, glacial acetic acid, formaldehyde, agar and water. Using this diet, 1000 moths can be reared for as little as one US dollar. Complete sterility induced by exposure to gamma rays occurs at a lower dose in females than in males. When males that are exposed as six-day-old pupae to 150 Gy are mated to untreated females, 67.5% of the eggs hatch. Further, when the sons of treated males are mated to untreated females, 42.8% of the eggs hatch, when daughters of treated males are mated to untreated males, 40.7% of the eggs hatch, and when sons and daughters of treated males are mated to each other, 9.1% of the eggs hatch. The amount of mortality following egg hatch was not recorded. However, in field cage experiments, F 1 larvae damaged 4, 8 and 0% of corn stalks for these respective crosses compared with the 76% damage by larvae from untreated parents. The corresponding yield of kernels of corn in grammes per plant was 57, 42, 46, and 27. In order to mark moths for filed studies they were reared on diet containing Calco red dye. Traps baited with the various enantiomers of the sex pheromone were used to study the dispersal of released moths and the dates of adult moth emergence in various regions of Romania. (author). 20 refs, 12 tabs
In agricultural crop improvement, yield under various stress conditions and limiting factors is assessed experimentally. Of the stresses on plants which affect yield are those due to insects. Ostrinia nubilalis, the European corn borer (corn borer) is a major pest in sweet and field corn in the U.S. There are many ways to fight crop pests such as the corn borer, including (1) application of chemical insecticides, (2) application of natural predators and, (3) improving crop resistance through plant genetics programs. Randomized field trials are used to determine the effectiveness of pest management programs. These trials frequently consist of randomly selected crop plots to which well-defined input regimes are instituted. For example, corn borers might be released onto crop plots in several densities at various stages of crop development, then sprayed with different levels of pesticide. These experiments are duplicated across regions and, in some cases across the country, to determine, in this instance for example, the best pesticide application rate for a given pest density and crop development stage. In order to release these pests onto crop plots, one must have an adequate supply of the insect pest. In winter months studies are carried out in the laboratory to examine chemical and natural pesticide effectiveness, as well as such things as the role of pheromones in moth behavior. The advantage in field trials is that yield data can be garnered directly. In this country, insects are raised for crop research primarily through the US Department of Agriculture, in cooperation with public Land Grant Universities and, by the private sector agricultural concerns - seed companies and others. This study quantifies the airborne allergen exposure of persons working in a Land Grant University entomology lab were allergy to European corn borer was suspected.
Bingye Xue; Alejandro P. Rooney; Wendell L. Roelofs
Acyl-coenzyme A (Acyl-CoA) desaturases play a key role in the biosynthesis of female moth sex pheromones.Desaturase genes are encoded by a large multigene family,and they have been divided into five subgroups on the basis of biochemical functionality and phylogenetic affinity.In this study both copy numbers and transcriptional levels of desaturase genes in the European corn borer (ECB),Ostrinia nubilalis,were investigated.The results from genome-wide screening of ECB bacterial artificial chromosome (BAC)library indicated there are many copies of some desaturase genes in the genome.An open reading frame (ORF) has been isolated for the novel desaturase gene ECB ezi-△11β from ECB gland complementary DNA and its functionality has been analyzed by two yeast expression systems.No functional activities have been detected for it.The expression levels of the four desaturase genes both in the pheromone gland and fat body of ECB and Asian corn borer (ACB),O.furnacalis,were determined by real-time polymerase chain reaction.In the ECB gland,△ 11 is the most abundant,although the amount of △14 is also considerable.In the ACB gland,△14 is the most abundant and is 100 times more abundant than all the other three combined.The results from the analysis of evolution of desaturase gene transcription in the ECB,ACB and other moths indicate that the pattern of △ 11 gene transcription is significantly different from the transcriptional patterns of other desaturase genes and this difference is tied to the underlying nucleotide composition bias of the genome.
