Search

Insects that evolved in mesic regions may have difficulty establishing in xeric regions. Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) was introduced into drier western North America from mesic eastern North America while Rhagoletis indifferens Curran is native to western North America. Here, we predicted that R. indifferens survives water deprivation longer than R. pomonella, as R. indifferens is more abundant than R. pomonella in dry central Washington (WA) State, USA. Sweet and bitter cherry-origin R. indifferens and apple- and hawthorn-origin R. pomonella from xeric central or mesic western WA were provided water throughout or were water-deprived at 2–4 and 14–18 d old and held at 20°C or 30/31°C and daily survival recorded. At 20°C and 30°C, western WA apple-origin R. pomonella provided water survived longer than sweet cherry-origin R. indifferens. When water-deprived, however, 2–4 d old R. indifferens, although smaller, survived significantly longer than western WA apple-origin R. pomonella of the same age. This was also generally true for 14–18 d old flies, although differences were less often significant. Central WA large-thorn hawthorn-origin R. pomonella survived water deprivation significantly longer than western WA apple-origin R. pomonella, and as long as R. indifferens. Water-deprived flies of both species survived longer at 20°C than 30/31°C. Survival analyses suggest that low water availability rather than high temperature contributes to lower R. pomonella than R. indifferens abundances in central WA, with R. pomonella populations in that region differing from western WA R. pomonella with respect to tolerance of xeric climates. [ABSTRACT FROM AUTHOR]

Invasive insect species threaten the productivity of ecosystems worldwide, and ecological niche models can be used to predict distributions of invaders and guide management efforts. Ecological niche models can also aid monitoring for invasive species that are globally distributed. One such species is the yellow spotted stink bug (Erthesina fullo Thunberg), a polyphagous pest native to Asia that has established in Europe and South America and threatens specialty crops. Here, we used ecological niche models to predict the potential distribution of E. fullo, and created a website to display predictions. We show that E. fullo has peak occurrence probability in areas with annual mean temperatures around 20°C, and that the occurrence probability increases as maximum monthly temperature reaches up to 38°C. The likelihood of occurrence decreased as annual precipitation increased, but increased with greater precipitation in the wettest and driest months. This suggests E. fullo is most suited to regions that are warm and dry and where most precipitation occurs across only a few months, such as southern North America, central and southern South America, southern Europe, southern Africa, and central and eastern Australia. Given that E. fullo is a highly mobile hitchhiking insect that travels through cargo and other containers to new areas, the potential spread of this species into new regions should be carefully monitored. [ABSTRACT FROM AUTHOR]

Target and non-target Rhagoletis Loew, 1862 (Diptera: Tephritidae) flies trapped in surveys can provide new information on fly abundances, ecologies, and distributions. Here, data from surveys for native R. indifferens Curran, 1932 in non-commercial sweet cherry trees and non-native R. pomonella (Walsh, 1867) in non-commercial apple, crabapple, and hawthorn trees in central Washington State, U.S.A. were used to determine relative abundances of target and non-target Rhagoletis on traps and to test the hypotheses that fly abundances are site, tree type, and seasonal period dependent. Rhagoletis indifferens was the most abundant Rhagoletis in cherry trees. Non-native R. completa Cresson, 1929 was the most abundant Rhagoletis caught in R. pomonella host trees, with overall results suggesting it is the most numerous and/or dispersive Rhagoletis in central Washington. With support from the literature, we infer that: R. pomonella is less tolerant of arid central Washington summers than R. completa, native R. zephyria Snow, 1894, R. indifferens, and native R. basiola (Osten Sacken, 1877); Rhagoletis species diversity is lower in suburban than rural habitats due to the predominant host plants present; all fly species disperse annually at similar relative abundances, resulting in geographic range expansions over a few generations; and peak seasonal dispersal of flies to non-natal tree species coincides with natal host fruit development, resulting in colonization of new fruiting host patches. Differential fly tolerances of arid summer climates due to adaptation or preadaptation, habitat type, and annual and seasonal dispersal patterns could explain abundances and distributions of native and non-native Rhagoletis species in central Washington. [ABSTRACT FROM AUTHOR]

