Effects of Bt+CpTI transgenic cotton on the performance of <em>Tetranychus</em><em> turkestani</em> (Acari: Tetranychidae)

Abstract

Transgenic cotton is very effective in controlling targeted pests such as cotton bollworm (Helicoverpa armigera). However, increases in spider mite (Acari: Tetranychidae) populations have been reported in fields of transgenic cotton. The objectives of our laboratory experiments were (i) to determine host plant preference (transgenic or non-transgenic cotton) of T. turkestani females and (ii) to compare the life table parameters of T. turkestani females reared on transgenic or non-transgenic cotton. Enzyme-linked immunosorbent assays indicated that T. turkestani females reared on transgenic cotton leaves contained 14.9±0.23 μ g Bt toxic protein per gram fresh weight, about 57.4% toxin in the transgenic cotton leaves. Results of dual-choice disc tests showed that T. turkestani females preferred to feed and lay eggs on non-transgenic cotton. Food source (transgenic or non-transgenic cotton) had no significant effect on the life table parameters of T. turkestani females. We conclude that increases in the population of spider mites in fields of transgenic cotton cannot be attributed to host plant preference or to the effects of Bt toxic protein on the non-targeted arthropods life cycle. Additional studies should be done to determine if the increases are due to less insecticide application or less competition with primary insects in transgenic cotton fields.

Behavior and development of Tetranychus ludeni Zacher, 1913 (Acari: Tetranychidae) and physiological stress in genetically modified cotton expressing Cry1F and Cry1Ac proteins

“…According to Rovenská et al (2005) T. urticae mites preferred transgenic plants for feeding and laying eggs relative to conventional plants. Li et al (2014) reported that mites Tetranychus turkestani Tetrtk, 1937 (Acari: Tetranychidae) preferred to feed and lay eggs in conventional plants than in transgenics. Few studies and the complexity of adequacy of the trials may be the reasons for variations in results and difficulty of comparisons.…”

Comparison of natural prey Tetranychus turkestani, date palm pollen, and bee pollen diets on development, reproduction, and life table parameters of the predator Amblyseius swirskii

“…It is a candidate for augmentative biological control of the strawberry spider mite Tetranychus turkestani Ugarov and Nikolskii (Acari: Tetranychidae) on crop plants in greenhouses and fields in Khuzestan province, southwestern Iran, and elsewhere. Tetranychus turkestani is an important pest of crop plants in multiple families in the southwestern region of Iran (Mossadegh andKocheili 2003; Sohrabi andShishehbor 2008) and other countries including Russia (Popov 1981), USA (Jeppson et al 1975), China (Li et al 2014), India and some European countries (Migeon and Dorkled 2021). Characterized by frequent outbreaks coupled with acaricide resistance, this mite poses a threat to field and glasshouse crop producers (Sohrabi and Shishehbor 2008).…”

Functional and numerical responses of the predator Amblyseius swirskii to its prey Tetranychus turkestani in the laboratory

“…Tetranychus turkestani Ugarov & Nikolskii (Acari: Tetranychidae) is an important pest of different field and glasshouse crops in the southwestern region of Iran (Mossadegh and Kocheili 2003), Russia (Popov 1981), USA (Jeppson et al 1975), China (Li et al 2014), India and some European countries (Zhang 2003). Characterized by frequent outbreaks coupled with acaricide resistance, this mite poses a threat to crop producers (Mossadegh and Kocheili 2003).…”