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A new species of Macrosiphum Passerini is described based on all life cycle morphs: fundatrix, apterous and alate viviparae, oviparae, and males. Macrosiphum ginajo lives throughout the growing season on glandular–sticky species of Silene (Caryophyllaceae) in dry forest habitats of western North America. The new species is compared to other Macrosiphum known to feed on Silene. A very similar species, Macrosiphum aetheocornum, which feeds on native Geranium species in similar habitats, is also discussed including measurements, illustrations, and detailed comparison to the new species.

Generalist predators that kill and eat other natural enemies can weaken biological control. However, pest suppression can be disrupted even if actual intraguild predation is infrequent, if predators reduce their foraging to lower their risk of being killed. In turn, predator-predator interference might be frequent when few other prey are available, but less common when herbivorous and detritus-feeding prey are plentiful. We used molecular gut-content analysis to track consumption of the predatory bug Geocoris sp. by the larger intraguild predator Nabis sp., in organic and conventional potato (Solanum tuberosum) fields.We found that higher densities of both aphids and thrips, two common herbivores, correlated with higher probability of detecting intraguild predation. Perhaps, Nabis foraging for these herbivores also encountered and ate more Geocoris. Surprisingly, likelihood of intraguild predation was not strongly linked to densities of either Nabis or Geocoris, or farming system, suggesting a greater importance for prey than predator community structure. Intriguingly, we found evidence that Geocoris fed more often on the detritus-feeding fly Scaptomyza pallida with increasing predator evenness. This would be consistent with Geocoris shifting to greater foraging on the ground, where S. pallida would be relatively abundant, in the face of greater risk of intraguild predation.Overall, our findings suggest that while herbivorous prey may heighten intraguild predation of Geocoris in the foliage, detritivores might support a shift to safer foraging on the ground. This provides further evidence that prey abundance and diversity can act to either heighten or relax predator-predator interference, depending on prey species identity and predator behavior. © 2022 Society of Chemical Industry.

Psyllids (Hemiptera: Psylloidea) are phloem-feeding insects that tend to be highly specific in their host plants. Some species are well-known agricultural pests, often as vectors of plant pathogens. Many pest psyllids colonize agricultural fields from non-crop reproductive hosts or from non-host transitory and winter shelter plants. Uncertainty about which non-crop species serve as sources of psyllids hinders efforts to predict which fields or orchards are at greater risk of being colonized by psyllids. High-throughput sequencing of trnL, trnF, and ITS was used to examine the dietary histories of three pest and two non-pest psyllid species encompassing a diversity of lifecycles: Cacopsylla pyricola (Förster) (Psyllidae), Bactericera cockerelli (Šulc) (Triozidae), Diaphorina citri Kuwayama (Liviidae), Aphalara loca Caldwell (Aphalaridae), and a Cacopsylla species complex associated with Salix (Malphighiales: Salicaceae). Results revealed an unexpectedly high level of feeding on non-host species by all five psyllid species. The identification of the dietary history of the psyllids allowed us to infer their landscape-scale movements prior to capture. Our study demonstrates a novel use for gut content analysis-to provide insight into landscape-scale movements of psyllids-thus providing a means to pinpoint the non-crop sources of pest psyllids colonizing agricultural crops. We observed previously unknown psyllid behaviors during our efforts to develop this method and discuss new research directions for the study of psyllid ecology.

Background Biological control by generalist predators can be mediated by the abundance and biodiversity of alternative prey. When alternative prey draw predator attacks away from the control target, they can weaken pest suppression. In other cases, a diverse prey base can promote predator abundance and biodiversity, reduce predator-predator interference, and benefit biocontrol. Here, we used molecular gut-content analysis to assess how community composition altered predation of Colorado potato beetle (Leptinotarsa decemlineata (Say)) by Nabis sp. and Geocoris sp. Predators were collected from organic or conventional potato (Solanum tuberosum L.) fields, encouraging differences in arthropod community composition. Results In organic fields, Nabis predation of potato beetles decreased with increasing arthropod richness and predator abundance. This is consistent with Nabis predators switching to other prey species when they were available and with growing predator-predator interference. In conventional fields these patterns reversed, however, with potato beetle predation by Nabis increasing with greater arthropod richness and predator abundance. For Geocoris, Colorado potato beetle predation was more frequent in organic than conventional fields. However, Geocoris predation of beetles was less frequent in fields with higher abundance of the detritus-feeding fly Scaptomyza pallida Zetterstedt, or of all arthropods, consistent with predators choosing other prey when available. Conclusion Alternative prey generally dampened predation of potato beetles, suggesting these pests were less-preferred prey. Nabis and Geocoris differed in which alternative prey were most disruptive to feeding on potato beetles, and in the effects of farm management on predation, consistent with the two predator species occupying complementary feeding niches. This article is protected by copyright. All rights reserved.

