Kurt C Showmaker
Full Text Available The tarnished plant bug (TPB, Lygus lineolaris (Palisot de Beauvois is a polyphagous, phytophagous insect that has emerged as a major pest of cotton, alfalfa, fruits, and vegetable crops in the eastern United States and Canada. Using its piercing-sucking mouthparts, TPB employs a "lacerate and flush" feeding strategy in which saliva injected into plant tissue degrades cell wall components and lyses cells whose contents are subsequently imbibed by the TPB. It is known that a major component of TPB saliva is the polygalacturonase enzymes that degrade the pectin in the cell walls. However, not much is known about the other components of the saliva of this important pest. In this study, we explored the salivary gland transcriptome of TPB using Illumina sequencing. After in silico conversion of RNA sequences into corresponding polypeptides, 25,767 putative proteins were discovered. Of these, 19,540 (78.83% showed significant similarity to known proteins in the either the NCBI nr or Uniprot databases. Gene ontology (GO terms were assigned to 7,512 proteins, and 791 proteins in the sialotranscriptome of TPB were found to collectively map to 107 Kyoto Encyclopedia of Genes and Genomes (KEGG database pathways. A total of 3,653 Pfam domains were identified in 10,421 sialotranscriptome predicted proteins resulting in 12,814 Pfam annotations; some proteins had more than one Pfam domain. Functional annotation revealed a number of salivary gland proteins that potentially facilitate degradation of host plant tissues and mitigation of the host plant defense response. These transcripts/proteins and their potential roles in TPB establishment are described.
Three genes encoding polygalacturonase (PG) have been identified in Lygus lineolaris (Palisot de Beauvois) (Miridae: Hemiptera). Earlier studies showed that the three PG gene transcripts are exclusively expressed in the feeding stages of L. lineolaris. In an earlier report, it was shown that all thr...
The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is a highly polyphagous insect pest. It is the most widely distributed Lygus species in North America, and it is the most prevalent member of the genus Lygus in the eastern half of the continent. We sampled multiple populations of L. l...
Three unique cDNAs encoding putative polygalacturonase enzymes were isolated from the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae). The three nucleotide sequences were dissimilar to one another, but the deduced amino acid sequences were similar to each other and ...
Probing behavior of Lygus lineolaris (Palisot de Beauvois), one of the most important pests affecting cotton production in mid-southern United States, has previously been characterized with electropenetrography (EPG). Cell rupturing (CR) and Ingestion (I) EPG waveforms were identified as two of the ...
The effect of temperature and exposure to Beauveria bassiana on tarnished plant bugs Lygus lineolaris (Heteroptera: Miridae) population dynamics and the broader implications of treating insects with entomopathogenic fungi
Tarnished plant bugs, Lygus lineolaris (Palisot de Beauvois) (Heteroptera, Miridae) are a major pest of cotton in most of the cotton growing regions of the Southern US. Studies were conducted to investigate how temperature and Beauveria bassiana (Balsamo) Vuilllemin infection impacted L. lineolaris...
The toxicity of Steward, a formulation of indoxacarb, was studied for the tarnished plant bug [Lygus lineolaris (Palisot de Beauvois)], a pest of cotton, and the big-eyed insect [Geocoris punctipes (Say)], a predator of pests in cotton. Both insects responded similarly to Steward in topical, tarsal ...
Plant bugs (Hemiptera: Miridae) are phytophagous pests of cultivated plants around the world. In the mid-South region of the United States, Lygus lineolaris is a primary pest of cotton, and causes economic damage. Previously published research about the volatiles produced by members of the genus Lyg...
In insects, the perception and discrimination of odorants requires the involvement of odorant binding proteins (OBPs). To gain a better molecular understanding of olfaction in the agronomic pest, Lygus lineolaris (tarnished plant bug), we used a transcriptomics-based approach to identify potential ...
Tarnished plant bugs, Lygus lineolaris and L. hesperus, are among the most important pests affecting production of cotton in the mid-southern and western United States, respectively. Previous studies have focused on feeding damage to cotton reproductive structures from destructive enzymatic saliva. ...
Zhu, Yu Cheng; Luttrell, Randall
Chemical spray on cotton is almost an exclusive method for controlling tarnished plant bug (TPB), Lygus lineolaris. Frequent use of imidacloprid is a concern for neonicotinoid resistance in this key pest. Information of how and why TPB becomes less susceptible to imidacloprid is essential for effective monitoring and managing resistance. Microarray analysis of 6688 genes in imidacloprid-selected TPB (Im1500FF) revealed 955 upregulated and 1277 downregulated (≥twofold) genes in Im1500FF, with 369 and 485 of them annotated. Five P450 and nine esterase genes were significantly upregulated, and only one esterase gene and no P450 genes were downregulated. Other upregulated genes include helicases, phosphodiesterases, ATPases and kinases. Pathway analyses identified 65 upregulated cDNAs that encode 51 different enzymes involved in 62 different pathways, including P450 and esterase genes for drug and xenobiotic metabolisms. Sixty-four downregulated cDNAs code only 17 enzymes that are associated with only 23 pathways mostly related to food digestion. This study demonstrated a significant change in gene expression related to metabolic processes in imidacloprid-selected TPB, resulting in overexpression of P450 and esterase genes for potential excess detoxification and cross/multiple resistance development. The identification of these and other enzyme genes establishes a foundation to explore the complicity of potential imidacloprid resistance in TPB. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
The entomopathogenic fungus Beauveria bassiana and the insect growth regulator novaluron are potential candidates for the control of Lygus lineolaris. Efforts are being made for their use in the Mississippi Delta. B. bassiana and novaluron highly affected TPB survival when they were applied directly...
Saliva is known to play a crucial role in tarnished plant bug (TPB, Lygus lineolaris) feeding. TPBs secrete saliva during feeding to facilitate the piercing into plant tissues. More importantly, the enzyme-rich saliva may be used for extra-oral digestion and for overcoming plant defense before the p...
Tillman, P Glynn; Hammes, Glenn G; Sacher, Matthew; Connair, Michael; Brady, E Angela; Wing, Keith D
Indoxacarb is a new oxadiazine insecticide that has shown outstanding field insecticidal activity. The toxicity of a 145 g litre-1 indoxacarb SC formulation (Steward) was studied on the tarnished plant bug Lygus lineolaris and the big-eyed bug Geocoris punctipes. Both insect species responded very similarly to indoxacarb in topical, tarsal contact and plant feeding toxicity studies. The topical LD50 of the formulation was c 35 ng AI per insect for both species. Prolonged tarsal contact with dry indoxacarb residues did not result in mortality for either insect species. However, both species were susceptible to feeding through dried residues of indoxacarb after spraying on young cotton plants. Feeding on water-washed plants resulted in lower mortality than that observed with unwashed plants, and toxicity declined even more dramatically after a, detergent rinse, indicating that much of the indoxacarb probably resides on the cotton leaf surface or in the waxy cuticle. These results were corroborated by HPLC-mass spectrometry measurements of indoxacarb residues on the plants. Greater mortality for both species was observed in a higher relative humidity environment. Higher levels of accumulated indoxacarb and its active metabolite were detected in dead G punctipes than in L lineolaris after feeding on sprayed, unwashed plants. When female G punctipes ate indoxacarb-treated Heliothis zea eggs, there was significant toxicity. However, only c 15% of the females consumed indoxacarb-treated eggs, and the rest of the females showed a significant diminution of feeding in response to the insecticide. Cotton field studies have shown that indoxacarb treatments at labelled rates lead to a dramatic decline in L lineolaris, with negligible declines in beneficial populations. A major route of intoxication of L lineolaris in indoxacarb-treated cotton fields thus appears to be via oral, and not cuticular, uptake of residues from treated cotton plants. The mechanisms for selectivity
Full Text Available The kudzu bug, Megacopta cribraria (F., is an urban nuisance and significant agricultural pest. The median lethal concentrations of three strains of Beauveria bassiana (Balsamo, including the Mississippi Delta native strain (NI8 isolated from Lygus lineolaris (Palisot de Beauvois, the commercial strain BotaniGard® (GHA (Victor, NY, USA, and the B. bassiana strain isolated from M. cribraria (KUDSC, were estimated on kudzu bug adults. A technique developed to evaluate B. bassiana against L. lineolaris was used. Younger adults (eight days after collection were treated with NI8 and GHA and older adult (50 days after collection were treated with NI8, GHA and KUDSC. Higher concentrations (n × 106, n × 107 of NI8 and GHA caused kudzu bug mortality two days after treatment in younger adults and similar concentrations of NI8, GHA, and KUDSC caused mortality one day after treatment in older adults. Lower concentrations (n × 104, n × 105 were not significantly different in mortality between strains. LS50 values of the KUDSC were significantly lower than NI8 and GHA values in older adults. This is the first available information on median lethal concentration of B. bassiana on kudzu bug adults bioassayed on artificial diet. It was determined that B. bassiana (KUDSC and NI8 are highly effective for young adults at very low doses (LC50 1.98–4.98 viable spores per mm2.
