Morphophysiological and cuticular chemical alterations caused byXenosentomophagus endoparasites in the social waspPolistes ferreri(Hymenoptera, Vespidae)

Abstract

Social wasps can face many challenges during their colony cycle, including the presence of parasites. The order Strepsiptera is among the main parasites of the wasp genus Polistes. The aim of this study was to evaluate the effect of an endoparasite species on the host Polistes ferreri, with the hypothesis that females of this social wasp would undergo morphophysiological alterations as well as changes in their cuticular chemical profile caused by the obligate endoparasite. On average, parasitism was found in 10% of the colonies studied. All the parasitized females showed filamentous ovarioles without developing oocytes, which indicates a physiological castration. Moreover, the endoparasites present in the gaster of females caused its volume to increase, and the presence of endoparasites changed the cuticular chemical profiles of females, confirming our hypothesis. It is likely that this parasitism effect could hamper the maintenance of wasp colonies.

Variation in Chemical Composition of Cuticular and Nonpolar Compounds of Venom of Apoica pallens and Polistes versicolor

“…This fact proves the adaptive plasticity of CHCs of wasps of the genus Polistes towards the influences in social environment (Lorenzi et al, 2014). It is likely that P. versicolor has greater susceptibility to parasitism because the occurrence of parasitism in this genus has been reported in several studies (Dapporto et al, 2007;Kudô et al, 2014;Lorenzi et al, 2014;Torres et al, 2016).…”

Cuticular hydrocarbons as cues of sex and health condition in Polistes dominula wasps

“…A higher parasite load could more strongly affect host hydrocarbon profiles, as described in P. ferreri (Torres et al 2016). The chemical alteration of the cuticular profile by parasites partially confirms previous analyses in P. dominula and P. ferreri females (Dapporto et al 2007;Torres et al 2016). The underlying mechanism leading to changes in epicuticular blend probably occurs during the development of the endoparasite inside wasp larvae (Giusti et al 2007).…”

“…Here, we did not consider parasite load, because P. dominula wasps rarely harbour more than one parasite (Hughes et al 2004b). A higher parasite load could more strongly affect host hydrocarbon profiles, as described in P. ferreri (Torres et al 2016). The chemical alteration of the cuticular profile by parasites partially confirms previous analyses in P. dominula and P. ferreri females (Dapporto et al 2007;Torres et al 2016).…”

“…Among the wide variety of semiochemicals (Keeling et al 2004), CHCs allow the recognition of species, colony, physiological status, and age in Polistes (Singer et al 1998;Lorenzi et al 1996;Howard and Blomquist 2005;Blomquist and Bagnères 2010). The chemical profile is altered by the widespread endoparasites of the genus Xenos in females of P. dominula (Dapporto et al 2007) and P. ferreri (Torres et al 2016) as well as by a cestode in the ant Temnothorax (formerly Leptothorax) nylanderi (Trabalon et al 2000) and by Varroa mites in the honeybee Apis mellifera (Cappa et al 2016b). Thus, the cuticular mixture may signal the physiological condition of the P. dominula female host, which is castrated by the X. vesparum parasite.…”