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It is essential to correctly identify and keep track of the abundance of thrips species on infested host crops to understand their population dynamics and implement control measures promptly. The current study was conducted to evaluate the performance of sticky traps in monitoring thrips species in exporters' eggplant and chili farms and to assess the impact of weather factors on thrips population dynamics. Thrips species were monitored using blue, yellow, and white sticky traps on chili and eggplant farms in Tuba, respectively, in 2020 and 2021. Each field was divided into 8 blocks, and in each replicate, all colors representing 3 treatments were randomly tied to stakes at the center of the respective crop. Data loggers were installed to record hourly weather variables. Three thrips species [ Thrips parvispinus Karny (Thysanoptera: Thripidae), Franklinella schultzei Trybom (Thysanoptera: Thripidae), and Thrips tabaci Lindeman (Thysanoptera: Thripidae)] were identified from both farms and the different species showed varied attractiveness to trap color for both seasons, with white proving more attractive to T. parvispinus. The population dynamics of the species varied significantly with the season and weather but not with the crop. Optimum temperatures (28–31 °C) and relative humidity (60%–78%) showed a positive linear relationship between the trapped insects with temperature and RH, while extreme temperatures (35 °C) negatively affected their abundance. All sticky trap colors attracted several nontarget organisms; however, yellow colors had higher populations, including the predator, Orius insidiosus. White sticky traps are recommended for inclusion in the country-wide monitoring for thrips, especially T. parvispinus. [ABSTRACT FROM AUTHOR]

The invasive brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae), has spread throughout most of Washington (WA) State since its detection in 2012. While it has emerged as a major agricultural and nuisance pest in the Pacific Northwest (PNW) west of the Cascade Mountains, pest pressure in the major tree fruit-growing areas in semi-arid northern and centralWA State remains low. The reasons for this are unclear, although both biotic and abiotic conditions may be contributing factors. We evaluated the suitability of a common shrub-steppe/riparian corridor plant assemblage for supporting H. halys development from egg to adult in summer and fall through controlled feeding studies. Nymphs successfully completed development on this diet of PNW native plants, though it generally resulted in lower survivorship and adult weight and longer developmental times than a modified colony diet or a diet of known hosts from the eastern United States. These developmental data were used to parameterize stage-structured matrix models to predict the impact of diet and extreme heat events on H. halys population growth. The predicted net reproductive rate (R0) of H. halys was consistently and substantially reduced by a diet of PNW native plants, and heat shock imposed further severe reductions in R0. Our results suggest that the combined population effects of suboptimal plant host quality and regional heat waves may explain the lack of landscape-level H. halys pest pressure in semi-arid regions of the PNW. [ABSTRACT FROM AUTHOR]

Helicoverpa armigera is one of the most destructive insect pests of economically valuable crops in the world. Despite its economic importance, the population genetic structure of this insect remains unexplored in Ethiopia. To investigate the genetic diversity and population structure of H. armigera , we sampled 170 individuals from 15 populations throughout Ethiopia. We sequenced a fragment of the mitochondrial cytochrome b (cyt b) gene and five exon-primed intron-crossing (EPIC) markers. Twenty cyt b haplotypes with low-to-moderate haplotype diversity (mean Hd = 0.537) and high nucleotide diversity (mean Pi = 0.00339) were identified. The most frequently observed and widely distributed cyt b haplotype was designated as Hap_1 (67.058%), which is identical to sequences found across the globe. Tajima's D and Fu's F for the cyt b data were negative, supporting a model of population expansion. Within populations, a mean of 2.493 alleles/locus was recorded across the five EPIC loci, ranging from 1.200 to 3.600 alleles/locus. The highest mean effective number of alleles/population was 2.369 and the lowest was 1.178. The mean observed heterozygosity (H O ) of the five loci (0–0.289; mean 0.104 ± 0.020) was lower than the expected heterozygosity (H E ) (0.095–0.523; mean 0.258 ± 0.028). AMOVA detected significant genetic structure with 61% of the total molecular genetic variation of EPIC genotypes occurring between populations, suggesting a considerable degree of differentiation among populations. STRUCTURE analyses clustered the H. armigera populations into three distinct population groups but very low isolation by distance (R 2 = 0.0132, P < 0.05). [ABSTRACT FROM AUTHOR]