Portilla, Maribel; Jones, Walker; Perera, Omaththage; Seiter, Nick; Greene, Jeremy; Luttrell, Randall
The kudzu bug, Megacopta cribraria (F.), is an urban nuisance and significant agricultural pest. The median lethal concentrations of three strains of Beauveria bassiana (Balsamo), including the Mississippi Delta native strain (NI8) isolated from Lygus lineolaris (Palisot de Beauvois), the commercial strain BotaniGard(®) (GHA) (Victor, NY, USA), and the B. bassiana strain isolated from M. cribraria (KUDSC), were estimated on kudzu bug adults. A technique developed to evaluate B. bassiana against L. lineolaris was used. Younger adults (eight days after collection) were treated with NI8 and GHA and older adult (50 days after collection) were treated with NI8, GHA and KUDSC. Higher concentrations (n × 10⁶, n × 10⁷) of NI8 and GHA caused kudzu bug mortality two days after treatment in younger adults and similar concentrations of NI8, GHA, and KUDSC caused mortality one day after treatment in older adults. Lower concentrations (n × 10⁴, n × 10⁵) were not significantly different in mortality between strains. LS50 values of the KUDSC were significantly lower than NI8 and GHA values in older adults. This is the first available information on median lethal concentration of B. bassiana on kudzu bug adults bioassayed on artificial diet. It was determined that B. bassiana (KUDSC and NI8) are highly effective for young adults at very low doses (LC50 1.98-4.98 viable spores per mm²).
付雪姣; Kim Hoelmer; 石旺鹏
盲蝽是一类世界性害虫,寄主广泛,主要为害棉花、苜蓿、果树和蔬菜等作物.在美国,对农业生产危害较严重的是美国牧草盲蝽Lygus lineolaris(Palisot de Beauvois),农民每年用于控制盲蝽的费用和盲蝽造成的损失达数亿美元,目前美国对牧草盲蝽的控制逐渐从化学防治转向生物防治.美国从欧洲引入用来防治欧洲长毛草盲蝽Lygus rugulipennis Poppius的寄生性天敌常室茧蜂属Peristenus Foerster,在东北部苜蓿地释放后,成功地控制了该地区牧草盲蝽数量,取得了巨大的经济和生态效益.美国同时对该类寄生性天敌的生理生态及生产应用技术等进行了大量的研究,这对我国开展盲蝽生物防治具有良好的借鉴作用.%Mirid bugs are worldwide pests with a wide host range,including cotton and alfalfa.The damage caused by the mirid genus, Lygus Hahn, is particularly great; the cost of controlling this pest and the losses caused by it amounting to hundreds of millions dollars per year in the United States alone.In the U.S., biological control has increasingly replaced chemical pesticides for the control of this pest.For example, Peristenus Foerster ( Hymenoptera:Braconidae ) ,introduced from Europe, has successfully prevented outbreaks of Lygus lineolaris ( Palisot de Beauvois) in northeastern USA.Extensive studies on the ecology and physiology of these groups of parasitoids and their application in biological control have been carried out.This experience should be used in China to improve control of the cotton mirid bug.
Lygus hesperus and L. lineolaris (Hemiptera: Miridae) are economically important pests affecting production of cotton in the western and mid-southern USA, respectively. Lygus feeding damage varies with instar; young nymphs are cell-rupture feeders performing laceration and maceration of plant tissue...
Byers, John A.; Fefer, Daniela; Levi-Zada, Anat
The plant bugs Lygus hesperus, Lygus lineolaris, and Lygus elisus (Hemiptera: Miridae) are major pests of many agricultural crops in North America. Previous studies suggested that females release a sex pheromone attractive to males. Other studies showed that males and females contain microgram amounts of ( E)-4-oxo-2-hexenal, hexyl butyrate, and ( E)-2-hexenyl butyrate that are emitted as a defense against predators. Using gas chromatography-mass spectrometry, we found that female L. lineolaris and L. elisus have a 4:10 ratio of hexyl butyrate to ( E)-2-hexenyl butyrate that is reversed from the 10:1 ratio in female L. hesperus (males of the three species have ~10:1 ratio). These reversed ratios among females of the species suggest a behavioral role. Because both sexes have nearly equal amounts of the major volatiles, females should release more to attract males. This expectation was supported because L. hesperus females released more hexyl butyrate (mean of 86 ng/h) during the night (1800-0700 hours) than did males (pheromone component for all three species, ( E)-2-hexenyl butyrate is essential for L. elisus and L. lineolaris, and hexyl butyrate is essential for L. hesperus. However, all three components are recognized by each species since ratios of the butyrate esters are critical for conspecific attraction and heterospecific avoidance by males and thus play a role in reproductive isolation among the three species. Because L. hesperus males and females are known to emit these major volatiles for repelling ant predators, our study links defensive allomones in Lygus bugs with an additional use as sex pheromones.
Cooper, WRodney; Nicholson, Scott J; Puterka, Gary J
.... Improved knowledge of L. hesperus salivary proteins could lead to a better understanding of Lygus-host interactions, and aid in the development of crops that are resistant or tolerant to injury caused by Lygus spp...
Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is the primary pest of cotton across the Midsouth of the United States. Movement into cotton fields occurs during the summer from other host plants, both cultivated and wild. Stable isotope analysis (SIA) has been used in other studies to ...
A laboratory bioassay was developed and used to test field populations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), for resistance development to the neonicitinoid insecticides imidacloprid (Trimax®) and thiamethoxam (Centric®). The bioassay determined LC50 values by feeding...
Aug 4, 2009 ... groups released from starch by α-amylase action are measured by the reduction .... Data were compared by one-way analysis of variance (ANOVA) followed by .... Lygus hesperus Knight and L. lineolaris (Palisot de. Beauvois) ...
The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is the major insect pest of cotton, Gossypium hirsutum (L.), within the Mid-South region. From 2001 to 2012, the tarnished plant bug has been the number one insect pest of cotton in Louisiana and Mississippi in eleven and nine of those...
The tarnished plant bug, (TPB), Lygus lineolaris (Palisot de Beauvois), (Hemiptera: Miridae) an important pest of cotton (Gosssypium hirsutum L.) found in the Mississippi Delta is naturally attacked by the entomopathogenic fungus Beauveria bassiana (Balsamo) Vueillemin. In this study, two isolates o...
A preliminary field study was conducted in 2012 to measure impact of spraying tassel-stage corn and blooming early-maturity-group soybean with Beauveria bassiana on tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) populations before they colonize cotton. Four-row strips of mustard (total...
Previous works reported that Beauveria bassiana (Balsamo) isolates from tarnished plant bug, TPB, Lygus lineolaris Palisot de Beauvois, (Hemiptera: Miridae) have shown a great potential to be used as a microbial control for TPB, particularly the NI8 strain, isolated from the TPB from Mississippi De...
Zeng, F; Cohen, A C
To better understand the nature of facultative phytophagy in the zoophytophagous Geocoris punctipes (Say), and facultative zoophagy in phytozoophagous Lygus hesperus (Knight) and Lygus lineolaris (Palisot de Beauvois), we compared the activities of both the starch digesting enzyme alpha-amylase and of general proteases in these species. The alpha-amylases and proteases were demonstrated in L. hesperus, L. lineolaris and G. punctipes. The presence of alpha-amylase in the salivary gland complexes of G. punctipes indicates a disposition of this species toward utilization of nutrients that can be derived only from plants, either directly from ingestion of plant macromolecules or from second-hand ingestion of plant material from the digestive system of their prey. The alpha-amylase activity in G. punctipes was much less than those of phytozoophagous L. hesperus and L. lineolaris. The relative importance of amylolytic activity and proteolytic activity is also discussed.
Esquivel, J F; Mowery, S V
The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), has taken on added importance as a pest of cotton in the Cotton Belt after successful eradication efforts for the boll weevil (Anthonomus grandis grandis Boheman). Because the Southern Blacklands region of Central Texas is in advanced stages of boll weevil eradication, blooming weeds and selected row crops were sampled during a 3-yr study to determine lygus species composition and associated temporal host plants. L. lineolaris was the sole lygus species in the region. Thirteen previously unreported host plants were identified for L. lineolaris, of which 69% supported reproduction. Rapistrum rugosum L. Allioni and Ratibida columnifera (Nuttall) Wooton and Standley were primary weed hosts during the early season (17 March to 31 May). Conyza canadensis L. Cronquist variety canadensis and Ambrosia trifida L. were primary weed hosts during the midseason (1 June to 14 August) and late-season (15 August to 30 November), respectively. Sisymbrium irio L. and Lamium amplexicaule L. sustained L. lineolaris populations during the overwintering period (1 December to 16 March). The proportion of females and numbers of nymphs found in R. rugosum, C. canadensis, A. trifida, and S. irio suggests these weeds supported reproductive adults during the early, mid-, and late season and overwintering period, respectively. Medicago sativa L. was the leading crop host for L. lineolaris; Glycine max L. Merrill did not yield L. lineolaris. Few L. lineolaris were collected in Gossypium hirsutum L. These results provide a more comprehensive assessment of host plants contributing to L. lineolaris populations in central Texas.
The genus Lygus is widely distributed in North American and Eurasian continents. It is the most-studied genus in the family Miridae. However, very less information on the genetic diversity of this genus is available. Studying genetic variation among Lygus pest species and thereby constructing a ...
