Suitable methods for determination of cherry fruit fly (Rhagoletis cerasi L.,Diptera: Tephritidae) flying period in Latvia

Abstract: Cherry fruit fly (Rhagoletis cerasi (L.)) is one of the most important pests in cherry inEurope. This insect in Latvia was found in 1970 in Riga region. As a consequence of theincreasing areas of sweet cherry (Prunus avium L.) the development and distribution of R. cerasiincreased and as well as the amount of damage that can achieves as far as 60 %.In Latvia few studies were carried out on the flying period of R. cerasi and on the methodsto monitore it, therefore there is the need to perform studies on the methods to forecast the flyingactivity of Cherry fruit fly.The present work refers to the trials carried out in 2008 and 2009 at Ltd “Pure HorticulturalResearch Centre” (western part of Latvia). The aim of the trials was to identify the suitablemethod to monitor the flight of R. cerasi; for the purpose the efficacy of pheromone traps andyellow sticky traps was evaluated.In 2008 vegetation season the first adults of R. cerasi were caught at the end of May(30.05.) both in the pheromone traps and in the yellow sticky traps. On the contrary in 2009 thefirst adults of R. cerasi were caught in the yellow sticky traps (26.05.), while the first fly wascaught in pheromone traps eight days later (02.06).In 2008 the critical threshold (3 adults/trap per week) was achieved in pheromone traps on30.05, while in the yellow sticky traps it was reached on 06.06. On the contrary in 2009 thecritical threshold was firstly received on yellow sticky traps (26.05) and then in the pheromoneones (02.06).The results of these trials indicated that the two methods provided different information and,therefore further studies are needed.