Colony collapse disorder (CCD), a phenomenon of honeybees disappearance, has been reported since 2006. Chronic exposure to neonicotinoid insecticides, particularly imidacloprid, has been suggested to impair forager’s ability for foraging and be a main cause of CCD. Recently, it has been reported that imidacloprid induces insulin resistance in animal cell line by blocking glucose uptake. Similarly to human insulin, insulin-like peptide (ILP) of insects is involved in maintaining blood glucose contents in hemolymph by regulating the concentration of trehalose and glycogen. Therefore, we have hypothesized that sublethal concentration of neonicotinoid may affect the metabolic pathway of honey bees as well. We investigated the transcription levels of the genes involved in the insulin/insulin-like signaling (IIS) pathway, such as AmILP and AmInR, following an acute or a chronic dietary exposure of sublethal concentrations of imidacloprid to foragers. In both experiments, honeybees showed increased expression levels of ILP and InR in a dose-dependent manner. Our results suggest that sublethal dose of imidacloprid likely upregulates IIS pathway, thereby rendering honey bees to become resistant to insulin.

This study was performed to investigate the effect of flonicamid and thiamethoxam treated at sublethal concentration (LC10, LC30) on development period, adult longevity and fecundity and the feeding behaviour of Myzus persicae adult. Developmental period of M. Persicae nymph took 5.9 days in LC10, and 6.1 days in LC30 in both insecticides, comparing with control (5.7 days), it showed longer than those of the control, but there was no significance. Adult longevity treated at LC10 and LC30 of flonicamid was showed 13.2 and 13.7 days, respectively, and LC10 of thiamethoxam was examined as 14.7 days, it showed longer than control of 11.6 days. Mean daily fecundity exhibited higher in LC10 (3.1) and LC30 (3.1) of flonicamid than that of control (2.5), but thiamethoxam are not. Total fecundity exhibited higher in LC10 (41.8) and LC30 (43.0) of flonicamid, in LC10 (42.1) of thiamethoxam than that of control (29.5). Feeding behavior was examined using EPG (electrical penetration graph). EPG data indicated that flonicamid and thiamethoxam increased the duration of non-probing periods and decreased the duration of phloem ingestion.

몇가지 살충제에 대한 파굴파리 충태별 약제 방제효과를 조사한 결과, 알 상태에서 엽면 살포시 spinosad, dimethoate, emamectin benzoate, cartap 등의 방제가가 83% 이상으로 효과적이었다. 유충에 대해서는 dimethoate와 cartap이 87% 이상의 살충활성을 나타내었다. Dimethoate와 cartap을 엽면살포 후 잔효력을 조사한 결과 dimethoate는 약제처리 후 3일까지 93.3%의 높은 활성을 유지하였다. 번데기에 대해서는 terbufos GR, cartap GR이 88.2% 이상의 살충활성을 보였으며, 성충에 대해서는 dimethoate와 cartap이 95%이상 살충활성을 나타내었다. 이상의 결과에서 알, 유충, 성충방제에는 dimethoate EC와 cartap SP, 번데기 방제에는 terbufos GR, cartap GR가 효과적이었다.