Temperature had various effects on the predacious efficacy of immature and mature stages of the coccinellid predator, Stethorus punctillum on the two-spotted spider mite, Tetranychus urticae. In the case of immature stages, food consumption at the lowest tested temperature (158C) was significantly higher than that at higher temperatures (25 and 358C). On the contrary, positive correlation between food consumption and temperature was evaluated in the case of adult predator. Regarding predator responses to different prey density, a high positive correlation between food consumption and prey density was evaluated among 4 th instar larvae of the predator, followed by adult predator, while younger instars did not show reasonable increases with increasing prey densities. These results confirm that larval and adult stages of S. punctillum exhibit ''Type II'' functional response. In conclusion, the 4 th instar larvae and adult predator are the most preferable stages in winter and summer crops to control T. urticae, respectively.

The present study was conducted to determine the effect of baits containing nano particles of silica against the fourth instar larvae of Agrotis ipsilon (Hufn.) along sequential daily intervals post treatment under laboratory conditions. The determined percentages of larval mortality due to the admixed baits with SiNPs increased up to 100% after 15 days of application. The admixing of nanoparticles of silica in the bait during the sensitive period of larval development caused morphological abnormalities that are generally irreversible and often lead to death, beside certain biochemical changes of some inorganic elements in the haemolymph of the treated insects. It could be concluded that the tested nanoparticles of silica were most effective and indicated the highest concentration reductions of inorganic constituents in larval haemolymph, especially calcium, sodium and potassium. Therefore, more attention must be directed towards the inorganic constituents in the larval haemolymph as biomarkers for SiNPs efficacy.

Three different concentrations (20, 10 and 5%) of ethanol, ethyl acetate, diethyl ether and chloroform extracts of Capparis aegyptia plant leaves were tested against 2 nd instar larvae of Agrotis ipsilon to study the toxicity and their effects on some biological parameters under laboratory conditions. Maximum mortality percentage was 40% at 5% of ethyl acetate extract, while treatment with ethanol extract recorded the lowest mortality percentages especially at 5%. Calculated LC 50 was ranged between 5.752 and 8.027 at treatments with ethanol extract and chloroform extract, respectively. Low concentrations were almost more toxic than high. Malformation percentages of emerged adults were observed with ethanol and diethyl ether extracts. Fecundity reduction percentages at treatments in comparison with control reached the maximum (100%) at treatment with ethyl acetate extract while the minimum was about 50% at chloroform extract treatment.

The latent delayed toxicity for two botanical Camphore and Jamson weed grass fine dusts on Agrotis ipsilon were studied. Whereas, all the evaluated rates of Camphor grass were highly efficient and the number of alive larvae ranged between 6 and 13 larvae out of 30 larvae compared to the untreated check (28 larvae). Furthermore, the delayed results clearly indicated the significant difference between the tested rates and their effect on the raised larvae and revealed its adverse biophysiological effects on the development of both (F1) and (F2) generation that followed by a complete failure of (F3) generation, compared to the untreated check. The tested rates of Jimson weed grass fine dust caused significant reduction of the mean numbers in the surviving alive larvae of A. ipsilon and shows rapid complete failure to the development of the parent generation after larval treatment. Finally , the obtained data showed the effectiveness of the mixture of each Jimson weed with Camphor at a rate of (3:1) and (3:3) gm. fine dusts on the developmental sequence of the larvae of the parent generation that were exposed to the prepared baits. Therefore, the aim of this study is to find alternative methods to reduce the effect of chemical pesticides on the environment.

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