The potato psyllid, Bactericera cockerelli (Šulc), is a major pest of potato (Solanales: Solanaceae) as a vector of 'Candidatus Liberibacter solanacearum' (Lso). Bactericera cockerelli colonizes potato from noncrop host plants, yet we do not yet know which noncrop species are the primary sources of Lso-infected psyllids. The perennial weed, Physalis longifolia Nutt., is a high-quality host for B. cockerelli and Lso under laboratory conditions but has been overlooked in recent field studies as a source of Lso-infected psyllids. Our current study had four objectives: 1) determine whether P. longifolia is abundant in potato-growing regions of Washington and Idaho, 2) determine whether stands of P. longifolia harbor B. cockerelli and Lso, 3) identify the psyllid haplotypes occurring on P. longifolia, and 4) use molecular gut content analysis to infer which plant species the psyllids had previously fed upon prior to their capture from P. longifolia. Online herbaria and field searches revealed that P. longifolia is abundant in western Idaho and is present at low densities in the Columbia Basin of Washington. Over 200 psyllids were collected from P. longifolia stands in 2018 and 2019, confirming that B. cockerelli colonizes stands of this plant. Gut content analysis indicated that a proportion of B. cockerelli collected from P. longifolia had arrived there from potato. Confirmation that P. longifolia is abundant in certain potato-growing regions of the Pacific Northwest, and that B. cockerelli readily uses this plant, could improve models to predict the risk of future psyllid and Lso outbreaks. [ABSTRACT FROM AUTHOR]

The spotted lanternfly Lycorma delicatula (White) is an invasive insect spreading throughout southeast Asia and eastern North America. The rapid spread of this species is facilitated by the prevalence of its preferred host, tree of heaven (Ailanthus altissima (Mill.) Swingle), as well as its use of many other host plants. While the spotted lanternfly has been previously reported to use over 65 plant species, most of these reports are from Asia and may not be applicable in North America. Additionally, many of the known hosts have not been specified as feeding hosts or as egg laying substrates. To better understand the potential impacts of this invasive insect on natural and cultivated systems in North America, we reviewed records from published and unpublished results and observations of host plant use by spotted lanternfly. We aggregated 172 host plant records worldwide and found feeding behaviors associated with 103 plant taxa across 33 families and 17 orders, 20 of which were not previously known to be associated with SLF and 15 of which were not confirmed as feeding hosts. North American records account for 56 of these taxa which include native, cultivated, and nonnative species. As a result, the spotted lanternfly has the potential to impact a wide assortment of ecosystems throughout its potential range and its North American distribution may not be limited by the presence of tree of heaven. [ABSTRACT FROM AUTHOR]

The spruce bark beetle (Ips typographus L.) is a destructive pest of Eurasian spruce forests. Although the gut bacteria of this insect are considered to play important roles in its lifecycle, the relationship between I. typographus and its gut bacterial community is poorly characterized. In this study, 16S rRNA gene sequencing was used to determine gut bacterial community composition across successive I. typographus life stages. Responses of the gut bacteria to α-pinene enantiomers were also explored. Ips typographus gut bacterial populations were dominated by the phyla Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, and the relative abundance of these phyla varied across different developmental stages of the beetle. Bacterial species diversity and richness indices increased with developmental stage progression. Relative abundances of the dominant genera, Erwinia (Enterobacteriales: Enterobacteriaceae), Pseudoxanthomonas (Xanthomonadales: Xanthomonadaceae), Serratia (Enterobacteriales: Enterobacteriaceae), and Romboutsia (Clostridiales: Peptostreptococcaceae), also varied across successive I. typographus life stages. Large disparities in the gut bacterial community of male adults were observed when the beetles were treated with S -(–)-α-pinene and R -(+)-α-pinene. The relative abundances of Lactococcus (Lactobacillales: Streptococcaceae) and Lelliottia (Enterobacteriales: Enterobacteriaceae) increased drastically with R -(+)-α-pinene and S -(–)-α-pinene treatment, respectively. This indicated a distinct enantiomer-specific effect of α-pinene on the I. typographus gut bacteria. This study demonstrated the plasticity of gut bacteria during I. typographus development, when α-pinene host monoterpenes are encountered. This study provides new insights into the relationship between ' I. typographus –gut bacteria' symbionts and host trees. [ABSTRACT FROM AUTHOR]

Scolytus schevyrewi Semenov (Coleoptera: Curculionidae: Scolytinae) is native to China and Central Asia. Damage by the adults and larvae weakens local apricot trees (Armeniaca spp.), often causing death to many host trees. In previous studies, freshly cut apricot logs were found to be highly attractive to S. schevyrewi adults. To explore the possibility of trapping and monitoring this bark beetle, we evaluated the effect of the apricot tree volatiles on S. schevyrewi behavior. Volatiles from the apricot logs were collected by headspace sampling and subjected to coupled gas chromatography-electroantennographic detection (GC-EAD) analysis. Behavioral responses to EAD-active compounds were assessed using two-choice Y-tube olfactometers. The results showed that the antennae of females responded to 21 volatile compounds from apricot logs. Seventeen compounds were confirmed with authentic compounds. The Y-olfactometer bioassays showed that at a stimulation dose of 100 µg, four compounds [(1 S)-(−)-α-pinene, (±)-limonene, (1 S)-(+)-3-carene, and 1-hexanol], and some binary mixtures of the four compounds [(1 S)-(−)-α-pinene plus (±)-limonene; (1 S)-(−)-α-pinene plus (1 S)-(+)-3-carene; (1 S)-(−)-α-pinene plus camphene; (1 S)-(−)-α-pinene plus (±)-limonene, (1 S)-(+)-3-carene, and 1-hexanol] were significantly attractive to both sexes (except (±)-limonene and (1 S)-(+)-3-carene for males), suggesting that these compounds may play a role in host tree selection by S. schevyrewi and should be evaluated as lures for population monitoring. In contrast, octanal, nonanal, decanal, linalool and N , N -diethylformamide appeared to repel S. schevyrewi adults in Y-tube at the concentration tested. [ABSTRACT FROM AUTHOR]

