Life table and biological studies of the predatory mite, Pachylaelaps aegypticus (Pachylaelapidae) feeding on Tyrophagus tropicus (Acaridae) and Rhabditella muscicola (Rhabditidae)

The development, reproductive performance and life table parameters of the predatory mite Pachylaelaps aegypticus Hafez & Nasr (Acari: Pachylaelapidae) was evaluated fed on eggs and immature stages of the acarid mite Tyrophagus tropicus Robertson as well as the free-living nematode Rhabditella muscicola Andrássy (Rabditidae) at 20 and 30°C (70±5% RH) in order to determine its biological control potential. Prey type significantly influenced most biological parameters (P<0.05). At 20°C, T. tropicus immature stages maximized female fecundity (62.40 eggs/female) and daily oviposition rate (2.93 eggs/female/day), but reduced longevity (33.92 days), while R. muscicola shortened pre-oviposition (2.95 days) and extended oviposition period (29.90 days) at the cost of lower fecundity (38.80 eggs/female). Males showed prolonged development when fed on nematodes. At 30°C, development was accelerated (e.g., life cycle 8.40-10.30 days vs. 13.41-18.49 days at 20°C), while T. tropicus immature stages caused the highest fecundity of P. aegypticus (72.20 eggs/female) and R. muscicola supported the fastest immature development. Life table analysis revealed enhanced demographic performance at 30°C, where net reproductive rate of P. aegypticus (R₀) up to 46.49 daughters/female, intrinsic rate of increase (rm) 0.238/day, and doubling time (DT) 2.91 days on T. tropicus immature stages—superior to 20°C values (R₀=34.04, rm=0.137, DT=5.05 days). Survival rates improved (90-92%), and generation time shortened (16.11-18.21 days). These findings demonstrate that T. tropicus immature stages should be adopted as the primary prey for laboratory rearing programs of the predatory mite P. aegypticus, as they support higher fecundity, faster development, and improved demographic parameters compared to R. muscicola. Future field evaluations should assess its predatory efficiency against various pest mites or nematodes under field conditions to confirm its adaptability and natural control efficacy.