Masking Behavior by Mepraia spinolai (Hemiptera: Reduviidae): Anti-predator Defense and Life History Trade-offs

Masking, a type of camouflage, has been argued to function as an anti-predator mechanism helping to avoid detection or recognition by a prey or predator. However, research focused on the effects of masking on life history traits is scarce. We evaluated under laboratory conditions whether developmental time and survivorship in the absence of predators, and the probability to be predated by a potential predator are affected when the blood-feeding triatomine Mepraia spinolai masks with sand particles. Theoretically, it is expected to find a positive anti-predator effect of masking and the presence of trade-offs between development time and survival. We assigned M. spinolai nymphs to a masked or non-masked treatment and subjected them to a lizard, a potential predator. Results show masked nymphs reach the fifth instar faster and survive longer than non-masked nymphs, which is inconsistent with the trade-offs hypothesis we expected to find. In predation experiments, higher number of masked nymphs detected lizards before lizards detected them compared to non-masked nymphs. We suggest that masking may be an adaptation to the extreme climatic conditions the nymphs must face, and seems to render selective advantages to M. spinolai nymphs even in the absence of selective forces.