Propensity towards cannibalism amongHypoaspis aculeiferandH. miles, two soil-dwelling predatory mite species

Abstract

In biological control programmes, the two predatory soil mites Hypoaspis aculeifer and H. miles are often applied against soil-borne pests like mushroom flies, springtails and mites. Although the mites show high consumption rates on varying prey types in Petri dish experiments and in greenhouses, their overall efficiency is sometimes limited. We hypothesized that intraspecific interactions, like cannibalism, could contribute to this decreased competence. Therefore, experiments were conducted to show the propensity of H. aculeifer and H. miles to cannibalise. Adult mites and nymphs were introduced as predators with conspecific eggs, larvae, nymphs, adult females or males as prey and the number of killed individuals was recorded. Additionally, the oviposition rate on conspecific prey was quantified and the correlation with the number of prey consumed was calculated to assess the influence of cannibalism on egg production. The results illustrate that cannibalism occurs infrequently in both Hypoaspis spp., the only exception being H. aculeifer nymphs, which cannibalised one conspecific egg per day. Moreover, cannibalism never occurred in the presence of alternative prey. Oviposition rate decreased during the experiment in both species but it was positively correlated with the cannibalism rate only for H. aculeifer. The benefit of cannibalism for populations of H. aculeifer and H. miles is discussed.

Development and reproduction of Stratiolaelaps scimitus (Acari: Laelapidae) with fungus gnat larvae (Diptera: Sciaridae), potworms (Oligochaeta: Enchytraeidae) or Sancassania aff. sphaerogaster (Acari: Acaridae) as the sole food source

“…It appears likely that all commercial cultures available under the name of H. miles are actually S. scimitus. What is less clear is the identity of mites identified as H. miles in earlier studies (Schereef et al 1980;Hoda et al 1986;Rasmy et al 1987) and from studies that do not clearly identify the source of the mites used Ali et al , 1999Berndt et al 2003).…”

“…For example, a number of papers have been published on Stratiolaelaps (=Hypoaspis) miles (Berlese), and on the related laelapid Geolaelaps (=Hypoaspis) aculeifer (Canestrini), most notably on their biology and ecology (Schereef et al 1980;Hoda et al 1986;Rasmy et al 1987;Enkegaard et al 1997;Ydergaard et al 1997;Berndt et al 2003) and on their potential use for managing pests in greenhouses (Gillespie and Quiring 1990;Chambers et al 1993;Brødsgaard et al 1996), mushroom production facilities (Ali et al , 1999Jess and Kilpatrick 2000), and in the field (Lesna et al 1995;Rat-Morris 1999). Stratiolaelaps miles is widely marketed in North America as a biological control agent to manage dark-winged fungus gnats, Bradysia spp.…”

Generalist-feeding subterranean mites as potential biological control agents of immature corn rootworms

“…One exception was for M. insignitus, where larvae were not replaced daily for a period of 2 days due to a lack of experimental organisms. Immature mites were removed from arenas immediately after detection to prevent cannibalism, although cannibalism is rare for G. aculeifer and S. miles (Berndt et al 2003). Experiments were maintained for 7-14 days, depending on the mite species (Table 2).…”

Effects of nonylphenol on a soil community using microcosms

“…The cannibalistic behavior observed in H. aculeifer might also had contributed to their decrease (Berndt et al 2003), but this should have been limited since this is only observed if no alternative prey is available (Usher and Davis 1983).…”