Comparing the Life Table and Population Projection of Gaeolaelaps aculeifer and Stratiolaelaps scimitus (Acari: Laelapidae) Based on the Age-Stage, Two-Sex Life Table Theory

Abstract

Predatory soil-dwelling mites, Gaeolaelaps aculeifer (Canestrini) and Stratiolaelaps scimitus (Womersley) (Mesostigmata: Laelapidae), are essential biocontrol agents of small soil arthropod pests. To understand the population characteristics of these two predatory mites, we investigated their development, survival, and fecundity under laboratory conditions. We used Tyrophagus putrescentiae (Schrank) as a food source and analyzed the data using the age-stage, two-sex life table. The duration from egg to adult for G. aculeifer was longer than that for S. scimitus, but larval duration was similar between the two species. Notably, G. aculeifer laid 74.88 eggs/female in 24.50 days, but S. scimitus laid 28.46 eggs/female in 19.1 days. Several population parameters, such as the intrinsic rate of increase, finite rate of increase, net reproductive rate, and gross reproductive rate of G. aculeifer, were significantly higher than those of S. scimitus. Using the bootstrap technique with 100,000 samples, we demonstrated that the life tables constructed based on the 2.5th and 97.5th percentiles of finite rate of increase (λ) net reproductive rate (R0) may characterize the variability in the survival and fecundity curves, as well as predict population growth uncertainty. These data provide important information for the practical application of predatory soil mites to manage agricultural pests.