The biological aspects and life table parameters of the spider mite, Tetranychus urticae Koch were studied under laboratory conditions on two kinds of host plants, tomato leaves and cucumber leaves. The study showed that the incubation period, the total immature stages, life cycle and generation of T. urticae on tomato leaves were higher than them on cucumber leaves. The life cycle was 13.58 and 9.52 days on tomato leaves and cucumber leaves, respectively. The generation period was 15.91 and 11.19 days on tomato leaves and cucumber leaves, respectively. On the other hand, longevity and life span of T. urticae were higher on cucumber than on tomato. Longevity was 15.33 and 19.97 days on tomato leaves and cucumber leaves, respectively. The life span was 28.91 and 29.49 days on tomato leaves and cucumber leaves, respectively. Also, the daily main number of laid eggs was higher on cucumber, 5.36, than on tomato, 4.71. Also, the results demonstrated that the population of T. urticae had the ability to multiply about 1.91 and 2.53 on tomato and cucumber leaves, respectively.

The two-spotted spider mite, Tetranychus urticae Koch is one of the most important pests responsible for yielding losses for many crops. For several years, chemical control of mites has been extensively practiced; a major problem in the control of T. urticae is the response to develop resistance to many acaricides, and so, scientists make efforts to replace the chemical acaricides with natural acaricides, as a mean to reduce negative impacts to human health and the environment. In the search for control alternatives, this study aimed to evaluate the effect of neem essential oil and the aqueous neem extract against adult females of Tetranychus urticae under laboratory conditions. Also, LC 50 of each treatment was established and the obtained results revealed that the active essential oil of neem was more effective than the aqueous neem extract. LC 50 : 33.99 ppm and 260.30 ppm for neem oil and aqueous extract respectively. However, LC 90 value was 238.83 ppm and 1813.70 ppm for neem oil and aqueous extract, respectively.

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The journal of Toxicology and pest control is one of the series issued twice by the Egyptian Academic Journal of Biological Sciences, and is devoted to publication of original papers related to the interaction between insects and their environment. The goal of the journal is to advance the scientific understanding of mechanisms of toxicity. Emphasis will be placed on toxic effects observed at relevant exposures, which have direct impact on safety evaluation and risk assessment. The journal therefore welcomes papers on biology ranging from molecular and cell biology, biochemistry and physiology to ecology and environment, also systematics, microbiology, toxicology, hydrobiology, radiobiology and biotechnology. www.eajbs.eg.net

arpoglyphus lactis (Linne.) was extracted from stored grains; wheat, maize and rice; samples were collected from granary stores of Dakhlyia Governorate. In this study experiments were conducted under laboratory conditions at 25±1ºC and 65±5 R.H. to study the effect of dry yeast granules, crushed wheat, crushed rice as a kind of food on biological aspects, fecundity and life table parameters, of the grain mite, C. lactis. The obtained data showed that the ability of mite C. lactis to feed and develop on the above mentioned diets as a sole food sources. The average of total immature stages lasted (13.4 &11.6), (16.5 &15.1) and (20.0 &18.6) days for female and male reared on the same diets, respectively. Female longevity durated 15.1, 18.5 and 19.5 days, while male adulthood averaged 19.3, 24.8 and 25.8 days, when mite fed on the above mentioned diets. Female oviposition period stayed 11.3, 12.9 and 13.6 days and the average number of deposited eggs/female was136.8, 113.9 and 70.5 eggs with a daily mean 12.1, 8.8 and 5.2 eggs on the same tested diets. The life table parameters of C. lactis were affected by different types of food whereas, the mean generation (T) was 20.7, 22.8 and 28.8, while the intrinsic rate of natural increase (rm) values were 0.39, 0.32 and 0.24 when mite fed on the same tested diets at the same pattern.