Eulophid larvae discovered in galleries of Agrilus cuprescens (Ménétries, 1832) within canes of Rubus sp. (Rosaceae) in the Pacific Northwest, U.S.A. region between 2018 and 2021 were identified as Baryscapus rugglesi (Rohwer, 1919) (subfamily Tetrastichinae). This species had previously only been found in eastern North America. Identification was based on numerous specimens reared from larvae collected from eight disparate locations in western Oregon and Washington State, U.S.A., in 2019 and 2021, and examination against its type series from 1919 in Minnesota, U.S.A. and specimens from 1938 in New York, U.S.A (Mundinger 1941). Both sexes of B. rugglesi are herein redescribed and illustrated. Additionally, DNA sequences from specimens collected in 2019 were direct sequence matches with original specimens collected in 2018. The ubiquitous occurrence of B. rugglesi suggests it is likely a predominant parasitoid of A. cuprescens in the region. Baryscapus rugglesi is a gregarious larval parasitoid of several native Agrilus spp. in North America, so it is presumably native to the Nearctic region and has adapted as an alternative parasitoid of A. cuprescens, a Eurasian-native pest introduced into North America. However, COI sequences of B. rugglesi were similar to those of an unidentified eulophid from Europe in the Barcode of Life Database (almost 96% identity), possibly indicating a Holarctic distribution. Observed wasp biology, behavior, and perspectives on the potential role of B. rugglesi as a natural enemy within integrated pest management programs for A. cuprescens control are discussed. [ABSTRACT FROM AUTHOR]

The Japanese beetle, Popillia japonica (Newman, 1841) (Coleoptera: Scarabaeidae), was first detected in southern Washington State in 2020. Widespread trapping efforts ensued, and over 23,000 individuals were collected in both 2021 and 2022 in this region known for specialty crop production. The invasion of Japanese beetle is of major concern as it feeds on over 300 plant species and has shown an ability to spread across landscapes. Here, we created a habitat suitability model for Japanese beetle in Washington and used dispersal models to forecast invasion scenarios. Our models predict that the area of current establishment occurs in a region with highly suitable habitat. Moreover, vast areas of habitat that are likely highly suitable for Japanese beetle occur in coastal areas of western Washington, with medium to highly suitable habitat in central and eastern Washington. Dispersal models suggested that the beetle could spread throughout Washington within 20 years without management, which justifies quarantine and eradication measures. Timely map-based predictions can be useful tools to guide management of invasive species while also increasing citizen engagement to invaders. [ABSTRACT FROM AUTHOR]

The apple maggot fly, Rhagoletis pomonella (Walsh) (Diptera: Tephritidae), was introduced from eastern North America into western North America via infested apples (Malus domestica Borkhausen) about 44 yr ago, where it subsequently adapted to 2 hawthorn species, Crataegus douglasii Lindley and C. monogyna Jacquin. Here, we test whether R. pomonella has also adapted to large-thorn hawthorn, Crataegus macracantha Loddiges ex Loudon, in Okanogan County, Washington State, USA. In 2020, 2021, and 2022, fruit of C. macracantha were shown to ripen in late September and were infested at rates from 0.7% to 3.0%. In laboratory rearing studies, large-thorn hawthorn flies from C. macracantha eclosed on average 9–19 days later than apple flies from earlier ripening apple (August–early September), consistent with large-thorn hawthorn flies having adapted to the later fruiting phenology of its host. In a laboratory no-choice test, significantly fewer (64.8%) large-thorn hawthorn than apple flies visited apples. In choice tests, greater percentages of large-thorn hawthorn than apple flies resided on and oviposited into C. macracantha versus apple fruit. Large-thorn hawthorn flies were also smaller in size than apple flies. Our results provide further support for the recursive adaptation hypothesis that R. pomonella has rapidly and independently specialized phenologically and behaviorally to different novel hawthorn hosts since its introduction into the Pacific Northwest of the USA, potentially leading to host race formation. [ABSTRACT FROM AUTHOR]