Alfalfa (Medicago sativa L.) is a highly attractive plant host to Lygus spp. and is used as a trap crop in California organic strawberries to influence the dispersion and dispersal of these pests, particularly L. hesperus. The abundance and distribution of Lygus spp. nymphs between two trap crops s...
The tarnished plant bug (TPB) has increasingly become an economically important pest of cotton. Heavy dependence on insecticides, particularly organophosphates and pyrethroids, for TPB control facilitated resistance development to multiple classes of insecticides. To better understand resistance and...
Detailed life-tables studies or more quantitative estimates of the impact of control agents on TPB life history require a bioassay option to study the impact of prolonged exposure for weeks following contact with the control agent. This is difficult with plant tissue that must be routinely replaced ...
Astakines are hematopoietic cytokines originally isolated from crustaceans. We identified three astakine-like transcripts in the tarnished plant bug, LlAst-1, LlAst-2, and LlAst-3, containing prokineticin domains. Quantitative real-time PCR demonstrated variation in expression patterns of astakines ...
Alfalfa trap crops can be used to manage Lygus spp. in organic strawberries on the California Central Coast. The retention of Lygus spp. in alfalfa creates aggregated distributions that provide improved opportunities for biological control by the introduced parasitoid Peristenus relictus (Ruthe). ...
ROBERT S. BOYD
Nickel hyperaccumulator plants contain unusually elevated levels of Ni (＞ 1 000 μg Ni/g). Some insect herbivores, including Lygus hesperus (Western tarnished plant bug), have been observed feeding on the California Ni hyperaccumulator Streptanthus polygaloides. This bug may be able to utilize S. polygaloides as a host either through its feeding behavior or by physiological tolerance of Ni. This experiment determined the Ni tolerance of L. hesperus by offering insects artificial diet amended with 0,0.4, 1, 2, 4.5,10, 20 and 40 mmol Ni/L and recording survival. Survival varied due to Ni concentration, with diets containing 10 mmol Ni/L and greater resulting in significantly lower survival compared to the control (0 mmol Ni/L) treatment. Insects tolerated diet containing as much as 4.5 mmol Ni/L, a relatively elevated Ni concentration. I conclude that L. hesperus can feed on S. polygaloides because it is Ni-tolerant, probably due to physiological mechanisms that provide it with resistance to plant chemical defenses including elemental defenses such as hyperaccumulated Ni.
The western tarnished plant bug, Lygus hesperus Knight, is an important pest of crops in the western U.S. Research on the basic biology of L. hesperus often relies on access to healthy insects, which are typically provided through laboratory cultures. However, maintenance of colony vigor often req...
Habibi, J.; Coudron, T.A.; Backus, E.A.; Brandt, S.L.; Wagner, R.M.; Wright, M.K.; Huesing, J.E.
Microdissection and transverse semithin sections were used to perform a light microscopy survey of the gross morphology and cellular anatomy of the alimentary canal, respectively, of Lygus hesperus Knight, a key pest of cotton (Gossypium hirsutum L.), alfalfa (Medicago sativa L.), and other crops. The gross morphology of the alimentary canal showed a relatively unadorned tube compared with other hemipterans, with variably shaped compartments and one small diverticulum. However, the epithelial cell anatomy of the gut was relatively complex, with the midgut having the most diverse structure and cell types. The midgut was typical of the "Lygus-type gut" seen in the older literature, i.e., it consisted of three major regions, the first (descending), second (ascending), and third (descending) ventriculi, with different variants of three major epithelial cell types in each region. Our light microscopy (LM) study suggests that the three cell types are nondifferentiated regenerative cells (which sparsely occurred throughout the midgut but were abundant in the anterior region of the first ventriculus), endocrine cells, and columnar cells. Although the Lygus gut cells strongly resemble those cell types seen in other insects, their identification should be confirmed via transmission electron microscopy to be considered definitive. These cell types differed in the size and opacity of vesicles, geometry of cell surface in the gut lumen, and size, shape, and concentration of brush-border microvilli and location within the gut. Comparison of gut structure in L. hesperus with that of other hemipterans, especially in relation to hemipteran phylogeny and feeding strategies, is discussed.
A new method for post-mortem quantification of predation on prey items marked with protein antigens is described. First, short-term protein marking retention tests were conducted on the targeted prey, immature Lygus hesperus Knight (Heteroptera: Miridae). Chicken IgG, rabbit IgG, or soy milk protein...
Mating induces behavioral and physiological changes in the plant bug Lygus hesperus Knight (Hemiptera: Miridae). Males enter a post-mating refractory period, lasting 24 hrs, during which they replenish the contents of their accessory glands and seminal vesicles. Females experience a similar loss of ...
Lygus hesperus Knight (Hemiptera: Miridae) is a key agricultural pest in the western United States. In a recent study, proteins from Pantoea ananatis and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) were identified in diet that was stylet-probed and fed upon by L. hesperus adults. P...
J Joe Hull
Full Text Available ATP-binding cassette (ABC transporters are a large superfamily of proteins that mediate diverse physiological functions by coupling ATP hydrolysis with substrate transport across lipid membranes. In insects, these proteins play roles in metabolism, development, eye pigmentation, and xenobiotic clearance. While ABC transporters have been extensively studied in vertebrates, less is known concerning this superfamily in insects, particularly hemipteran pests. We used RNA-Seq transcriptome sequencing to identify 65 putative ABC transporter sequences (including 36 full-length sequences from the eight ABC subfamilies in the western tarnished plant bug (Lygus hesperus, a polyphagous agricultural pest. Phylogenetic analyses revealed clear orthologous relationships with ABC transporters linked to insecticide/xenobiotic clearance and indicated lineage specific expansion of the L. hesperus ABCG and ABCH subfamilies. The transcriptional profile of 13 LhABCs representative of the ABCA, ABCB, ABCC, ABCG, and ABCH subfamilies was examined across L. hesperus development and within sex-specific adult tissues. All of the transcripts were amplified from both reproductively immature and mature adults and all but LhABCA8 were expressed to some degree in eggs. Expression of LhABCA8 was spatially localized to the testis and temporally timed with male reproductive development, suggesting a potential role in sexual maturation and/or spermatozoa protection. Elevated expression of LhABCC5 in Malpighian tubules suggests a possible role in xenobiotic clearance. Our results provide the first transcriptome-wide analysis of ABC transporters in an agriculturally important hemipteran pest and, because ABC transporters are known to be important mediators of insecticidal resistance, will provide the basis for future biochemical and toxicological studies on the role of this protein family in insecticide resistance in Lygus species.
J. Joe Hull
Full Text Available The Gα subunits of heterotrimeric G proteins play critical roles in the activation of diverse signal transduction cascades. However, the role of these genes in chemosensation remains to be fully elucidated. To initiate a comprehensive survey of signal transduction genes, we used homology-based cloning methods and transcriptome data mining to identity Gα subunits in the western tarnished plant bug (Lygus hesperus Knight. Among the nine sequences identified were single variants of the Gαi, Gαo, Gαs, and Gα12 subfamilies and five alternative splice variants of the Gαq subfamily. Sequence alignment and phylogenetic analyses of the putative L. hesperus Gα subunits support initial classifications and are consistent with established evolutionary relationships. End-point PCR-based profiling of the transcripts indicated head specific expression for LhGαq4, and largely ubiquitous expression, albeit at varying levels, for the other LhGα transcripts. All subfamilies were amplified from L. hesperus chemosensory tissues, suggesting potential roles in olfaction and/or gustation. Immunohistochemical staining of cultured insect cells transiently expressing recombinant His-tagged LhGαi, LhGαs, and LhGαq1 revealed plasma membrane targeting, suggesting the respective sequences encode functional G protein subunits.
Asiimwe, Peter; Naranjo, Steven E; Ellsworth, Peter C
Variation in plant quality and natural enemy abundance plays an important role in insect population dynamics. In manipulative field studies, we evaluated the impact of varying irrigation levels and insecticide type on densities of Lygus hesperus Knight and the arthropod predator community in cotton. Three watering levels were established via irrigations timed according to three levels of percent soil water depletion (SWD): 20, 40, or 60, where 40% SWD is considered standard grower practice, 60% represents a deficit condition likely to impose plant productivity losses, and 20% represents surplus conditions with likely consequences on excessive vegetative plant production. The two key L. hesperus insecticides used were the broad-spectrum insecticide acephate and the selective insecticide flonicamid, along with an untreated check. We hypothesized that densities of L. hesperus and its associated predators would be elevated at higher irrigation levels and that insecticides would differentially impact L. hesperus and predator dynamics depending on their selectivity. L. hesperus were more abundant at the higher irrigation level (20% SWD) but the predator densities were unaffected by irrigation levels. Both L. hesperus and its predators were affected by the selectivity of the insecticide with highest L. hesperus densities and lowest predator abundance where the broad spectrum insecticide (acephate) was used. There were no direct interactions between irrigation level and insecticides, indicating that insecticide effects on L. hesperus and its predators were not influenced by the irrigation levels used here. The implications of these findings on the overall ecology of insect-plant dynamics and yield in cotton are discussed.