Zapletal, Michal; Fric, Zdeněk; Beneš, Jiří; Konvička, Martin
Roč. 49, 1-2 (2013), s. 95-105 ISSN 1210-6100 R&D Projects: GA ČR GAP505/10/2167; GA MŽP SP/2D3/62/08 Institutional support: RVO:60077344 Keywords : Lepidoptera * distribution * faunistics Subject RIV: EH - Ecology, Behaviour
Böttger, Rita; Schaller, Jörg; Lintow, Sven; Gert Dudel, E
The increasing cultivation of genetically modified corn plants (Zea mays) during the last decades is suggested as a potential risk to the environment. One of these genetically modified variety expressed the insecticidal Cry1Ab protein originating from Bacillus thuringiensis (Bt), resulting in resistance against Ostrinia nubilalis, the European corn borer. Transgenic litter material is extensively studied regarding the decomposition in soils. However, only a few field studies analyzed the fate of the Cry1Ab protein and the impact of green and senescent leaf litter from corn on the decomposition rate and related ecosystem functions in aquatic environments. Consequently, a microbial litter decomposition experiment was conducted under controlled semi-natural conditions in batch culture using two maize varieties: one variety with Cry1Ab and another one with the appertaining Iso-line as control treatment. The results showed no significant differences between the treatment with Cry1Ab and the Iso-line regarding loss of total mass in dry weight of 43% for Iso-line and 45% for Bt-corn litter, lignin content increased to 137.5% (Iso-line) and 115.7% (Bt-corn), and phenol loss decreased by 53.6% (Iso-line), 62.2% (Bt-corn) during three weeks of the experiment. At the end of the experiment Cry1Ab protein was still detected with 6% of the initial concentration. A slightly but significant lower cellulose content was found for the Cry1Ab treatment compared to the Iso-line litter at the end of the experiment. The significant higher total protein (25%) and nitrogen (25%) content in Bt corn, most likely due to the additionally expression of the transgenic protein, may increase the microbial cellulose degradation and decrease microbial lignin degradation. In conclusion a relevant year by year input of protein and therefore nitrogen rich Bt corn litter into aquatic environments may affect the balanced nutrient turnover in aquatic ecosystems. Copyright © 2014 Elsevier Inc. All rights
Bhati, Dheeraj; Parvez, Asif; Kausar, Hina; Srivastava, Meera
suppression by irradiation include Spodoptera litura, S.exigua, S.frugiperda, Helicoverpa armigera, H.zea, Pectinophora gossypiella, Diatraea saccharalis, Cydia pomonella, C.molesta, Ectomyelois ceratoniae, Ephestia kuehniella, Crocidolomia binotalis, Chilo suppressalis, Ostrinia furnacalis, O.nubilalis, Plutella xylostella and Spilosoma obliqua. (author)
Su, H.; Li, H.
A series of essential oils oriented ester derivatives have been designed, synthesized and characterized based on the skeleton of fenvalerate. The preliminary bioassay results indicated that some of the newly synthesized compounds showed better insecticidal activities against Pyrausta nubilalis and Heliothis armigera than that of the control trans-prallethrin chloride. (author)
He Lihua; Chen Jin'e; Liu Yan; Wang Yongqiang; Liu Peigang; Meng Zhiqi
To gain an in-depth understanding of the fineness and regulation mechanism of body color mutant of Helicoverpa armigera Hbner, the protein composition differences between adult of dominant mutant, recessive mutant and wild type were studied using the SDS-PAGE combined with MALDI-TOF-TOF/MS and bioinformatics analysis. The results indicated that the protein composition of the dominant mutant and wild type had little difference. However, there were obvious differences between the recessive mutant and wild-type. Three specific stripe were chosen for mass spectrometry and bioinformatics analysis, and two types of proteins related to energy metabolism and cytoskeleton were identified. These findings suggested that the two types of proteins may be associated with occurrence and regulation of body color mutant traits of H. armigera. (authors)
