Do spider mites avoid alternative foods for predators?
2026 - Volume: 66 Issue: Suppl pages: 188
https://doi.org/10.24349/6a4h-dhlh
ICA 2026 - XVII International Congress of Acarology, 20-24 July 2026, Montpellier
Keywords
Spider mite
Predatory mite
Alternative food
Pollen
Abstract
Prey can avoid encounters with predators not only by distancing themselves from predators but also from their traces. From the same perspective, it can be predicted that prey should avoid locations where encounters with predators are likely even in the absence of predator traces; however, no such prior research exists. Many generalist predators utilize plant-derived alternative foods, such as pollen to stave off hunger. This study tested the hypothesis that the prey species, the Kanzawa spider mite Tetranychus kanzawai avoids environments where alternative foods for predators are present. We conducted non-choice tests and oviposition experiments using leaf squares with and without alternative foods such as pollen. We also tested whether the predatory mite Euseius sojaensis, that prey on spider mites could thrive on each alternative food. Each experiment was repeated using approximately 30 individuals. In non-choice experiments, mated female adults of T. kanzawai avoided pollen from Camellia sinensis/ Hibiscus syriacus/ Oenothera speciosa/ Erigeron annuus/ Lycoris radiata/ Solidago altissima/ Osmanthus fragrans/ Anemone hupehensis/ Camellia japonica/ Camellia sasanqua and pearl bodies of Cayratia japonica. Furthermore, we confirmed that the numbers of eggs laid by unmated T. kanzawai females is not affected by the presence or absence of alternative foods for predators. These results suggest that alternative foods do not directly reduce the fitness of T. kanzawai, but rather that they avoid biological environments where alternative foods were present. Among the pollens avoided by T. kanzawai, tea (Camellia sinensis) and sasanqua (Camellia sasanqua) pollen were suitable as food for E. sojaensis, and it is known that minute pirate bugs that prey on spider mites are frequently observed on Erigeron annuus and Solidago altissima. These findings suggest that T. kanzawai avoid the surrounding microhabitats of alternative foods that are likely to be utilized by many generalist predators, considering them ‘dangerous zones.’ These alternative foods for predators have the potential to be applied in innovative spider mite control.
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