More Like this

1. A framework for integrating inferred movement behavior into disease risk models

   https://doi.org/10.1186/s40462-022-00331-8  

   Dougherty, Eric R. ; Seidel, Dana P. ; Blackburn, Jason K. ; Turner, Wendy C. ; Getz, Wayne M. ( July 2022 , Movement Ecology)

   Movement behavior is an important contributor to habitat selection and its incorporation in disease risk models has been somewhat neglected. The habitat preferences of host individuals affect their probability of exposure to pathogens. If preference behavior can be incorporated in ecological niche models (ENMs) when data on pathogen distributions are available, then variation in such behavior may dramatically impact exposure risk. Here we use data from the anthrax endemic system of Etosha National Park, Namibia, to demonstrate how integrating inferred movement behavior alters the construction of disease risk maps. We used a Maximum Entropy (MaxEnt) model that associated soil, bioclimatic, and vegetation variables with the best available pathogen presence data collected at anthrax carcass sites to map areas of most likelyBacillus anthracis(the causative bacterium of anthrax) persistence. We then used a hidden Markov model (HMM) to distinguish foraging and non-foraging behavioral states along the movement tracks of nine zebra (Equus quagga) during the 2009 and 2010 anthrax seasons. The resulting tracks, decomposed on the basis of the inferred behavioral state, formed the basis of step-selection functions (SSFs) that used the MaxEnt output as a potential predictor variable. Our analyses revealed different risks of exposure during different zebra behavioral states,more »which were obscured when the full movement tracks were analyzed without consideration of the underlying behavioral states of individuals. Pathogen (or vector) distribution models may be misleading with regard to the actual risk faced by host animal populations when specific behavioral states are not explicitly accounted for in selection analyses. To more accurately evaluate exposure risk, especially in the case of environmentally transmitted pathogens, selection functions could be built for each identified behavioral state and then used to assess the comparative exposure risk across relevant states. The scale of data collection and analysis, however, introduces complexities and limitations for consideration when interpreting results.

   « less
2. ‘Mother knows best’: Maternal oviposition effects of a range‐expanding insect herbivore degrade coastal wetlands by targeting juvenile foundation plant species

   https://doi.org/10.1002/ldr.4369  

   Ning, Zhonghua ; Chen, Cong ; Cui, Baoshan ; Zhang, Yihui ; Xie, Tian ; Wang, Qing ; Zhu, Zhenchang ; Bai, Junhong ; Bouma, Tjeerd J. ( August 2022 , Land Degradation & Development)

   Species range expansion induced by climate change and human activities threaten native populations and communities across the biosphere. Insect herbivores, important consumers of plants, are known to expand or contract their range under global change, with potential consequences to the newly reached environment. The selection of oviposition sites by herbivorous insects could notably impact offspring performance. However, the role of such effects in impacting the receiving ecosystem has been rarely explored. Here, we provide the first evidence showing that a terrestrial range‐expanding phytophagous wood‐borer moth (Zeuzera leuconotumButler) heavily attacked the saplings of a foundation plant species tamarisk (Tamarix chinensis) in salt marshes. Long‐term field surveys and laboratory behaviour experiments revealed that the oviposition preference of adult females was beneficial to their larval performance. The preference to oviposit on young branches of the new host plants, which were often softer and contained enough nutrients for larval development, indicates that females could still make the right choice on novel host‐plants. This finding supports the ‘mother knows best’ hypothesis that female insects will evolve to oviposit on hosts on which their offspring fare best. Consequently, the survival of host‐plant saplings decreased dramatically under this top‐down control, revealing that herbivory of this range‐expandingmore »insect has a profound negative impact on the recruitment and succession of coastal foundation species, thereby potentially leading to saltmarsh degradation. These findings highlight the importance of the maternal oviposition effects in range‐expanding insects and how these populations can establish using novel host‐plants and threaten coastal wetlands.

   « less
3. Ultrastructural variation and adaptive evolution of the ovipositor in the endemic Hawaiian Drosophilidae

   https://doi.org/10.1002/jmor.20884  

   Craddock, Elysse M. ; Kambysellis, Michael P. ; Franchi, Lisa ; Francisco, Peter ; Grey, Marques ; Hutchinson, Angela ; Nanhoo, Shawn ; Antar, Shyar ( November 2018 , Journal of Morphology)

