Rhagidia (R.) qaliubiensis Abou-Awad, El-Sawaf and Abdel-Khalek

Abou-Awad, B. A., El-Sawaf, B. M., Reda, A. S. & Abdel-Khalek, A. A., 2011, Comparative Morphological And Biological Studies Of Two Rhagidiid Mites: Robustocheles (R.) Deltacus And Rhagidia (R.) Qaliubiensis, Acarologia 51 (3), pp. 381-393 : 386-388

Rhagidia (R.) qaliubiensis Abou-Awad, El-Sawaf and Abdel-Khalek

It was found that feeding R. (R.) qaliubiensis on T. harzairum had accelerated female longevity and life span than those fed on F. solani and F. oxysporum ( Table 1). When feeding the predator on L. insertus larvae, it was found that the total life cycle being completed in 35.30 days for females and 34.4 days for males. Males emerged earlier than females for a period of one day ( Table 6).

It is of interest to note that the feeding habits, oviposition and hatching process were similar to that of R. (R.) deltacus . Insemination took place after female emergence from the last quiescent stage. Unfertilized females were found to produce only female offspring, similar to other previous allied species, while both males and females were produced by fertilized females.

Eggs are oval in outline, females laid their eggs either singly or in clusters of about 2- 3 eggs. Females deposited an average number of 13.80 eggs ( Table 7) during an average oviposition period 5.8 days and then survived an average postoviposition period 31.9 days ( Table 6). During the pre-oviposition period, adult female ate an average of 18.00 L. insertus larvae. This rate of consumption increased during short egg laying period to 61.60 individuals and greatly increased to 258.6 prey during post-oviposition period ( Table 7). The mean generation time of population ( T = 41.49 days), would increase 11.58 times (Ro = 11.58) ( Table 5) .

It is noticeable that cannibalism constitutes a great problem in rhagidiid rearing. It was observed in immature and adult stages. This phenomenon did not relate to scarcity of suitable prey, but it seems that it is a specific character among the individuals of rhagidiid predators.

It can be concluded that the previous data and Robustocheles (R.) deltacus .

showed that both rhagidiid mites R. (R.) deltacus and R. (R.) qaliubiensis may be considered as predacious not fungivorus mites. To the contrary, Abou- Awad et al. (2008) confirmed that the eupodid mites Benoinysus momeni (Abou-Awad) and Eupodes bakeri A. E. & A. could successfully feed and develop on several fungi diets. However, the examined rhagidiid species might play an important role in affecting the population of soil pests, but this might encourage to carry further investigations to determine the biological rate.