emamectin-benzoate and bifenthrin

Harmonia axyridis (Coleoptera: Coccinellidae) is a beneficial predatory arthropod in the agricultural ecosystem. For the success and development of integrated pest management strategies, it is essential to assess the toxicity risks of commonly used pesticides to nontarget arthropods.. The glass tube residue method was used to determine the risk of nine pesticides to H. axyridis after second-instar exposure. To assess the potential risk of the selected pesticides, the pre-adult LR. The four neonicotinoid insecticides (imidacloprid, dinotefuran, thiamethoxam, and acetamiprid), pyrethroid bifenthrin, and organophosphorus dimethoate showed a high risk to H. axyridis. Emamectin benzoate, tebuconazole, and myclobutanil showed a low risk to H. axyridis under both exposure scenarios. The results provide critical scientific evidence to guide future regulation of pesticide management practices and protection of nontarget arthropods like H. axyridis. © 2022 Society of Chemical Industry.

Topics: Animals; Coleoptera; Dimethoate; Ecosystem; Pesticides; Risk Assessment; Thiamethoxam

Helicoverpa armigera is a major devastating insect pest on a wide range of vegetables and cash crops. Insecticides are presently indispensable for its control in nearly all crops. H. armigera has acquired resistance against almost all insecticides because of the activity of detoxification enzymes used for the defensive mechanism. The current research was carried out to evaluate the activity of detoxification enzymes, i.e., acetylcholinesterase and alkaline and acid phosphatases in chlorpyrifos-, bifenthrin-, lufenuron-, lambda cyhalothrin-, and emamectin benzoate-treated larvae of H. armigera. The maximum AChE activity was recorded in emamectin benzoate-treated larval samples followed by chlorpyrifos, lufenuron, lambda cyhalothrin and bifenthrin, respectively, while the highest alkaline phosphatases' activity was recorded in emamectin and the lowest in bifenthrin-treated H. armigera. As far as acid phosphatases' activity is concerned, the highest activity was noted in lufenuron samples while the lowest in lambda cyhalothrin samples, respectively. Comparatively, activities of alkaline and acid phosphatases were higher than AChE. The elevated activities of detoxification enzymes can possibly lead to increase in resistance development against synthetic chemical insecticides.

Topics: Acetylcholinesterase; Acid Phosphatase; Alkaline Phosphatase; Animals; Chlorpyrifos; Disaccharides; Inactivation, Metabolic; Insect Proteins; Insecticide Resistance; Insecticides; Ivermectin; Larva; Moths; Nitriles; Pyrethrins

Fusarium dieback (FD) is a new vascular disease of hardwood trees caused by Fusarium spp. and other associated fungal species which are vectored by two recently introduced and highly invasive species of ambrosia beetle (Euwallacea spp. nr. fornicatus). One of these ambrosia beetles is known as the polyphagous shot hole borer (PSHB) and the other as the Kuroshio shot hole borer (KSHB). Together with the fungi that they vector, this pest-disease complex is known as the shot hole borer-Fusarium dieback (SHB-FD) complex. Mitigation of this pest-disease complex currently relies on tree removal; however, this practice is expensive and impractical given the wide host range and rapid advancement of the beetles throughout hardwoods in southern California. This study reports on the assessment of various pesticides for use in the management of SHB-FD. In vitro screening of 13 fungicides revealed that pyraclostrobin, trifloxystrobin, and azoxystrobin generally have lower effective concentration that reduces 50% of mycelial growth (EC

Topics: Animals; California; Coleoptera; Fungicides, Industrial; Fusarium; Host-Pathogen Interactions; Insect Vectors; Insecticides; Introduced Species; Ivermectin; Plant Diseases; Pyrethrins; Species Specificity; Trees; Triazoles

House flies, Musca domestica L., are important pests of dairy operations worldwide, with the ability to adapt wide range of environmental conditions. There are a number of insecticides used for their management, but development of resistance is a serious problem. Insecticide mixtures could enhance the toxicity of insecticides in resistant insect pests, thus resulting as a potential resistance management tool. The toxicity of bifenthrin, cypermethrin, deltamethrin, chlorpyrifos, profenofos, emamectin benzoate and fipronil were assessed separately, and in mixtures against house flies. A field-collected population was significantly resistant to all the insecticides under investigation when compared with a laboratory susceptible strain. Most of the insecticide mixtures like one pyrethroid with other compounds evaluated under two conditions (1∶1-"A" and LC50: LC50-"B") significantly increased the toxicity of pyrethroids in the field population. Under both conditions, the combination indices of pyrethroids with other compounds, in most of the cases, were significantly below 1, suggesting synergism. The enzyme inhibitors, PBO and DEF, when used in combination with insecticides against the resistant population, toxicities of bifenthrin, cypermethrin, deltamethrin and emamectin were significantly increased, suggesting esterase and monooxygenase based resistance mechanism. The toxicities of bifenthrin, cypermethrin and deltamethrin in the resistant population of house flies could be enhanced by the combination with chlorpyrifos, profenofos, emamectin and fipronil. The findings of the present study might have practical significance for resistance management in house flies.

Topics: Animals; Chlorpyrifos; Disaccharides; Drug Combinations; Houseflies; Insecticide Resistance; Insecticides; Ivermectin; Nitriles; Pyrazoles; Pyrethrins