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Open access publications by faculty, staff, postdocs, and graduate students in the Department of Entomology and Wildlife Ecology.
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Item Larval development and parasitism of emerald ash borer (Agrilus planipennis) in Oregon ash (Fraxinus latifolia) and European olive (Olea europaea): implications for the West Coast invasion(Journal of Economic Entomology, 2025-01-18) Callahan, Heather L.; Duan, Jian J.; Ragozzino, Max L.; Tallamy, Douglas W.The invasive emerald ash borer (Agrilus planipennis Fairmaire) (EAB) has been devastating North American ash (Fraxinus spp.) resources for over 2 decades. In its native range, EAB attacks and kills primarily stressed ash trees. In North America, however, EAB also attacks healthy trees of every Fraxinus species encountered, most recently Oregon ash (Fraxinus latifolia Benth.). Successful EAB development has also been reported in European olive (Olea europaea L.). The recent detection of EAB in Oregon puts the future of these 2 hosts into question, as little is known about EAB’s development in these species or how introduced biocontrol agents will respond. We conducted laboratory and field infestations of olive and ash in Delaware and Oregon to assess EAB development and associated parasitoid responses. We found no difference in the net population growth rate of EAB developing in Oregon ash versus green ash. However, these species supported significantly more population growth than olive, in which EAB net population growth rate was zero, with most larvae dying prematurely. Artificially infested olives were small, which may have negatively impacted phloem availability and larval survival. Future studies should be conducted investigating EAB development on larger olive material. Although no parasitism was observed in infested olive, as EAB larvae seldom reached life stages (third or fourth instars) susceptible to larval parasitism, late-instar larvae developing in Oregon ash were attacked by both Tetrastichus planipennisi Yang and Spathius galinae Belokobylskij and Strazanac, suggesting that biocontrol is a suitable option for this newly invaded region.Item First whole-genome sequence of Triatoma sanguisuga (Le Conte, 1855), vector of Chagas disease(Genes | Genomes | Genetics, 2025-02-17) Peterson, Jennifer K.; MacDonald, Madolyn L.; Ellis, Vincenzo A.Triatoma sanguisuga is the most widespread triatomine bug species in the United States. The species vectors the human parasite Trypanosoma cruzi, which causes Chagas disease. Vector-borne Chagas disease is rarely diagnosed in the United States, but T. sanguisuga has been implicated in a handful of cases. Despite its public health importance, little is known about the genomics or population genetics of T. sanguisuga. Here, we used long-read sequencing to assemble the first whole-genome sequence for T. sanguisuga using DNA extracted from 1 adult specimen from Delaware. The final size of the genome was 1.162 Gb with 77.7× coverage. The assembly consisted of 183 contigs with an N50 size of 94.97 kb. The Benchmarking Universal Single-Copy Ortholog complete score was 99.1%, suggesting a very complete assembly. Genome-wide GC content was 33.56%, and DNA methylation was 18.84%. The genome consists of 62.75% repetitive DNAs and 17,799 predicted coding genes. The assembled T. sanguisuga genome was very close in size and BUSCO score to that of Triatominae species T. dimidiata (1.16 Gb with 99.1% BUSCO score for T. sanguisuga vs 1.22 Gb with 98.7% BUSCO score for T. dimidiata) and slightly larger than that of T. infestans and Rhodnius prolixus (949 Mb with 90.4% BUSCO score and 706 Mb with 96.5% BUSCO score, respectively). The T. sanguisuga genome is the first North American triatomine species genome to be sequenced, allowing for deeper investigations into epidemiologically relevant aspects of triatomines in temperate climates, thus providing potential vector-borne disease management targets and strengthening public health preparedness.Item Predictive habitat occupancy models for North American river otters along inland streams in New Jersey(Wildlife Biology: A journal for wildlife science, 2025-01-23) Williams, Christopher K.; Bennett, Curtis; Schley, Hannah; Castelli, PaulThe North American river otter Lontra canadensis is a semi-aquatic furbearer species that historically ranged throughout North America. Starting in the mid-1800s and continuing through the early 1900s, the negative effects associated with anthropogenic disturbances (i.e. overharvest, development and ultimately habitat alternation) led to local extinctions. Researchers debate whether current land use patterns are affecting river otter occupancy. New Jersey is the most densely populated state in the United States, thus it provides a perfect study area to test potential