Lygus hesperus (western tarnished plant bug) is an agronomically important pest species of numerous cropping systems. Similar to other insects, a critical component underlying behaviors is the perception and discrimination of olfactory cues. Consequently, the molecular basis of olfaction in this spe...
Full Text Available BACKGROUND: The western tarnished plant bug Lygus hesperus is an economically important pest that belongs to a complex of morphologically similar species that makes identification problematic. The present study provides evidence for the use of DNA barcodes from populations of L. hesperus from the western United States of America for accurate identification. METHODOLOGY/PRINCIPAL FINDINGS: This study reports DNA barcodes for 134 individuals of the western tarnished plant bug from alfalfa and strawberry agricultural fields in the western United States of America. Sequence divergence estimates of <3% reveal that morphologically variable individuals presumed to be L. hesperus were accurately identified. Paired estimates of F(st and subsequent estimates of gene flow show that geographically distinct populations of L. hesperus are genetically similar. Therefore, our results support and reinforce the relatively recent (<100 years migration of the western tarnished plant bug into agricultural habitats across the western United States. CONCLUSIONS/SIGNIFICANCE: This study reveals that despite wide host plant usage and phenotypically plastic morphological traits, the commonly recognized western tarnished plant bug belongs to a single species, Lygus hesperus. In addition, no significant genetic structure was found for the geographically diverse populations of western tarnished plant bug used in this study.
Christie, Andrew E; Hull, J Joe; Richer, Josh A; Geib, Scott M; Tassone, Erica E
Many strategies for controlling insect pests require an understanding of their hormonal signaling agents, peptides being the largest and most diverse single class of these molecules. Lygus hesperus is a pest species of particular concern, as it is responsible for significant damage to a wide variety of commercially important plant crops. At present, little is known about the peptide hormones of L. hesperus. Here, transcriptomic data were used to predict a peptidome for L. hesperus. Fifty-three L. hesperus transcripts encoding peptide precursors were identified, with a subset amplified by PCR for sequence verification. The proteins deduced from these transcripts allowed for the prediction of a 119-sequence peptidome for L. hesperus. The predicted peptides include isoforms of allatostatin A, allatostatin B (AST-B), allatostatin C, allatotropin, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone/ion transport peptide, diuretic hormone 31, GSEFLamide, insulin-like peptide, myosuppressin, neuroparsin, neuropeptide F, orcokinin, orcomyotropin, pyrokinin, short neuropeptide F, SIFamide, sulfakinin and tachykinin-related peptide. Of note were several isoforms of AST-B that possess -WX7Wamide carboxyl-termini rather than the stereotypical -WX6Wamide (e.g., KWQDMQNPGWamide), an allatotropin ending in -SARGFamide rather than -TARGFamide (GLKNGPLNSARGFamide), a GSEFLamide ending in -GTEFLamide (TVGTEFLamide), several orcokinins with PMDEIDR- rather than NFDEIDR- amino-termini (e.g., PMDEIDRAGFTHFV), and an eight rather than 12 amino acid long isoform of SIFamide (PPFNGSIFamide). Collectively, the L. hesperus peptidome predicted here provides a resource for initiating physiological investigations of peptidergic signaling in this species, including studies directed at the biological control of this agricultural pest.
Naranjo, Steven E; Ellsworth, Peter C; Dierig, David A
Lesquerella, Physaria fendleri (A. Gray) S. Watson, is a mustard native to the western United States and is currently being developed as a commercial source of valuable hydroxy fatty acids that can be used in a number of industrial applications, including biolubricants, biofuel additives, motor oils, resins, waxes, nylons, plastics, corrosion inhibitors, cosmetics, and coatings. The plant is cultivated as a winter-spring annual and in the desert southwest it harbors large populations of arthropods, several of which could be significant pests once production expands. Lygus spp. (Hemiptera: Miridae) are common in lesquerella and are known pests of a number of agronomic and horticultural crops where they feed primarily on reproductive tissues. A 4-yr replicated plot study was undertaken to evaluate the probable impact of Lygus spp. on production of this potential new crop. Plant damage and subsequent seed yield and quality were examined relative to variable and representative densities of Lygus spp. (0.3-4.9 insects per sweep net) resulting from variable frequency and timing of insecticide applications. Increasing damage to various fruiting structures (flowers [0.9-13.9%], buds [1.2-7.1%], and seed pods [19.4-42.5%]) was significantly associated with increasing pest abundance, particularly the abundance of nymphs, in all years. This damage, however, did not consistently translate into reductions in seed yield (481-1,336 kg/ha), individual seed weight (0.5-0.7 g per 1,000 seed), or seed oil content (21.8-30.4%), and pest abundance generally explained relatively little of the variation in crop yield and quality. Negative effects on yield were not sensitive to the timing of pest damage (early versus late season) but were more pronounced during years when potential yields were lower due to weed competition and other agronomic factors. Results suggest that if the crop is established and managed in a more optimal fashion, Lygus spp. may not significantly limit yield
Cooper, W Rodney; Nicholson, Scott J; Puterka, Gary J
Lygus hesperus Knight (Hemiptera: Miridae) is a key agricultural pest in the western United States. In a recent study, proteins from Pantoea ananatis and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) were identified in diet that was stylet probed and fed on by L. hesperus adults. P. ananatis and S. marcescens are ubiquitous bacteria that infect a wide range of crops. The objective of our study was to determine whether L. hesperus transfer P. ananatis and S. marcescens to food substrates during stylet-probing activities. Sucrose (5%) was spread under parafilm and exposed to adult L. hesperus for 24 h. Diet similarly prepared but not exposed to insects was used for controls. MacConkey agar was inoculated with stylet-probed or control diets and incubated at 25 degrees C. After 24 h, bacterial colonies were observed on agar that was inoculated with stylet-probed diet, but were not observed on agar inoculated with control diet. Isolated bacterial colonies were putatively identified as either Pantoea spp. or S. marcescens using the API 20e identification kit. These results indicate that L. hesperus is capable of vectoring P. ananatis and S. marcescens.
Zhang, Li-Juan; Cai, Wan-Zhi; Luo, Jun-Yu; Zhang, Shuai; Wang, Chun-Yi; Lv, Li-Min; Zhu, Xiang-Zhen; Wang, Li; Cui, Jin-Jie
Lygus pratensis (L.) is an important cotton pest in China, especially in the northwest region. Nymphs and adults cause serious quality and yield losses. However, the genetic structure and geographic distribution of L. pratensis is not well known. We analyzed genetic diversity, geographical structure, gene flow, and population dynamics of L. pratensis in northwest China using mitochondrial and nuclear sequence datasets to study phylogeographical patterns and demographic history. L. pratensis (n = 286) were collected at sites across an area spanning 2,180,000 km2, including the Xinjiang and Gansu-Ningxia regions. Populations in the two regions could be distinguished based on mitochondrial criteria but the overall genetic structure was weak. The nuclear dataset revealed a lack of diagnostic genetic structure across sample areas. Phylogenetic analysis indicated a lack of population level monophyly that may have been caused by incomplete lineage sorting. The Mantel test showed a significant correlation between genetic and geographic distances among the populations based on the mtDNA data. However the nuclear dataset did not show significant correlation. A high level of gene flow among populations was indicated by migration analysis; human activities may have also facilitated insect movement. The availability of irrigation water and ample cotton hosts makes the Xinjiang region well suited for L. pratensis reproduction. Bayesian skyline plot analysis, star-shaped network, and neutrality tests all indicated that L. pratensis has experienced recent population expansion. Climatic changes and extensive areas occupied by host plants have led to population expansion of L. pratensis. In conclusion, the present distribution and phylogeographic pattern of L. pratensis was influenced by climate, human activities, and availability of plant hosts. PMID:28369108
Griffin, T W; Zapata, S D
The concept of insecticide termination timing is generally accepted among cotton (Gossypium hirsutum) researchers; however, exact timings are often disputed. Specifically, there is uncertainty regarding the last economic insecticide application to control fruit-feeding pests including tarnished plant bug (Lygus lineolaris (Palisot de Beauvois)), boll weevil (Anthonomus grandis), bollworm (Helicoverpa zea), tobacco budworm (Heliothis virescens), and cotton fleahopper (Pseudatomoscelis seriatus). A systematic review of prior studies was conducted within a meta-analytic framework. Nine publicly available articles were amalgamated to develop an optimal timing principle. These prior studies reported 53 independent multiple means comparison field experiments for a total of 247 trial observations. Stochastic plateau theory integrated with econometric meta-analysis methodology was applied to the meta-database to determine the shape of the functional form of both the agronomic optimal insecticide termination timing and corresponding yield potential. Results indicated that current university insecticide termination timing recommendations are later than overall estimated timing suggested. The estimated 159 heat units (HU) after the fifth position above white flower (NAWF5) was found to be statistically different than the 194 HU termination used as the status quo recommended termination timing. Insecticides applied after 159 HU may have been applied in excess, resulting in unnecessary economic and environmental costs. Empirical results also suggested that extending the insecticide termination time by one unit resulted in a cotton lint yield increase of 0.27 kilograms per hectare up to the timing where the plateau began. Based on economic analyses, profit-maximizing producers may cease application as soon as 124 HU after NAWF5. These results provided insights useful to improve production systems by applying inputs only when benefits were expected to be in excess of the
Outward, Randy; Sorenson, Clyde E; Bradley, J R
The influence, if any, of 5m wide, feral, herbaceous field borders on pest and beneficial arthropods in commercial cotton, Gossypium hirsutum (L.) (Malvales: Malvaceae), fields was measured through a variety of sampling techniques over three years. In each year, 5 fields with managed, feral vegetation borders and five fields without such borders were examined. Sampling was stratified from the field border or edge in each field in an attempt to elucidate any edge effects that might have occurred. Early season thrips populations appeared to be unaffected by the presence of a border. Pitfall sampling disclosed no differences in ground-dwelling predaceous arthropods but did detect increased populations of crickets around fields with borders. Cotton aphid (Aphis gossypii Glover) (Hemiptera: Aphididae) populations were too low during the study to adequately assess border effects. Heliothines, Heliothis virescens (F.) and Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), egg numbers and damage rates were largely unaffected by the presence or absence of a border, although in one instance egg numbers were significantly lower in fields with borders. Overall, foliage-dwelling predaceous arthropods were somewhat more abundant in fields with borders than in fields without borders. Tarnished plant bugs, Lygus lineolaris (Palisot de Beauvois) (Heteroptera: Miridae) were significantly more abundant in fields with borders, but stink bugs, Acrosternum hilare (Say), and Euschistus servus (Say) (Hemiptera: Pentatomidae) numbers appeared to be largely unaffected by border treatment. Few taxa clearly exhibited distributional edge effects relative to the presence or absence of border vegetation. Field borders like those examined in this study likely will have little impact on insect pest management in cotton under current insect management regimens.
