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Mites associated with abandoned fig trees in Egypt were observed during a 2-year study. This study included species diversity and seasonal fluctuations as well as some biological aspects of common eriophyoid species. Three phytophagous species consisted of the fig bud mite Aceria ficus (Cotte), the fig leaf mite Rhyncaphytoptus ficifoliae Keifer and the twospotted spider mite Tetranychus urticae Koch, representing a basic trophic level, were fed upon by three of predacious mites (Pronematus ubiquitus (McGregor), Amblyseius swirskii Athias-Henriot, Agistemus exsertus Gonzalez). Population abundance of the injurious mites were affected by the prevailing climatic conditions, action of predators and leaf age. A control measure of one summer pesticide (abamectin) application throughout the year seemed to be the most successful management of harmful mites. Life table parameters showed that the population of A. ficus multiplied 28.52 times in a generation time of 17.90 days, while R. ficifoliae population increasod 16.50 times in a generation time of 14.61 days. Field and laboratory studies indicated that the viviparity is a typical character in the reproduction of R. ficifoliae.

The biology of Typhlodromips swirskii (Athias-Henriot), Typhlodromus athiasae Porath and Swirski and Paraseiulus talbii (Athias-Henriot) was studied using Aculops lycopersici (Massee) active stages as food source. For T. swirskii, development was faster and reproduction was higher than in T. athiasae. Survival of immatures of P. talbii was low on A. lycopersici and all failed to develop to adulthood. A total of 35.4 and 30.3 eggs per female, respectively, were obtained when T. swirskii and T. athiasae were fed on active stages of the tomato rust mite. A diet of A. lycopersici provided the shortest female longevity and highest mean total fecundity, which resulted in the highest net reproductive rate (Ro ¼ 26.785), intrinsic rate of natural increase (r m ¼ 0.235) and finite rate of increase (l ¼ 1.265) for T. swirskii. The mean generation time ranged between 13.97 and 17.85 days for T. swirskii and T. athiasae, respectively.

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Background The predatory mites, Neoseiulus californicus (McGregor), N. barkeri (Hughes), and Amblyseius swirskii Athias-Henriot, are important predators attacking many insect and mite pests. They can coexist in the same habitat and engage in intraguild predation (IGP). Main body IGP was assessed among the exotic one N. californicus and the native species N. barkeri and A. swirskii as Intraguild predator (IG-predator)/intraguild prey (IG-prey) in either absence or presence of extra-guild prey Tetranychus urticae Koch (EG-prey). In the laboratory, the physiological parameters, longevity, fecundity, and predation rate of these predatory mites’ females, fed on EG-prey, were evaluated, where phytoseiid larvae are considered as (IG-prey) or combined IG-prey with EG-prey. All predatory species consumed larval stages of each other’s, but in case of N. californicus, females failed to sustain oviposition on N. barkeri larvae. Also, it was noticed that N. californicus females killed 3 times more A. swirskii larvae than N. barkeri larvae, whereas A. swirskii consumed more N. californicus than N. barkeri larvae, respectively. Neoseiulus californicus lived longer on T. urticae and A. swirskii larvae than on N. barkeri, while the latter survived longer on T. urticae only than on the other prey or with combinations with T. urticae. Amblyseius swirskii lived shorter when fed exclusively on T. urticae or IG-prey than on EG-prey combined with IG-prey. In choice experiments, N. californicus showed a higher preference to consume more T. urticae than any of phytoseiid larvae. The comparison between T. urticae and IG-prey diets definite the higher influence of T. urticae on the fecundity in N. californicus and N. barkeri than on IG-prey, whereas in A. swirskii fecundity was as equal on T. urticae as on IG-prey N. californicus larvae. Conclusion A. swirskii seemed to be the strongest IG-predator.

The two rhagidiid species: Robustocheles (R.) deltacus and Rhagidia (R.) qaliubiensis were able to develop successfully from egg to adult on different fungal diets, but failed to lay eggs. When they were reared on larvae of cotton springtail Lepidocenitus insertus (Hand.), larvae of housefly Musca domestica L. and immatures of the tydeid soil mite Tydeus aegyptiaca (Rasmy and El-Bagoury), they laid eggs. They passed through egg, larvae, proto-, deuto-, tritonymph and adult stages. The durations of the immature and adult stages, as well as life table parameters were determined. Feeding on L. insertus gave the highest reproductive rate as compared to that on M. domestica and T. aegyptiaca. Ontogenetic setal development in the comparative study of the life stages of the two rhagidiid species indicated that the dorsal idiosomal chaetotaxy and the number of anal setae remained unchanged throughout the life cycle; a single adanal pair appears only in R. (R.) qaliubiensis protonymph and its successive stages. The increase in genital flap length at each moult is accompained by an increase in the number of setae situated on the flaps and the number of setae provides the simplest method of separating the nymphal stages. Patterns of leg chaetotaxy and solenidia also provide a method to separate nymphal stages. KEYWORDS -biology; ontogeny; Robustocheles deltacus; Rhagidia qualiubiensis; Rhagidiidae; predacious mites COPYRIGHT Abou-Awad B. A. et al.. Acarologia is under free license. This open-access article is distributed under the terms of the Creative Commons-BY-NC-ND which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited.

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