Tea saponin (TS) is extracted from the seeds of the tea plant and is generally regarded as a safe compound that has insecticidal properties and can act synergistically with other compounds. In this study, the activities of antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and the levels of malondialdehyde (MDA) were compared in midgut tissues of third instar larvae of the diamondback moth (DBM), Plutella xylostella L. (Lepidoptera: Plutellidae). The larvae were fed on three different host plants, cabbage (Brassica oleracea L. var. capitata [Capparales: Brassicaceae]), radish (Raphanus sativus L. var. radiculus Persi [Capparales: Brassicaceae]), or rape (Brassica campestris L. [Capparales: Brassicaceae]), that had been treated with TS. Higher SOD, POD, and CAT activities were found in DBM larvae fed on cabbage after LC20 (concentration that induced 20% larval mortality) or LC50 (concentration that induced 50% larval mortality) treatment than on the control. On rape, TS treatments led to lower SOD and CAT activities than in the control and to higher POD activities after 24 h. MDA content increased in larvae fed on rape but decreased in larvae fed on radish after 12 h. Our results indicated that DBM larvae are more susceptible to TS on rape than on cabbage and radish, suggesting that this treatment may be an economic and effective means of controlling DBM on rape. [ABSTRACT FROM AUTHOR]

The melonworm, Diaphania hyalinata L. (Lepidoptera: Crambidae), is one of the most serious insect problems affecting cucurbit production. We evaluated the relative preference and suitability of yellow squash, zucchini, cucumber, and watermelon to melonworm by measuring its oviposition, larval feeding preference, survivorship, and developmental responses in the laboratory. Whole plants were used for oviposition study, whereas host leaf discs were used for all the other studies. Watermelon feeding resulted in the longest larval development period (14.3 d), greatest prepupal weights and survivals rates (92%; first instar to adult) among the four crops. However, for watermelon, adult oviposition preference (199.5 eggs/$), egg survival (70%), and larval feeding (4.1% defoliation) were numerically or statistically lowest, and larval head capsule widths and wholebody lengths were smallest. When differences occurred among these variables, yellow squash, zucchini, and cucumber were each typically higher (or quicker to develop) than watermelon. So why do melonworm adults not prefer watermelon, or at least select it as frequently as squash and cucumber when ovipositing? The answer likely is that there might be some variation in the important chemical components among these cucurbits. We suggest that comparison of kairomones and allomones from watermelon and related cucurbits would be very useful for determining the combination resulting in the lowest risk of damage to the more susceptible cucurbits (assuming the levels can be modified without seriously affecting the crops). [ABSTRACT FROM AUTHOR]

The oriental fruit moth Grapholita molesta (Busck) is a globally important insect pest. In some parts of its geographic range, the oriental fruit moth shifts its attack from peach orchards to pear orchards late in the growing season. The phenological effects of host plants on the performance of the moth were evaluated by examining the development and fecundity of the moth reared on peach (Prunus persica variety "Shahong") and pear (Pyrus bretshneideri variety "Dangshan Su") collected at various times of the growing season under laboratory conditions. Results showed that the moth developed faster on shoots and fruits of peach than on those of pear. The preimaginal survival rate was the highest on peach shoots, and the moth could not survive on pear fruit collected on May 10. For both peach and pear, the boring rates of neonatal larvae were significantly higher on shoots than on fruits, and the pupal mass of females was significantly higher on fruits than on shoots. The boring rate increased with pear fruits growing during later days. Fecundity was significantly less on pear shoots than on the other plant materials. The results of this study suggest a possible host adaptation process in oriental fruit moth. [ABSTRACT FROM AUTHOR]