Lalancette, Norman; Belding, Robert D; Shearer, Peter W; Frecon, Jerome L; Tietjen, William H
Hydrophobic and/or hydrophilic kaolin particle film treatments to peach (Prunus persica (L) Batsch) trees were evaluated for crop and pest management capabilities in six studies from 1997 to 2000. Unsprayed control and standard treatments, the latter consisting of a commercial pesticide program, were included for comparison. Treatments in initial studies were applied via handgun, which resulted in a uniform and heavy deposit of kaolin after the first application. In contrast, treatments in subsequent studies used airblast equipment, which provided a uniform but less dense coverage, even after multiple applications. Results showed that both formulations of kaolin provided control of oriental fruit moth (Grapholita molesta (Busck)), plum curculio (Conotrachelus nenuphar (Herbst)) and Japanese beetle (Popillia japonica Newman) that was comparable with or better than the standard pesticide program. Effective management of late season catfacing insects (tarnished plant bugs Lygus lineolaris (Palisot de Beauvois) and stinkbugs Acrosternum hilare (Say), Euschistus servus (Say), and E tristigmus (Say)) and leafrollers (undetermined species) was also observed, although kaolin applications significantly increased phytophagous mite (Panonychus ulmi (Koch)) levels. In contrast to arthropod management, kaolin failed to control either peach scab (Cladosporium carpophilum (Von Thumen)) or rusty spot (Podosphaera leucotricha (Ell and Ev) ES Salmon) in any of the 4 years of the study. However, hydrophobic kaolin provided effective brown rot (Monilinia fructicola (G Winter) Honey) control when applied via handgun, and partial control when applied via airblast; hydrophilic kaolin failed to provide any control. These results suggest that hydrophobicity and deposit density may be important factors for effective disease management. The application of kaolin significantly delayed fruit maturation, increased fruit size and increased soluble solids relative to the standard. This effect
Precision-based agricultural application of insecticide relies on a non-random distribution of pests; tarnished plant bugs (Lygus lineolaris) are known to prefer vigorously growing patches of cotton. Management zones for various crops have been readily defined using NDVI (Normalized Difference Vege...
Tarnished plant bugs (TPB, Lygus lineolaris) were collected from multiple locations in the Delta regions of Mississippi, Arkansas, and Louisiana (covering 200 miles in E-W and N-S directions), and were subjected to bioassays to acephate, imidacloprid, dicrotophos, thiamethoxam, and sulfoxaflor (repr...
The tarnished plant bug (TPB), Lygus lineolaris, is a generalist pest of many crops including cotton, strawberries, and alfalfa. While studying gene expression and gene knockdown through RNA interference, my lab was frustrated by an observation. We were unable to replicate knock down effects observe...
门兴元; 于毅; 张安盛; 李丽莉; 张君亭; 戈峰
组建了5个不同温度(17,20,23,26和29℃)下绿盲蝽Lygus lucorum实验种群的生命表.结果表明:在17～29℃温度范围内,随温度升高绿盲蝽的发育速率加快,并符合Logistic模型;在实验温度范围内,若虫期、产卵前期、卵期和世代历期分别为10.04～27.63,8.33～19.33,6.74～15.00,25.11～61.96 d.绿盲蝽的若虫、产卵前期和卵的发育起点温度分别为9.45,7.28和6.28℃,有效积温分别为210.25、191.83和160.12日度,完成整个世代需要的有效积温为555.04日度.在实验温度范围内,23℃时绿盲蝽的世代存活率最高(82.3%),雌成虫的产卵历期最长(41.67 d),单雌繁殖若虫数最多(35.42头/雌),种群趋势指数也最高(14.58);在较低的温度(17℃)和较高的温度(29℃)下,绿盲蝽的的种群趋势指数分别仅为8.44和9.06,均不利于其种群数量增加.
张兴华; 田绍仁; 李捷; 杨兆光; 涂祈钧; 乔艳艳
研究了棉盲蝽在转基因抗虫棉药剂防治与不使用药剂防治上的发生差异,及棉田周边杂草上棉盲蝽发生动态,结果:①不防治类型棉田各棉盲蝽百株虫口总发生量为879头,其中:中黑盲蝽274头,绿盲蝽189头,杂毛合垫盲蝽407头,赣棉淡盲蝽9头,虫种比依次为:31∶22∶46∶1,杂毛合垫盲蝽为优势种;②常规防治类型棉田各棉盲蝽百株虫口总发生量为588头,其中:中黑盲蝽371头,绿盲蝽104头,杂毛合垫盲蝽94头,烟盲蝽17头,赣棉淡盲蝽2头,虫种比依次为:63∶18∶16∶3∶0.3,中黑盲蝽为优势种.9月22日～11月2日棉田边盲蝽杂草寄主和虫口发生量:赣棉淡盲蝽杂草寄主有18种,虫口发生量779头,排位第一;绿盲蝽杂草寄主14种,虫口发生量180头,排第二位;异须单突盲蝽杂草寄主5种,虫口发生量104头,排第三位;其他几种棉盲蝽杂草寄主少发生量小,以小飞蓬杂草发生棉盲蝽种类最多,达6种.%The author studied the occurrence of cotton lygus in transgenic insect - resistant cotton fields (conducting chemical control or not) and their surrounding weeds. The results showed that; ① in the cotton fields without chemical control, the total quantity of cotton lygus per 100 plants was 879 heads, including 274 Adelphocoris suturalis, 189 Apolygus lueorums, 407 Orthotylus flavosparsus and 9 Creontiades bipuanctatus, the population ratio of the four species was 31: 22: 46: 1 , and Orthotylus flavosparsus was the dominant species among them; ② in the conventional control cotton fields, the total quantity of cotton lygus in every one hundred cotton plants was 588 heads, including 371 Adelphocoris suturalis, 104 Apolygus lucorum, 94 Orthotylus flavosparsus, 17 Cyrtopeltis tenuis and 2 Creontiades bipuanctatus, the population ratio of the five species was 63: 18: 16: 3: 0. 3, and Adelphocoris suturalis was the dominant species among them. From September 22 to November 2, the surrounding weed host
刘效明; 章炳旺; 吴习水; 曾斌; 钟直琳
[目的]为明确20％呋虫胺SG对棉盲蝽象的防治效果,开展了该药的田间药效试验.[结果]20％呋虫胺SG450、300、225、150 g a.i./hm2和50％马拉硫磷EC 750 mL a.i./hm2对棉盲蝽象的防效,药后ld依次为100％、80％、81.82％、75％和50％,药后3d的防效依次为100％、100％、94.29％、80.25％和46.45％；药后7d的防效依次为100％、95.15％、95％、80.11％和41.86％.[结论]20％呋虫胺SG防治棉盲蝽象具有速效、持效且对棉花安全的特点,是防治棉盲蝽象理想药剂.在中等偏轻发生年份用量为150～225 g a.i./hm2,在中等以上发生程度年份用量为225～300 g a.i./hm2.%[Aims] The field efficacy trial of dinotefuran 20% SG was conducted to confirm the control effect on Lygus lucorum Meyer-dur. [Results] The results showed that the efficacy of dinotefuran 20% SG at 450, 300, 225, 150 g a.I./ha and malathion 50% EC at 750 mL a.I./ha were 100, 80, 81.82, 75 and 50% respectively against L. Lucorum Meyer-dur on the first day after treatment, the efficacy were 100, 100, 94.29, 80.25 and 46.45% on the third day, and 100, 95.15, 95, 80.11 and 41.86% on the seventh day. [Conclusions] Dinotefuran 50% SG has advantages of readily availability, persistence and safety on cotton, which is an ideal pesticide in protecting cotton from L. Lucorum Meyer-d(u)r, the usage is 150-225 g a.I./ha in medium to light years, while 225-300 g a.I./ha in medium to large years
Tillman, Glynn; Schomberg, Harry; Phatak, Sharad; Mullinix, Benjamin; Lachnicht, Sharon; Timper, Patricia; Olson, Dawn
In fall 2000, an on-farm sustainable agricultural research project was established for cotton, Gossypium hirsutum L., in Tift County, Georgia. The objective of our 2-yr research project was to determine the impact of several cover crops on pest and predator insects in cotton. The five cover crop treatments included 1) cereal rye, Secale cereale L., a standard grass cover crop; 2) crimson clover, Trifolium incarnatum L., a standard legume cover crop; 3) a legume mixture of balansa clover, Trifolium michelianum Savi; crimson clover; and hairy vetch, Vicia villosa Roth; 4) a legume mixture + rye combination; and 5) no cover crop in conventionally tilled fields. Three main groups or species of pests were collected in cover crops and cotton: 1) the heliothines Heliothis virescens (F.) and Helicoverpa zea (Boddie); 2) the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois); and 3) stink bugs. The main stink bugs collected were the southern green stink bug, Nezara viridula (L.); the brown stink bug, Euschistus servus (Say); and the green stink bug, Acrosternum hilare (Say). Cotton aphids, Aphis gossypii Glover, were collected only on cotton. For both years of the study, the heliothines were the only pests that exceeded their economic threshold in cotton, and the number of times this threshold was exceeded in cotton was higher in control cotton than in crimson clover and rye cotton. Heliothine predators and aphidophagous lady beetles occurred in cover crops and cotton during both years of the experiment. Geocoris punctipes (Say), Orius insidiosus (Say), and red imported fire ant, Solenopsis invicta Buren were relatively the most abundant heliothine predators observed. Lady beetles included the convergent lady beetle, Hippodamia convergens Guérin-Méneville; the sevenspotted lady beetle, Coccinella septempunctata L.; spotted lady beetle, Coleomegilla maculata (DeGeer); and the multicolored Asian lady beetle, Harmonia axyridis (Pallas). Density of G. punctipes was