The fourteen aphid species recorded as feeding on Holodiscus (Rosaceae) are listed, discussed, and a key to species provided. One new species is described, Acyrthosiphon rockspirea new species, which lives throughout the year on Holodiscus in a wide range of habitats. Two names, Aphis coweni Palmer and Aphis holodisci Robinson are declared to be new junior synonyms of Aphis cercocarpi Gillette and Palmer and much taxonomic data and information are provided to support these conclusions. The heteroecious life cycle of A. cercocarpi between Holodiscus and Veratrum (Melanthiaceae) is described, and biological and taxonomic information, and a key to aphids known from Veratrum, are provided. The correct host plant, monoecious life cycle, and taxonomic features of Illinoia gracilicornis (MacGillivray) are discussed, including brief descriptions of all morphs. The heteroecious life cycle of Macrosiphum walkeri Robinson is documented for the first time, with brief descriptions of the oviparae and males.

An insect trap constructed using three-dimensional (3D) printing technology was tested in potato (Solanum tuberosum Linnaeus; Solanaceae) fields to determine whether it could substitute for the standard yellow sticky card used to monitor Bactericera cockerelli (Šulc) (Hemiptera: Psylloidea: Triozidae). Sticky cards have shortcomings that prompted search for a replacement: cards are messy, require weekly replacement, are expensive to purchase, and accumulate large numbers of nontarget insects. Bactericera cockerelli on sticky cards also deteriorate enough that specimens cannot be tested reliably for the presence of vectored plant pathogens. A prototype trap constructed using 3D printing technology for monitoring Diaphorina citri Kuwayama (Hemiptera: Psylloidea: Liviidae) was tested for monitoring B. cockerelli. The trap was designed to attract B. cockerelli visually to the trap and then funnel specimens into preservative-filled vials at the trap bottom. Prototype traps were paired against yellow sticky cards at multiple fields to compare the captures of B. cockerelli between cards and traps. The prototype trap was competitive with sticky cards early in the growing season when B. cockerelli numbers were low. We estimated that two or three prototype traps would collect as many B. cockerelli as one sticky card under these conditions. Efficacy of the prototype declined as B. cockerelli numbers increased seasonally. The prototype trap accumulated nontarget taxa that are common on sticky cards (especially Thysanoptera and Diptera), and was also found to capture taxa of possible interest in integrated pest management research, including predatory insects, parasitic Hymenoptera, and winged Aphididae (Hemiptera), suggesting that the traps could be useful outside of the purpose targeted here. We believe that 3D printing technology has substantial promise for developing monitoring tools that exploit behavioural traits of the targeted insect. Ongoing work includes the use of this technology to modify the prototype, with a focus on making it more effective at capturing psyllids and less susceptible to capture of nontarget species.

Ericaphisvoegtlinisp. n. living on Chamaebatiafoliolosa (Rosaceae) in California is described based on apterous and alate viviparous females. The new species differs from all other species of the genus Ericaphis Börner, 1939 in several important morphological characters including very long and rigid dorsal setae and distinctly swollen siphunculi with clearly visible polygonal reticulation.

The Palearctic psyllid Heterotrioza chenopodii (Reuter) (Hemiptera: Psylloidea: Triozidae) belongs to a complex of psyllids having plants in the Amaranthaceae (including the former Chenopodiaceae) as hosts. Geographic records for this introduced species in North America date from 1988, and include a number of coastal regions in eastern Canada, the Northeastern U.S., inland Virginia, coastal British Columbia, California, and wetland habitats near Lincoln, Nebraska. We updated North American records for H. chenopodii to include inland Washington and Oregon, southwestern Idaho, northcentral California, western Colorado, and southern and central Alberta. Psyllids were collected from Atriplex micrantha (Amaranthaceae) and unidentified Atriplex species, and from yellow sticky cards that had been placed in potato fields to monitor arthropod pests of potatoes. Traits of the adult psyllid, fifth-instar nymph, and egg used in identifying specimens are summarized.We provide the first photographs of the egg, fifthinstar nymph, and terminalia of the adult male psyllid. Rearing trials showed that H. chenopodii developed on A. micrantha, A. hortensis, Chenopodium album, C. berlandieri, and garden beet, Beta vulgaris, but failed to develop on Amaranthus tricolor. Development was most rapid on the two Atriplex species. Heterotrioza chenopodii has been shown in Europe to exhibit photoperiod-controlled dimorphism in wing size, producing a long-winged form in spring and summer, and a short-winged form in autumn. We confirmed in rearing trials and by field collections that populations of H. chenopodii from central Washington State also exhibit this dimorphism. Short-winged forms began replacing long-winged forms in field populations between late August and early October.