anthropogenic effects on river otters. Using occupancy modeling to examine river otter habitat preferences, we measured presence/absence at 244 low order streams from January–April 2011–2012 along with 19 corresponding site/landscape covariates in both northern and southern New Jersey. In southern New Jersey, we detected otters at 83/141 sites (58.9%) with a detection probability of 97.7% across repeat visits and a predicted occupancy of 59.4 ± 0.04%. In northern New Jersey we detected otters at 31/103 sites (30.1%) with a detection probability of 44.5% across repeat visits and a predicted occupancy of 58.8 ± 0.04%. We determined the influence of habitat covariates on otter occupancy and found that water depth, water quality, stream width and mink presence were positively correlated with otter occupancy. The % commercial, industrial, transportation and recreational habitat, % low intensity development, bank slope, and distance to lake were negatively correlated with otter occupancy. Knowing the location of occupied stream and latrine sites will assist biologists in their efforts to monitor river otter populations and help estimate river otter density for harvest and conservation efforts.Item The Role of Host-Range Expansion and Co-Speciation in Host–Parasite Associations With the Divergence of the Great Tit Species Complex(Ecology and Evolution, 2025-01-21) Huang, Xi; Ellis, Vincenzo A.; Peng, Yangyang; Ishtiaq, Farah; Wang, Haitao; Liang, Wei; Wu, Qiang; Bensch, Staffan; Dong, LuDuring the evolution of parasites, co-speciation and host-range expansion are thought to play roles in establishing associations with hosts, while sorting events can lead to dissolution of those associations. To address the roles of these processes, we focus on avian haemosporidian parasites infecting hosts of the intensively studied great tit species complex. We estimated the phylogeography of lineages detected in the species complex, and quantified their transition probabilities among hosts. Lineages detected in different host species presented a strong geographical signal but did not form monophyletic groups. Yet, distributions of lineages are not merely the result of their dispersal limitations, as many lineages that infect only one focal species can be found in birds sympatric with other focal species. Besides, closely related lineages that infect the same host species reach more similar rates of infection than expected by chance. Finally, Haemoproteus and Leucocytozoon lineages infecting P. major, the most recently dispersed species, were more generalized than others, consistent with a pattern of generalist parasites expanding their host ranges by infecting newly encountered host species. Our results suggest that host–parasite associations in this system are mainly the result of sorting events and host-range expansion of parasites, rather than co-speciation.Item A generalist vector-transmitted parasite exhibits population genetic structure among host genera(Parasitology, 2025-01-21) Ellis, Vincenzo A.; Duc, Mélanie; Ciloglu, Arif; Hellgren, Olof; Bensch, StaffanGeneralist parasites experience selective pressures from the various host species they infect. However, it is unclear if parasite transmission among host species precludes the establishment of host-specific adaptations and population genetic structure. We assessed the population genetic structure of the vector-transmitted avian haemosporidian parasite Haemoproteus majoris (lineage WW2; n = 34 infections) in a single site in southern Sweden among 10 of its host species. The 2 best-sampled host genera were Phylloscopus (2 species, n = 15 infections) and Sylvia (4 species, n = 15). We designed a sequence capture protocol to isolate 1.13 Mbp (ca. 5%) of the parasite genome and identified 1399 variable sites among the sequenced infections. In a principal components analysis, infections of Phylloscopus and Sylvia species mostly separated along the first 2 principal components. Sites with the highest FST values between the genera were found in genes that have mostly not been implicated in infection pathways, but several sites code for amino acid changes. An analysis of molecular variance confirmed significant variation among host genera, but not among host species within genera. The distribution of Tajima’s D among sequenced loci was negatively skewed, plausibly reflecting a history of bottleneck followed by population expansion. Tajima’s D was lower in infections of Phylloscopus than Sylvia, plausibly because WW2 began infecting Phylloscopus hosts after it was already a parasite of Sylvia hosts. Our results provide evidence of vector-transmitted parasite population differentiation among host species in a single location. Future work should focus on identifying the mechanisms underlying this genetic population structure.Item On the identity of the Caribbean planthopper Jamaha