Seasonal temperatures select for eclosion timing of temperate insects and their parasitoids. In western North America, the fruit fly Rhagoletis zephyria Snow (Diptera: Tephritidae) is parasitized by the hymenopterous wasps Utetes lectoides (Gahan), an egg parasite, and Opius downesi Gahan, a larval parasite (both Braconidae). Eclosion of wasps should be timed with the presence of susceptible fly stages, but reports indicate U. lectoides ecloses in the absence of flies under no-chill conditions. Based on this, we tested the hypotheses that chill durations and no-chill temperatures both differentially regulate eclosion times of R. zephyria and its parasitic wasps. When fly puparia were chilled at ∼3°C for 130–180 d, U. lectoides and O. downesi always eclosed on average later than flies. However, after 180-d chill, flies eclosed on average earlier than after 130- and 150-d chill, whereas eclosion times of U. lectoides and O. downesi were less or not affected by chill duration. When fly puparia were exposed to 20–22°C (no chill), U. lectoides eclosed before flies, with 88.9% of U. lectoides versus only 0.61% of flies eclosing. Taken together, findings show that eclosion times of flies are more sensitive to changes in chill duration than those of wasps. Flies are less sensitive than wasps to no-chill in that most flies do not respond by eclosing after no-chill while most wasps do. Our results suggest that shorter winters and longer summers due to climate change could cause mismatches in eclosion times of flies and wasps, with potentially significant evolutionary consequences. [ABSTRACT FROM AUTHOR]

Brown marmorated stink bug (BMSB), Halyomorpha halys Stål, 1855, is a polyphagous agricultural insect pest which causes serious production losses. BMSB also has human lifestyle impacts which arise from its habit of overwintering in homes. The invasiveness of BMSB and the harm it causes is making it a pest of increasing global importance. Over the past 30 years, the bug has spread from its native range in East Asia to North America and Europe. On November 2017 and January 2018, BMSBs were found at two Western Sydney locations in goods imported from northern Italy. While BMSB detections in imports are common in Australia, these encounters were significant because of sightings of bugs outside the infested premises, indicating possible spread into the local environment. Measures undertaken in Western Sydney to contain and eradicate BMSB included fumigation of infested goods, insecticide treatment of the warehouse site and surroundings and delimiting surveillance. Before commencing widespread surveillance, a vegetation survey was conducted to identify known host and potential BMSB host plants around the infested premises. ESRI Collector for ArcGIS™ was used to compile host plant location data which served as the basis for pheromone trap deployment and physical inspection. Surveillance continued until May 2018. No live BMSBs were detected. DNA analysis of dead BMSBs collected from infested goods discerned the presence of two different haplotypes (H): H1 (previously detected in North America, Europe and China) and H23 (North America and Japan). [ABSTRACT FROM AUTHOR]

Plasmid shuttle vectors capable of replication in both Saccharomyces cerevisiae and Escherichia coli and optimized for controlled modification in vitro and in vivo are a key resource supporting yeast as a premier system for genetics research and synthetic biology. We have engineered a series of yeast shuttle vectors optimized for efficient insertion, removal, and substitution of plasmid yeast replication loci, allowing generation of a complete set of integrating, low copy and high copy plasmids via predictable operations as an alternative to traditional subcloning. We demonstrate the utility of this system through modification of replication loci via Cre recombinase, both in vitro and in vivo, and restriction endonuclease treatments. [ABSTRACT FROM AUTHOR]

