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Abstract Maternally transmitted microbes are ubiquitous. In insects, maternal microbes can play a role in mediating the insect immune response. Less is known about how ecological factors, such as resource use, interact with maternal microbes to affect immunity.In the context of a recent colonization of a novel host plant by the Melissa blue butterflyLycaeides melissa, we investigated the interaction between host plant use and vertically transmitted, extracellular egg‐associated microbes in determining the strength of the insect immune response.We reared larvae on two different host plant species: a native hostAstragalus canadensisand a novel hostMedicago sativa. Egg‐associated microbes were removed through a series of antimicrobial egg washes prior to hatching. Immune response was measured through three assays: standing phenoloxidase (PO), total PO and melanization.We detected strong effects of microbial removal. Egg washing resulted in larvae with an increased immune response as measured by total PO—contrary to reports from other taxa. The effect of washing was especially strong for larvae consuming the native host plant.This result may explain why consumption of the egg casing is not a universal behaviour in insects, due to negative effects on larval immunity. Read the freePlain Language Summaryfor this article on the Journal blog.
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The effects of different cold‐temperature regimes on development, growth, and susceptibility to an abiotic and biotic stressor
<ext-link href='http://Abstract'>Abstract</ext-link> Global climate change is expected to both increase average temperatures as well as temperature variability.Increased average temperatures have led to earlier breeding in many spring‐breeding organisms. However, individuals breeding earlier will also face increased temperature fluctuations, including exposure to potentially harmful cold‐temperature regimes during early developmental stages.Using a model spring‐breeding amphibian, we investigated how embryonic exposure to different cold‐temperature regimes (control, cold‐pulse, and cold‐press) affected (a) compensatory larval development and growth, (b) larval susceptibility to a common contaminant, and (c) larval susceptibility to parasites.We found: (a) no evidence of compensatory development or growth, (b) larvae exposed to the cold‐press treatment were more susceptible to NaCl at 4‐days post‐hatching but recovered by 17‐days post‐hatching, and (c) larvae exposed to both cold treatments were less susceptible to parasites.These results demonstrate that variation in cold‐temperature regimes can lead to unique direct and indirect effects on larval growth, development, and response to stressors. This underscores the importance of considering cold‐temperature variability and not just increased average temperatures when examining the impacts of climate disruption.
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- PAR ID:
- 10457548
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Ecology and Evolution
- Volume:
- 9
- Issue:
- 6
- ISSN:
- 2045-7758
- Page Range / eLocation ID:
- p. 3355-3366
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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