No abstract

The volatile oils of golden pillar, Cupressus macrocarpa and galangal, Alpinia officinarum were extracted and their constituents were identified. Alpha pinene and trans-caryophyllene were the major isolated constituents of C. macrocarpa oil, and 1,8 cineole and 4-terpeniol were the major compounds of A. officinarum oil.The present study revealed that the botanical volatile oils used, had morphogenic effects against S. nudiseta stages. These include larval-pupal intermediates, pupal-adult intermediates, deformed adults with crumpled wings and/ or deformed thorax and abdomen. Also some adults couldn't emerge and remained in their puparia.The histological effects induced by oils treatment in the body wall were represented by degeneration and detachment of hypodermis and dissolving of the exocuticle in some regions. The histopathological effects that appeared in the midgut were shrinkage in some epithelial cells and swelling of other cells.

Current research has focused on the inhibitory effects on the reproductive organs of cotton leafworm, Spodoptera littoralis resulting from 4 th instar larvae treated with sublethal concentration (LC 25) of methoxyfenozide. Results showed elongation in the immature stages and longevity of adults than control, as well as reduce pupal weight, oviposition period, fecundity and hatchability percentages. Anatomical structures of virgin moths surviving from larvae treated with LC 25 of methoxyfenozide showed general atrophy and abnormal features for ovaries and testes than that of untreated ones. Histological disruptions were recorded in ovaries in vitellogenesis and post vitellogensis stages as deformation in follicular shape, clumping of the chromatin material in nurse cells and disorganization of yolk and appearance of vacuoles between yolk and chorion. While in treated testes the testicular wall disappeared and vacuoles between follicles take place. Methoxyfenozide caused alterations in the amounts of both total soluble protein and total lipids and also in the activities of acid and alkaline phosphatases and phenol oxidase in the ovaries and testes of the resulted adults as compared to control adults.

Essential oils composed of mixtures of bioactive compounds, are secondary metabolites abundant in aromatic plants. These oils contain a number of compounds such as monotrepens and sesquiterpens [15] , used as contact, fumigant insecticides [16] as well as anti-food agents [17] . Volatile oils possess aromatic properties that compel insects

Pyrethroid insecticides have widely been used to control the house fly, Musca domestica. Toxicological and biochemical studies were conducted for monitoring housefly tolerance to three pyrethroid insecticides λ -cyhalothrin, deltamethrin and α-cypermethrin. Based on the LC 50 values of third larval instar laboratory (LS) and field strains (FS) exposed for 72 h using a poisonous media technique, flies showed resistance ratios ranging from 4.06 to 7.59-fold. The highest house fly population homogeneity was observed with deltamethrin in LS (2.13) and α-cypermethrin in FS (1.66). The biochemical evaluation was conducted in the third larval instar after exposure to estimated LC 50 values of the tested insecticides on both strains. The protein content of FS was significantly higher in the control and λcyhalothrin and decreased following treatment with deltamethrin and α-cypermethrin. In contrast, mixed function oxidase enzymes (MFOs) were significantly higher in FS under all treatments, while β-esterase was significantly highest in λ-cyhalothrin FS. The α-esterase activity declined significantly with different pyrethroid treatments of FS. Glutathione-S-transferase enzyme (GST) activity was highest in all treatments of FS, except α-cypermethrin was lower in LS. The activity of Acetylcholinesterase enzyme (AChE) following pyrethroid treatments decreased significantly in FS compared with LS and control treatments. Carboxylesterase was significantly higher in all pyrethroid treatments of FS. Significant interactions were observed between strains and pyrethroid treatments. The development of pyrethroid resistance in FS, and the role of mixed-function oxidases and β-esterase in the degradation of different pyrethroids, in addition to, β-esterase and GST with λ-cyhalothrin detoxification, may explain the highest tolerance ratio (7.59).