Jhee, Edward M; Boyd, Robert S; Eubanks, Micky D
No study of a single nickel (Ni) hyperaccumulator species has investigated the impact of hyperaccumulation on herbivores representing a variety of feeding modes. Streptanthus polygaloides plants were grown on high- or low-Ni soils and a series of no-choice and choice feeding experiments was conducted using eight arthropod herbivores. Herbivores used were two leaf-chewing folivores (the grasshopper Melanoplus femurrubrum and the lepidopteran Evergestis rimosalis), a dipteran rhizovore (the cabbage maggot Delia radicum), a xylem-feeder (the spittlebug Philaenus spumarius), two phloem-feeders (the aphid, Lipaphis erysimi and the spidermite Trialeurodes vaporariorum) and two cell-disruptors (the bug Lygus lineolaris and the whitefly Tetranychus urticae). Hyperaccumulated Ni significantly decreased survival of the leaf-chewers and rhizovore, and significantly reduced population growth of the whitefly cell-disruptor. However, vascular tissue-feeding insects were unaffected by hyperaccumulated Ni, as was the bug cell-disruptor. We conclude that Ni can defend against tissue-chewing herbivores but is ineffective against vascular tissue-feeding herbivores. The effects of Ni on cell-disruptors varies, as a result of either variation of insect Ni sensitivity or the location of Ni in S. polygaloides cells and tissues.
The desert-adapted crops vernonia (Centrapalus pauciflorus), lesquerella (Physaria fendleri), and camelina (Camelina sativa) are being grown in the arid southwestern USA as potential feedstock for biofuel and/or other environmentally friendly products. A plant feeding choice test was conducted to de...
The G-alpha subunits of heterotrimeric G proteins play critical roles in the activation of diverse signal transduction cascades. However, the role of these genes in chemosensation remains to be fully elucidated. To initiate a comprehensive survey of signal transduction genes, we used homology-base...
Full Text Available BACKGROUND: Many polyphagous pests sequentially use crops and uncultivated habitats in landscapes dominated by annual crops. As these habitats may contribute in increasing or decreasing pest density in fields of a specific crop, understanding the scale and temporal variability of source and sink effects is critical for managing landscapes to enhance pest control. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated how local and landscape characteristics affect population density of the western tarnished plant bug, Lygus hesperus (Knight, in cotton fields of the San Joaquin Valley in California. During two periods covering the main window of cotton vulnerability to Lygus attack over three years, we examined the associations between abundance of six common Lygus crops, uncultivated habitats and Lygus population density in these cotton fields. We also investigated impacts of insecticide applications in cotton fields and cotton flowering date. Consistent associations observed across periods and years involved abundances of cotton and uncultivated habitats that were negatively associated with Lygus density, and abundance of seed alfalfa and cotton flowering date that were positively associated with Lygus density. Safflower and forage alfalfa had variable effects, possibly reflecting among-year variation in crop management practices, and tomato, sugar beet and insecticide applications were rarely associated with Lygus density. Using data from the first two years, a multiple regression model including the four consistent factors successfully predicted Lygus density across cotton fields in the last year of the study. CONCLUSIONS/SIGNIFICANCE: Our results show that the approach developed here is appropriate to characterize and test the source and sink effects of various habitats on pest dynamics and improve the design of landscape-level pest management strategies.
Cogongrass, Imperata cylindrica (L.) Palisot de Beauvois (Cyperales: Poaceae), is a noxious invasive weed in the southeastern USA. Surveys for potential biological control agents of cogongrass were conducted in Asia and East Africa from 2013 to 2016. Several insect herbivores were found that may hav...
The entomopathogenic fungus Beauveria bassiana Delta native strain NI8 have shown great potential for the management of tarnished plant bug adults when compared with the commercial strain GHA. Population of L lineolaris in cages was reduced by 50% 10 days after application of the NI8 native strain a...
This presentation investigates an algorithm to fuse the Normalized Difference Vegetation Index (NDVI) with LiDAR elevation data to produce a map useful for the site-specific scouting and pest management (Willers et al. 1999; 2005; 2009) of the cotton insect pests, the tarnished plant bug (Lygus lin...
Gross, Kevin; Rosenheim, Jay A
Secondary pest outbreaks occur when the use of a pesticide to reduce densities of an unwanted target pest species triggers subsequent outbreaks of other pest species. Although secondary pest outbreaks are thought to be familiar in agriculture, their rigorous documentation is made difficult by the challenges of performing randomized experiments at suitable scales. Here, we quantify the frequency and monetary cost of secondary pest outbreaks elicited by early-season applications of broad-spectrum insecticides to control the plant bug Lygus spp. (primarily L. hesperus) in cotton grown in the San Joaquin Valley, California, USA. We do so by analyzing pest-control management practices for 969 cotton fields spanning nine years and 11 private ranches. Our analysis uses statistical methods to draw formal causal inferences from nonexperimental data that have become popular in public health and economics, but that are not yet widely known in ecology or agriculture. We find that, in fields that received an early-season broad-spectrum insecticide treatment for Lygus, 20.2% +/- 4.4% (mean +/- SE) of late-season pesticide costs were attributable to secondary pest outbreaks elicited by the early-season insecticide application for Lygus. In 2010 U.S. dollars, this equates to an additional $6.00 +/- $1.30 (mean +/- SE) per acre in management costs. To the extent that secondary pest outbreaks may be driven by eliminating pests' natural enemies, these figures place a lower bound on the monetary value of ecosystem services provided by native communities of arthropod predators and parasitoids in this agricultural system.
Müller, Günter C; Hogsette, Jerome A; Revay, Edita E; Kravchenko, Vasiliy D; Leshvanov, Andrey; Schlein, Yosef
The horse fly fauna (Diptera: Tabanidae) of Jordan is, after Israel, the richest in the Levant, with 24 known species. During the 20-year project "The Ecology and Zoogeography of the Lepidoptera of the Near East," we regularly collected blood-feeding flies, resulting in 11 additional species of Tabanidae for Jordan. The new records are: Atylotus quadrifarius (Loew, 1874), Chrysops caecutiens (Linnaeus, 1758), Dasyrhamphis nigritus (Fabricius, 1794), Haematopota pallens Loew, 1871, Nemorius irritans (Ricardo, 1901), Philipomyia graeca (Fabricius, 1794), Tabanus cordiger Meigen, 1820, Tabanus taeniola Palisot de Beauvois, 1806, Tabanus quatuornotatus Meigen, 1820, Tabanus separatus Effllatoun, 1930, and Tabanus spectabilis Loew, 1858. Most of the new records (10/11) are of Palearctic origin; of these, six are of a Mediterranean and one each of West Palearctic, Euroasiatic, Irano-Turanian, and Eremic providence. Only one species, T. taeniola, is an Afrotropical-Eremic element. © 2011 The Society for Vector Ecology.
