cis-Jasmone treatments affect multiple sucking insect pests and associated predators in cotton

Abstract

Defense induction by exogenous applications of natural plant defense elicitors is an alternative pest control method. Such deployments not only provide resistance against herbivores but also attract their natural enemies. The influences of different doses of the plant defense elicitor cis-jasmone (CJ) (25, 50, 100 g/ha and an untreated control) on cooccurring sucking cotton, Gossypium hirsutum Linnaeus, insect pests from different feeding guilds (Thrips tabaci, Aphis gossypii, Empoasca decipiens) and their predators (Aeolothrips intetmedius, Chrysoperla carnea, Coccinella septempunctata) were examined under field conditions in 2012 and 2013. CJ treatments, coinciding with different plant growth stages, were made per growing season. The abundance of apterous A. gossypii was lower on CJ-sprayed cotton plants than on untreated control plants. Similarly, the overall abundance of T. tabaci was lower on treated cotton plants irrespective of the tested dose comparing with untreated control plants. Empoasca decipiens abundance was lowest on plants treated with the lowest CJ dose (25 g/ha). An attractive effect of CJ treatments on the predatory thrips A. intermedius was detected; its highest abundances were recorded on plants treated with 100 g/ha CJ. The highest abundances of C. carnea were detected on plants treated with 100 g/h CJ in 2012, whereas no such dose-specific attraction was recorded in 2013. CJ treatments had no significant effect on C. septempunctata and alate A. gossypii abundances. The different CJ doses used had no phytotoxic effects on cotton plants and cotton yield. The results are discussed in terms of possible CJ deployment in cotton pest management.