Use of safflower as a trap crop for managing the mirid bug, Lygus pratensis Linnaeus (Hemiptera: Miridae), in cotton fields.

Abstract

Cotton has been increasingly harmed by the mirid bug (Lygus pratensis Linnaeus) in Xinjiang Uyghur Autonomous Region, China. Using trap plants within or around the border of the cotton may be a beneficial management strategy for this pest of cotton. The potential of safflower (Carthamus tinctorius Linn) as a trap plant for managing L. pratensis was evaluated in laboratory and field experiments. Y-tube olfactometer assays demonstrated that L. pratensis was highly attracted to volatiles derived from safflower. Field experiments showed that safflower plots hosted more L. pratensis (adults and nymphs) than cotton plots. Early-sown safflower had more L. pratensis than mid-sown or late-sown safflower, and was more conducive to the settlement and reproduction of L. pratensis. The density of L. pratensis on safflower trap crops in three sowing patterns was significantly higher than on adjacent cotton. The pattern of intercropping safflower trap crops was more effective at reducing densities of L. pratensis on cotton than placing safflower as 'spot' trap crops or peripheral trap crops. However, this result also may be related to the overall area of the safflower trap crops. With regular chemical control of L. pratensis on safflower trap crops, the number of cotton bolls was increased by 10.04%, whereas the rate of boll damage was reduced by 33.44%, compared to cotton without safflower trap crops and insecticide sprays. Safflower shows promise as an effective trap crop for L. pratensis, and may contribute to controlling L. pratensis in cotton. © 2020 Society of Chemical Industry.