No abstract

Abamectin (Avermectin B1a), is a natural fermentation product derived from the soil bacterium Streptomyces avermitilis. Abamectin (Avermectin B1a) is widely used as an insecticide, acaricide, and anthelmintic. The present study assessed the effects of repeated subacute and subchronic exposure to the commercial formulation of abamectin (Vertemic, 1.8% EC) in albino male rats. The toxic effects of abamectin were studied. The various biochemical parameters and histopathological changes were noted. A stomach tube was used to orally administer sublethal doses of abamectin suspended in corn oil to the rats. The animals were divided into four groups. Rats of the group T1 were orally administered a sublethal dose of 30 mg/kg body weight (b.wt.) (1/10 LD50) three times a week for 30 days and the animals in group T2 were exposed to 10 mg/kg b.wt. (1/30 LD50) for 210 days, once a week. Two control groups (C1 and C2) were used in parallel studies, where animals were administered a corn oil vehicle. At the end of the study period, blood samples were collected from all groups to measure plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST) activities, and the levels of creatinine and urea. Also, total protein and RNA contents were determined in the liver and kidney tissues. Changes in biochemical parameters were more intense in male rats from group T2 than those reported in group T1. The levels of ALT, AST, urea and creatinine were significantly elevated in rats from group T2 when compared to the control. In group T2, a significant decrease in the levels of total protein and RNA in both the liver and kidneys was observed. Fertility was also significantly reduced in male rats ingesting abamectin in group T2. The number of offspring was significantly reduced. Histopathological changes were more intense in male rats from group T2 than those from group T1. In conclusion, the results of this study demonstrate that subchronic oral administration of abamectin altered some biochemical parameters which correlated with histopathological changes

No abstract

The varroa mite, Varroa destructor (Anderson and Trueman) (Acari: Varroidae), is known as the most serious ectoparasitic mite on honeybee, Apis mellifera (Hymenoptera: Apidae) in the world. Based on the spores of entomopathogenic fungi, two commercial preparations; Bioranza (Metarhizium anisopliae) and Biovar (Beauveria bassiana) were evaluated through application into the hives against varroa mite. Data showed significant differences between treatments with Bioranza and Biovar, the results were significant after 7 and 14 days post-treatment. Mean a daily fallen mite individual was significantly different between the hives before and after the applications of the two biopesticides and wheat flour. Also, mites' mortality was, significantly, different between the hives before and after treatments. There were significant differences between treatments with the two biopesticides in worker's body weight. Bioranza and Biovar did not infect the honeybee in larval, prepupal, pupal and adult stages. Scanning and transmission electron microscopy images showed spores and hyphae penetration through stigma and wounds on varroa. The results suggest that Bioranza and Biovar are potentially are effective biopesticides against V. destructor in honeybee colonies.

No abstract