الفهرس 
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Abstract
The house fly, Musca domestica and common house mosquito, Culex pipiens are widely distributed in Egypt and they are very important pests form the standpoint of medical and \ eterinary importance.
Musca domestica were collected as adults from Moshtohor, Qalyubia Governorate; whereas Cx. pipiens were collected as egg rafts and larvae from Meit El- Attar, Qalyubia Governorate. Both insects were reared in the insectary. In case of the common house mosquito, two strains were used, field strain (FS) and laboratory strain (LS).
In seeking replacement for chemicals, the present work aimed to meet this need by using natural and environmentally benign materials for controlling both insects. Such materials were three plant oils (nigella, Nigella sativa, Onion, Allium cepa and sesame, Sesamum indicum), two insect growth regulators (IGRs) (diflubezuron, Dimilin and pyriproxyfen, Sumilarv). In addition, four microbial agents, a bacterium (Bacillus thuringiensis israelensis, Vectobac) and three fungi; one commercial (Beauveria bassiana, Biosect) and 2 isolated fungi, Entomophthora spp. for house flies and Lagenidium spp. for common house mosquito.
Two fungi were isolated for the first time in Egypt, Entomophthora spp. from adult stage of M domestica and Lagenidium spp. from larval stages of Cx. pipiens. Such fungi were isolated, identified, propagated and used as entomopathogenic fungi. Furthermore, the number of the viable spores/ ml was counted for the isolated fungi as well as for the commercial product, Biosect. The sex ratios were also affected by treatment of the larvae with the applied materials; generally, there was a domination of males over females, especially, after treatment with lower concentrations of both IGRs.
Most of the morphological aberrations were recorded due to treatment with lower concentrations. Most of the larval abnormalities were larval pigmentations, weak cuticle with ulceration and maceration, and larval-pupal intermediates. The main pup:11 malformations were small sized pupae, Larviform, and thin shelled pupae. Moreover. the adult aberrations were failure of eclosion, small sized adults, deformed wings and legs.
The effect of the used materials on some biological activities of Culex pipiens
Treatment of the late 3rd and early 4th larval instars of Culex pipiens, (L3 / L4) field strain (FS), induced moralities of the developmental stages which were directly proportional to concentrations. At the highest concentration, plant oils, nigella, onion, and sesame, induced 100 %, 83.3 %, and 85.7 % larval moralities at 1600, 160, and 1600 ppm, respectively, 72 h post treatment, in addition; they induced 100 %, 47.2 %, and 100 % pupal mortalities, respectively. Such materials were more effective against the laboratory strain of Cx. pipiens and induced 100 % mortalities at 200, 160, and 1600 ppm, 3 days post application.
IGRs (Dimilin and Sumilarv), at 40 ppm, induced 90% and 92.6 % larval mortalities after three days of application. IGRs significantly affected the pupal formation there was no emerged adults by both materials. The sex ratios following treatment of oils at the lowest indicated a domination of males over females especially nigella and sesame oils. IGRS, especially Dimilin caused also dominations of males. Microbial agents, mainly Biosect which caused deviation of the sex ratios at low conc.
Most of the morphological abnormalities were detect at the lower concentrations. Most of the larval abnormalities were larval pigmentation thoracic swellings, and pharate pupae. The pupal abnormalities were Albino, elephantoid, and distended pupae, blackish cephalothoraxes. Adult abnormalities included various forms of failure eclosion, deformed wings, abdomen, and legs.
Lastly, plant oils (nigella, onion, and sesame) had good lethal effects against M. domestica and Cx. pipiens instars, especially against LS of Cx. pipiens. Sesame and onion oils were the best plant oils against M domestica and Cx. pipiens, respectively. On the other hand, Insect growth regulators (Dimilin and Sumilarv) had better effect against the chosen insects with more potent effect on Cx. pipiens. Sumilary had superior lethal effect against both insects when compared with Dimilin. Furthermore, the microbial agents were effective against both insects. We concluded that the use of the previous materials at low conc. could lead to significant mortality, deformity among the developing stages of both insects besides deviation of the sex ratios, leading to decreasing the number of the adult females which were considered the most dangerous
stage.