Effect of spring application of an insect growth regulator (IGR) on the population development of the summerfruit tortricid Adoxophyes orana (F. v. R.) in an apple orchard in the Netherlands
Dejong, D.J.; Beeke, H.
Mededelingen van de Faculteit Landbouwwetenschappen - Rijksuniversiteit Gent 42: 1373-1381
ISSN/ISBN: 0368-9697 Accession: 000644275
The effect of spring application of the insect growth regulator ACR 2019 E, which contains 50% epofenonane on the overwintered larvae of Adoxophyes orana (Fisch v. Roesl.) in an apple orchard near Wilhelminasdorp in the Netherlands was studied in 1976. Observation of treated and untreated larvae indicated a considerable reduction in the numbers of normal fertile adults, and this was confirmed by catches in sex-pheromone traps. In July, the larval population (comprising the progeny of the adults of the first flight) was lower in the IGR-treated orchard than in the surrounding orchards that had been treated with organophosphates. However, the numbers of adults trapped during the second flight in August were similar to those caught in the surrounding orchards, and the numbers caught during the third flight were greater in the IGR-treated orchard than in the organophosphate-treated ones; this is attributed to immigration of moths from other orchards. It is concluded that the best effects of treatment with insect growth regulators will be obtained either in isolated orchards or if whole orchard complexes are treated together.