Cannibalism, predation rate, and intrigued predation of two predatory mites, Protogamasellopsis rhizoglyphusi (Rhodacaridae) and Gaeolaelaps aculeifer (Laelapidae)

The The effects of individual predatory include predatory capacity, cannibalism, starvation, and different interactions of predatory on each other which causes effects on the population of the prey and the population of the predatory. Intraguild predation is a combination of competition and predatory. This study investigates the predatory capacity, intraguild predation, and cannibalism of Gaeolaelaps aculeifer and Protogamasellopsis predatory mites. All the tests were studied at 25 ± 1 ºC, with a relative humidity of 60 ± 10%, and at darkness conditions and in transparent plastic bottles (4 cm diameter and 4 cm height) filled with a mixture of Paris plaster and charcoal (7: 1) and a lid covered by a nylon mesh with 0.05 mm pore size and with 30 repetitions. A sufficient amount of C. lactis or R. echinopus including nymph and egg stages was provided as food. The results showed that in predatory capacity, the highest amount of daily egg feeding is related to Gaeolaelaps aculeifer mite feeding on Carpoglyphus lactis eggs and the lowest feeding amount is related to protonymph of Protogamasellopsis rhizoglyphusi mite feeding on Rhizoglyphus echinopus (onion mite). Also, the highest number of prey nymphs used in adults is related to dry fruit mites with 24 prey nymphs per day, which is used by G. aculeifer, and the lowest number of nymphs used is related to P. rhizoglyphusi, which feeds on 10 nymphs of onion mite. The results of cannibalism showed that the survival rate of egg cohorts for predators in predators of 20 eggs was 19.8 days for P. rhizoglyphusi mites and 24.1 days for predators of 30 eggs for G. aculeifer mites. Mites of the same age never fed each other except from the corpses or during molting, when mite locomotory activity and resistance decreased. The results of intraguild predation showed that the predation is asymmetrical IGP. Predatory mite G. aculeifer feed on all the protonymph and deutonymph of P. rhizoglyphusi mites when there is no food. Only 6.7% of the adult female mites of P. rhizoglyphusi survived. Because they are much smaller. When the immature stage of both types of mites is present along with prey mites, the survival rate of P. rhizoglyphusi reaches more than 60%. In the adults of both predators, this rate reaches 100% survival for both species of adult female mites.