Competition between scavengers and microorganisms for the nutrients within carrion is well documented. As a significant contributor to food web energetics, carrion serves not only as a food source for scavengers, but also as a reproductive resource for many insects. One example are the burying beetles of the Nicrophorus genus (Coleoptera: Silphidae) whose reproduction is dependent on locating and successfully sequestering vertebrate carrion. Throughout the cooperative preparation of carrion and feeding of the larval offspring, parental beetles coat the carrion with oral and anal secretions known to attenuate the growth of molds and bacteria in the laboratory. We test the hypotheses that Nicrophorus secretions attenuate the growth of naturally occurring microorganisms likely to be found colonizing the carrion resource, and that the active antimicrobial components of the secretions are small antimicrobial peptides (AMPs) similar to those produced by other insects.

National efforts to improve equitable teaching practices have led to an increase in research on the barriers to student participation and performance, as well as solutions for overcoming these barriers. This report summarizes the conclusions of a meeting exploring our understanding of how these practices differ among institutions and geographic locations.

Insects make use of sound in a variety of behavioral and reproductive contexts. Acoustic signals are known to serve in defense, sexual advertisement, prey location, and in cooperative activities such as offspring care and group foraging. In airborne signals produced by insects, information associated with species identification is often related to the temporal structure of the sound, while spectral quality is more closely associated with intraspecific variation. The Nicrophorine burying beetles (Insecta: Coleoptera: Silphidae) are a group known to produce sound through dorso-ventro stridulation, but the bioacoustics of this group remains understudied. Here, we examine the stridulatory sound produced by eight North American species of Nicrophorus burying beetles, testing the hypothesis that interspecific differences will be encoded in temporal characteristics of the sound, and that signal divergence will be explained by one of three mechanisms: selection as an intraspecific signal, selection for interspecific aposematism, or random divergence through drift. We digitally recorded stridulation in each species, and analyzed recordings to describe each in respect to four spectral and eight temporal acoustic characters. All species produced a low amplitude biphastic sound pulse consisting of from 58 to 126 syllables, and exhibiting weak dominant frequencies (5.8–12.7 kHz). Collapsing the 12 variables into three rotated factors using principal component analysis, we found no sex-related differences in sound, but significant interspecies divergence in respect to all three factors. We constructed a phylogeny for the group based on the morphology of the stridulatory structures and the acoustic characters, and found weak support for an intraspecific signal divergence model.

Some insects produce and use sound during multiple behaviors including many aspects of reproduction. Variation in call structure depends on the evolved morphological structures used to produce the sound and encode function. Beetles in the genus Nicrophorus produce stridulation by rubbing plectra, located on the ventral side of the elytra, against a pars stridens, located on the caudal end on the fourth and fifth abdominal segment in females and males, respectively. During field surveys for the endangered N. americanus, survey crews have historically used a small V-shaped notch cut in the caudal end of the right elytron to serves as a permanent marking method. No study, however, has examined the effect of this marking technique on the characters of stridulation or consequences for reproductive behavior and fitness. Here we show that one temporal and one spectral character of sound change significantly following elytron clipping, and that reproductive success is significantly decreased in all breedings in which a parent beetle is elytron-clipped. We recommend replacement of this marking technique with non-invasive methods to ensure conservation of this endangered species.