Entomopathogenic nematodes (EPNs) of families Heterorhabditidae and Steinernematidae are known to be effective against a variety of pests. In the present work, different EPNs that are isolated from the Egyptian environment were tested against the onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), under field conditions. The Egyptian EPNs were tested at different concentrations and against different onion thrips stages (adult and nymph). When used as a foliage spray, the tested EPN isolates were efficient against both adult and nymph stages. Differences in pathogenicity were observed within the same EPN species as in Heterorhabditis indica (EGAZ3) that caused higher reduction in population of T. tabaci (adult and nymph) after 24 and 48 h at a concentration of 10,000 infective juveniles (IJs)/ml compared to H. indica (EGAZ2) after 24 h post treatment at a concentration of 15,000 IJs/ml. The same pattern was observed with Heterorhabditis bacteriophora (HP88), where a higher reduction percent was recorded after 24 h at a concentration of 20,000 IJs/ml. On the other hand, Steinernema carpocapsae (All), S. carpocapsae (EGAZ9), and S. carpocapsae (BA2) isolates were less effective in controlling onion thrips (adult and nymph) population. In general, controlling T. tabaci at the nymphal stage was more efficient than at the adult stage (12-73% reduction at the nymph stage compared to 6-65% at the adult stage). It was also found that increasing inoculation concentration above 15,000 IJs/ml had no significant difference in controlling onion thrips populations.

The journal of Toxicology and pest control is one of the series issued twice by the Egyptian Academic Journal of Biological Sciences, and is devoted to publication of original papers related to the interaction between insects and their environment. The goal of the journal is to advance the scientific understanding of mechanisms of toxicity. Emphasis will be placed on toxic effects observed at relevant exposures, which have direct impact on safety evaluation and risk assessment. The journal therefore welcomes papers on biology ranging from molecular and cell biology, biochemistry and physiology to ecology and environment, also systematics, microbiology, toxicology, hydrobiology, radiobiology and biotechnology. www.eajbs.eg.net

The present investigation was carried out to study the effect of Juvenile Hormone Mimic (JHM), Pyriproxyfen 10% EC on toxicological and biological aspects of the two spotted spider mite, Tetranychus urticae Koch under laboratory conditions. The effects of Pyriproxyfen on mortality, life cycle, duration period, adult longevity, ovipositional period and female fecundity were evaluated. Results indicated that the candidate compound exhibited direct contact toxicity against all the different developmental stages of T. urticae, but protonymphs were more susceptible than adult females. The LC50's were 4.21 and 4.36 ppm after 72 hr. post exposure for protonymphs and females, respectively. Also it had contact ovicidal activity influenced by egg age. 48-72 hr. eggs were significantly more sensitive than eggs of the other ages. According to LC50 values LC50's were 117.07, 7.95 and 2.91ppm for the three tested ages (0-24 hr, 24-48 hr and 48-72 hr old), respectively. Also, all the tested concentrations prolongated the incubation, larval, protonymphal and deutonymphal periods, but the maximum conc. level (10 ppm) produced the highest increase. Also, the longevity of males and females were increased, the highest increase was observed with 10 ppm, it produced 23.42 days/♀ and 18.5 days/♂ compared with 15.59 days/♀ and 15.92 days/♂ in the control. On the otherhand, oviposition periods were also influenced as concentration dependant response. The mean number of laid eggs/♀ were highly decreased as conc. increased, the highest decrease was observed with T. urticae females treated with conc. 10 ppm, it gave 14.17 eggs/♀ compared with 124 eggs/♀ in untreated females. Results suggest that JHM, pyriproxyfen could be a good alternative and interesting component in Integrated Pest Management (IPM) for controlling TSSM, T. urticae and minimizing the usage of conventional pesticides.