Efficacy of acetamiprid, phosmet, chlorpyrifos and pyriproxyfen on the fixing and development of nymphs of Diaspidiotus perniciosus (Hemiptera: Diaspididae) on apple fruits

The effect of acetamiprid (Mospilan 20 PS®) 0.5 g / L, fosmet (Imidan 70 WP®) 1 g / L, clorpirifos (Lorsban 75 WG®) 0.8 g / L and pyriproxyfen ( Admiral 10 EC®) 0.6 ml / L, on the fixing and development of nymphs of Diaspidiotus perniciosus  Comstock, “San Jose scale”, in apples var Fuji was evaluated. The spraying was carried out under field conditions in a commercial orchard using 2500 L / ha. Six apples per treatment were collected at 0, 5, 10, 15 and 20 DAA, and infested with 100 nymphs / apple at the laboratory. The material was maintained at 24 + / 1 ° C, 70% RH and photoperiod 16: 8, for 20 days until final evaluation. A completely randomized design was used, with five treatments, six replicates and an apple as an experimental unit. Fixed living nymphs (%) and second instar nymphs were determined. It was concluded that acetamiprid directly affects the setting and further development of nymphs for 20 DDA chlorpyrifos, for 15 DAA. In addition, pyriproxyfen did not prevent the fixing of nymphs, however once established for a period of 20 DAA it limited their development. Finally, fosmet partially reduced the fixing and development for 15 DAA.