Trissolcus japonicus (Ashmead), an Asian parasitoid of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), was first detected in North America in 2014. Although testing in quarantine facilities as a candidate for classical biological control is ongoing, adventive populations have appeared in multiple sites in the United States, Canada, and Europe. Extensive laboratory testing of T. japonicus against other North American pentatomids and H. halys has revealed a higher rate of parasitism of H. halys , but not complete host specificity. However, laboratory tests are necessarily artificial, in which many host finding and acceptance cues may be circumvented. We offered sentinel egg masses of three native pentatomid (Hemiptera: Pentatomidae) pest species (Chinavia hilaris (Say), Euschistus conspersus Uhler, and Chlorochroa ligata (Say)) in a field paired-host assay in an area with a well-established adventive population of T. japonicus near Vancouver, WA. Overall, 67% of the H. halys egg masses were parasitized by T. japonicus during the 2-yr study. Despite the 'worst case' scenario for a field test (close proximity of the paired egg masses), the rate of parasitism (% eggs producing adult wasps) on all three native species was significantly less (0.4–8%) than that on H. halys eggs (77%). The levels of successful parasitism of T. japonicu s of the three species are C. hilaris > E. conspersus > C. ligata. The potential impact of T. japonicus on these pentatomids is probably minimal. [ABSTRACT FROM AUTHOR]

Background: Invasive species threaten the productivity and stability of natural and managed ecosystems. Predicting the spread of invaders, which can aid in early mitigation efforts, is a major challenge, especially in the face of climate change. While ecological niche models are effective tools to assess habitat suitability for invaders, such models have rarely been created for invasive pest species with rapidly expanding ranges. Here, we leveraged a national monitoring effort from 543 sites over 3 years to assess factors mediating the occurrence and abundance of brown marmorated stink bug (BMSB, Halyomorpha halys), an invasive insect pest that has readily established throughout much of the United States., Results: We used maximum entropy models to estimate the suitable habitat of BMSB under several climate scenarios, and generalized boosted models to assess environmental factors that regulated BMSB abundance. Our models captured BMSB distribution and abundance with high accuracy, and predicted a 70% increase in suitable habitat under future climate scenarios. However, environmental factors that mediated the geographical distribution of BMSB were different from those driving abundance. While BMSB occurrence was most affected by winter precipitation and proximity to populated areas, BMSB abundance was influenced most strongly by evapotranspiration and solar photoperiod., Conclusion: Our results suggest that linking models of establishment (occurrence) and population dynamics (abundance) offers a more effective way to forecast the spread and impact of BMSB and other invasive species than simply occurrence-based models, allowing for targeted mitigation efforts. Implications of distribution shifts under climate change are discussed. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Reliable monitoring of the invasive Halyomorpha halys abundance, phenology and geographic distribution is critical for its management. Halyomorpha halys adult and nymphal captures on clear sticky traps and in black pyramid traps were compared in 18 states across the Great Lakes, Mid-Atlantic, Southeast, Pacific Northwest and Western regions of the United States. Traps were baited with commercial lures containing the H. halys pheromone and synergist, and deployed at field sites bordering agricultural or urban locations with H. halys host plants. Nymphal and adult captures in pyramid traps were greater than those on sticky traps, but captures were positively correlated between the two trap types within each region and during the early-, mid- and late season across all sites. Sites were further classified as having a low, moderate or high relative H. halys density and again showed positive correlations between captures for the two trap types for nymphs and adults. Among regions, the greatest adult captures were recorded in the Southeast and Mid-Atlantic on pyramid and sticky traps, respectively, with lowest captures recorded in the West. Nymphal captures, while lower than adult captures, were greatest in the Southeast and lowest in the West. Nymphal and adult captures were, generally, greatest during July-August and September-October, respectively. Trapping data were compared with available phenological models showing comparable population peaks at most locations. Results demonstrated that sticky traps offer a simpler alternative to pyramid traps, but both can be reliable tools to monitor H. halys in different geographical locations with varying population densities throughout the season., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)