Effects of chitosan and emamectin benzoate on the reproductive system of Eobania vermiculata (Muller) land snails

摘要

The reproductive system of snails represents essential organ that affects snail population size. Therefore, the present research was directed to evaluate the effect of two biopesticides chitosan (Ch) and emamectin benzoate (EMB) LC50 on the reproductive system of Eobania vermiculata (Muller). Land snails were treated using thin-film layer technique. Snails were dissected and organs of reproductive system were weighted and examined for any pathological changes at 24, 48 and 72?h post treatment. Moreover, steroidal hormones were determined after 72?h of treatment with either chitosan or emamectin benzoate in comparison to untreated snails. Results revealed that the penis and dart sac increased in size, while ovotestis was decreased at the 3 different periods than the same organs of untreated snails. In addition, there was swelling in the size of some organs, i.e penis and vagina. While there was stunting in the albumen gland at 72?h of treatment with Ch or EMB. However, histological examination showed damage of the ovotestis and atrophy of induced cells in the dart sac and penis. The incidents of both compounds on the level of steroidal hormones gave fluctuating results, either increasingly or decreasingly. In conclusion, data emphasize that both tested compounds caused reduction in the numerical density of the E. vermiculata reproductive system and consequently decreased their fertility, as well as reduction in its population.