The broad feeding habits of generalist predators can lead to uncertainty about their impacts on particular pests. Due to prey switching, consumption of one pest species by generalist predators might decrease as densities of attractive alternative prey increase. To test this, we used molecular tools to examine presence/absence of two-spotted spider mites (Tetranychus urticae) in the guts of predatory Nabis and Geocoris bugs, in potato (Solanum tuberosum) crops grown using either organic or conventional farming methods. Previous work suggested that organic potato fields house relatively high densities of alternative prey, which might disrupt predators’ consumption of spider mites. While densities of spider mites and of the attractive alternative prey green peach aphids (Myzus persicae) did not consistently differ between farming systems, their densities varied widely between years and among fields within each year. The likelihood of detecting spider mite predation was not correlated with spider mite densities, such that we often recorded mite consumption in fields where these pests were rare. Spider mite consumption also was not significantly altered when we detected predation of green peach aphids. However, we found consistently higher numbers of both predator taxa in organic fields than in conventional fields. Altogether, we found that generalist predators continue to consume spider mites against a background of changing numbers of mites and aphids. This suggests that diverse alternative prey availability may not weaken the impact of robust populations of natural enemies found on organic farms.

Two new species of Macrosiphum are described, both of which live in similar dry forest habitats of the inland northwestern U.S.A.: Macrosiphum dewsler n. sp. from Linum lewisii (Linaceae), and Macrosiphum garyreed n. sp. from Geum triflorum (Rosaceae). Information is presented about the habitats, host plant biology, distribution, and taxonomy of both species.

Potato psyllid, Bactericera cockerelli (Sulc), causes economic damage to potato crops throughout the major potato growing regions of western North America. When cultivated crops are not available, potato psyllid often occurs on non-crop hosts. In the southern U.S. and northern Mexico, native species of Lycium (Solanaceae) are important non-crop hosts for the psyllid. We determined whether Old World species of Lycium now widespread in the Pacific Northwest are reservoirs of potato psyllid in this growing region. We examined Lycium spp. across a wide geographic region in Washington, Oregon, and Idaho at irregular intervals during three growing seasons. Potato psyllids were present at all locations. To determine whether Lycium is also a host during intervals of the year in which the potato crop is not available, we monitored a subset of these sites over the entire year. Six sites were monitored at 1- to 3-week intervals from June 2014 to June 2016. Psyllids were present on Lycium throughout the year at all sites, including during winter, indicating that Lycium is also a host when the potato crop is seasonally not available. Psyllid populations included a mixture of Northwestern and Western haplotypes. We observed well-defined spring and fall peaks in adult numbers, with peaks separated by long intervals in which psyllid numbers were very low. Seasonal patterns in psyllid numbers on these non-native Lycium hosts were very similar to what has been observed on native Lycium in the desert southwest region of the U.S. Our findings demonstrate that potato psyllid associates with Lycium across a broad geographic region within the Pacific Northwest. These results will assist in predicting sources of potato psyllid colonizing potatoes in this important growing region.

The Nearctic psyllid Bactericera maculipennis (Crawford) (Hemiptera: Psylloidea: Triozidae) is one of only five known species of Psylloidea worldwide whose host plants include species of Convolvulaceae (Solanales). Current checklists of North American Psylloidea report B. maculipennis only from California and Utah. Our surveys of field bindweed, Convolvulus arvensis L. (Convolvulaceae), an Old World plant introduced into North America, show that B. maculipennis is considerably more widespread than indicated by historical accounts. We update the psyllid's geographic range to include four states (Washington, Idaho, Oregon, Montana) not previously included in contemporary checklists. The egg and fifth instar nymph are described. We provide characters of the egg and nymph that distinguish this species from a congeneric species, Bactericera cockerelli (Sulc), occasionally found on field bindweed. Photographs of the male and female terminalia are provided. Bactericera maculipennis developed successfully on field bindweed and on several species of Ipomoea (Convolvulaceae) in laboratory assays. Overwintering females collected from leaf litter and dead or dormant stems of C. arvensis at locations in Central Washington mated and began to oviposit within 7 days of removal from the field, suggesting that B. maculipennis overwinters in a temperature-controlled quiescence rather than in a true reproductive diapause. Eggs and nymphs of B. maculipennis were found on stems of C. arvensis well into November in Central Washington, suggesting that this psyllid also may overwinter in pre-adult stages, as indicated by literature accounts from the 1940s and 1950s. Lastly, we propose that successful colonization of the invasive and exotic weed C. arvensis by B. maculipennis has allowed the psyllid to expand its geographic range well beyond historical boundaries. This conclusion is based upon the scarcity of native Convolvulaceae within regions in which the psyllid is newly recorded, combined with the now extensive distribution of the invasive C. arvensis in North America.

