Search

Bumble bees (Bombus spp., Hymenoptera, Apidae) play a crucial role in pollinating greenhouse tomato crops. However, tomato production is constantly threatened by different invasive pests that often lead to the increased use of pesticides, with negative consequences for pollinators. The cotton mealybug Phenacoccus solenopsis has recently been reported in Mediterranean tomatoes and its chemical control raises concerns also regarding bumble bees. In the laboratory, we evaluated the acute toxicity and sublethal effects in B. terrestris workers exposed to the diet contaminated with four insecticides (acetamiprid, pyriproxyfen, sulfoxaflor, and thiamethoxam), potentially used to control P. solenopsis. Sulfoxaflor and thiamethoxam significantly reduced the survival of B. terrestris , while acetamiprid and pyriproxyfen altered its feeding behaviour, and the bumble bees were unable to detect the contaminated solution. Moreover, neurotoxic symptoms were observed in bees exposed to acetamiprid and alterations of the midgut were detected in bees exposed to both acetamiprid and pyriproxyfen. These results show that insecticides with low levels of toxicity to bumble bees (e.g. acetamiprid and pyriproxyfen), can cause sublethal effects on them, increasing concern about the use of these substances. Our findings provide valuable insights as regards optimizing bumble bee pollination services with chemical pest control within the context of Integrated Pest and Pollinator Management. [Display omitted] • Sulfoxaflor and thiamethoxam reduced bumble bee survival after their ingestion. • Acetamiprid and pyriproxyfen altered the feeding behaviour and midgut of bumble bees. • The bumble bees did not detect the insecticide-contaminated diet. • Ingestion of acetamiprid caused neurotoxic symptoms in bumble bees. [ABSTRACT FROM AUTHOR]

Neonicotinoid pesticides are widely used within agroecosystems. Due to their systemic nature and high solubility, neonicotinoids are frequently recorded in soil, water, untreated plant matter and non-target organisms. Studies have demonstrated their capacity to induce invertebrate mortality, however, very little research has been conducted beyond pollinator exposure, particularly under field conditions. Typically, many neonicotinoids are applied via seed-dressings, reducing their direct contact with pollinators, but offering an unintended soil-exposure pathway. Soil biology underpins many vital functions, from regulating water and gas flow, to maintaining physical soil structure. In this study we investigated the effect of a commercial neonicotinoid pesticide (Insyst®) on the abundance, richness, and composition of both the mesofaunal and microbial communities and associated metabolome during oilseed rape (Brassica napus L.) production. Our results showed that over a single growing season, foliar application of Insyst® (250 g ha−1, 50 g ha−1 of the active ingredient, acetamiprid) had no significant effect (P > 0.05) on the measured soil biological indexes. Seasonal variation was a significantly greater driver in regulating biological communities within the soil than Insyst® application. In addition, we showed that the active ingredient (acetamiprid) was rapidly degraded by the soil microbial community (theoretical half-life = 119 days) during the summer cropping season. These results help highlight the need for realistic field studies, as agricultural pesticides are never pure, often containing surfactants, adjuvants, or emulsifiers which alter their behaviour and ecotoxicity. Understanding the biological interactions of vital soil fauna with necessary pesticide usage will enable proper risk alleviation measures to maintain soil biological and ecological health. • Field study of the impact of neonicotinoid insecticide on soil meso- and microbiology. • Application of Insyst® (20% acetamiprid) had no significant impacts on soil biology. • Soil metabolomic function was little affected by insecticide exposure. • Active ingredient (acetamiprid) was rapidly degraded by the soil microbiome. • Seasonal variation is a greater driver of soil ecology than insecticidal compound. [ABSTRACT FROM AUTHOR]

Abstract: Contamination of organophosphate and carbamate (OP/C) insecticides in vegetables is a serious problem in China. An increasing number of acute poisoning accidents caused by OP/C residues in vegetables have brought great concerns on food safety. Four OP/C commercial enzymatic assay kits were compared on their sensitivity (half maximum inhibition concentration, IC50), matrix interference (i.e., background noise), accuracy (i.e., recovery) and precision (i.e., standard deviations), assay stability, simplicity of analysis, and cost. This work is not to advocate one company''s products over others. Research intention is only to provide some useful information to potential users such as various characteristics on their performance and their particular applications of the four kits. The results showed that the four kit tests have various advantages. In general, kit 1 exhibited better precision, while kit 4 had better sensitivity. Kit 1 exhibited better recovery data for the organophosphates and kit 4 had better recoveries for the carbamates than the other kits. Kit 1, kit 3 and kit 4 were more stable than kit 2 under the same temperature condition. In addition, the operation of kit 4 was the easiest. According to the performance comparison results and the cost-effective factor, kit 1 and kit 4 were more suitable for the local market. [Copyright &y& Elsevier]

Abstract: Ordinary differential equation models for insecticide induced sublethal damage and delayed death in insect populations are considered. It is shown that such models with time-varying mortality rates provide excellent fits to experimental data for populations subjected to numerous levels of insecticide exposure. The effects on fecundity rates are also examined. [Copyright &y& Elsevier]