Effects of the pesticide dimethoate on a non-target generalist carabid,Pterostichus melas italicus(Dejean, 1828) (Coleoptera: Carabidae)

Abstract

This study draws attention to the toxicity of dimethoate at sub-lethal concentration to beneficial carabid beetles living in olive groves agroecosystem of Calabria, Italy. Short-and long-term effects of dimethoate on a non-target generalist predator in agroecosystems, Pterostichus melas italicus (Dejean, 1828) (Coleoptera, Carabidae) adults, were quantified by toxicity test, total haemocyte counts and morphometric analyses. In laboratory toxicity tests, beetles of both sexes exposed to field concentration of this toxicant showed a reduction of activity and a mortality of 10% after 72 h. Moreover, the impact of dimethoate on the total haemocyte counts (THCs) was recorded as a significantly lower number of circulating haemocytes in treated animals compared to controls at 48 h. Morphometric analyses showed that dimethoate caused long-term sub-lethal effects as a reduction of some morphometric parameters in P. melas italicus populations from two olive groves (treated and natural). In addition, a significant reduction in body size of females from long-term treated olive grove and a sexual dimorphism alteration were observed. As a result, data suggested that dimethoate may cause sub-lethal effects on this non-target carabid species.

An exploratory study of energy reserves and biometry as potential tools for assessing the effects of pest management strategies on the earwig, Forficula auricularia L

“…Marcus and Fiumera (2016) showed that exposure to atrazine, the one of the most widely used herbicides significantly affected male and female adult body size of Drosophila melanogaster. In Pterostichus melasitalicus, a carabidae, morphometric analyses also showed that dimethoate application caused a reduction in body or elytra lengths in females (Giglio et al 2011). Giglio et al (2017) showed in another carabidae, Calathus fuscupes, that morphological parameters e.g.…”

Impact of Systemic Insecticides on Organisms and Ecosystems

“…Longevity and survival of Aphidius ervi, an important parasitoid of the pea aphid (Acyrthosiphon pisum), were significantly reduced after treating with LC25 concentrations of dimethoate or pirimicarb [11]. A significant reduction in body size of females of the predator carabid Pterostichus melas italicus and altered sexual dimorphism were observed after longterm exposure in olives groves treated with dimethoate at a rate that caused 10% mortality after three days [104]. Unlike other insecticides, no behavioural effects of dimethoate or triazamate on honey bees were recorded [67].…”

PESTICIDES TOXICITY FOR Neoseiulus barkeri (ACARI: PHYTOSEIIDAE) AND NON-TARGET ORGANISMS

“…Imidacloprid, thiamethoxam, clothianidin and acetamiprid were found highly toxic to beneficial fauna in comparison with spirotetramate, buprofezin and fipronil (Kumar et al, 2012). Dimethoate had significantly decreased the body size, haemocyte counts and morphometric factors in carabid beetle (Giglio et al, 2011). Sulfonylurea herbicides-chlorsulfuron, metasulfuron methyl and thifensulfuron methyl reduced the growth rate of fluorescent bacteria Pseudomonas strains (Boldt and Jacobson, 1998).…”