No abstract

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is one of the most important pests affecting agricultural and ornamental crops worldwide. In fact many of natural plant (bioactive compounds) have fewer side effects compared with chemical pesticides. So, this study aimed to evaluate the effect of rue leaves essential oil, Ruta graveolens L. as fumigant toxicity (Sapindales: Rutaceae) against eggs and adult females of T. urticae. Gas chromatography–mass spectrometry (GC-MS) data cleared that the basic constituents were 2-undecanone (60.54%) and 2-nonaone (17.71%) which belonged to methyl ketones that represented by 81.65% of the total oil. The ovicidal activity of rue essential oil mentioned that according to LC50 values, the one-day-old eggs were more susceptible than three -days-old eggs recording 0.008 and 0.011 µl/ml air after 7 days post fumigant for 24 h, respectively. Furthermore, the adult female mortality recorded 0.018 and 0.0724 µl/ml air for LC50 and LC90, respectively. Additionally, results demonstrated that significant reduction in the mean number of deposited eggs/female/day recorded 3.182 eggs compared to 6.561 eggs for control. Finally, a significant reduction in acid phosphatase for eggs and Aacetylcholine esterase (AChE) for adults of T. urticae were recorded.

Spiders associated with cotton and maize plants were recorded in Sharkia Governorate, Egypt, during 2009 season, Results revealed th e occ unen ce of eighteen sp ider species belonging to nine families. Ei ght and sixteen species were co ll ected from cotton an d mai ze plants, respectively. Thomisus spini(er Cambridge was th e most t!-equent spec ies, with 100.00 and 20.45 % for absolute frequency and relative freq uency of occUJTence, respectively, wh il e all Erigone sp., Gnathonarium den/alum (W ider), Ewyopis sp., and Cyrtuphora citricola (Forskal) recorded the lowest freque ncy occurrence 5.5 and l.l 3 %, respectively. Life cycle and female fec undity of Ko chiura aulica (Koch) (Theridiidae) were studied when fed on Spodoptera littorals (Boisd .) second instar larvae. Feeding capacity was also estimated. Obtained data cleared that K. aulica can be used as a biocontrol agent in integrated pest management program.

The three different life styles phytoseiid predatory mite species, Phytoseiulus macropilis (Banks), Amblyseius californicus (McGregor) and A. cucumeris (Oudemans) were observed to investigate their ability to survive without food, young females were caged individually in the absence of prey, either with or without water.In general, the female survival time with water was four to six and half times as long as the survival times without water regardless of the species. In the survival experiment without water, P. macropilis and A. cucumeris both lived shorter than A. californicus. In the survival experiment with water, A. californicus lived nearly 2 times longer than P. macropilis or A. cucumeris. Amblyseius californicus females showed a strong capacity to survive without food, which could be an important factor contributing to the persistence of A. californicus in comparison to other phytoseiids.

Scheloribates Jaevigatus (Koch) was able to develop and reproduce when fed on mixture of free-living nematod, Eudiplogaster phlagellicaudatus (Andrassy) and potato. Temperature had a significant effect on duration of the life cycle and all life span of this species. As temperature changed between 25 and 30°C, the incubation period decreased. Both male and female immature stages decreased when temperature increased between 25 and 30°C. Life cycle of male reached adulthood in a shorter period than that of female. This period decreased from 24.67 ± 0.26 to 21.25 ± 0.53 days for male and from 28.01 ± 0.66 to 23.16 ± 0.98 days for female at 25 and 30°C, respectively. Temperature also negatively affected the adult female longevity and fecundity. It was found that the greatest average number of eggs deposited by female was 36.88 ± 2.13 at 25°C; this decreased to 29.63 ± 2.55 at 30°C.