Full Text Available Introduction: Parasitoid wasp, Trichogramma brassicae (Bezdenko (Hym.: Trichogrammatidae has excellent position in mass production technology, scope of application, wide geographical distribution and unmatched talent to adapt to different climatic conditions that can be easily reared on Mediterranean flour moth (MFM, Ephestia kuehniella Zeller (Lep.: Pyralidae. The parasitoid use is in order to control Chilo suppressalis (Walker (Lep.: Pyralidae, Helicoverpa armigera (Lep.: Noctuidae, Ostrinia nubilalis (Hübner (Lep.: Pyralidae, Ectomyelois ceratoniae (Zeller (Lep.: Phycitidae and Cydia pomonella (Lep.: Tortricidae (38. The studies have been shown that the quantity and quality of the host diet affect growth period, size of adults, adult longevity, fecundity and sex ratio of the parasitoid. The objective of current research was to evaluate the effect of four different MFM diets on the fitness of second and forth generations of the parasitoid wasp, T. brassicae. Materials and Methods: The four diets ((I wheat flour, wheat bran, corn flour, bread yeast and glycerin; (II wheat flour, wheat bran, barley flour, bread yeast and glycerin; (III barley flour, bread yeast and glycerin and (IV wheat flour, barley flour and corn flour were sterilized at 51 °C for 24 hours. After cooling at ambient temperature, the diets were contaminated with the eggs of MFM and then were maintained at 25±1° C, 60±5 % RH and a photoperiod of 14 L: 10 D. The MFM adults emerged after 35 to 40 days and their eggs were collected daily to use for investigation of the parasitoid biology. For rearing the parasitoid wasps on the MFM eggs obtained from each diet, some cards containing the parasitoid pre-pupae were put inside cages (25 × 25 × 25 cm and reared for one generation. The adults were fed honey (20% for one day and then were provided with one-day-old sterile MFM eggs. To prevent egg hatching and sterile them, they were kept at 15°C for four h. The tests were
Beukeboom, Leo W.
A recent study in the lepidopteran Ostrinia scapulalis shows that endosymbionts can actively manipulate the sex determination mechanism of their host. Wolbachia bacteria alter the sex-specific splicing of the doublesex master switch gene. In ZZ males of this female heterogametic system, the female
Grieshop, Matthew J; Flinn, Paul W; Nechols, James R
Host-foraging responses to different intra- and interpatch densities were used to assess three Trichogramma spp. (Hymenoptera: Trichogrammatidae) Trichogramma deion Pinto and Oatman, T. ostriniae Pang and Chen, and T. pretiosum Riley - as potential biological control agents for the Indian meal moth, Plodia interpunctella Hübner (Lepidoptera: Pyralidae). Single naïve females were allowed 6 h to forage in Plexiglas arenas with four different spatial arrangements of host eggs, nine single-egg patches), nine four-egg patches, 36 single-egg patches, and 36 four-egg patches. No significant differences were found among species in the number of patches parasitized. As expected, all three species parasitized the most eggs in the 36 four-egg patch treatment and the least in the nine single-egg patch treatment. T. deion parasitized significantly more eggs than T. pretiosum on the nine four-egg patches. T. ostriniae parasitized significantly more patches when intrapatch density was greater, regardless of interpatch density. In contrast, T. deion only parasitized more patches at the greater intrapatch density when the interpatch density was low. Patch density had no effect on T. pretiosum. The spatial pattern of parasitism was more aggregated for T. deion and T. ostriniae in the 36 four-egg patches treatment compared to the 36 single-egg patches treatment. Therefore, intrapatch density was more important than interpatch density for T. ostriniae, and potentially for T. deion, but not for T. pretiosum. T. deion may be the best candidate for augmentative biological control because it parasitized either slightly or significantly more eggs than the other two species in all four treatments. Furthermore, the pattern of parasitism by T. deion in the 36 four-egg patches treatment was the most aggregated among the three species, suggesting a more thorough searching pattern. In contrast, T. pretiosum had the least aggregated pattern of parasitism and therefore may have used a more
Kjellsson, Gøsta; Sørensen, Jesper Givskov; Damgaard, Christian
"Den genmodificerede fire-stakkede majskrydsning adskiller sig fra konventionelle majs ved at have indsat gener der gør planterne tolerante over for herbiciderne glufosinat-ammonium og glyfosat. Desuden er majsen tolerant over for angreb af sommerfuglearter såsom kornboreren (Ostrinis nubilalis) og...... and/or dispersal of GMO-seed leading to cultivation of the GMO, DCE suggests that case-specific environmental monitoring is needed for detection of possible adverse effects on insect populations, especially vulnerable species of leaf beetles (Chrysomelidae) and butterflies (Lepidoptera)."...