Nonmanaged plants occurring along forest edges and in suburban settings were sampled for brown marmorated stink bug, Halyomorpha halys (Stål), in North Carolina (NC) and Virginia (VA) over the course of three growing seasons. Commercial soybeans (Glycine max), an attractive cultivated host, were also sampled in 2014 in NC and in VA from 2010-2014. Very few H. halys were found on nonmanaged plants or soybean fields in the coastal plain region of either state, but substantial populations were recorded in the piedmont and mountain regions. From 2011 to 2013, H. halys comprised from 51 to 97% of all stink bug species observed on nonmanaged plants in the piedmont and mountain regions. In VA, the distribution expanded from detection in 12 counties in 2010 to 53 counties in 2014, with economically damaging levels occurring in the piedmont region. During these studies, H. halys were observed to complete one and a partial second generation per year in western NC and southwestern VA, similar to that previously observed in regions farther north. Several plants were identified as preferred hosts, with tree of heaven, catalpa, yellowwood, paulownia, cherry, walnut, redbud, and grape having consistently high numbers of H. halys. Knowing that these plants are preferred by H. halys during certain stages of the insects' development will aid in the search for H. halys in new areas, as well as serve as one predictor of the likelihood of a certain area to attract and sustain large H. halys populations. [ABSTRACT FROM AUTHOR]

A longitudinal study to identify the species of Liriomyza leafminer, their distribution, relative abundance, and seasonal variation, including their host range, was conducted in vegetable fields at three altitudes in Kenya from November 2011 to November 2012. Three main species were identified: Liriomyza huidobrensis (Blanchard), Liriomyza sativae Blanchard, and Liriomyza trifolii (Burgess), of which L. huidobrensis was the most abundant across all altitudes irrespective of the cropping season and accounting for over 90% of the total Liriomyza specimens collected. Liriomyza species were collected from all infested incubated leaves of 20 crops surveyed belonging to seven families: Fabaceae, Solanaceae, Cucurbitaceae, Malvaceae, Brassicaceae, Amaranthaceae, and Amaryllidaceae. However, more than 87.5% of the Liriomyza species were obtained from only four of these crops: Pisum sativum L., Phaseolus vulgaris L., Solanum lycopersicum L., and Solanum tuberosum, thereby demonstrating that Fabaceae and Solonaceae crops are the most important hosts with regard to Liriomyza species richness and relative abundance. L. huidobrensis had the widest host range (20 crops), followed by L. sativae (18 crops) and L. trifolii (12 crops). Although L. trifolii has been considered the dominant Liriomyza leafminer in Kenya, this study suggests that this may not be the case anymore, as L. huidobrensis dominates at all altitudes. [ABSTRACT FROM AUTHOR]

The impact of symbionts on their hosts depends on their infection density. In the current study, we investigated the effects of host plant and insecticide resistance on the relative amount of symbionts PorHera, Hamiltonella, Rickettsia, and Cardiniwm in the whitefly Bemisia tabaci (Gennadius) B biotype. The relative amount of symbionts in three host plant-adapted subpopulations (cucumber, Cucumis sativus L.; cabbage, Brassica oleracea L.; and cotton, Gossypium herbaceum L.) with the same genetic background and insecticide (thiamethoxam)-resistant and -susceptible sub-populations with the same genetic background were measured by quantitative polymerase chain reaction. The results showed that the cucumber population harbored more Portiera than the cabbage and cotton populations, the cabbage population harbored more Hamiltonella than the cucumber population, Hamiltonella amount did not statistically differ between the cotton and cucumber or the cotton and cabbage populations, and the cabbage population harbored more Rickettsia and Cardinium than the cucumber and cotton populations. In addition, the thiamethoxam-susceptible population harbored more Portiera and Hamiltonella than the thiamethoxam-resistant population, whereas the thiamethoxam-resistant population harbored more Rickettsia than the thiamethoxam-susceptible population. These results indicated that relative amounts of symbionts were affected significantly by host plant-adaption and insecticide resistance, and the response to host plant and insecticide differed among the symbionts. [ABSTRACT FROM AUTHOR]

Arthropod communities in an array of temperate ecosystems follow similar phenological patterns of distinct compositional turnovers during the course of a season. The arthropod community inhabiting leaf ties is no exception. Many caterpillars build leaf ties, shelters between overlapping leaves attached together with silk, which are colonized secondarily by a variety of arthropods. We created experimental leaf ties by clipping overlapping leaves together with metal clips. We censused the arthropod community within experimental ties on two host plants, American beech (Fagus grandifolia Ehrhart), and white oak (Quercus alba L.), weekly for 10 wk during the summer of 2009. Diversity measures for leaf-tying caterpillars and the entire arthropod community within ties varied little between tree species and sampling periods, but caterpillar and arthropod density per tie was significantly higher on white oak than beech and abundance increased on both tree species as the season progressed. The composition (i.e., species presence and abundance) of the leaf-tying caterpillar community and the arthropod community as a whole differed between host-tree species and sampling periods. Although the arthropod communities on American beech and white oak differed, they showed similar patterns of compositional turnover, with distinct communities in early and late summer and a transitional community midsummer. [ABSTRACT FROM AUTHOR]