elevans (Walker, 1858) (Hemiptera: Fulgoroidea: Nogodinidae)(Proceedings of the Zoological Institute RAS, 2024-11-18) Gnezdilov, V.M.; Bartlett, C.R.; Malenovský, I.The specimens on which the record of the nogodinid planthopper Jamaha elevans (Walker, 1858) (Nogodinidae, Colpopterinae, Colpopterini) from Haiti published by Melichar (1902) was based were examined. These specimens were misidentified and belong to the flatid planthopper, Euhyloptera haitiana Fennah, 1965 (Flatidae, Flatinae, Selizini). Illustrations are provided for E. haitiana and the holotype of J. elevans. As far as is known, J. elevans is endemic to Jamaica.Item Snow leopard phylogeography and population structure supports two global populations with single refugial origin(Biodiversity and Conservation, 2024-10-12) Cancellare, Imogene A.; Weckworth, Byron; Caragiulo, Anthony; Pilgrim, Kristine L.; McCarthy, Thomas M.; Abdullaev, Alisher; Amato, George; Bian, Xiaoxing; Bykova, Elena; Dias-Freedman, Isabela; Gritsina, Mariya; Hennelly, Lauren M.; Janjua, Safia; Johansson, Orjan; Kachel, Shannon; Karnaukhov, Alexander; Korablev, Miroslav; Kubanychbekov, Zairbek; Kulenbekov, Rahim; Liang, Xuchang; Lkhagvajav, Purevjav; Meyer, Tara K.; Munkhtsog, Bariushaa; Munkhtsog, Bayaraa; Nawaz, Muhammad A.; Ostrowski, Stephane; Paltsyn, Mikhail; Poyarkov, Andrey; Rabinowitz, Salisa; Rooney, Thomas; Rosen, Tatjana; Rozhnov, Viatcheslav V.; Sacks, Benjamin N.; Schwartz, Michael K.; McCarthy, Kyle P.Snow leopards (Panthera uncia) inhabit the mountainous regions of High Asia, which experienced serial glacial contraction and expansion during climatic cycles of the Pleistocene. The corresponding impacts of glacial vicariance may have alternately promoted or constrained genetic differentiation to shape the distribution of genetic lineages and population structure. We studied snow leopard phylogeography across High Asia by examining range-wide historical and contemporary genetic structure with mitochondrial DNA and microsatellite markers. We genotyped 182 individuals from across snow leopard range and sequenced portions of the mitogenome in a spatially stratified subset of 80 individuals to infer historical biogeographic and contemporary patterns of genetic diversity. We observed a lack of phylogeographic structure, and analyses suggested a single refugial origin for all sampled populations. Molecular data provided tentative evidence of a hypothesized glacial refugia in the Tian Shan-Pamir-Hindu Kush-Karakoram mountain ranges, and detected mixed signatures of population expansion. Concordant assessments of microsatellite data indicated two global genetic populations, though we detected geographic differences between historical and contemporary population structure and connectivity inferred from mitochondrial and microsatellite data, respectively. Using the largest sample size and geographic coverage to date, we demonstrate novel information on the phylogeographic history of snow leopards, and corroborate existing interpretations of snow leopard connectivity and genetic structure. We recommend that conservation efforts incorporate genetic data to define and protect meaningful conservation units and their underlying genetic diversity, and to maintain the snow leopard’s adaptive potential and continued resilience to environmental changes.Item Influence of weed species and density on lima bean yield and other pests(Frontiers in Agronomy, 2024-06-27) Sankula, Sujatha; Everts, Kathryne L.; Whalen, Joanne M.; VanGessel, Mark J.Weeds interfere with lima bean production by reducing crop yield, hindering harvest, and contributing contaminants to harvested beans, yet there are very few trials documenting the impact of weeds on lima bean. This research was designed to evaluate weeds on lima bean yield, quality, as well as Rhizoctonia solani and pod-feeding insects in order to assist in implementing a more integrated approach to pest management. Field studies at four sites evaluated the impact of common cocklebur (Xanthium strumarium L.), jimsonweed (Datura stramonium L.), and ivyleaf morningglory [Ipomoea hederacea (L.) Jacq.] at densities of 0, 7, 10, or 20 plants 10 m-1 row in the presence and absence of Rhizoctonia solani on lima bean (Phaseolus lunatus L.). The planting dates of late June to mid-July represented a typical planting period for the mid-Atlantic region of USA, while one site represented an early planting date in this region (28 May). Differences in response to weed competition for total lima bean yield, marketable yield, yield components, and R. solani discoloration on lima bean occurred at one or more sites. Weed competition from 7 plants 10 m-1 of row or higher, reduced number lima bean pods by as much as 40%. However, weed density had little impact on percentage of flat, plump, or dry pods. Marketable yield was reduced at two sites in response to 7 