Effects of Humidity and Temperature on Burying Beetle (Coleoptera: Silphidae) Survival and Flight
Abstract
Terrestrial arthropods must prevent lethal desiccation during activity in dry environments. The small size of arthropods and high surface area to volume ratios increase the tremendous challenges to limit desiccation especially at warmer temperatures and lower humiditys. Among the insects, beetles in the family Silphidae include most species with shortened elytra and exposed abdomens. The silphids occur in communities that contain between 5 and 20 closely-related species that use carrion for food and reproduction. In the subfamily Nicrophorinae, burying beetles must locate appropriately sized, recently deceased vertebrates and bury them in the ground before they are discovered and consumed by predators or competitors. This activity requires the capacity for long sustained flights. The largest and most studied Silphidae is the endangered American burying beetle (ABB), Nicrophorus americanus, which is nocturnal and uses the largest carcasses. This study compared field data of activity patterns of the ABB with closely related species in Nebraska and Oklahoma. Laboratory studies of flight were conducted on Nicrophorus orbicollis, a proxy for ABBs, at temperatures between 10oC and 40oC, at three different relative humidity settings (INSERT THESE). The lowest and highest temperatures affected short flight activity while humidity did not. Desiccation rates were tested for three Silphinae and five Necrophorinae with different ecological and morphological traits at 23oC. Water loss rates varied among species and were not tightly linked to subfamily, size, or activity pattern, suggesting that other ecological factors are important for members of the Silphidae. These data are useful for modeling Silphidae niches and niche overlap based on environmental factors. Based on the results, increasing daily temperatures could affect the activity of day-active species, but are unlikely to limit the activity of ABB and other night—active species. Shifts in weather pattern and droughts are likely to affect carrion beetle communities, increasing some species while eliminating others.
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- OSU Theses [15752]