The present study is a trial to investigate the toxic effects of the bio-pesticide Bacillus thuringiensis (Bt) on male reproductive system of rats. Rats received dietary doses each approximately equivalent to 1/10 or 1/100 of the LD50 value of the Bt bio-pesticide (Agerin) for 90 consecutive days. Sex organs weight, semen picture, concentrations of the hormones [i.e., testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH)], and histopathological changes in testes were the criteria used to evaluate the reproductive toxicity on the treated rats. Btat the higher dose caused a significant decrease in the weight of testes and seminal vesicles as compared with control. Both Bt doses decreased sperm count associated with an increase in the morphologically abnormal spermatozoa; however sperm motility was significantly decreased in treated rats with the higher dose only. The concentration of serum testosterone was significantly reduced in both treated groups; however LH and FSH levels were significantly reduced in treated rats with the higher dose. Histopathological examination of Agerin-treated male rat's testes revealed that both Bt doses caused testicular degeneration in a dose-dependent manner. In conclusion, Agerin may decreases fertility in adult male rats by affecting the concentrations of pituitary gonadotrophins, testosterone and thus subsequent spermatogenic impairment

A field strain of pink bollworm Pectinophora gossypiella (Saund.) collected from Sharquia Governorate, Egypt was exposed to the selection pressure of the for-mulation of Bacillus thuringiensis subsp. Kurstaki, Dipel 2x under laboratory condi-tions. Resistance ratio attained 16-fold based on the susceptible strain after 14 gen-erations of selection. Study the response of Dipel 2x resistant strain to some insecti-cides indicated that there is no cross resistance to the conventional insecticides, es-fenvalerate, chlorpyriphos and thiodicarb or the bioinsecticides Ecotech and Agerin. These data may be emphasizing the possibility of rotation the Dipel 2x with these insecticides in pest control program of pink bollworm to manage resistance to Bt products.

The corn stem borers larvae (species Sesamia cretica Led., Sesamia nonagrioides Lef. and Os-trinia nubilalis (Hübner)) are considered the major pests attacking Zea mays L. The larvae bore into stems and ears which cause a significant decrease of both quantity and quality of yield. This research was completed at Eastern region of Syria during 2004 and 2005 corn growing season, aiming to control these corn borer species with some insec-ticides; Avaunt 150SC (Indoxacarb 150 g / L),Sumialpha 5EC (Esfenvalerate 50 g / L), Proclaim 05SG (Emamectin benzoate 50 g / Kg), Comply 25WP (Fenoxycarb 205 g / Kg) and Agerin 6.5WP (Bacillus thuringiensis kurstaki 32000 IU / Mg). The results showed that in corn attacked by Sesa-mia cretica, Sesamia nonagrioides and Ostrinia nubilalis the infested rate reached up to 38 % on stems and 18.5 % on ears at control plots. Results also showed high efficacy of insecticides Avaunt 150SC, Sumialpha 5EC, Proclaim 05SG, Comply 25WP and Agerin 6.5WP in reducing the infested rate in stems to about 6, 8.1, 11.5, 13.5 and 21.2 %, respectively. And to about 4.5, 6.1, 7.2, 7.9 and 11.1 % in ears by Avaunt 150SC, Sumialpha 5EC, Proclaim 05SG, Comply 25WP and Agerin 6.5WP, respectively. These results gave rise to a positive increase in the yield of corn seeds.

Preparationof either Bacillus thuringiensis or Trichoderma harzianum  were used as seed coating or soil application for management of root-knot and root rot disease complex caused by the root-knot nematode, Meloidogyne javanica and the fungus Rhizoctonia solani on soybean plants. Number of galls, root galling, egg masses and disease severity were reduced sharply on plants treated with both biocontrol agents, either as seed or soil application compared with non-treated plants. Soil application with both biocontrol agents was the best method in reducing nematode and fungus disease severity. Plant growth parameters i.e. fresh shoot and root weight, dry weight and number of pods and bacterial nodules were markedly increased with all treatments of biocontrol agent either with seed or soil treatment compared to plants grown in infested soil with either pathogens alone or combined. Results show that plant survival was more affected when R. solani was alone or combined with M. javanica. Seed coating was considered the effective method in increasing survival plants. The biochemical analysis of treated plants with both biocontrol agents were affected compared to non-treated plants grown in pathogen infested soil. The biochemical parameters i.e. chlorophyll A and B, carotein, phenols and amino acids were enhanced in bioagent treated plants compared to non-treated plants