Flight patterns of the European corn borer, Ostrinia nubilalis, in Slovenian hop gardens in 1999-2016

The suitability of a light trap (from 1999 to 2016), and pheromone traps and pheromone + phenylacetaldehyde (PAA) baited traps (from 2010 to 2012), in the monitoring of European corn borer (ECB), Ostrinia nubilalis (Hubner), moth flights in Slovenian hop gardens was studied. In 18 years light trap collected a total of 13381 specimens (with an average of 743 specimens per year), the number of ECB varied from a minimum of 184 specimens in 2014 to a maximum of 2060 specimens collected during 2003. From 2010 to 2016, of the 5327 specimens captured, 3778 were males (70.70%) and 1566 were females (29.30%). In general, during the ECB first annual fly the captured moths increased after the third week of May, with a peak on 10 June; between the last week of June and the second week of August, the ECB second fly can be observed with a peak during the last week of July; third annual fly was revealed from last week of August to last week of September with a peak of adults at the end of August. Pheromone and pheromone + PAA traps (wing sticky and mesh netting cone models) demonstrated low suitability for capturing ECB males and females. Adult trapped by light trap and pheromone and pheromone + PAA traps, respectively, displayed similar pattern. Average daily temperature and precipitation level influenced the flight patterns of ECB moths. ECB field infestations in hop gardens could be surveyed by counting egg masses on plants and observing signs of early damages by first-instar larvae. Monitoring of moth flights by means of easily handled pheromone traps provides valuable information.