plants 10-1 row (19% yield loss) and higher weed densities resulted in 29 to 33% yield loss. The presence of lima bean resulted in 40 to 60% reduction of common cocklebur and jimsonweed biomass and burs or seeds compared to weeds grown without crop competition. Weed competition in lima bean was influenced by many factors including weed species and planting date. Weed management is important to not only preserve yield but limit weed seed return to the soil seedbank and maintain harvest efficiency.Item Recycled Concrete Aggregate for Oyster Aquaculture(Waste, 2024-06-27) Kang, Dong-Hee; Hunter, James G.; Chirnside, AnastasiaRecycled Concrete Aggregate (RCA) of the chemical and biological effects must be understood to avoid potential adverse impacts to the bay’s aquatic ecosystem. RCA application as a base material for oyster reefs did not adversely affect oyster spat growth and survival, or the surrounding environment. Evaluated RCA leaching for petroleum byproducts showed that RCA as a base material for oyster reefs did not leach any hydrocarbon chemicals, and no water extractable SVOC were detected. The research found potential RCA application to the Chesapeake Bay watershed as a bottom conditioning material for oyster aquaculture. Overall, the findings support the use of RCA for oyster aquaculture.Item First Report of Chagas Disease Vector Species Triatoma sanguisuga (Hemiptera: Reduviidae) Infected with Trypanosoma cruzi in Delaware(The American Journal of Tropical Medicine and Hygiene, 2024-03-26) Peterson, Jennifer K.; Hoyos, Juliana; Bartlett, Charles R.; Gottdenker, Nicole L.; Kunkel, Brian; Murphy, Carrie; Alvarado, AntonioIn July and October 2023, two live triatomine bugs were found inside a home in New Castle County, Delaware. The bugs were identified as Triatoma sanguisuga, the most widespread triatomine bug species in the United States. Triatoma sanguisuga is a competent vector of Trypanosoma cruzi, the causative agent of Chagas disease. The two specimens were tested via real-time PCR (qPCR) for infection with T. cruzi, and one of the specimens was positive. Despite T. sanguisuga being endemic to the area, attainment of accurate species identification and T. cruzi testing of the bugs required multiple calls to federal, state, private, and academic institutions over several months. This constitutes the first report of T. sanguisuga infected with T. cruzi in Delaware. In addition, this is the first published report of T. sanguisuga in New Castle County, the northernmost and most densely populated county in Delaware. New Castle County still conforms to the described geographic range of T. sanguisuga, which spans from Texas to the East Coast of the United States. The T. cruzi infection prevalence of the species has not been studied in the northeastern United States, but collections in southern states have found prevalences as high as 60%. The Delaware homeowner’s lengthy pursuit of accurate information about the vector highlights the need for more research on this important disease vector in Delaware.Item Neonicotinoid exposure increases Varroa destructor (Mesostigmata: Varroidae) mite parasitism severity in honey bee colonies and is not mitigated by increased colony genetic diversity(Journal of Insect Science, 2024-05-28) Bartlett, Lewis J.; Alparslan, Suleyman; Bruckner, Selina; Delaney, Deborah A.; Menz, John F.; Williams, Geoffrey R.; Delaplane, Keith S.Agrochemical exposure is a major contributor to ecological declines worldwide, including the loss of crucial pollinator species. In addition to direct toxicity, field-relevant doses of pesticides can increase species’ vulnerabilities to other stressors, including parasites. Experimental field demonstrations of potential interactive effects of pesticides and additional stressors are rare, as are tests of mechanisms via which pollinators tolerate pesticides. Here, we controlled honey bee colony exposure to field-relevant concentrations of 2 neonicotinoid insecticides (clothianidin and thiamethoxam) in pollen and simultaneously manipulated intracolony genetic heterogeneity. We showed that exposure increased rates of Varroa destructor (Anderson and Trueman) parasitism and that while increased genetic heterogeneity overall improved survivability, it did not reduce the negative effect size of neonicotinoid exposure. This study is, to our knowledge, the first experimental field demonstration of how neonicotinoid exposure can increase V. destructor populations in honey bees and also demonstrates that colony genetic diversity cannot mitigate the effects of neonicotinoid pesticides.Item Records of fleas (Siphonaptera) from Delaware(Journal of Medical Entomology, 2024-05-17) Kennedy, Ashley C.; Winter, Wil S.; Gardner, Alfred L.; Woodman, Neal; Shifflett, Scarlet A.; Redus, Sierra; Newcomer, Jeffrey R.; Eckerlin, Ralph P.We present an annotated checklist of