Newly introduced phytophagous insects can affect native and introduced plant species. If the native plant species evolved without undergoing selective pressure from these insects, insect-plant interactions may be different for native and introduced plant species. In particular, this difference may involve mechanisms of plant defense against herbivores. If native plants lack such mechanisms, they may be more palatable to insects than exotic plants. On isolated sub-Antarctic islands, native plant species have evolved in the absence of sap-feeding insects, subsequently introduced a few decades ago. In this study, performance of an introduced aphid species, Myzus ascalonicus Doncaster, was experimentally compared on three native [Pringlea antiscorbutica Hook.f., Acaena magellanica (Lam) Vah, and Leptinella plumosa Hook.f.] and three exotic plant species (Taraxacum officinale F.H. Wigg, Cerastiumfontanum Baumg., and Senecio vulgaris L.) found on the Kerguelen Islands. Counts and weights of aphid colonies were 2-7 times higher on native plants than on exotic plants depending on experimental conditions. The results are discussed in light of the possibility of an absence or ineffective defense mechanisms in native plants. [ABSTRACT FROM AUTHOR]

The life history ofBrontispa longissima (Gestro) (Coleoptera: Hispidae), reared under laboratory conditions on leaves of coconut (Cocos nucifera L.), royal palm [Roystonea regia (Kunth) O.F.Cook], bottle palm [Hyophorbe lagenicaulis (L. Bailey) H.E.Moore], and fishtail palm (Caryota ochlandra Hance) was analyzed using age-stage, two-sex life table. Means and standard errors of population growth parameters were calculated using the jackknife method. Moreover, survival rate and fecundity data were applied to project the population for revealing the different stage structure. The mean intrinsic rates of population growth when reared on each respective leaf type were 0.032, 0.031, 0.019, and 0.044. Individuals reared on C. nucifera achieved the highest net reproduction rate at 114.5 offspring per female. The mean generation times ofB. longissima ranged from 93.2 d (reared on C. ochlandrai) to 161.5 d (reared on H. lagenicaulis). Projections from survival rate and fecundity data indicated that B. longissima populations can row considerably faster on C. ochlandra than on the other three host plants. The results validate the two-stage life history approach taken, providing an essential tool for developing and testing future control strategies. [ABSTRACT FROM AUTHOR]

Studies were designed to examine the effects of host plants (apricot, Prunus armeniaca L.; plum, Prunus salicina L.; peach, Prunus persica L.; jujube, Zizyphus jujuba Will.; apple, Malus domestica Mill.; and pear, Pyrus sorotina Will) on the development and life table parameters of the peach fruit moth, Carposina sasakii Matsumura (Lepidoptera: Carposinidae) under laboratory conditions. Peach fruit moth developed faster (12.48 d) and had the highest preimaginal survival rate (50.54%) on plum compared with the other host plants. Adult longevity was significantly longer on jujube for both female and male moths. Adult females from larvae reared on jujube and peach laid significantly greater numbers of eggs (214.50 and 197.94 eggs per female, respectively) compared with those reared on the other four host plants. Life-table parameters were calculated for each host plant and compared by jackknife procedures. The intrinsic rate of natural increase (rm) was significantly greatest on plum (0.1294 eggs per female per d), followed by jujube and apricot (0.1201 and 0.1128 eggs per female per d), respectively. Implications of the various measures of population performance are discussed. [ABSTRACT FROM AUTHOR]

Thirteen plant species were tested for their suitability as hosts for Abagrotis orbis (Grote), a climbing cutworm pest of grapevines in British Columbia. Choice tests were also conducted to investigate larval feeding preferences for the Brassicaceae species joi choi, Brassica rapa variety. Chinensis L., spring draba; Draba verna L.; and shepherd's purse, Capsella bursa-pastoris (L.) Medik; compared with postdormant buds of grape, Vitis vinifera L. (Vitaceae), and leaves of nine other plant species from several families. Results showed that tah tsai, Brassica rapa L. variety rosularis (M. Tsen & S. H. Lee) Hanelt (Brassicaceae), is a superior host for A. orbis based on shorter time to adult eclosion, heavier pupae, and higher rates of survival. Later-instar larvae died when fed draba, whereas those reared on shepherd's purse did not survive beyond the third instar. White clover, Trifolium repens L. (Fabaceae), and grape leaves were unsuitable hosts throughout development. Fifth-instar A. orbis preferred plants of the Brassicaceae family, dandelion, Taraxacum officinale Weber (Asteraceae), and strawberry, Fragaria sp. L. (Rosaceae), compared with postdormant grape buds. The results of this study suggest that the winter annual mustards draba and shepherd's purse that often grow abundantly in vine rows might help reduce climbing cutworm damage to the buds of grapevines. [ABSTRACT FROM AUTHOR]

