Effect of neem seed oil (Azadirachta indica) on Gyropsylla spegazziniana (Lizer & Trelles) on Paraguay tea plants (Ilex paraguariensis St. Hil.)

Abstract

Gyropsylla spegazziniana (Lizer & Trelles) is one of the important pests of the Paraguay tea (Ilex paraguariensis), and it causes hypertrophy and gall formation in new leaves where the nymph development occurs. As the use of chemical insecticides is forbidden, alternatives to the control of this insect are requested. This study aimed to evaluate the action of a commercial product based on neem seed oil on G. spegazziniana in field conditions. The product was pulverized at the 5 and 10% of concentration. Each treatment was composed by 3 galls per tree, being 10 plants per treatment. The galls were pulverized and folded with voile tissue. The control group was only folded with voile tissue. After 7 days, the galls were removed and the emergence and mortality of the adults were evaluated. The emergence of the adults was significantly lower on the plants treated with neem at 5 and 10% (14.6 and 21.6 individuals, respectively). The efficiency of the product was 53% at the higher concentration. Complementary studies should be conducted, but the potential of the product to this insect is evident.