Nakano, Ryo; Skals, Niels; Takanashi, Takuma
level at 1 cm) adapted for private sexual communication in the Asian corn borer moth, Ostrinia furnacalis. During courtship, the male rubs specialized scales on the wing against those on the thorax to produce the songs, with the wing membrane underlying the scales possibly acting as a sound resonator....... The male's song suppresses the escape behavior of the female, thereby increasing his mating success. Our discovery of extremely low-intensity ultrasonic communication may point to a whole undiscovered world of private communication, using "quiet" ultrasound....
Wang Huasong; Liu Qiongru; Lu Daguang; Wang Endong; Kang Wen; Li Yongjun; He Qiulan; Hu Jianguo
The dispersal ability of F-1 male Asian corn borer, Ostrinia furnacalis (Guenee), irradiated with 100, 150 and 200 Gy Separately in parental generation were tested by marking (with Calco oil red or Sudan blue internally)-releasing-recapturing (with synthesized sex pheromone) method in the field where the farthest distance from release point to pheromone trap was 550 m. The results showed that, as compared with the normal male moths, despite of the fact that a part of the irradiated F-1 males had lost dispersal ability or taxis to sex pheromone, there was no significant difference between the captured rates of irradiated F-1 males and normal males in the trap 550 m from release point, indicated that the dispersal ability or taxis to sex pheromone of irradiated F-1 males arrived at 550 m from release point are still well matched with the normal ones
Full Text Available Pathogens are known to manipulate the reproduction and development of their hosts for their own benefit. Wolbachia is an endosymbiotic bacterium that infects a wide range of insect species. Wolbachia is known as an example of a parasite that manipulates the sex of its host's progeny. Infection of Ostrinia moths by Wolbachia causes the production of all-female progeny, however, the mechanism of how Wolbachia accomplishes this male-specific killing is unknown. Here we show for the first time that Wolbachia targets the host masculinizing gene of Ostrinia to accomplish male-killing. We found that Wolbachia-infected O. furnacalis embryos do not express the male-specific splice variant of doublesex, a gene which acts at the downstream end of the sex differentiation cascade, throughout embryonic development. Transcriptome analysis revealed that Wolbachia infection markedly reduces the mRNA level of Masc, a gene that encodes a protein required for both masculinization and dosage compensation in the silkworm Bombyx mori. Detailed bioinformatic analysis also elucidated that dosage compensation of Z-linked genes fails in Wolbachia-infected O. furnacalis embryos, a phenomenon that is extremely similar to that observed in Masc mRNA-depleted male embryos of B. mori. Finally, injection of in vitro transcribed Masc cRNA into Wolbachia-infected embryos rescued male progeny. Our results show that Wolbachia-induced male-killing is caused by a failure of dosage compensation via repression of the host masculinizing gene. Our study also shows a novel strategy by which a pathogen hijacks the host sex determination cascade.
Full Text Available A Bt corn hybrid (AcIe with two Bt genes (cry1Ie and cry1Ac was derived by breeding stack from line expressing Cry1Ie and a line expressing Cry1Ac. Efficacy of this pyramided Bt corn hybrid against the Asian corn borer (ACB, Ostrinia furnacalis, was evaluated. We conducted laboratory bioassays using susceptible and resistant ACB strains fed on artificial diet or fresh plant tissues. We also conducted field trials with artificial infestations of ACB neonates at the V6 and silk stages. The toxin-diet bioassay data indicated that mixtures of Cry1Ac and Cry1Ie proteins had synergistic insecticidal efficacy. The plant tissue bioassay data indicated that Bt corn hybrids expressing either a single toxin (Cry1Ac or Cry1Ie or two toxins had high efficacy against susceptible ACB. Damage ratings in the field trials indicated that the Bt corn hybrids could effectively protect against 1st and the 2nd generation ACB in China. The hybrid line with two Bt genes showed a higher efficacy against ACB larvae resistant to Cry1Ac or CryIe than the hybrid containing one Bt gene, and the two gene hybrid would have increased potential for managing or delaying the evolution of ACB resistance to Bt corn plants.
