The soil mite Gaeolaelaps (Hypoaspis) aculeifer (Canestrini) (Acari: Laelapidae) as a predator of the invasive citrus mealybug Delottococcus aberiae (De Lotto) (Hemiptera: Pseudococcidae): Implications for biological control

Soil-dwelling predatory mites are important biocontrol agents of several pests. Despite their wide prey range, they have never been evaluated as predators of mealybugs that inhabit the soil. Here, we tested the potential of the soil mite Gaeolaelaps (Hypoaspis) aculeifer (Canestrini) (Acari: Laelapidae) as a predator of the invasive citrus mealybug Delottococcus aberiae (De Lotto) (Hemiptera: Pseudococcidae). The predation, and fecundity of mites over a 14-day period were analyzed when fed on three different diets under laboratory conditions: D. aberiae eggs, first instar nymphs, and without food. Gaeolaelaps aculeifer preyed on D. aberiae and both predation rates and the proportion of females that laid eggs were significantly higher when females preyed on mealybug nymphs than on eggs. These data prompted the evaluation of G. aculeifer as a biological control agent of D. aberiae under semi-field conditions. Infestation levels of D. aberiae on citrus potted plants were reduced in response to G. aculeifer releases. The implications of these results on conservation biological control of mealybugs are discussed.