Survey on the soil predaceous prostigmatid mites indicated the occurrence of 12 species. These were six from Cunaxidae and three from each Cheyletidae and Bdellidae. Population dynamics for a whole year showed that Gunaxids and Cheyletids increased in numbers during spring and summer while decreased in cold months of winter. On the contrary Bdellid population flourished in autumn and winter and decreased in summer. Zusammenfassung Zur Populationsdynamik einiger räuberischer Bodenmilben der Gruppe Prostigmata in Ägypten Bei Bodenuntersuchungen auf dem Gelände der Farmen der Landw. Fakultät in Giza wurden in der Streu unter Sträuchern und Bäumen 12 prostigmate Milbenarten: 6 aus der Familie Cunaxidae und je 3 aus den Familien Cheyletidae und Bdellidae gefunden. Ein Jahr lang durchgeführte Populationsstudien zeigten, daß die Individuenzahl der Cunaxidae und Cheyletidae während des Frühjahrs und Sommers anstieg und in der kälteren Jahreszeit absank. Im Gegenteil hierzu zeigten die Bdellidae im Herbst und Winter die größte Populationsdichte und im Sommer die geringste.

Cunaxa capreolus BERLESE failed to develop on diets of plant material but developed equally well on diets of booklice (Psocoptera) or of the citrus brown mite, Eutetranychus orientalis (KLEIN), which were eaten in their active stages and not as eggs. Cannibalism occurred during shortage of food. Although the growth of the immature stages of C. capreolus was accompanied by an increasing consumption of prey, yet their total consumption was less than 30 ~ of that of the female adult. The number of prey individuals consumed by C. capreolus was inversely related to temperature but consumption rate increased slightly with increasing temperature.The feeding habits of the cunaxid mites and their role in biological control have not been fully investigated. The mites are cosmopolitan and free livings; some inhabit trees but most are associated with fallen leaves and top soil layers (LORD, 1949; MEYER & RYKE, 1959;MUMA, 1960 MUMA, , 1965 ZAHER et al. 1970, RASMY et al., 1972.During work on predaceous prostigmatid mites in litter under shrubs and trees in Giza ;Cunaxa capreolus BERLESE was the dominant species, but in Florida MUMA (1965) found this mite inhabiting citrus trees. The food preference of C. capreolus has therefore been investigated and special attention has been paid to the effect of temperature on the amount of food consumed. MATERIALS AND METHODSThe food preference and capacity of C. capreolus and the effect of food type on its development were studied using two animal diets : booklice (Psocoptera) and the citrus brown mite Eutetranychus orientalis (KLEIN) and three plant diets: date palm pollen, and slices of potato, alone or in diluted yeast solution. For each treatment about 35 newly hatched larvae of C. capreolus were confined singly in glass rings of 1 cm diameter and 7 mm deep. The rings were fixed to glass slides and each was covered with another glass slide held in position with rubber bands. When the young reached maturity the sexes were allowed to mate and the females were retained to complete their oviposition. The food preference experiments were carried out at 30~ 4-1 ~ and those on feeding capacity at 15, 20, 25 and 30~ 4-1 ~ respectively. RESULTS FEEDING HABITS AND BEHAVIOLIRWhen supplied with any of the plant diets C. capreolus failed to develop and reproduce and died within few days. It developed and reproduced on either of the animal

Relative humidity of 70 to 85% proved to be the most suitable for Typhlodrompis swirskii (Athias-Henriot) at 25 o C as it accelerated development (10.0 & 10.8 days) and increased female fecundity (13.0 & 12.0 eggs/♀/10 days) on Eutetranychus. orientalis immatures. Low temperature (5 & 9 o C) prolonged egg incubation and decreased hatchability as well as female survival. After one to four weeks, egg hatchability ranged from 90 to 50% and from 100 to 64% and female survival from 50 to 0% and from 80 to 10% at 5 and 9 o C, respectively. Multiple mating due to male company through the whole female longevity or sporadically for 12 hours every 5 days increased female fecundity and longevity as it averaged 47.0 & 35.0 eggs and 37.6 & 35.0 days compared with 25.0 eggs and 29.2 days for once mated female. For food attraction and /or kairomone emitted that affects predator, T. swirskii females showed greater percentage of attractance in a shorter period to more advanced prey stage and to mites than insects tested. Also fed females showed more attraction than 24 starved females and the latters better than 48 hours starved ones. E. orientalis adults gave the greatest percentage attraction (60%) in the shortest time (3.20 minutes) for fed female, while castor been pollens gave the smallest (1%) and the longest time (121.6 minutes). Host plants of different leaf texture, affected female fecundity, averaging the greatest (15.8 eggs/♀/10 days) on smooth leathery leaf of grape fruit, while coarse reticulated leaf of guava resulted in the least number of deposited eggs (10.8 eggs/♀/10 days).

No abstract

Field and laboratory studies revealed that the eggplant Black baity cultivar rccordcd the highly significant susceptible to infestation with Tetrarychtrs urticae Koch compared with Baity cuitivar.Susccptibility of eggplant cultivars to int'estation rnay be affected by plant leaf morphological structurc; length, thickness and density of leaf trichomes.Ar.erage number of trichomes /mm2 leaf was 2l .l and 21.6 fbr Baity and Black traity cultivars. respectively" The hrgirest mean number oi T. wlicae movable stages on lcaves of Black baity cultivar was associated with higher 1eve1s of torai arnino acids and total carbohydrates and with the lowest leve1s of total phenolic compounds and tannins. Durations of cgg. different immature stages, life cycle and hfe span of T. urticae female were thLe shortest when reared on leaves of Black baity cultivar and the iongest on leaves of Baity cultivar. The two cggplant cuitivars affected the iife table paremelers of T. urticae.The shortest mean generation time (T) was 12.08 days on Black baity cultivar, and the longest u,as 13.21days on Baity cultivar.The highest net reproductive rate (R") was 32.01 femaies/female cm Black baity cultivar, and the lowest was 21.13 females/female on Baity cultivar.