Life history of Oligonychus tylus Baker and Pritchard (Acari: Tetranychidae) on five host plants along the western Indian coastline

Oligonychus tylus has recently emerged as a new pest of date palm (Phoenix dactylifera L.) in India's coastal regions, raising concerns given the crop's economic significance and the growing threat of mite infestations. Understanding the basic biology of this species is a critical first step toward assessing the risk it poses- information that has, until now, been largely lacking. To address this gap, we studied the comparative biology and life-table parameters of O. tylus on different host plants under controlled laboratory conditions (28 ± 2 °C, 70 ± 5% RH, 16:8 h L). Interestingly, while both male and female mites lived longest when reared on maize followed by pearl millet, sorghum, and sugarcane, with the shortest lifespan recorded on date palm-the population growth told a different story. The net reproductive rate (R0) was highest on date palm (10.33 ± 0.49 females/female/generation) and lowest on maize (6.17 ± 0.31). The intrinsic rate of natural increase (rm) was highest on date palm (0.084 day⁻¹) and lowest on maize (0.050 day⁻¹). In other words, although date palm shortened individual mite lifespans, it supported faster population growth overall, suggesting that this host provides especially favorable conditions for the species to multiply. Given that date palm is commonly grown alongside sugarcane, sorghum, and pearl millet in India's coastal belts, this finding raises an important concern: O. tylus populations building up on date palm could readily spill over and threaten these neighboring crops as well. These results offer valuable baseline data for future pest-risk assessments and integrated management strategies targeting this emerging mite pest.