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

Abstract

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) LC 50 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.

Emamectin benzoate as a potential molluscicide against white garden snail, Theba pisana in association with biochemical defects

“…EMB, an avermectin, has the potential to intoxicate insects via ingestion as well as contact 44,45 . The obtained data clearly indicate that EMB contact toxicity is lethal to T. pisana and corroborate the results of Kandil et al 24 . who, using a residual film technique, found a 72‐h median lethal concentration (LC 50 ) of 120.13 μg cm −2 for EMB against Massylaea vermiculata (Syn: Eobania vermiculata ).…”

“…42,43 EMB, an avermectin, has the potential to intoxicate insects via ingestion as well as contact. 44,45 The obtained data clearly indicate that EMB contact toxicity is lethal to T. pisana and corroborate the results of Kandil et al 24 who, using a residual film technique, found a 72-h median lethal concentration (LC 50 ) of 120.13 μg cm −2 for EMB against Massylaea vermiculata (Syn: Eobania vermiculata). Poison bait treatment with EMB under shade-net conditions has also been shown to be highly effective against the slug, Filicaulis alte, recording an average of 10.50 dead slugs per plot.…”

“…To date, there have been far fewer reports on the molluscicidal performance of EMB against land gastropods 24,25 compared with insect pests. Therefore, the objective of this study was to evaluate the contact acute toxicity of EMB against T. pisana to investigate this pesticide as a potential molluscicide that could achieve the goals of controlling this snail.…”

Usage of pharmaceutical contraceptive drug for controlling Eobania vermiculata snails by baits technique

“…There was a marked increase in the size of the ovotestis number of oocytes in Achatina fulica snails injected with estradiol and progesterone ( Kruatrachue et al., 1996 ). Chitosan and emamectin benzoate caused prevention of egg production in treated E. vermiculata snails ( Patel et al., 2016 ; Kandil et al., 2020 ). Finally, the squeaky decreases of the tested reproductive hormones levels, malformations of sperms and ova and complete egg cessation at the third week after treatment of snails with contraceptive pills as baits may assure the efficacy of this method in controlling high population densities of E. vermiculata devouring citrus trees at Sharkia Governorate, Egypt.…”

Biochemical, Histological Changes, Protein Electrophoretic Pattern, and Field Application of CuPb–Ferrite/TiO2 Nanocomposites for Controlling Terrestrial Gastropod Eobania vermiculata (Müller)

“…2 cm 3 of each prepared NPs with concentrations 250, 500, 750, and 1000 ppm were added to Petri dish (9 cm in diameter), keeping the gentle moving of the dish in regular circles until the perfect distribution of TiO 2 -based NPs. 17 The snails were added after complete evaporation of the solvent at room temperature within 5 min, leaving the previous thin layer. For 7 days, 10 adult individual snails were exposed to various concentrations of nanomaterials.…”