Development, survivorship, longevity, reproduction, and life table parameters of the glassy-winged sharpshooter, Homalodiscavitripennis (Germar), were examined in the laboratory using three host plants, sunflower (Helianthus annuum L), Chrysanthemum morifolium L., and euonymus (Euonymus japonica Thurb. ). Females deposited similar-sized egg masses on all three plants. Hatching was highest with eggs deposited on euonymus and lowest for those deposited on sunflower. Embryonic development time among host plants was similar while nymph development time was shortest on sunflower and longest on euonymus. Nymph survival to adulthood ranged from 32% on euonymus to 82% for those reared on sunflower. Adult females had similar life spans on sunflower and chrysanthemum. H. vitripennis completed a lengthy egg-to-adult development on euonymus, however, mating did not occur. The onset of mating was contingent on maturation of adult females. The majority of mating activity occurred within the first three days after onset. Premating periods ranged from 6 to 7 d on sunflower to 27 d on chrysanthemum, with overall mating rates of 77.4 and 19.8%, respectively. Females typically mated more than once and they had the longest oviposition period and highest egg production on sunflower; ≈50 and 67% of total number of eggs were deposited within first 45 d after the start of oviposition on sunflower and chrysanthemum, respectively. Adult size and weight related to which host plant was consumed throughout development. Greater intrinsic and finite rates of increase and net reproduction rate, and shorter population doubling time occurred when the sharpshooters were allowed to develop on sunflower. The overall developmental and reproductive parameters obtained in this study indicate that a mixed host plant system, composed of sunflower and euonymus or chrysanthemum plants, is an efficient means for optimizing egg production and colony maintenance of the glassy-winged sharpshooter. [ABSTRACT FROM AUTHOR]

The cotton fleahopper, Pseudatomoscelis seriatus (Reuter), is an early-season pest of developing cotton in Central Texas and other regions of the Cotton Belt. Cotton fleahopper populations develop on spring weed hosts and move to cotton as weed hosts senesce or if other weed hosts are not readily available. To identify weed hosts that were seasonably available for the cotton fleahopper in Central Texas, blooming weed species were sampled during early-season (17 March-31 May), mid-season (1 June-14 August), late-season (15 August-30 November), and overwintering (1 December-16 March) periods. The leading hosts for cotton fleahopper adults and nymphs were evening primrose (Oenothera speciosa T. Nuttall) and Mexican hat [Ratibida columnifera (T. Nuttall) E. Wooton and P. Standley], respectively, during the early season. During the mid-season, silver-leaf nightshade (Solanum elaeagnifolium A. Cavanilles) was consistently a host for fleahopper nymphs and adults. Woolly croton (Croton capitatus A. Michaux) was a leading host during the late season. Cotton fleahoppers were not collected during the overwintering period. Other suitable hosts were available before previously reported leading hosts became available. Eight previously unreported weed species were documented as temporary hosts. A compendium of reported hosts, which includes >160 plant species representing 35 families, for the cotton fleahopper is provided for future research addressing insect- host plant associations. Leading plant families were Asteraceae, Lamiaceae, and Onagraceae. Results presented here indicate a strong argument for assessing weed species diversity and abundance for the control of the cotton fleahopper in the Cotton Belt. [ABSTRACT FROM AUTHOR]

We studied the life history, geographic distribution, behavior, and ecology of Larinus filiformis Petri (Coleoptera: Curculionidae) in its native range to determine whether it is worthy of further evaluation as a classical biological control agent of yellow stat-thistle, Centaurea soistitialis (Asteraceae: Cardueae). Larinus filiformis occurs in Armenia, Azerbaijan, Turkey, and Bulgaria and has been reared only from C. soistitialis. At field sites in central and eastern Turkey, adults were well synchronized with the plant, being active from mid-May to late July and ovipositing in capitula (flowerheads) of C. solstitialis from mid-June to mid-July. Larvae destroy all the seeds in a capitulum. The insect is univoltine in Turkey, and adults hibernate from mid-September to mid-May. In the spring, before adults begin ovipositing, they feed on the immature flower buds of C. soistitialis, causing them to die. The weevil destroyed 25-75% of capitula at natural field sites, depending on the sample date. Preliminary host specificity experiments on adult feeding indicate that the weevil seems to be restricted to a relatively small number of plants within the Cardueae. Approximately 57% of larvae or pupae collected late in the summer were parasitized by hymenopterans [Bracon urinator, B. tshitsherini (Braconidae) and Exevistes roborator (Ichneumonidae), Aprostocetus sp. (Eulophidae), and unidentified species of Eurytomidae and Ormyridae]. This weevil may be a better choice than the other capitula insects already established in the United States, particularly in colder parts of the plant's range. [ABSTRACT FROM AUTHOR]

