The banded net-wing beetle, Calopteron terminale has brilliant yellow orange elytra (front wings) with purplish black at the tips. Yellow and black is effective warning coloration. The lycids are typically predatory as larvae and feed as adults on insects or dead plant material. They produce toxic phenols and foul smelling pyrazines that deter predators such as insectivorous birds..
Interestingly, the net-wing beetles are attacked by another type of beetle, a cerambycid that mimics the color of the net-winged beetle. The cerambycids can consume the net winged beetles toxins and process them safely. The cerambycids sequester the net-winged beetle toxins and use them for their own protection.The pair of net-winged beetles in the photo were busy mating. Note that the male is much smaller than the female.
Is it common among insects for the male to be so much smaller than the female?
Many insects, the female is at least slightly larger especially when she is full of eggs. There are extreme cases such as stick insects with females almost twice as large as males. Larger size disparities are less common than smaller size disparities but some size disparity is common.
That’s interesting. Is that because reproduction is more costly in females, so having a larger body size increases the probability of success when it comes to supporting the eggs until they are ready to be laid (or hatched inside the female, as is the case in some species, right?). Is the severity of size disparity correlated in any way to the mating system (i.e. sexual, parthenogenesis, etc)?
Mature insect eggs are relatively large compared to body size of insects, so the female must be large enough to accommodate them. The male can be smaller because sperm are much smaller than eggs. I don’t know of any correlation between mating system and size disparity. Insects have evolved many interesting characters. However, if male territoriality is important, there can be sexual selection for larger males that are more capable of taking and defending territory from other males.
Hello,
Very neat stuff. Do you have a reference for the Cerambycid that attacks the net-wings? I’m looking as well in your literature. Thank you!!
Best,
Kenny
Tom Eisner wrote about the mimicry in the 1960s.
Lycid Predation by Mimetic Adult Cerambycidae (Coleoptera)
T. Eisner, F. C. Kafatos and E. G. Linsley
Evolution . Vol. 16, No. 3, Sep., 1962 of 316-324
This paper would reference previous work:
Defensive chemistry of lycid beetles and of mimetic cerambycid beetles that feed on them
Author(s): Eisner Thomas; Schroeder Frank C.; Snyder Noel; et al.
CHEMOECOLOGY Volume: 18 Issue: 2 Pages: 109-119 DOI: 10.1007/s00049-007-0398-4 Published: JUN 2008
Jon,
Thank you very much, should have figured it was Tom’s work :-). Very cool stuff. Got the articles on the way.
Best,
Kenny
I just saw one of these bugs in my yard and then my cat ran up and ate it… are they toxic to animals?
They have warning coloration. I doubt that they taste good.
Toxic insects typically cause regurgitation. They rarely kill.