fleas (Siphonaptera) known to occur in the state of Delaware based on an examination of Siphonaptera collections at the University of Delaware and the Carnegie Museum of Natural History, as well as new specimens of fleas we collected from wildlife, other hosts, and tick flags. We review published records and compile them herein with our new records, which include 3 species previously unreported from Delaware. With these additions, there are now 18 flea species from 19 avian and mammalian hosts documented from Delaware.Item Genome divergence and reproductive incompatibility among populations of Ganaspis near brasiliensis(Genes | Genomes | Genetics, 2024-05-08) Hopper, Keith R.; Wang, Xingeng; Kenis, Marc; Seehausen, M. Lukas; Abram, Paul K.; Daane, Kent M.; Buffington, Matthew L.; Hoelmer, Kim A.; Kingham, Brewster F.; Shevchenko, Olga; Bernberg, ErinDuring the last decade, the spotted wing drosophila, Drosophila suzukii, has spread from eastern Asia to the Americas, Europe, and Africa. This fly attacks many species of cultivated and wild fruits with soft, thin skins, where its serrated ovipositor allows it to lay eggs in undamaged fruit. Parasitoids from the native range of D. suzukii may provide sustainable management of this polyphagous pest. Among these parasitoids, host-specificity testing has revealed a lineage of Ganaspis near brasiliensis, referred to in this paper as G1, that appears to be a cryptic species more host-specific to D. suzukii than other parasitoids. Differentiation among cryptic species is critical for introduction and subsequent evaluation of their impact on D. suzukii. Here, we present results on divergence in genomic sequences and architecture and reproductive isolation between lineages of Ganaspis near brasiliensis that appear to be cryptic species. We studied five populations, two from China, two from Japan, and one from Canada, identified as the G1 vs G3 lineages based on differences in cytochrome oxidase l sequences. We assembled and annotated the genomes of these populations and analyzed divergences in sequence and genome architecture between them. We also report results from crosses to test reproductive compatibility between the G3 lineage from China and the G1 lineage from Japan. The combined results on sequence divergence, differences in genome architectures, ortholog divergence, reproductive incompatibility, differences in host ranges and microhabitat preferences, and differences in morphology show that these lineages are different species. Thus, the decision to evaluate the lineages separately and only import and introduce the more host-specific lineage to North America and Europe was appropriate.Item Evolving wildlife management cultures of governance through Indigenous Knowledges and perspectives(The Journal of Wildlife Management, 2024-04-17) Fisk, Jonathan James; Leong, Kirsten Mya; Berl, Richard E. W.; Long, Jonathan W.; Landon, Adam C.; Adams, Melinda M.; Hankins, Don L.; Williams, Christopher K.; Lake, Frank K.; Salerno, JonathanWithin governance agencies, academia, and communities alike, there are increasing calls to recognize the value and importance of culture within social-ecological systems and to better implement Indigenous sciences in research, policy, and management. Efforts thus far have raised questions about the best ethical practices to do so. Engaging with plural worldviews and perspectives on their own terms reflects cultural evolutionary processes driving paradigm shifts in 3 fundamental areas of natural resource management: conceptualizations of natural resources and ecosystems, processes of public participation and governance, and relationships with Indigenous Peoples and communities with differing worldviews. We broadly describe evolution toward these paradigm shifts in fish and wildlife management. We then use 3 case studies to illustrate the ongoing cultural evolution of relationships between wildlife management and Indigenous practices within specific historical and social-ecological contexts and reflect on common barriers to appropriately engaging with Indigenous paradigms and lifeways. Our case studies highlight 3 priorities that can assist the field of wildlife management in achieving the changes necessary to bridge incommensurable worldviews: acknowledging and reconciling historical legacies and their continued power dynamics as part of social-ecological systems, establishing governance arrangements that move beyond attempts to extract cultural information from communities to integrate Indigenous Knowledges into dominant management paradigms, and engaging in critical reflexivity and reciprocal, accountable relationship building. Implementing these changes will take time and a commitment to processes that may initially feel uncomfortable and unfamiliar but have potential to be transformative. Ethical and culturally appropriate methods to include