Effects of pesticides on eggs and hatchlings of the Italian wall lizard (Podarcis siculus) exposed via maternal route

In oviparous species, pesticides may affect embryo survival via maternal transfer or contaminant absorption from the soil, thus representing an important cause of population decline. Maternal transfer is a source of contamination during vitellogenesis and oviductal egg retention. Currently, there is still limited evidence of the potential risk of embryonic exposure routes in reptiles. We investigated whether different agricultural treatments affect embryo, egg, and hatchling development and survival in the Italian wall lizard. We kept gravid females from conventional and control fields in captivity until oviposition and, after eggs being incubated in a pesticide-free environment, offspring morphology and performance (running speed) were assessed. Our results showed that the size of the mother positively influences the number of the eggs and offspring, as well as hatching body condition. Bigger females from conventional treatments tended to lay more eggs. Moreover, at equal female body conditions, eggs and hatchlings from conventional treatments had worse quality (i.e., smaller size and lower body condition) than those from control areas. No effect of treatment was observed on hatchling locomotor performance. In conclusion, our study provided new insights of the direct and indirect effects of field management (i.e., pesticide exposure) on females' reproductive success through the alteration of female's behaviour, which in turn may affect offspring development and health.