Castro-Huertas, Valentina; Schwertner, Cristiano F; Fernández, Fernando
New records of genera and species of stink bugs (Hemiptera: Pentatomidae) from Colombia are provided. Two genera are new records for South America: Alathetus and Schraderiellus. Fifteen genera are new record for Colombia: Agaclitus, Boea, Ceratozygum, Euthyrhynchus, Eritrachys, Doesburguedessa, Lopadusa, Marmessulus, Paralincus, Patanius, Peromatus, Phalaecus, Phoeacia, Rio, and Tyrannocoris. Forty-nine species from five subfamiles are recorded for the first time in Colombia. Asopinae: Coryzorhaphis carneolus Erichson, Coryzorhaphis superba Breddin, Euthyrhynchus floridanus (Linnaeus), Podisus sagitta Fabricius, Stiretrus anchorago (Fabricius), Stiretrus cinctellus Germar, Tylospilus peruvianus Horvath, Tyrannocoris nigriceps Thomas. Cyrtocorinae: Ceratozygum horridum (Germar). Discocephalinae: Agaclitus dromedarius Stål, Antiteuchus melanoleucus (Westwood), Antiteuchus sepulcralis (Fabricius), Dinocoris gibbosus (Fallou), Dinocoris variolosus (Linnaeus), Discocephalessa terminalis (Walker), Dryptocephala crenata Ruckes, Dryptocephala dentifrons (Latreille), Eurystethus ovalis Ruckes, Paralcippus dimidiatus (Ruckes), Alathetus rufitarsus Dallas, Eritrachys bituberculata Ruckes, Paralincus bimaculatus (Ruckes), Schraderiellus cinctus (Ruckes), Xynocoris recavus (Garbelotto & Campos). Edessinae: Brachystethus cribus (Fabricius), Brachystethus tricolor Bolívar, Doesburguedessa elongatispina Fernandes and Lopadusa fuscopunctata (Distant). Pentatominae: Banasa fulgida Thomas, Banasa paraexpallescens Thomas, Dichelops divisus (Walker), Dichelops nigrum Bergroth, Euschistus carbonerus Rolston, Mormidea bovilla (Distant), Mormidea triangularis (Walker), Murgantia bifasciata Herrich-Schaeffer, Murgantia violascens (Westwood), Oebalus pugnax (Fabricius), Oebalus ypsilon-griseus (DeGeer), Odmalea concolor (Walker), Patanius vittatus Rolston, Proxys albopunctulatus (Palisot), Proxys punctulatus (Palisot), Rhyncholepta grandicallosa Bergroth, Rio insularis Ruckes, Roferta
Full Text Available The family Miridae is one of the most species-rich families of insects. To better understand the diversity and evolution of mirids, we determined the mitogenome of Lygus pratenszs and re-sequenced the mitogenomes of four mirids (i.e., Apolygus lucorum, Adelphocoris suturalis, Ade. fasciaticollis and Ade. lineolatus. We performed a comparative analysis for 15 mitogenomic sequences representing 11 species of five genera within Miridae and evaluated the potential of these mitochondrial genes as molecular markers. Our results showed that the general mitogenomic features (gene content, gene arrangement, base composition and codon usage were well conserved among these mirids. Four protein-coding genes (PCGs (cox1, cox3, nad1 and nad3 had no length variability, where nad5 showed the largest size variation; no intraspecific length variation was found in PCGs. Two PCGs (nad4 and nad5 showed relatively high substitution rates at the nucleotide and amino acid levels, where cox1 had the lowest substitution rate. The Ka/Ks values for all PCGs were far lower than 1 (<0.59, but the Ka/Ks values of cox1-barcode sequences were always larger than 1 (1.34 –15.20, indicating that the 658 bp sequences of cox1 may be not the appropriate marker due to positive selection or selection relaxation. Phylogenetic analyses based on two concatenated mitogenomic datasets consistently supported the relationship of Nesidiocoris + (Trigonotylus + (Adelphocoris + (Apolygus + Lygus, as revealed by nad4, nad5, rrnL and the combined 22 transfer RNA genes (tRNAs, respectively. Taken sequence length, substitution rate and phylogenetic signal together, the individual genes (nad4, nad5 and rrnL and the combined 22 tRNAs could been used as potential molecular markers for Miridae at various taxonomic levels. Our results suggest that it is essential to evaluate and select suitable markers for different taxa groups when performing phylogenetic, population genetic and species identification
James R. Hagler
Full Text Available The sweetpotato whitefly, Bemisia tabaci (Gennadius is fed on by a wide variety of generalist predators, but there is little information on these predator-prey interactions. A laboratory investigation was conducted to quantify the foraging behavior of the adults of five common whitefly predators presented with a surfeit of whitefly eggs, nymphs, and adults. The beetles, Hippodamia convergens Guérin-Méneville and Collops vittatus (Say fed mostly on whitefly eggs, but readily and rapidly preyed on all of the whitefly lifestages. The true bugs, Geocoris punctipes (Say and Orius tristicolor (Say preyed almost exclusively on adult whiteflies, while Lygus hesperus Knight preyed almost exclusively on nymphs. The true bugs had much longer prey handling times than the beetles and spent much more of their time feeding (35-42% than the beetles (6-7%. These results indicate that generalist predators vary significantly in their interaction with this host, and that foraging behavior should be considered during development of a predator-based biological control program for B. tabaci.
Hagler, James R; Jackson, Charles G; Isaacs, Rufus; Machtley, Scott A
The sweetpotato whitefly, Bemisia tabaci (Gennadius) is fed on by a wide variety of generalist predators, but there is little information on these predator-prey interactions. A laboratory investigation was conducted to quantify the foraging behavior of the adults of five common whitefly predators presented with a surfeit of whitefly eggs, nymphs, and adults. The beetles, Hippodamia convergens Guerin-Meneville and Collops vittatus (Say) fed mostly on whitefly eggs, but readily and rapidly preyed on all of the whitefly lifestages. The true bugs, Geocoris punctipes (Say) and Orius tristicolor (Say) preyed almost exclusively on adult whiteflies, while Lygus hesperus Knight preyed almost exclusively on nymphs. The true bugs had much longer prey handling times than the beetles and spent much more of their time feeding (35-42%) than the beetles (6-7%). These results indicate that generalist predators vary significantly in their interaction with this host, and that foraging behavior should be considered during development of a predator-based biological control program for B. tabaci.
Feng, Hongqiang; Jin, Yinli; Li, Guoping; Feng, Hongyun
The plant bug Apolygus lucorum (Meyer-Dür) is a major pest on Bt cotton and multiple crops in northern China. A modified NI artificial diet called T7 was developed to rear this pest for 10 successive generations both individually and in groups. This T7 diet was similar in components and preparation process to the NI diet used for Lygus hesperus in North America, but was comprised of more whole chicken eggs, soybean lecithin, and Vanderzant vitamin mixture, and less brewer's yeast, wheat germ, lima bean meal, soy flour, and sugars than NI diet. While being reared individually on T7 diet, A. lucorum nymphs had a developmental duration of approximately 12 d and survival rate of approximately 80%, which was not significantly different from that on green beans. While being reared in groups, nymphal survival rate was above 81% (indeed above 90% for the first four generations), the weight of adults was heavier than on green beans and the average fecundity had a logistic increase through generations. The replacement rate of A. lucorum populations was expected to be approximately 29 times per generation while being reared at a density of 100 nymphs per box (20 x 12 x 7 cm). This is the first successful artificial diet reported for rearing A. lucorum and is superior to green beans. The diet offers an economic means for producing natural enemies for biological control of this pest on Bt cotton. The possibility of further improvement of the present artificial diet is also discussed.