   Ecological diversification of the endemic Hawaiian Drosophilidae has been accompanied by striking divergence in egg morphology, and ovarian structure and function. To determine how these flies successfully oviposit in a variety of breeding substrates, we used Scanning Electron Microscopy to examine the ultrastructure of the ovipositor of a sample of 65Drosophilaspecies and fiveScaptomyzaspecies of this hyperdiverse monophyletic group. TheDrosophilaspecies analyzed included representatives of the fungus‐breedinghaleakalaegroup, the leaf‐breedingantopocerusand modified tarsus groups, the modified mouthparts species group, thenudidrosophila, and the picture wing clade; the latter sample of 41 species from four species groups included stem‐ and bark‐breeders, as well as tree sap flux‐breeders. Ovipositor length was found to vary more than 12‐fold among Hawaiian drosophilids, with the longest ovipositors observed in the bark‐breeding species and the shortest among theScaptomyzaand fungus‐breeders. More noteworthy is the striking variation in overall shape and proportions of the ovipositor, in the shape of the apical region, and in the pattern of sensory structures or ovisensilla. Ultrastructural observations of the pair of long subapical sensilla on the ventral side identify these, for the first time, as taste bristles. Ovipositor form correlates strongly with the oviposition substrate used by the species, being of a distinctive shape and sizemore »in each case. We infer that the observed morphological divergence in the ovipositor is adaptive and the product of natural selection for successful reproduction in alternate microhabitats. The array of ovipositor forms that have evolved among the HawaiianDrosophilaspecies represent a series of ecomorphs that along with other divergent traits of the female reproductive system, have contributed to the successful adaptive radiation of this remarkable fauna.

   « less
4. Evaluation of Additional Drosophila suzukii Male-Only Strains Generated Through Remobilization of an FL19 Transgene

   https://doi.org/10.3389/fbioe.2022.829620  

   Yamamoto, Akihiko ; Yadav, Amarish K. ; Scott, Maxwell J. ( March 2022 , Frontiers in Bioengineering and Biotechnology)

   Drosophila suzukii (D. suzukii) (Matsumura, 1931; Diptera: Drosophilidae), also known as spotted wing Drosophila , is a worldwide pest of fruits with soft skins such as blueberries and cherries. Originally from Asia, D. suzukii is now present in the Americas and Europe and has become a significant economic pest. Growers largely rely on insecticides for the control of D. suzukii . Genetic strategies offer a species-specific environmentally friendly way for suppression of D. suzukii populations. We previously developed a transgenic strain of D. suzukii that produced only males on a diet that did not contain tetracycline. The strain carried a single copy of the FL19 construct on chromosome 3. Repeated releases of an excess of FL19 males led to suppression of D. suzukii populations in laboratory cage trials. Females died as a consequence of overexpression of the tetracycline transactivator (tTA) and tTA-activated expression of the head involution defective proapoptotic gene. The aim of this study was to generate additional male-only strains that carried two copies of the FL19 transgene through crossing the original line with a piggyBac jumpstarter strain. Males that carried either two chromosome 3 or a singleX-linked transgene were identified through stronger expression of the red fluorescent proteinmore »marker gene. The brighter fluorescence of the X-linked lines was likely due to dosage compensation of the red fluorescent protein gene. In total, four X-linked lines and eleven lines with two copies on chromosome 3 were obtained, of which five were further examined. All but one of the strains produced only males on a diet without tetracycline. When crossed with wild type virgin females, all of the five two copy autosomal strains examined produced only males. However, the single copy X-linked lines did not show dominant female lethality. Five of the autosomal lines were further evaluated for productivity (egg to adult) and male competition. Based on these results, the most promising lines have been selected for future population suppression experiments with strains from different geographical locations.« less
5. Comparative Skip-Oviposition Behavior Among Container Breeding Aedes spp. Mosquitoes (Diptera: Culicidae)

   https://doi.org/10.1093/jme/tjab084  

   Reinbold-Wasson, Drew David ; Reiskind, Michael Hay ( May 2021 , Journal of Medical Entomology)

   Yee, Donald (Ed.)

   Abstract Container Aedes mosquitoes are the most important vectors of human arboviruses (i.e., dengue, chikungunya, Zika, or yellow fever). Invasive and native container Aedes spp. potentially utilize natural and artificial containers in specific environments for oviposition. Several container Aedes spp. display ‘skip-oviposition’ behavior, which describes the distribution of eggs among multiple containers during a single gonotrophic cycle. In this study, we compared individual skip-oviposition behavior using identical eight-cup testing arenas with three container Aedes species: Aedes aegypti (Linnaeus), Aedes albopictus (Skuse), and Aedes triseriatus (Say). We applied the index of dispersion, an aggregation statistic, to individual mosquitoes’ oviposition patterns to assess skip-oviposition behavior. Aedes aegypti and Ae. albopictus utilized more cups and distributed eggs more evenly among cups than Ae. triseriatus under nutritionally enriched oviposition media (oak leaf infusion) conditions. When presented with a nutritionally unenriched (tap water) oviposition media, both Ae. aegypti and Ae. albopictus increased egg spreading behavior. Aedes albopictus did not modify skip-oviposition behavior when reared and assessed under fall-like environmental conditions, which induce diapause egg production. This study indicates specific oviposition site conditions influence skip-oviposition behavior with ‘preferred’ sites receiving higher amounts of eggs from any given individual and ‘non-preferred’ sites receive a limited contribution ofmore »eggs. A further understanding of skip-oviposition behavior is needed to make the best use of autodissemination trap technology in which skip-ovipositing females spread a potent larvicide among oviposition sites within the environment.« less