Full Text Available A strain of the Asian corn borer (ACB, Ostrinia furnacalis (Guenée, has evolved >800-fold resistance to Cry1Ie (ACB-IeR after 49 generations of selection. The inheritance pattern of resistance to Cry1Ie in ACB-IeR strain and its cross-resistance to other Bt toxins were determined through bioassay by exposing neonates from genetic-crosses to toxins incorporated into the diet. The response of progenies from reciprocal F1 crosses were similar (LC50s: 76.07 vs. 74.32 μg/g, which suggested the resistance was autosomal. The effective dominance (h decreased as concentration of Cry1Ie increased. h was nearly recessive or incompletely recessive on Cry1Ie maize leaf tissue (h = 0.02, but nearly dominant or incompletely dominant (h = 0.98 on Cry1Ie maize silk. Bioassay of the backcross suggested that the resistance was controlled by more than one locus. In addition, the resistant strain did not perform cross-resistance to Cry1Ab (0.8-fold, Cry1Ac (0.8-fold, Cry1F (0.9-fold, and Cry1Ah (1.0-fold. The present study not only offers the manifestation for resistance management, but also recommends that Cry1Ie will be an appropriate candidate for expression with Cry1Ab, Cry1Ac, Cry1F, or Cry1Ah for the development of Bt maize.
Jiang, Fan; Zhang, Tiantao; Bai, Shuxiong; Wang, Zhenying; He, Kanglai
A Bt corn hybrid (AcIe) with two Bt genes (cry1Ie and cry1Ac) was derived by breeding stack from line expressing Cry1Ie and a line expressing Cry1Ac. Efficacy of this pyramided Bt corn hybrid against the Asian corn borer (ACB), Ostrinia furnacalis, was evaluated. We conducted laboratory bioassays using susceptible and resistant ACB strains fed on artificial diet or fresh plant tissues. We also conducted field trials with artificial infestations of ACB neonates at the V6 and silk stages. The toxin-diet bioassay data indicated that mixtures of Cry1Ac and Cry1Ie proteins had synergistic insecticidal efficacy. The plant tissue bioassay data indicated that Bt corn hybrids expressing either a single toxin (Cry1Ac or Cry1Ie) or two toxins had high efficacy against susceptible ACB. Damage ratings in the field trials indicated that the Bt corn hybrids could effectively protect against 1st and the 2nd generation ACB in China. The hybrid line with two Bt genes showed a higher efficacy against ACB larvae resistant to Cry1Ac or CryIe than the hybrid containing one Bt gene, and the two gene hybrid would have increased potential for managing or delaying the evolution of ACB resistance to Bt corn plants.
Wang, Yueqin; Yang, Jing; Quan, Yudong; Wang, Zhenying; Cai, Wanzhi; He, Kanglai
A strain of the Asian corn borer (ACB), Ostrinia furnacalis (Guenée), has evolved >800-fold resistance to Cry1Ie (ACB-IeR) after 49 generations of selection. The inheritance pattern of resistance to Cry1Ie in ACB-IeR strain and its cross-resistance to other Bt toxins were determined through bioassay by exposing neonates from genetic-crosses to toxins incorporated into the diet. The response of progenies from reciprocal F₁ crosses were similar (LC 50 s: 76.07 vs. 74.32 μg/g), which suggested the resistance was autosomal. The effective dominance ( h ) decreased as concentration of Cry1Ie increased. h was nearly recessive or incompletely recessive on Cry1Ie maize leaf tissue ( h = 0.02), but nearly dominant or incompletely dominant ( h = 0.98) on Cry1Ie maize silk. Bioassay of the backcross suggested that the resistance was controlled by more than one locus. In addition, the resistant strain did not perform cross-resistance to Cry1Ab (0.8-fold), Cry1Ac (0.8-fold), Cry1F (0.9-fold), and Cry1Ah (1.0-fold). The present study not only offers the manifestation for resistance management, but also recommends that Cry1Ie will be an appropriate candidate for expression with Cry1Ab, Cry1Ac, Cry1F, or Cry1Ah for the development of Bt maize.
