Ethology of Waste Management and Nest Relocation of Stigmaeopsis inthanonsis (Acari: Tetranychidae)

Abstract

Stigmaeopsis inthanonsis Saito, Kongchuensin and Sahara has been reported recently from Miscanthus spp. in Thailand. Like many other species of the genus Stigmaeopsis, S. inthanonsis has characteristics of nest weaving behavior on the host plant surface. Waste management behaviour of many Stigmaeopsis species are well described by many scientists but waste management behaviour of S. inthanonsis is still unknown. Here, we studied nest relocation and waste management behaviour of S. inthanonsis. Results showed that fecal piles, dead bodies and exuviae are the waste materials of S. inthanonsis nests. The defecation behaviour showed that S. inthanonsis deposited the less fecal pellets at the entrance of nest and more fecal pellets near their original feces using both tactile cues and excrement cues. More than 80% S. inthanonsis used excrement cues during defecation. Nest relocation patterns showed that S. inthanonsis could relocate when nest was completely damaged. Relocation pattern was different among immature-stages and adults. Nymphs and larvae relocated nest when there was abundance of exuviae whereas adults did not relocate. Adults could extend their original nest when it was filled with exuviae. Alive individuals lived with dead individuals and they did not remove the dead ones from nests. These findings highlight the hygienic challenges, adaptation of social living organisms, and demonstrated how sanitary behaviour can result from a combination of evolutionary history. Nest relocation findings suggest that larvae, nymphs and adults adjust relocation patterns based on conditions they faced.