plural and multivocal perspectives and worldviews on their own terms are needed to transform wildlife management to achieve more effective and just management outcomes for all.Item Moths are less attracted to light traps than they used to be(Journal of Insect Conservation, 2024-04-19) Battles, Ian; Burkness, Eric; Crossley, Michael S.; Edwards, Collin B.; Holmstrom, Kristian; Hutchison, William; Ingerson-Mahar, Joseph; Owens, David; Owens, Avalon C.S.As evidence of global insect declines continues to mount, insect conservationists are becoming increasingly interested in modeling the demographic history of at-risk species from long-term survey data. However, certain entomological survey methods may be susceptible to temporal biases that will complicate these efforts. Entomological light traps, in particular, may catch fewer insects today than they once did due solely to increases in anthropogenic light pollution. Here we investigate this possibility by comparing the demographic histories of corn earworm moths (Helicoverpa zea) estimated from pairs of blacklight and pheromone traps monitored at the same farms. We find a stark decline in blacklight trap efficacy over 25 years of monitoring in Delaware, USA, mirrored over 10 years of monitoring in New Jersey, USA. While the precise causes of this decline remain a subject for discussion, the practical consequences are clear: insect conservationists cannot fully rely on long-term trends from entomological light traps.Item Diversity and host specificity of Borrelia burgdorferi’s outer surface protein C (ospC) alleles in synanthropic mammals, with a notable ospC allele U absence from mixed infections(Infection and Immunity, 2023-12-15) Shifflett, Scarlet A.; Ferreira, Francisco C.; González, Julia; Toledo, Alvaro; Fonseca, Dina M.; Ellis, Vincenzo A.Interactions among pathogen genotypes that vary in host specificity may affect overall transmission dynamics in multi-host systems. Borrelia burgdorferi, a bacterium that causes Lyme disease, is typically transmitted among wildlife by Ixodes ticks. Despite the existence of many alleles of B. burgdorferi’s sensu stricto outer surface protein C (ospC) gene, most human infections are caused by a small number of ospC alleles [“human infectious alleles” (HIAs)], suggesting variation in host specificity associated with ospC. To characterize the wildlife host association of B. burgdorferi’s ospC alleles, we used metagenomics to sequence ospC alleles from 68 infected individuals belonging to eight mammalian species trapped at three sites in suburban New Brunswick, New Jersey (USA). We found that multiple allele (“mixed”) infections were common. HIAs were most common in mice (Peromyscus spp.) and only one HIA was detected at a site where mice were rarely captured. ospC allele U was exclusively found in chipmunks (Tamias striatus), and although a significant number of different alleles were observed in chipmunks, including HIAs, allele U never co-occurred with other alleles in mixed infections. Our results suggest that allele U may be excluding other alleles, thereby reducing the capacity of chipmunks to act as reservoirs for HIAs.Item Biology and Management of Lesser Mealworm Alphitobius diaperinus (Coleoptera: Tenebrionidae) in Broiler Houses(Journal of Integrated Pest Management, 2023-01-30) Sammarco, Ben C.; Hinkle, Nancy C.; Crossley, Michael S.Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), the lesser mealworm, is a ubiquitous generalist pest of poultry broiler and layer facilities, originating in southern Africa and now found worldwide. They spend their full life cycle within the litter and manure of poultry, causing structural damage to poultry houses, injuring birds, and acting as a reservoir for several avian pathogens, notably Salmonella spp. and Escherichia coli. Management commonly consists of spraying walls and floors of poultry houses with organophosphates, pyrethroids, neonicotinoids, or spinosyns between flocks, and periodic removal and replacement of litter. Populations have been observed to become resistant to specific insecticides after ca. 10 yr of consistent use and exhibit cross resistance to insecticides of the same mode of action. Alternative cultural and biological control methods have been identified but are not currently implemented. More research is needed regarding the economic impact of A. diaperinus, the mechanisms of its insecticide resistance, and patterns and mechanisms of colonization for effective integrated pest management programs to be devised and implemented.Item Artificial light at night is a top predictor of bird migration stopover density(Nature Communications, 2023-12-04) Horton, Kyle G.; Buler, Jeffrey J.; Anderson, Sharolyn J.; Burt, Carolyn S.; Collins, Amy C.; Dokter, Adriaan M.; Guo, Fengyi; Sheldon, Daniel; Tomaszewska, Monika Anna; Henebry, Geoffrey M.As billions of