Herbaceous Weeds as Potential Host Plants for Tetranychus urticae and Predation Efficacy of Typhlodromips capsicum on Preferred Host Plants

Abstract

The two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most serious polyphagous pests worldwide. During intercropping periods, TSSM transfers to available green plants either economic or weeds. The objective of the current study was to determine the host suitability of alternative host plants. The selected promotive host plant for TSSM growth received the phytoseiid predator Typhlodromips capsicum Mostafa to feed on TSSM based on biological features and reproductive potential for prey and predator. Leaves of cheeseweed, bindweed and mint were promotive for TSSM females' longevity which lasted for 16.9, 16.3 and 16.3 days, respectively. The highest significant deposited eggs per TSSM female was recorded on cheeseweed leaves (43.6 eggs, and 3.57eggs/day) with a sex ratio of 2.6: 1 (72.25 % females). Based on TSSM longevity and fecundity, slender amaranth, groundsel, fleabane, wild oat and Jimson weed were less suitable host plants as sorted in descending order. The longevity, prey consumption and fecundity of T. capsicum females were studied on the most suitable plants for TSSM comprising rocket, parsley, mint, bindweed and cheeseweed as sorted in ascending order. The longevity of T. capsicum females on TSSM preferred plants were closely related and the highest significant prey consumption (total 75 and daily 3.95 prey individuals) reared on cheeseweed leaves accompanied by the greatest number of deposited eggs per female (total 38 eggs, and 2.54 eggs/day). The alternative host plants may play a role as a reservoir plant for phytophagous mites also provide food and habitat required for predators conservation during absence periods of major crops to keep biodiversity and natural balance.