Publications by authors named "Alison Ravenscraft"

Pentatomomorphan bugs can form symbiotic associations with bacteria belonging to the supergenus . This relationship has become a model for understanding environmental symbiont acquisition. Host insects can utilize various symbiont strains from across ; however, host colonization success and benefits conferred vary by bacterial clade.

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Nonpathogenic bacteria likely play important roles in the biology and vector competence of ticks and other arthropods. Coxiella, a gram-negative gammaproteobacterium, is one of the most commonly reported maternally inherited endosymbionts in ticks and has been associated with over 40 tick species. Species-specific Coxiella-like endosymbionts (CLEs) have been reported in the brown dog tick, Rhipicephalus sanguineus sensu lato (Acari: Ixodidae), throughout the world, while recent research suggests low Coxiella diversity among tick species.

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Microbial symbionts are critical for the development and survival of many eukaryotes. Recent research suggests that the genes enabling these relationships can be localized in horizontally transferred regions of microbial genomes termed "symbiotic islands." Recently, a putative symbiotic island was found that may facilitate symbioses between true bugs and numerous species, based on analysis of five symbionts.

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s.l. (Latreille, 1806), the brown dog tick, is the most widely distributed tick species in the world.

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Many beneficial symbioses between bacteria and their terrestrial arthropod hosts are vertically transmitted from mother to offspring, ensuring that the progeny acquire necessary partners. Unusually, in several families of coreoid and lygaeoid bugs (Hemiptera), nymphs must instead ingest the beneficial symbiont, (), from the environment early in development. We studied the effects of on development of two species of leaf-footed bug (Coreidae) in the genus , and We found no evidence for vertical transmission of the symbiont but found stark differences in performance between symbiotic and aposymbiotic individuals.

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Article Synopsis
  • The study focused on the gut symbionts of Wickham's stilt bug and how various factors like location and diet influence the diversity of microbial strains present in these insects.
  • Researchers found that a dominant strain of symbiont accounted for a significant portion of the gut flora, with location being the main factor explaining the variation in symbionts among individuals.
  • In terms of benefits, the presence of these symbionts was linked to better developmental and reproductive success, and there was evidence of horizontal transmission of symbionts from adults to nymphs through the environment.
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Facultative, intracellular bacterial symbionts of arthropods may dramatically affect host biology and reproduction. The length of these symbiont-host associations may be thousands to millions of years, and while symbiont loss is predicted, there have been very few observations of a decline of symbiont infection rates. In a population of the sweet potato whitefly species (Bemisia tabaci MEAM1) in Arizona, USA, we documented the frequency decline of a strain of Rickettsia in the Rickettsia bellii clade from near-fixation in 2011 to 36% of whiteflies infected in 2017.

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Gut microbes are believed to play a critical role in most animal life, yet fitness effects and cost-benefit trade-offs incurred by the host are poorly understood. Unlike most hosts studied to date, butterflies largely acquire their nutrients from larval feeding, leaving relatively little opportunity for nutritive contributions by the adult's microbiota. This provides an opportunity to measure whether hosting gut microbiota comes at a net nutritional price.

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Bombardier beetles (Carabidae: Brachininae) are well known for their unique explosive defensive chemistry. These beetles are found in riparian corridors throughout the American Southwest, where they commonly form large diurnal multispecies aggregations in moist areas under rocks, in crevices, and in leaf litter. Using high throughput 16S amplicon sequencing, we provide the first microbiome survey of a bombardier beetle, , collected from two sites in Arizona.

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Many arboreal ants depend on myrmecophytic plants for both food and shelter; in return, these ants defend their host plants against herbivores, which are often insects. Ant-plant and other mutualisms do not necessarily involve the exchange of costly rewards or services; they may instead result from by-product benefits, or positive outcomes that do not entail a cost for one or both partners. Here, we examined whether the plant-ant Allomerus octoarticulatus pays a short-term cost to defend their host plants against herbivores, or whether plant defense is a by-product benefit of ant foraging for insect prey.

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Evolutionary dietary shifts have major ecological consequences. One likely consequence is a change in nutrient limitation-some nutrients become more abundant in the diet, others become more scarce. Individuals' behavior should change accordingly to match this new limitation regime: they should seek out nutrients that are deficient in the new diet.

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How strong is selection for cheating in mutualisms? The answer depends on the type and magnitude of the costs of the mutualism. Here we investigated the direct and ecological costs of plant defense by ants in the association between Cordia nodosa, a myrmecophytic plant, and Allomerus octoarticulatus, a phytoecious ant. Cordia nodosa trees produce food and housing to reward ants that protect them against herbivores.

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