nocturnal avian migrants traverse North America, twice a year they must contend with landscape changes driven by natural and anthropogenic forces, including the rapid growth of the artificial glow of the night sky. While airspaces facilitate migrant passage, terrestrial landscapes serve as essential areas to restore energy reserves and often act as refugia—making it critical to holistically identify stopover locations and understand drivers of use. Here, we leverage over 10 million remote sensing observations to develop seasonal contiguous United States layers of bird migrant stopover density. In over 70% of our models, we identify skyglow as a highly influential and consistently positive predictor of bird migration stopover density across the United States. This finding points to the potential of an expanding threat to avian migrants: peri-urban illuminated areas may act as ecological traps at macroscales that increase the mortality of birds during migration.Item Seasonal patterns and protection status of stopover hotspots for migratory landbirds in the eastern United States(Current Biology, 2024-01-22) Guo, Fengyi; Buler, Jeffrey J.; Smolinsky, Jaclyn A.; Wilcove, David S.Summary Migratory landbirds in North America are experiencing dramatic population declines. Although considerable research and conservation attention have been directed toward these birds’ breeding and wintering grounds, far less is known about the areas used as stopover sites during migration. To address this knowledge gap, we used 5 years of weather surveillance radar data to map seasonal stopover densities of landbirds across the eastern United States during spring and autumn migration. We identified stopover hotspots covering 2.47 million ha that consistently support high densities of migratory landbirds in spring or autumn. However, only 16.7% of these sites are hotspots in both seasons. The distribution of hotspots is shifted eastward in autumn compared with spring. Deciduous forest is the most important habitat type in both seasons, with deciduous forest fragments embedded in broadly deforested regions having the highest probability of being hotspots. The concentration of birds in these forest fragments is stronger in spring, especially in the agricultural Midwest. We found generally higher stopover densities in protected areas than in unprotected areas in both seasons. Nonetheless, only one-third of identified stopover hotspots have some sort of protected status, and more than half of these protected hotspots are subject to extractive uses. A well-distributed network of well-protected stopover areas, complementing conservation efforts on the breeding and wintering grounds, is essential to sustaining healthy populations of migratory landbirds in North America.Item New extralimital breeding records of saltmarsh sparrows (Ammospiza caudacuta) and Nelson's sparrows (Ammospiza nelsoni) and their implications(Ecology and Evolution, 2023-09-19) Ruskin, Katharine J.; Clark, Jonathan D.; Hotopp, Alice; Kovach, Adrienne I.; Guido, Nicole A.; Hernandez, Dean L.; Peña, Colin; Webb, Samantha N.; Shriver, W. GregorySaltmarsh (Ammospiza caudacuta) and Nelson's (A. nelsoni) sparrows are sister taxa that breed in tidal marshes along the coast of the Northeastern United States and Canada. The Saltmarsh Sparrow breeds from mid-coast Maine south to Virginia, while the Acadian Nelson's Sparrow breeds from the Canadian maritime provinces south to northern Massachusetts. Here, we present three extralimital observations of breeding Saltmarsh (n = 2) and Nelson's (n = 1) sparrows. In 2021 and 2022, we observed Saltmarsh Sparrow females attending nests at Mendall Marsh, ME, and Milbridge, ME, respectively, approximately 60 and 110 km beyond the documented northern extent of the Saltmarsh Sparrow breeding range. In 2022, we observed a breeding-condition male Nelson's sparrow singing in the upriver portion of a marsh on Cape Cod, Massachusetts, approximately 115 km beyond the previously documented southern extent of the Nelson's Sparrow breeding range. We confirmed morphological species identification using a panel of microsatellite DNA loci. Due to both the well-documented population declines of these species in the region and the intensity of sampling effort undertaken in recent years, we suggest that these observations likely are not indicative of range expansion. However, they do indicate that these 2 taxa have the capacity to use and successfully reproduce in marshes well beyond their established breeding limits. Our findings provide novel insight into the potential for these taxa to occur and successfully breed outside their documented breeding ranges. Given increased interest in their conservation, these results support the idea that management actions aimed at creating or maintaining nesting habitat across both species ranges could benefit both taxa.