The Biocontrol Agent Has the Highest Lethal Weight Ratio Compared with Its Prey and the Most Dramatic Body Weight Change during Pregnancy.

spp. are small, toxic, ectoparasitic mites that suppress Coleoptera, Hemiptera, and Lepidoptera plant pests. To explore their potential use as a biocontrol agent, we studied the reproductive development, paralytic process, time to lethality and mortality, and searching ability of on different developmental stages of the oriental leafworm moth, . gained 14,826 times its body weight during pregnancy. One single female could rapidly kill one egg and first to third instar larvae, but not fourth to sixth instar larvae, prepupae, or pupae within 720 min. could develop on eggs, first to sixth larvae, and pupae, but only produced offspring on the eggs and pupae. A single female (an average weight of 23.81 ng) could paralyze and kill one third instar larvae (an average weight of 16.29 mg)-680,000 times its own weight. Mites significantly affected the hatch rate of eggs, which reduced with increasing mite densities on eggs. Releasing 50 or 100 in a 2 cm searching range resulted in significantly higher mortality rates of first instar larvae within 48 h compared to second and third instar larvae in searching ranges of 4.5 and 7.5 cm within 24 h. To the best of our knowledge, this is the first study to reveal that undergoes the greatest changes in weight during pregnancy of any adult female animal and has the highest lethal weight ratio of any biocontrol agent.