European corn borer females Ostrinia nubilalis Hübner (Lepidoptera, Pyralidae) exhibited upwind flight to three main host plants, corn Zea mays, hemp Cannabis sativa and hop Humulus lupulus, in a laboratory wind tunnel. Within a 15-min experimental period, 22.9% to 24.3% mated females flew toward and landed on a single potted corn plant. A potted hemp plant attracted 25.7% females. In a choice test, significantly more females landed on a hemp plant than on an adjacent corn plant. In contrast, paprika Capsicum annuum did not elicit attraction. Headspace collections from corn, hemp, and hop contained 18 compounds which consistently elicited a response from female antennae. Four of these, (Z)-3-hexenyl acetate, β-caryophyllene, (E)-β-farnesene, and (E,E)-α- farnesene co-occurred in three host plants studied. A 4-component blend of these compounds did not attract female moths in the wind tunnel. Availability of a wind tunnel bioassay is, however, a step toward the identification of plant volatiles guiding long-range attraction of gravid corn borer females. [ABSTRACT FROM AUTHOR]

Vision is considered to be an important component of the sensory system used by herbivorous in sects to locate host plants. We investigated preferences for transmissive colors and contrasts in the apple blossom weevil, Anthonomus pomorum L., which colonizes apple trees, Malus domestica Borkh., in early spring. The main components of the supposed visual system, green, blue, and UV light, were offered to the weevils versus black or versus each other in a dual choice arena. Furthermore, silhouettes of two different achromatic contrasts were offered in front of the colors blue and green. We also tested whether visual preferences change with time, i.e., 2, 4, and 6 d after termination of diapause in early spring. Female weevils chose UV, green, and blue over black, whereas males only chose UV over black in a series of dual choice experiments. Both sexes preferred blue to green. Weevil response to silhouettes of different contrasts was influenced by the background color, i.e., the silhouette with the higher contrast was preferred in front of green, whereas the silhouette with the lower contrast was preferred in front of blue. The preferences during visual orientation did not change with time after diapause. The more discriminating response of females may reflect a greater visual acuity or a greater visual responsiveness in females than in males because of a higher affinity for the host plant. Our findings indicate that weevils might have a trichromatic visual system and that they are able to include visual cues for the location of host plants in the field. [ABSTRACT FROM AUTHOR]

The predation rate per hour of Macrolophus pygmaeus Rambur (Hemiptera: Miridae) under light and dark phase was examined in relation to the host plant, photoperiod, temperature, and life stage of the predator. Individuals from each nymphal stage plus adults of both sexes of M. pygmaeus were put individually into petri dishes on an eggplant or pepper plant leaf infested with nymphs of Myzus persicae (Sulzer) (Homoptera: Aphididae). The experiments were conducted at three photoperiods (8:16,12:12, and 16:8 h [L:D]) and temperatures (20,25, and 30°C) on eggplant and pepper plants. Generally, the predation rate was significantly higher in the dark than in the light phase, particularly in the case of larger in stars and adults. Interactions between factors showed that the preference of this predator to feed at night is much higher on pepper plants than on eggplant, and this difference is more prominent at 30°C. The importance of these results in understanding foraging behavior and how aspects of this behavior affect the predator's potential in biological control are discussed. [ABSTRACT FROM AUTHOR]

Survival, development, and oviposition of the polyphagous insect Mamestra configurata Walker (Lepidoptera: Noctuidae) were compared on different host plant species of the families Brassicaceae [Brassica rapa L., Brassica napus L., Brassica juncea (L.) Cosson, Sinapis alba L., and Thlaspi arvense L.], Compositae [Cirsium arvense (L.) Scop.], Leguminosae (Pisum sativum L. and Medicago sativa L) , Linaceae (Linum usitatissimum L.) , and Chenopodiaceae (Chenopodium album L.). Larvae developed faster on intact host plant tissue of all species than they did on excised leaf tissue. First instars of M. configurata did not survive on leaves of T. arvense. Although 97% of larvae survived to the sixth instar on M. sativa, complete mortality was observed on this host plant before pupation. On the other host plants studied, survival rates to sixth instar and pupation were similar. C. album was significantly more preferred than all other species in larval feeding choice experiments, whereas B. juncea and M. sativa were significantly less preferred than the other species. Pupal weights were highest on C. album and S. alba and were lowest on P. sativum and B. juncea. Larval development was most rapid on C. album and was slowest on B. juncea. C. album was significantly more preferred for oviposition than B. napus, B. rapa, C. arvense, and B. juncea. The ovipositional and feeding preferences for C. album suggest that species of Chenopodiaceae were important hosts of M. configurata before vast monocultures of B, napus and B. rapa were introduced to western North America. [ABSTRACT FROM AUTHOR]