Changing climate and land‐use practices have the potential to bring previously isolated populations of pest insects into new sympatry. This heightens the need to better understand how differing patterns of host–plant association, and unique endosymbionts, serve to promote genetic isolation or integration. We addressed these factors in populations of potato psyllid, Bactericera cockerelli (Šulc), a generalist herbivore that vectors a bacterial pathogen (Candidatus Liberibacter solanacearum, causal pathogen of zebra chip disease) of potato (Solanum tuberosum L.). Genome‐wide SNP data revealed two major genetic clusters—psyllids collected from potato crops were genetically similar to psyllids found on a common weed, Lycium spp., but dissimilar from those found on another common non‐crop host, Solanum dulcamara L. Most psyllids found on Lycium spp. and potato represented a single mitochondrial cytochrome oxidase I (COI) haplotype that has been suggested to not be native to the region, and whose arrival may have been concurrent with zebra chip disease first emerging. The putatively introduced COI haplotype usually co‐occurred with endosymbiotic Wolbachia, while the putatively resident COI haplotype generally did not. Genetic intermediates between the two genetic populations of insects were rare, consistent with recent sympatry or reproductive isolation, although admixture patterns of apparent hybrids were consistent with introgression of genes from introduced into resident populations. Our results suggest that both host–plant associations and endosymbionts are shaping the population genetic structure of sympatric psyllid populations associated with different non‐crop hosts. It is of future interest to explicitly examine vectorial capacity of the two populations and their potential hybrids, as population structure and hybridization might alter regional vector capacity and disease outbreaks.

Characterizing factors affecting insect pest populations across variable landscapes is a major challenge for agriculture. In natural ecosystems, insect populations are strongly mediated by landscape and climatic factors. However, it has proven difficult to evaluate if similar factors predict pest dynamics in agroecosystems because control tactics exert strong confounding effects. We addressed this by assessing whether species distribution models could effectively characterize dynamics of an insect pest in intensely managed agroecosystems. Our study used a regional multi-year data set to assess landscape and climatic drivers of potato psyllid (Bactericera cockerelli) populations, which are often subjected to calendar-based insecticide treatments because they transmit pathogens to crops. Despite this, we show that psyllid populations were strongly affected by landscape and climatic factors. Psyllids were more abundant in landscapes with high connectivity, low crop diversity, and large natural areas. Psyllid population dynamics were also mediated by climatic factors, particularly precipitation and humidity. Our results show that many of the same factors that drive insect population dynamics in natural ecosystems can have similar effects in an intensive agroecosystem. More broadly, our study shows that models incorporating landscape and climatic factors can describe pest populations in agroecosystems and may thus promote more sustainable pest management.

Greater arthropod diversity may promote biological control by bringing together predator species that occupy complementary feeding niches. Diverse prey communities could further accentuate such niche differences and decrease predator-predator antagonism. However, much evidence of these effects comes from simple experiments that do not reflect the ecological complexity of real agricultural fields. Here we used molecular gut-content analysis to examine how predator and prey biodiversity impacted consumption of aphids by two generalists, Nabis sp. and Geocoris sp., in potato (Solanum tuberosum) crops. We show that both predator species were more likely to have fed on aphids when they foraged in fields with greater overall predator richness, an apparent benefit of predator biodiversity for aphid biocontrol consistent with greater complementarity. However, Geocoris saw less-frequent aphid predation with increasing predator evenness, perhaps because they foraged less when dangerous intraguild predators were common. For both predator species, higher thrips (Frankliniella occidentalis) abundance also correlated with greater aphid predation, as did higher total arthropod richness for Nabis. Altogether, beneficial complementarity appeared to be enhanced by greater predator or prey richness, although, for Geocoris, this was opposed by a negative effect of predator evenness. Strong prey-species-identity effects generally enhanced, rather than disrupted, aphid predation. Overall, the full diversity of biodiversity-biocontrol relationships suggested by smaller-scale experiments also appeared to be impactful in complex, working agricultural fields.

Traps baited with a sex attractant were used to determine if the invasive noctuid moth Hecatera dysodea (Denis & Schiffermuller, 1775) is generally distributed in the state of Idaho. The insect, which originated from Europe, utilizes species of Lactuca (lettuce) (Asteraceae) as a larval host. It was previously reported from northern Oregon and southern Washington but not the state of Idaho. The moth was subsequently captured in traps in six Idaho counties ranging from the south of the state near Utah to the north of the state in the panhandle area. A larva was also found on wild lettuce, Lactuca serriola L., near Boise, Idaho, and adults were captured in a light-trap near the southern border of the state. We conclude that the moth is generally distributed in the state at lower elevations where L. serriola is present.

Two hundred and sixty-two adventive aphids (Hemiptera: Aphidoidea) have been previously reported in North America north of Mexico. We update this to include 25 previously unrecorded species, and include information on the location and date of first discovery, biogeographic origin, and economically important North American hosts for these species. The number of adventive species introduced per year has decreased overall since 1930.We discuss aphids intercepted at United States ports of entry and identified by the Systematic Entomology Laboratory from 2000–2016 and comment on how the composition of species intercepted may affect the adventive species that become established.