D'Ovidio, Renato; Raiola, Alessandro; Capodicasa, Cristina; Devoto, Alessandra; Pontiggia, Daniela; Roberti, Serena; Galletti, Roberta; Conti, Eric; O'Sullivan, Donal; De Lorenzo, Giulia
Polygalacturonase-inhibiting proteins (PGIPs) are extracellular plant inhibitors of fungal endopolygalacturonases (PGs) that belong to the superfamily of Leu-rich repeat proteins. We have characterized the full complement of pgip genes in the bean (Phaseolus vulgaris) genotype BAT93. This comprises four clustered members that span a 50-kb region and, based on their similarity, form two pairs (Pvpgip1/Pvpgip2 and Pvpgip3/Pvpgip4). Characterization of the encoded products revealed both partial redundancy and subfunctionalization against fungal-derived PGs. Notably, the pair PvPGIP3/PvPGIP4 also inhibited PGs of two mirid bugs (Lygus rugulipennis and Adelphocoris lineolatus). Characterization of Pvpgip genes of Pinto bean showed variations limited to single synonymous substitutions or small deletions. A three-amino acid deletion encompassing a residue previously identified as crucial for recognition of PG of Fusarium moniliforme was responsible for the inability of BAT93 PvPGIP2 to inhibit this enzyme. Consistent with the large variations observed in the promoter sequences, reverse transcription-PCR expression analysis revealed that the different family members differentially respond to elicitors, wounding, and salicylic acid. We conclude that both biochemical and regulatory redundancy and subfunctionalization of pgip genes are important for the adaptation of plants to pathogenic fungi and phytophagous insects. PMID:15299124
D'Ovidio, Renato; Raiola, Alessandro; Capodicasa, Cristina; Devoto, Alessandra; Pontiggia, Daniela; Roberti, Serena; Galletti, Roberta; Conti, Eric; O'Sullivan, Donal; De Lorenzo, Giulia
Polygalacturonase-inhibiting proteins (PGIPs) are extracellular plant inhibitors of fungal endopolygalacturonases (PGs) that belong to the superfamily of Leu-rich repeat proteins. We have characterized the full complement of pgip genes in the bean (Phaseolus vulgaris) genotype BAT93. This comprises four clustered members that span a 50-kb region and, based on their similarity, form two pairs (Pvpgip1/Pvpgip2 and Pvpgip3/Pvpgip4). Characterization of the encoded products revealed both partial redundancy and subfunctionalization against fungal-derived PGs. Notably, the pair PvPGIP3/PvPGIP4 also inhibited PGs of two mirid bugs (Lygus rugulipennis and Adelphocoris lineolatus). Characterization of Pvpgip genes of Pinto bean showed variations limited to single synonymous substitutions or small deletions. A three-amino acid deletion encompassing a residue previously identified as crucial for recognition of PG of Fusarium moniliforme was responsible for the inability of BAT93 PvPGIP2 to inhibit this enzyme. Consistent with the large variations observed in the promoter sequences, reverse transcription-PCR expression analysis revealed that the different family members differentially respond to elicitors, wounding, and salicylic acid. We conclude that both biochemical and regulatory redundancy and subfunctionalization of pgip genes are important for the adaptation of plants to pathogenic fungi and phytophagous insects.
Matthew H Meisner
Full Text Available Crop rotation has been practiced for centuries in an effort to improve agricultural yield. However, the directions, magnitudes, and mechanisms of the yield effects of various crop rotations remain poorly understood in many systems. In order to better understand how crop rotation influences cotton yield, we used hierarchical Bayesian models to analyze a large ecoinformatics database consisting of records of commercial cotton crops grown in California's San Joaquin Valley. We identified several crops that, when grown in a field the year before a cotton crop, were associated with increased or decreased cotton yield. Furthermore, there was a negative association between the effect of the prior year's crop on June densities of the pest Lygus hesperus and the effect of the prior year's crop on cotton yield. This suggested that some crops may enhance L. hesperus densities in the surrounding agricultural landscape, because residual L. hesperus populations from the previous year cannot continuously inhabit a focal field and attack a subsequent cotton crop. In addition, we found that cotton yield declined approximately 2.4% for each additional year in which cotton was grown consecutively in a field prior to the focal cotton crop. Because L. hesperus is quite mobile, the effects of crop rotation on L. hesperus would likely not be revealed by small plot experimentation. These results provide an example of how ecoinformatics datasets, which capture the true spatial scale of commercial agriculture, can be used to enhance agricultural productivity.
Meisner, Matthew H; Rosenheim, Jay A
Crop rotation has been practiced for centuries in an effort to improve agricultural yield. However, the directions, magnitudes, and mechanisms of the yield effects of various crop rotations remain poorly understood in many systems. In order to better understand how crop rotation influences cotton yield, we used hierarchical Bayesian models to analyze a large ecoinformatics database consisting of records of commercial cotton crops grown in California's San Joaquin Valley. We identified several crops that, when grown in a field the year before a cotton crop, were associated with increased or decreased cotton yield. Furthermore, there was a negative association between the effect of the prior year's crop on June densities of the pest Lygus hesperus and the effect of the prior year's crop on cotton yield. This suggested that some crops may enhance L. hesperus densities in the surrounding agricultural landscape, because residual L. hesperus populations from the previous year cannot continuously inhabit a focal field and attack a subsequent cotton crop. In addition, we found that cotton yield declined approximately 2.4% for each additional year in which cotton was grown consecutively in a field prior to the focal cotton crop. Because L. hesperus is quite mobile, the effects of crop rotation on L. hesperus would likely not be revealed by small plot experimentation. These results provide an example of how ecoinformatics datasets, which capture the true spatial scale of commercial agriculture, can be used to enhance agricultural productivity.
Michael J Raupach
Full Text Available During the last few years, DNA barcoding has become an efficient method for the identification of species. In the case of insects, most published DNA barcoding studies focus on species of the Ephemeroptera, Trichoptera, Hymenoptera and especially Lepidoptera. In this study we test the efficiency of DNA barcoding for true bugs (Hemiptera: Heteroptera, an ecological and economical highly important as well as morphologically diverse insect taxon. As part of our study we analyzed DNA barcodes for 1742 specimens of 457 species, comprising 39 families of the Heteroptera. We found low nucleotide distances with a minimum pairwise K2P distance 2.2% were detected for 16 traditionally recognized and valid species. With a successful identification rate of 91.5% (418 species our study emphasizes the use of DNA barcodes for the identification of true bugs and represents an important step in building-up a comprehensive barcode library for true bugs in Germany and Central Europe as well. Our study also highlights the urgent necessity of taxonomic revisions for various taxa of the Heteroptera, with a special focus on various species of the Miridae. In this context we found evidence for on-going hybridization events within various taxonomically challenging genera (e.g. Nabis Latreille, 1802 (Nabidae, Lygus Hahn, 1833 (Miridae, Phytocoris Fallén, 1814 (Miridae as well as the putative existence of cryptic species (e.g. Aneurus avenius (Duffour, 1833 (Aradidae or Orius niger (Wolff, 1811 (Anthocoridae.
Estudio entomofaunístico del cultivo de amaranto (Amaranthus hypochondriacus L. en Puebla México Entomofaunistic study in of the cultivation of amaranth (Amaranthus hypochondriacus L. in Puebla Mexico
Betzabeth Cecilia Pérez Torres
Full Text Available El amaranto es un cultivo de gran importancia para la asociación de productores agrícolas de los alrededores del Popocatépetl, Puebla; por su alto contenido de nutrientes y por la elaboración de diferentes productos que enriquecen su alimentación; pero las pérdidas por daños que ocasionan los insectos plaga, hacen que los rendimientos no sean satisfactorios para los agricultores. El objetivo del presente estudio fue determinar taxonómicamente a los insectos asociados al cultivo de amaranto y describir el rol de cada una de las especies en el agrosistema. Para la captura de insectos, durante el ciclo agrícola 2008 se realizaron muestreos en tres parcelas donde se efectuaron colectas con aspirador, red y de forma manual, revisando tallos, nudos, entre nudos, hojas (haz y envés, panoja y raíz. Los organismos colectados en etapa larval fueron conservados en alcohol al 70%, mientras que los adultos fueron montados en alfileres entomológicos; todo el material fue identificado y depositado en la colección entomológica del Instituto de Ciencias de la Benemérita Universidad Autónoma de Puebla (BUAP. Se obtuvo un total de 1 883 morfoespecies de las cuales se identificaron 20 géneros y 18 especies que fueron las más abundantes durante el ciclo agrícola; ocho especies fueron las causantes de los daños que presenta el cultivo: Sphenarium purpurascens, Epicauta cinerea, Spodoptera exigua, Pholisora catullus, Ligys lineolaris, Herpetogramma bipunctalis, Amauromyza abnormalis y Phyllophaga ilhuicaminai.Amaranth is a very important crop for the agricultural producers association around the Popocatepetl, Puebla, for its high nutrients content and for the preparation of various enriched food products. But losses from damage caused by insect pests, make not satisfactory yields for farmers. The aim of this study was to taxonomically determinate the amaranth cultivation related insects and to describe each species role in the agrosystem. To catch
曹海祥; 高晓媚; 宋晓斌
对清涧县危害枣树的有害生物进行了调查分析.结果表明,在清涧危害枣树的主要有害生物有3大类:有害动物主要有野兔(Lepus sinensis)、达乌尔鼠兔(Ochotona daurca)、甘肃鼢鼠(Myospalax cansus)、中华鼢鼠(Myospalax fontanierii);危害枣树的昆虫有48种,螨类有2种;病原微生物有植原体、真菌和细菌.其中,枣飞象在东部沿黄枣区发生严重,绿盲蝽在西部枣区发生严重,枣缩果病在大果型的鲜食枣上发生重于其他制干品种.2012年锈病流行,造成大量落叶.提出了相应的防控对策.%Pests occurring on jujube trees were investigated in Qingjian County,Shaanxi,China.It was found that there existed 3 categories of pests on jujube trees.The first one was harmful animals,including Lepus sinensis,Ochotona daurca,Myospalax cansus and Myospalax fontanierii.The second was insects and mites,including 48 species of insects and 2 species of mites.The third was germs,including 1 specie PLO,1 specie of bacteria,and 8 species of fungi.Scythropus yasumatsui seriously occurred in the east part of the county along the Yellow River.Lygus lucorum however,was found in west part of the county.The disease that caused shrieked fruit seriously occurred in freshly consuming cultivars.Some suggestions for pest management were put forward.