Captures of MFO-resistant Cydia pomonella adults as affected by lure, crop management system and flight

Abstract

The main resistance mechanism of codling moth (Cydia pomonella) in the tree fruit area of Lleida (NE Spain) is multifunction oxidases (MFO). We studied the frequency of MFO-resistant adults captured by different lures, with and without pear ester, and flights in orchards under different crop management systems. The factor year affected codling moth MFO-resistance level, particularly in the untreated orchards, highlighting the great influence of codling moth migration on the spread of resistance in field populations. Chemical treatments and adult flight were also very important but mating disruption technique showed no influence. The second adult flight showed the highest frequency, followed by the first flight and the third flight. In untreated orchards, there were no significant differences in the frequency of MFO-resistant individuals attracted by Combo and BioLure. Red septa lures baited with pear ester (DA) captured sufficient insects only in the first generation of 2010, obtaining a significantly lower proportion of MFO-resistant adults than Combo and BioLure. In the chemically treated orchards, in 2009 BioLure caught a significantly lower proportion of MFO-resistant adults than Combo during the first and third flight, and also than DA during the first flight. No significant differences were found between the lures or flights in 2010. These results cannot support the idea of a higher attractiveness of the pear ester for MFO-resistant adults in the field but do suggest a high influence of the response to the attractant depending on the management of the orchard, particularly with regard to the use of chemical insecticides.

Keywords: Cydia pomonella; adult flight; codlemone; crop management; mixed function oxidases; monitoring; pear ester.

Fig. 1.

Mean weekly codling moth adults caught in mating disruption (MD) and non-MD orchards using BioLureTM CM 10X and Pherocon CM-DA ComboTM lures and period of time (rectangle area) when the MFO activity was measured in each flight (gray area). Number of traps =30 (2009) and 58 (2010). Solid bars show the beginning of each generation.

Fig. 2.

Percentage of MFO-resistant codling moth adults in the three field flights captured by delta traps lured with Pherocon CM-DA ComboTM, BioLureTM CM 10X and the pear ester DA (3.0 mg of pear ester) in two untreated and 18 treated orchards of the production area of Lleida during the year 2009. Number within the brackets represents the number of insects processed.

Fig. 3.

Percentage of MFO-resistant codling moth adults in the three field flights captured by delta traps lured with Pherocon CM-DA ComboTM, BioLureTM CM 10X and the pear ester DA (3.0 mg of pear ester) in untreated (three orchards) and treated orchards (22 orchards) of the production area of Lleida during the year 2010. Numbers within the brackets represent the number of insects processed.