Several members of the Psylloidea vector pathogens of agricultural crops in the Pacific Northwest (“PNW”) U.S. states of Idaho, Montana, Oregon and Washington. These crop-production concerns have renewed interest in the biodiversity of this superfamily in the region. We compiled a checklist of this group by examining published records and collections. This revealed 118 species of psyllids from 23 genera; 29 of these species had not been previously reported in the PNW. Our species list provides a useful starting point for entomologists investigating the ecology of emerging insect-transmitted plant pathogens in the region.

We report 39 species, belonging to 22 genera of aphids (Hemiptera: Aphididae), collected within and near the boundary of the Valles Caldera National Preserve in the Jemez Mountains of northern New Mexico, USA. Of these, 26 (67%) represent new distribution records for New Mexico. Plant genera/species from which the specimens were collected also are listed when available.

The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) is a small phloem-feeding insect that develops almost exclusively on plants within the Solanaceae (Fig. 1A). The psyllid was described in 1909 by Karel Sulc from specimens collected in Boulder, Colorado, and is found in Mexico, Central America, the western U.S., and southern Canada, and as an introduction in New Zealand (Wallis 1955, Teulon et al. 2009, Munyaneza 2012). Outbreaks of potato psyllid in North America occurred at regular intervals in potatoes, tomatoes, and peppers beginning in the late 1800s and extending into the mid-1900s, largely along a corridor on both sides of the Rocky Mountains. The outbreaks failed to extend into the Pacific Northwest. That pattern changed dramatically in 2011, when an outbreak of potato psyllid caused massive economic losses to potato growers in Washington, Oregon, and Idaho. Losses were due to a new tuber disorder (“zebra chip”; Fig. 1 B-C), now known to be associated with a bacterium that is vectored by potato psyllid. Fig. 1. (A) Adult potato psyllid. (B, C) Discoloration of infected fresh tubers and of tuber slices after frying. The historical absence of psyllid problems in the Pacific Northwest means that our understanding of psyllid biology under Pacific Northwest conditions is woefully lacking. The outbreak in 2011, coupled with our limited …

Two new species of Macrosiphum Passerini are described from western North America. Macrosiphum clum Jensen, new species lives on Clematis ligusticifolia Nutt. (Ranunculaceae) without host alternation. Macrosiphum schimmelum Jensen, new species lives on Lonicera utahensis S. Watson (Caprifoliaceae) without host alternation. Notes on taxonomy, distribution, and field biology are provided for both species.

We discuss two insects feeding on foliage of sea lavender (Plumbaginaceae: Limonium carolinianum (Walt.) Britt.) in Maine and Massachusetts, USA. Staticobium Mordvilko (Hemiptera: Aphididae) is documented in North America for the first time. A revision of the genus is needed before these aphids can be placed to species. We report the rearing of Gynnidomorpha romonana (Kearfott) (Lepidoptera: Tortricidae) and a parasitoid (Braconidae: Microgastrinae) from larvae mining sea lavender leaves.

The aphid genus Myzaphis van der Goot, 1913 from the tribe Macrosiphini is revised to include eight species. Apterous and alate viviparous females, known fundatrices and known sexual morphs (oviparous females and males) of Myzaphis bucktoni, M. juchnevitschae, M. rosarum, M. tianshanica and M. turanica are re-described and illustrated. Lectotype and paralectotypes of Myzaphis bucktoni and M. turanica are designated. The status of M. komatsubarae nomen dubium is discussed. Myzaphis avariolosa is regarded as a species belonging to the genus Ericaphis. Three new species: M. oezdemirae Kanturski & Barjadze sp. nov., M. tuatayae Kanturski & Barjadze sp. nov. from Turkey and M. rezwanii Kanturski & Barjadze sp. nov. from Iran are described and illustrated. Myzaphis bucktoni is recorded from Portugal for the first time. Diagnosis of the genus Myzaphis van der Goot, 1913 is redefined and a new genus Richardsaphis Kanturski & Barjadze gen. nov. is erected with the type species R. canadensis (Richards) comb. nov. Richardsaphis is for the first time recorded from the USA and hitherto unknown oviparous female and alate male are described and illustrated. Original keys to species of the genus Myzaphis and aphid genera of the tribe Macrosiphini with 2-2-2 first tarsal chaetotaxy are also provided.

A new species of Macrosiphum Passerini is described from western North America based on the apterous and alate viviparous females. Macrosiphum glawatz n. sp. lives on Potentilla gracilis (Rosaceae), apparently without host alternation, being commonly attended by ants in the genus Formica L. Details are provided regarding its similarity to other Macrosiphum, especially Macrosiphum mentzeliae Wilson, as which it was initially mis-identified. New information about biology and taxonomy of M. mentzeliae is provided for comparison purposes. New information is also provided about two other Macrosiphum recorded from Potentilla: Macrosiphum potentillae (Oestlund) and Macrosiphum potentillicaulis Miller. Comparative taxonomic details about M. potentillae are provided based on Oestlund's original material and the lectotype. We report the location of the type slide of M. potentillicaulis and declare it a junior synonym of Macrosiphum valerianae (Clarke), new synonymy.

