Repository logo
 

Aposematism in the burying beetle? Dual function of anal fluid in parental care and chemical defense

Accepted version
Peer-reviewed

No Thumbnail Available

Type

Article

Change log

Authors

Lindstedt, C 
Boncoraglio, G 
Cotter, S 
Gilbert, J 
Kilner, RM 

Abstract

Burying beetles (Nicrophorus vespilloides) bear distinctive and variable orange-black patterning on their elytra and produce an anal exudate from their abdomen when threatened. During breeding, the anal exudates contribute to the antimicrobial defence of the breeding resource. We investigated whether the anal exudates also provide a responsive chemical defence, which is advertised to potential avian predators by the beetle’s orange and black elytral markings. We found that that the orange-black elytral markings of the burying beetle are highly conspicuous for avian predators against range of backgrounds, by using computer simulations. Using bioassays with wood ants, we also showed that the burying beetle’s anal exudates are aversive to potential predators. From these results, and other evidence in the literature, we conclude that the evidence for aposematism in the burying beetle is as strong as the evidence for many other classically aposematic species, such as defended Hymenopterans, ladybirds or poisonous frogs. Nevertheless, we also report unexpectedly high levels of individual variation in coloration and chemical defences, as well as sex differences. We suggest that this variation might be due partly to conflicting selection pressures, particularly on the dual function of the exudates, and partly to nutritional differences in the developmental environment. The ecology of the burying beetles (Nicrophorus spp.) differs markedly from better-studied aposematic insects. This genus thus offers new potential for understanding the evolution of aposematism in general.

Description

Keywords

aposematism, public goods, responsive defense, social immunity, variation in coloration, warning signals

Journal Title

Behavioral Ecology

Conference Name

Journal ISSN

1045-2249
1465-7279

Volume Title

28

Publisher

Oxford University Press (OUP)
Sponsorship
European Commission (252120)
The Royal Society (wm140111)
European Research Council (310785)
Royal Society Marie Curie