Afidchao, Miladis M; Musters, C J M; de Snoo, Geert R
The Asian corn borer (ACB), Ostrinia furnacalis (Guenée), has become the most damaging pest in corn in south-east Asia. Corn farmers in the Philippines have incurred great yield losses in the past decades because of ACB infestation. Bacillus thuringiensis (Bt) and Bt herbicide-tolerant (BtHT) corns have been developed to reduce borer attacks worldwide. This study assessed the extent of ACB and non-ACB pest infestations in both GM and non-GM corn in Isabela Province, the Philippines. Specific aims were to reinvestigate the efficacy of Bt corn in controlling ACB, to evaluate what parts of Bt corn plants are susceptible to ACB, to monitor the potential development of ACB resistance and to evaluate whether secondary pests dominate in an ACB-free Bt corn environment. The study involved preparatory interviews with farmers, site selection, field scouting and visual inspection of 200 plants along 200 m transect lines through 198 cornfields. Bt corn can efficiently reduce the ACB pest problem and reduce borer damage by 44%, to damage levels in Bt and BtHT corn of 6.8 and 7% respectively. The leaves of Bt corn were more susceptible, while cobs of Bt corn were less affected by ACB. Non-ACB pests were common in Bt toxin-free cornfields and reduced in non-GM cornfields where ACB was abundant. No secondary pest outbreaks were found in ACB-free Bt cornfields. Bt and BtHT corn hybrids containing the Cry1Ab protein performed well in Isabela Province. Reduced cob damage by ACB on Bt fields could mean smaller economic losses even with ACB infestation. The occurrence of ACB in Bt and BtHT cornfields, although at a moderate and insignificant level, could imply the potential development of resistance to Bt toxin. © 2012 Society of Chemical Industry.
Full Text Available Transgenic corn producing Cry1Ac toxins from Bacillus thuringiensis (Bt provides effective control of Asian corn borer, Ostrinia furnacalis (Guenée, and thus reduces insecticide applications. However, whether Bt corn exerts undesirable effects on non-target arthropods (NTAs is still controversial. We conducted a 2-yr study in Shangzhuang Agricultural Experiment Station to assess the potential impact of Bt corn on field population density, biodiversity, community composition and structure of NTAs. On each sampling date, the total abundance, Shannon's diversity index, Pielou's evenness index and Simpson's diversity index were not significantly affected by Bt corn as compared to non-Bt corn. The "sampling dates" had a significant effect on these indices, but no clear tendencies related to "Bt corn" or "sampling dates X corn variety" interaction were recorded. Principal response curve analysis of variance indicated that Bt corn did not alter the distribution of NTAs communities. Bray-Curtis dissimilarity and distance analysis showed that Cry1Ac toxin exposure did not increase community dissimilarities between Bt and non-Bt corn plots and that the evolution of non-target arthropod community was similar on the two corn varieties. The cultivation of Bt corn failed to show any detrimental evidence on the density of non-target herbivores, predators and parasitoids. The composition of herbivores, predators and parasitoids was identical in Bt and non-Bt corn plots. Taken together, results from the present work support that Bt corn producing Cry1Ac toxins does not adversely affect NTAs.
Full Text Available The chemical similarity of cellulose and chitin supports the idea that their corresponding hydrolytic enzymes would bind β-1,4-linked glucose residues in a similar manner. A structural and mutational analysis was performed for the plant cellulolytic enzyme BGlu1 from Oryza sativa and the insect chitinolytic enzyme OfHex1 from Ostrinia furnacalis. Although BGlu1 shows little amino-acid sequence or topological similarity with OfHex1, three residues (Trp(490, Glu(328, Val(327 in OfHex1, and Trp(358, Tyr(131 and Ile(179 in BGlu1 were identified as being conserved in the +1 sugar binding site. OfHex1 Glu(328 together with Trp(490 was confirmed to be necessary for substrate binding. The mutant E328A exhibited a 8-fold increment in K(m for (GlcNAc(2 and a 42-fold increment in K(i for TMG-chitotriomycin. A crystal structure of E328A in complex with TMG-chitotriomycin was resolved at 2.5 Å, revealing the obvious conformational changes of the catalytic residues (Glu(368 and Asp(367 and the absence of the hydrogen bond between E328A and the C3-OH of the +1 sugar. V327G exhibited the same activity as the wild-type, but acquired the ability to efficiently hydrolyse β-1,2-linked GlcNAc in contrast to the wild-type. Thus, Glu(328 and Val(327 were identified as important for substrate-binding and as glycosidic-bond determinants. A structure-based sequence alignment confirmed the spatial conservation of these three residues in most plant cellulolytic, insect and bacterial chitinolytic enzymes.