We report and describe the first species of Atheroides Haliday presumed to be native to North America, collected at the Valles Caldera National Preserve, New Mexico, USA. We hypothesize its placement among the Siphini based on morphological, phylogenetic analysis and extend the distribution of the genus to the Holoarctic. We expand the key of the known Atheroides to include the new species and discuss the current hypotheses of the geographic distribution of the type species, Atheroides serrulatus Haliday.

Beet leafhoppers (Circulifer tenellus Baker) have been identified as the vector for a plant-pathenogenic phytoplasma known as beet leafhopper-transmitted virescence agent. Beet leaf-hopper-transmitted virescence agent causes purple top disease in potatoes, which can reduce yields and tuber quality. A trapping network, composed of ≈100 sites, monitors leafhoppers in the Columbia Basin of Oregon and Washington through a collaborative effort of regional researchers and stakeholders. Yellow sticky cards were used to determine the timing and spatial distribution of beet leafhoppers in the Columbia Basin; insects were counted weekly from early April through late October in 2006, 2007, and 2008. Weather data collected from a network of weather stations in Oregon and Washington were used in a nonparametric multiplicative regression analysis to determine which abiotic environmental variables might influence beet leafhopper populations. Weather conditions (mean temperature, dew point, precipitation, and wi...

One new species of the aphid genus Macrosiphum Passerini is described from the Pacific Northwest of North America. Macrosiphum opportunisticum n. sp. lives on a diverse range of shrubs mostly in mountainous habitats, without host alternation. The alate vivipara of Macrosiphum parvifolii Richards is briefly described, and the host range and biology of this species is discussed. The life cycle of Macrosiphum tolmiea (Essig) is reported to be holocyclic with notes on the morphology of the fundatrix. Macrosiphum kiowanepus (Hottes) is declared a junior synonym of Macrosiphum valerianae (Clarke) syn. nov. with notes on biology, host plants, and diagnostic features of the species.

A new species of Macrosiphum is described from southern Mexico City, Mexico based on apterous and alate viviparous females and alate males. Macrosiphum tonantzin, n. sp., was found living year-round on Pittosporum undulatum (Pittosporaceae), a plant native to Australia and grown in Mexico as an ornamental. Relationships of this species to other Macrosiphum are discussed, as well as hypotheses about its possible geographic origin and life cycle.

Uroleucon (Lambersius) escalantii (Knowlton) (syn. nov.) is declared a junior synonym of Uroleucon (Lambersius) erigeronense (Thomas) based on examination of slide mounted material from many hosts and localities, using data from host plant transfers, and DNA sequences. A diagnosis and new information on the host plant biology of the species are also provided.

One species of Macrosiphum Passerini is described from the Pacific Northwest of North America. Macrosiphum dicentrae n. sp. lives on Dicentra formosa, Corydalis aurea, and Corydalis scouleri (Fumariaceae) without host alternation. The identity and biology of Macrosiphum corydalis (Oestlund) n. comb. is clarified. The relationship of these species to other Macrosiphum in North America is discussed.

Leafhopper-transmitted phytoplasma diseases are increasingly becoming important in the Pacific Northwest. An epidemic of purple top disease of potato (Solanum tuberosum L.) occurred in the Columbia Basin of Washington and Oregon in the 2002 growing season and caused significant yield losses to potato fields and a reduction in tuber quality. The disease was also observed during ensuing years, especially in potato fields not treated with insecticides. In 2003, 2004, and 2005, leafhopper sampling was conducted in the Columbia Basin of Washington and Oregon and Yakima Valley to determine the seasonal occurrence and abundance of the beet leafhopper, Circulifer tenellus Baker, the primary vector of the potato purple top disease phytoplasma in this major potato producing region of the USA. Leafhoppers were sampled using sweep nets and yellow sticky traps at weekly intervals around potato fields throughout the Columbia Basin and in Yakima Valley from April to October. Leafhoppers were also sampled in two experimental potato fields not treated with insecticides in both 2003 and 2004. Leafhoppers in the samples were sorted, identified, and counted. The beet leafhopper was common and abundant in weeds near potato fields from mid-April to mid-October and had at least three generations per year. The beet leafhopper appeared into potato fields as early as April, but generally arrived in early May, and was present in potatoes throughout the remainder of the growing season. This leafhopper was abundant in potatoes in May to early July, suggesting that potatoes more likely are infected with the purple top disease phytoplasma during early summer; however, it is not clear how far into the growing season potato infection occurs. Several other leafhopper species were abundant in the study area and included economically important species such as Macrosteles spp., Ceratagallia spp., and Colladonus spp. All the leafhopper species found in weeds in the vicinity of potatoes were also present within potato fields. Further studies of the role C. tenellus and other potential leafhopper vectors play in purple top will be needed to improve management of this disease in the Pacific Northwest.