The oriental fruit moth Grapholita molesta (Busck) is a globally important insect pest. In some parts of its geographic range, the oriental fruit moth shifts its attack from peach orchards to pear orchards late in the growing season. The phenological effects of host plants on the performance of the moth were evaluated by examining the development and fecundity of the moth reared on peach (Prunus persica variety "Shahong") and pear (Pyrus bretshneideri variety "Dangshan Su") collected at various times of the growing season under laboratory conditions. Results showed that the moth developed faster on shoots and fruits of peach than on those of pear. The preimaginal survival rate was the highest on peach shoots, and the moth could not survive on pear fruit collected on May 10. For both peach and pear, the boring rates of neonatal larvae were significantly higher on shoots than on fruits, and the pupal mass of females was significantly higher on fruits than on shoots. The boring rate increased with pear fruits growing during later days. Fecundity was significantly less on pear shoots than on the other plant materials. The results of this study suggest a possible host adaptation process in oriental fruit moth., (© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

The spatial distribution of Mussidia nigrivenella Ragonot was studied in maize fields and on four major wild host plants in the Republic of Benin, West Africa. Maize ears were sampled at harvest in 1994 and1995, and fruits of the wild host plants were collected monthly fromJanuary 1996 to December 1997 during the fruiting periods of the respective host species. The spatial distribution was analyzed using thevariance-to-mean ratio (s2/m), an index of departure fromPoisson distribution, Iwao's patchiness regression, and Taylor's power law. The variance-to-mean ratio and the index of departure from Poisson gave similar results of nonrandom distribution of M nigrivenella populations on the different host plants out of Gardenia sokotensisHutch (Rubiaceae). On this specific host plant, the variance-to-meanratio was not different from 1, whereas there was no overlap of the observed population and the Poisson distribution. Iwao's patchiness regression was inappropriate for our data as shown by the nonhomogeneity of variance, whereas Taylor's power law fitted the data well. Based on Taylor's power law, M. nigrivenella was aggregated on all host plants out of G. sokotensis. The degree of aggregation of M. nigrivenella was positively correlated with the fruit size of the host plants.The optimal number of secondary sampling units needed to estimate M.nigrivenella densities on the respective host plants in Benin, varied from four fruits on G. sokotensis to 10 pods on P. biglobosa. Thesevalues were used to calculate the time expenditure needed to sample maize fields or wild host plant trees to achieve a predefined precision level of 25%. [ABSTRACT FROM AUTHOR]

The ear borer Mussidia nigrivenella Ragonot is a polyphagous insect pest that feeds on various cultivated and wild plants. Surveys in four agro-ecological zones of Benin, conducted between 1993 and 1997, revealed ~20 plant species from 11 plant families hosting the borer, but only 13 host plants enable the borer to develop to the pupal stage.Whereas, a maize crop usually supports one generation per season, several generations of M. nigrivenella were recorded on Parkia biglobosa (Jacq.) Benth. and Gardenia spp. Agro-ecological variation in the availability of wild host plants was noticed. The high abundance of wild hosts in the Guinea Savannas reflects the diversity of the naturalflora in these zones. This abundance of M. nigrlvenella host plants,coupled with their overlapping fruiting periods may be the main reason for the high pest densities on maize, although only one maize cropper year is grown in the Northern Guinea savanna. In a field experiment, the highest infestation levels and densities of M. nigrivenella occurred on Canavalia enseiformis (L.) DC. and Mucuna pruriens DC, two popular cover crops in West Africa. Maize and cotton were about equally suitable hosts. Thus, fruiting periods of C. enseiformis and M. pruriens should not precede that of maize, to avoid emerging M. nigrivenella populations shifting from the cover crops to maize. [ABSTRACT FROM AUTHOR]

We used field bioassays to evaluate maize silk volatiles with electroantennogram (EAG) activity in western corn rootwonn. Diahrotica virgifera virgifera LeConte, for effects on the behavior of feral adult western and northern corn rootworm, D. harberi Srnith and Lawrence. Test volatiles from maize silk were 2-tridecanone. (i:.Z)-2,6-nonadienal, (E,E)-:3;5-octadien-2-one. and (E)-2-nonenal. Two analogs of the silk volatiles, (E,Z)-3,7-decadien-2-one auul :3-nonene-2-one. arlso were tested. None of the EAG-active maize silk volatiles was attractive to either Diainolira species. whether tested alone or in selected mixtures. although there was evidence of slight attraction to (E,Z)-.3,7-decadien-2-one by northern corn rootworm females. A mixture of 2-tridecanone. (t-Z)2,6-nonadienal, (E,E)-3,5-octadien-2-one, and (EZ)-3,7-decadien-2-one markedly reduced capture of both sexes and species on traps also baited with a standard lure. In some cases, the same mixture when tested by itself reduced northern corn rootworm capture below that on control traps, suggesting mixture repellency. Activity was traced primarily to 2-tridecanone for northern corn rootworm, but this ketone had no tendency to repel western corn rootworm. (E,Z)-2,6-Nonadienal interfered weakly with western corn rootworm response to the standard lure, but did not account for mixture potency. Potential applications of adult repellents to protect maize from corn rootworm damage are discussed. [ABSTRACT FROM AUTHOR]