Zhong, R Q; Chen, L; Gao, L X; Zhang, L L; Yao, B; Yang, X G; Zhang, H F
The objective of the present study was to investigate the effect of feeding two transgenic corn lines containing the mCry1Ac gene from Bacillus thuringiensis strain (BT-799) and the maroACC gene from Agrobacterium tumefaciens strain (CC-2), respectively, on growth, egg quality and organ health indicators. Expression of the mCry1Ac gene confers resistance to Pyrausta nubilalis and the maroACC gene confers tolerance to herbicides. Healthy hens (n=96 placed in cages; 3 hens/cage) were randomly assigned to one of four corn-soybean meal dietary treatments (8 cages/treatment) formulated with the following corn: non-transgenic near-isoline control corn (control), BT-799 corn, CC-2 corn and commercially available non-transgenic reference corn (reference). The experiment was divided into three 4-week phases (week 1 to 4, week 5 to 8 and week 9 to 12), during which hens were fed mash diets. Performance (BW, feed intake and egg production) and egg quality were determined. Following slaughter at the end of 12 weeks of feeding (n=8/treatment), carcass yield and organ weights (heart, liver, spleen, lung, kidneys, stomach and ovary) were recorded; organs and intestines were sampled for histological analysis. Analysis of serum biochemistry parameters to assess the liver and kidney function were performed. No differences in BW, egg production and production efficiency were observed between hens consuming the control diet and hens consuming the BT-799 or CC-2 diet. Haugh unit measures and egg component weights were similar between the control and test groups. Carcass yield was not affected by the diet treatment. Similar organosomatic indices and serum parameters did not indicate the characteristics of organ dysfunction. All observed values of the BT-799 and CC-2 groups were within the calculated tolerance intervals. This research indicates that the performance, egg quality, organ health and carcass yield of laying hens fed diets containing the BT-799 or CC-2 corn line were similar
Liu, Yonglei; Wang, Yinglong; Shu, Changlong; Lin, Kejian; Song, Fuping; Bravo, Alejandra; Soberón, Mario; Zhang, Jie
Genetically modified crops that express insecticidal Bacillus thuringiensis (Bt) proteins have become a primary approach for control of lepidopteran (moth) and coleopteran (beetle) pests that feed by chewing the plants. However, the sap-sucking insects (Hemiptera) are not particularly susceptible to Bt toxins. In this study, we describe two Cry toxins (Cry64Ba and Cry64Ca) from Bt strain 1012 that showed toxicity against two important hemipteran rice pests, Laodelphax striatellus and Sogatella furcifera Both of these proteins contain an ETX/MTX2 domain and share common sequence features with the β-pore-forming toxins. Coexpression of cry64Ba and cry64Ca genes in the acrystalliferous Bt strain HD73 - resulted in high insecticidal activity against both hemipteran pests. No toxicity was observed on other pests such as Ostrinia furnacalis , Plutella xylostella , or Colaphellus bowringi Also, no hemolytic activity or toxicity against cancer cells was detected. Binding assays showed specific binding of the Cry64Ba/Cry64Ca toxin complex to brush border membrane vesicles isolated from L. striatellus Cry64Ba and Cry64Ca are Bt Cry toxins highly effective against hemipteran pests and could provide a novel strategy for the environmentally friendly biological control of rice planthoppers in transgenic plants. IMPORTANCE In Asia, rice is an important staple food, whose production is threatened by rice planthoppers. To date, no effective Bacillus thuringiensis (Bt) protein has been shown to have activity against rice planthoppers. We cloned two Bt toxin genes from Bt strain 1012 that showed toxicity against small brown planthoppers ( Laodelphax striatellus ) and white-backed planthoppers ( Sogatella furcifera ). To our knowledge, the proteins encoded by the cry64Ba and cry64Ca genes are the most efficient insecticidal Bt Cry proteins with activity against hemipteran insects reported so far. Cry64Ba and Cry64Ca showed no toxicity against some lepidopteran or coleopteran pests
