Companion crops and insecticides to control populations of Thrips tabaci L. and Liriomyza trifolii B. in onion

Abstract

For three consecutive years, the companion crops Rosmarinus officinalis L., Ocimum sanctus L., Ocimum basilicum L., Lippia micronera B. and Plectranthus amboinicus L., and the insecticides cypermethrin and avermectin were evaluated for controlling Thrips tabaci L. and Liriomyza trifolii B. in onion. Populations of T. tabaci and L. trifolii were kept at low levels in all treatments during the three-year study. Populations of T. tabaci nymphs and adults decreased significantly in the third year of treatments with companion crops and applications of cypermethrin plus avermectin. Similar trends were observed the first year; however, this decrease was not observed for L. trifolii. Populations of L. trifolii did not follow any particular pattern in response to the treatments.