Pre-ovipositional and ovipositional behaviour of <i>Lasioseius ometes</i> (Oudemans) and <i>Hypoaspis kargi</i> Costa (Acari: Dermanyssiae: Ascidae, Laelapidae) with notes on egg protection strategies in Mesostigmata

Egg deposition by the soil mites <i>Lasioseius ometes</i> (Oudemans, 1903) and <i>Hypoaspis kargi</i> Costa, 1968 was observed using continuous video-monitoring. The process in both species was found to consist of four distinct phases. In Phase 1, both species engage in pre-ovipositional activity prior to the egg being extruded from the genital opening. In <i>L. ometes</i>, the female often selects a substrate depression for egg laying and examines the depression carefully with the gnathosoma and legs I before oviposition. In <i>H. kargi</i>, egg deposition sites are chosen without regard for substrate depressions. Phase 1 lasted approximately 3 minutes for both species. Phase 2 involved egg extrusion and holding of the egg beneath the gnathosoma. Phase 2 lasted approximately 20 times longer in <i>L. ometes</i> (5 minutes) than in <i>H. kargi</i>. Alteration of the egg surface in the form of thorn-like outgrowths was recorded in <i>L. ometes</i>. Egg deposition occurs in Phase 3, and in <i>L. ometes</i> the egg is generally placed at the deposition site using the chelicerae. <i>Hypoaspis kargi</i> also uses the chelicerae for egg manipulation, but also adjusts orientation of the egg with legs I. The sticky nature of egg surface in <i>H. kargi</i> may provide a means for the female to effectively cover the exposed egg with a protective layer of soil particles. Egg deposition in both species occurred in less than 90 seconds. Phase 4 involves egg covering, but behaviour of the female during this last phase differs markedly between the two species. In <i>L. ometes</i>, the female tends to remain close to the egg, whereas in <i>H. kargi</i> the female moves away from the egg to search for substrate particles appropriate for its covering. The average time for Phase 4 in <i>H. kargi</i> was approximately four times longer (80+ minutes) than in <i>L. ometes</i>.