Bittersweet nightshade ( Solanum dulcamara L.) is a key noncrop host of the potato psyllid ( Bactericera cockerelli Sulc), proposed to be a source of the psyllids that colonize potato ( Solanum tuberosum L.) fields in the northwestern United States. Here, we describe the broader community of arthropod potato pests, and also predatory arthropods, found in bittersweet nightshade patches. Over 2 yr, we sampled arthropods in patches of this weed spanning the potato-growing region of eastern Washington State. The potato psyllid was the most abundant potato pest that we found, with reproduction of these herbivores recorded throughout much of the growing season where this was measured. Aphid, beetle, and thrips pests of potato also were collected on bittersweet nightshade. In addition to these herbivores, we found a diverse community of >40 predatory arthropod taxa. Spiders, primarily in the Families Dictynidae and Philodromidae, made up 70% of all generalist predator individuals collected. Other generalist predators included multiple species of predatory mites, bugs, and beetles. The coccinellid beetle Stethorus punctillum (Weise) was observed eating psyllid eggs, while the parasitoid wasp Tamarixia triozae (Burks) was observed parasitizing potato psyllid nymphs. Overall, our survey verified the role of bittersweet nightshade as a potato psyllid host, while suggesting that other potato pests also use these plants. At the same time, we found that bittersweet nightshade patches were associated with species-rich communities of natural enemies. Additional work is needed to directly demonstrate movement of pests, and perhaps also predators, from bittersweet nightshade to potato fields.

A new species of the previously monotypic aphid genus Aphthargelia is described and the genus reviewed. The new species, A. rumbleboredomia is heteroecious, alternating between host plants in Symphoricarpos and Aconogonon in the mountains of northwestern North America. Descriptive notes on A. symphoricarpi are given, along with diagnostic features for separating the two species of the genus. A key to related genera is presented, and biological information on both species of Aphthargelia is summarized.

In the northwestern United States, insect pests of potatoes (Solanumtuberosum L.) have typically been controlled using broad-spectrum insecticides. However, the loss or impending loss of many broad-spectrum chemicals is increasing the use of selective insecticides, and organic potato production is growing in the region. In the 2001 and 2002 growing seasons, we intensively sampled the arthropods in 31 (14 in 2001 and 17 in 2002) production potato Þelds under three pest management regimens: conventional Þelds treated with broad-spectrum insecticides (Hard), conventional Þelds treated with selective insecticides (Soft), and organic Þelds treated with insecticides certiÞed for organic production (Organic). All Þelds were within the Columbia Basin of Washington, grown under center-pivot irrigation. We sampled arthropods using three techniques: D-vac suction sampling, pitfall trapping, and visual searching. Geocoris spp. and Nabis spp. bugs (Hemiptera) and spiders (Araneae) were the most abundant predators in plant foliage, together making up 90% of the foliar predator community in both years. Total predator densities and densities of Geocoris, Nabis, and spiders not in the family Linyphiidae were highest in Organic and Soft, and lowest in Hard Þelds. Linyphiid spider densities were marginally elevated in Soft compared with Hard Þelds. On the ground, carabid (Coleoptera: Carabidae) and staphylinid (Coleoptera: Staphylinidae) beetles and a diverse group of spiders dominated the community, together making up 90% of the ground-active predator com- munity in both years. Total predator densities and densities of carabid beetles, staphylinid beetles, and linyphiid spiders were highest in Organic and Soft and lowest in Hard Þelds, whereas densities of these arthropods did not differ between Organic and Soft. Densities of nonlinyphiid spiders were highest in Organic, intermediate in Soft, and lowest in Hard Þelds. While predator densities were generally high in organic Þelds, these Þelds also had the highest densities of the two most injurious insect pests, the green peach aphid (Myzus persicae Sulzer) and the Colorado potato beetle (Leptinotarsa decem- lineata Say). Selective insecticides allowed conventional growers to achieve predator densities similar to those seen in organic Þelds while retaining low pest densities typical of Þelds treated with broad-spectrum insecticides.

A large subset of the whitefly genus Dialeurodes was analysed using cladistics. Thirty-five characters and thirty-five species were analysed. The results suggest that the species can be divided into three groups. Appropriate generic names are assigned to these groups based on the placement of the type species of Dialeurodes Cockerell, Massilieurodes Goux and Singhiella Sampson, to each of which species are assigned based on their placement in the cladograms or based on examination of original descriptions. Thirteen species are assigned to Dialeurodes, twenty-four to Singhiella (twenty-three new combinations) and fifteen to Massilieurodes including eleven new combinations and four new species, Massileurodes alabamensis sp.n., M. americanus sp.n., M. curiosa sp.n. and M. myricae sp.n. Discussions of the three genera are provided, along with keys for the identification of the Nearctic species. Descriptions of the adults of three previously described species are presented. Illustrations are provided for all North American members of the three genera.