Chen, Wei; Qu, Mingbo; Zhou, Yong; Yang, Qing
Chitin is a linear homopolymer of N -acetyl-β-d-glucosamines and a major structural component of insect cuticles. Chitin hydrolysis involves glycoside hydrolase family 18 (GH18) chitinases. In insects, chitin hydrolysis is essential for periodic shedding of the old cuticle ecdysis and proceeds via a pathway different from that in the well studied bacterial chitinolytic system. Group II chitinase (ChtII) is a widespread chitinolytic enzyme in insects and contains the greatest number of catalytic domains and chitin-binding domains among chitinases. In Lepidopterans, ChtII and two other chitinases, ChtI and Chi-h, are essential for chitin hydrolysis. Although ChtI and Chi-h have been well studied, the role of ChtII remains elusive. Here, we investigated the structure and enzymology of Of ChtII, a ChtII derived from the insect pest Ostrinia furnacalis We present the crystal structures of two catalytically active domains of Of ChtII, Of ChtII-C1 and Of ChtII-C2, both in unliganded form and complexed with chitooligosaccharide substrates. We found that Of ChtII-C1 and Of ChtII-C2 both possess long, deep substrate-binding clefts with endochitinase activities. Of ChtII exhibited structural characteristics within the substrate-binding cleft similar to those in Of Chi-h and Of ChtI. However, Of ChtII lacked structural elements favoring substrate binding beyond the active sites, including an extra wall structure present in Of Chi-h. Nevertheless, the numerous domains in Of ChtII may compensate for this difference; a truncation containing one catalytic domain and three chitin-binding modules ( Of ChtII-B4C1) displayed activity toward insoluble polymeric substrates that was higher than those of Of Chi-h and Of ChtI. Our observations provide the last piece of the puzzle of chitin hydrolysis in insects. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.
Full Text Available The Asian corn borer (ACB, Ostrinia furnacalis (Guenée (Lepidoptera: Crambidae, is the most destructive insect pest of corn in China. Susceptibility to the Cry1F toxin derived from Bacillus thuringiensis has been demonstrated for ACB, suggesting the potential for Cry1F inclusion as part of an insect pest management program. Insects can develop resistance to Cry toxins, which threatens the development and use of Bt formulations and Bt crops in the field. To determine possible resistance mechanisms to Cry1F, a Cry1F-resistant colony of ACB (ACB-FR that exhibited more than 1700-fold resistance was established through selection experiments after 49 generations of selection under laboratory conditions. The ACB-FR strain showed moderate cross-resistance to Cry1Ab and Cry1Ac of 22.8- and 26.9-fold, respectively, marginally cross-resistance to Cry1Ah (3.7-fold, and no cross-resistance to Cry1Ie (0.6-fold. The bioassay responses of progeny from reciprocal F1 crosses to different Cry1 toxin concentrations indicated that the resistance trait to Cry1Ab, Cry1Ac and Cry1F has autosomal inheritance with no maternal effect or sex linked. The effective dominance (h of F1 offspring was calculated at different concentrations of Cry1F, showing that h decreased as concentration of Cry1F increased. Finally, the analysis of actual and expected mortality of the progeny from a backcross (F1 × resistant strain indicated that the inheritance of the resistance to Cry1F in ACB-FR was due to more than one locus. The present study provides an understanding of the genetic basis of Cry1F resistance in ACB-FR and also shows that pyramiding Cry1F with Cry1Ah or Cry1Ie could be used as a strategy to delay the development of ACB resistance to Bt proteins.