Summary The phytophagous insect fauna of ferns has often been described as depauperate, and some have pointed to the paucity of evidence for adaptive radiation of insect groups feeding specifically on ferns. This paper examines the world's species of fern-specific Macrosiphum aphids and attempts to determine whether fern-feeding is a monophyletically derived trait in Macrosiphum. All sixteen species reported to feed on ferns, including three new species, were included in a cladistic analysis, along with fifteen other Macrosiphum species selected to represent the diversity of the genus, Papulaphis sleesmani (Pepper), because of its similarity to fern-feeding Macrosiphum, and Sitobion avenae (Fabricius), which was used as outgroup. The results gave good support for the monophyly of fifteen of the sixteen fern-feeders, and also supported a clade consisting of these fifteen fern-feeders plus Macrosiphum equiseti (Holman), an Equisetum-specific aphid. One species, Macrosiphum lapponicum Shaposhnikov, from northern Russia, was concluded to be unrelated to other fern-feeding Macrosiphum. Whether this species truly feeds on a fern requires confirmation. Taxonomic and biological notes are provided for all fern-feeding Macrosiphum of the world. These include one new combination, Macrosiphum cyatheae (Holman) comb.n., and three new species: Macrosiphum longirostratum sp.n. on Woodsia mollis and Woodsia sp. from Mexico (Michoacan), Macrosiphum miho sp.n. on ‘Aspidium’ sp. from the U.S.A. (Illinois) and Macrosiphum rebecae sp.n. on Adiantum sp. from Mexico (Michoacan). Keys to apterous and alate viviparae of Macrosiphum living on ferns are given.

Alatae and apterae of the genus Hyalomyzus , including 2 new species, Hyalomyzus orphnophlebos n. sp. and Hyalomyzus pocosinus n. sp., are described, illustrated, and keys are provided for identification. Hyalomyzus tissoti Nielsson & Habeck is considered a synonym of Hyalomyzus jussiaeae Smith. Cladistic analysis of 17 taxa using 25 morphological characters is discussed.

The cladistic relationships were examined within a large sample of the world's diversity of Dialeurodes Cockerell. Forty-one species were analyzed, including 27 species placed in Dialeurodes, 1 previously misclassified species, Dialeurodes fici Takahashi stat. rev., 2 undescribed species of Dialeurodes, 3 species of Rusostigma Quaintance & Baker, 4 Kanakarajiella David & Sundararaj, and 2 species of Dialeuronomada Quaintance & Baker, with 2 species of Cockerelliella Sundararaj & David used as outgroups. The analysis found 2,068 equally parsimonious trees of length 183. Several well-defined groups were present in all these trees. The important characters that define these groups are discussed, and the distinctness of these groups from the type species of the genus Dialeurodes is noted.

The types of Aphis mali var. fulviventris, var. nigricollis, var. nigriventris, var. obsoleta, var. pallidicornis, var. tergata, var. thoracica, and var. triseriata (all Fitch 1855) were rediscovered in the aphid collection of the United States of America National Museum of Natural History. Previously considered nomina dubia, we here establish them, along with Fitch's other two A. mali varieties, var. bivincta and var. immaculata, as junior synonyms of Rhopalosiphum oxyacanthae (Schrank) [=R. insertum (Walker)].

A landscape-scale study from 2004 to 2006 investigated the spatial and temporal dynamics of a new pest to the Columbia Basin of the Pacific Northwest, the potato tuberworm, Phthorimaea operculella (Zeller). Male P. operculella were monitored in spring, summer, and fall each year with a pheromone-baited trapping network in Oregon and Washington. The objectives of the study were to (1) describe the temporal and spatial dynamics of the recent outbreak of P. operculella in the region and (2) examine the relationship of the spatial and temporal distribution of the outbreak and weather (air temperature, precipitation, and dew point) and geographic variables (elevation and latitude). Weather data during the P. operculella outbreak were compared with a reference period (1993–1999) that occurred before the outbreak. The outbreak in 2004, which caused the first widespread tuber damage in the region, was positively associated with warmer temperatures in the preceding fall and in the spring, summer, and fall of the growing season. October and November 2003 and March 2004 were also drier than the reference period. However, the winter of 2003/2004 was colder than the reference period and thus mild winter conditions did not explain the outbreak. The importance of environmental variables on the seasonal spatial distribution of the pest each year was examined using nonparametric multiplicative regression. Locations with higher spring, summer, or fall temperatures were associated with increased trapping rates in most seasons. Elevation and latitude seemed to play a constraining role, because low trapping rates of P. operculella were associated with higher elevations and latitudes.

A new species of the previously monotypic aphid genus Aphthargelia is described and the genus reviewed. The new species, A. rumbleboredomia is heteroecious, alternating between host plants in Symphoricarpos and Aconogonon in the mountains of northwestern North America. Descriptive notes on A. symphoricarpi are given, along with diagnostic features for separating the two species of the genus. A key to related genera is presented, and biological information on both species of Aphthargelia is summarized.