Response of male codling moths (Cydia pomonella) to components of conspecific female sex pheromone glands in flight tunnel tests

Abstract

In flight tunnel tests, the percentages of oriented upwind flights of male codling moths culminating in contacting a source of different compositions of female sex pheromone gland components were determined over a dosage range of 0.1-100,000Μg. The following compositions were tested: (1) (E,E)-8,10-dodecadien-1-ol of 99.7% isomeric purity; (2) 1 + dodecanl-ol + tetradecan-1-ol; (3) 2 + decan-1-ol + (E)-9-dodecen-1-ol; and (4) an equilibrium mixture of 8,10-dodecadien-1-ol isomers (61%EE, 5%ZZ, 14%ZE, and 20%EZ). The ratios of the components in compositions 2 and 3 were chosen to produce vapor ratios equal to the natural ratios found in the female effluvium by Arn and coworkers. As the dose of composition 1 was increased from 0.1 to 10Μg, response increased from 0 to about 80% and then was approximately constant from 10 to 300Μg. Over the range 0.1-300Μg, the percentage of males contacting the septum was virtually the same as the percentage flying upwind. From 300 to 100,000Μg, the percentage of males flying upwind and contacting the source steadily decreased from about 80 to 0%. The male responses to compositions 2 and 3 were virtually identical to the response to 1. These results indicate, contrary to published reports, that dodecan-1-ol and tetradecan-1-ol in combination with 1 do not increase the responses of the behavioral modes determining degree of attractancy and disruption of sexual communication over that of 1 alone. These results also show that decan-1-ol and (E)-9-dodecen-1-ol do not enhance response in the five-component mixture. The response to composition 4 increased from 0% at a dose of 0.3Μg to 26% at a dose of 30Μg and then decreased to 0% at a dose of 3000Μg. Thus, the inhibiting effect of the isomers on response was greater at the higher doses.

Laboratory and field experiments towards the development of an attract and kill strategy for the control of the codling moth, Cydia pomonella

“…Upon transferring the results of laboratory experiments to the field situation, it was decided to increase the concentration of codlemone slightly to 0.1%, in order to extend the period over which the formulation would remain attractive. Although the absolute amounts of pheromone used differed, the pattern which emerged matches that found for codling moths by McDonough et al (1993) when examining the effect codlemone loads applied to rubber septa, fitted to traps placed in a wind tunnel. While the pheromone release rates depend strongly on the release matrix (oil or rubber septum), too high a pheromone concentration in the vicinity of trapbaits or attract and kill formulations results in a loss in efficacy, possibly due to sensory adaptation and other sensory 'overload'-effects implicated as putative mechanisms of mating disruption (Cardé & Minks, 1995;Sanders, 1997).…”

“…Both the composition of the attractant and its release rate are of the utmost importance in pheromone signalling (for reviews see Baker, 1989;Howse et al, 1998). Although some evidence suggests that minor components of the codling moth sex pheromone enhance the attractiveness of low codlemone doses in traps (Arn et al, 1985;Einhorn et al, 1984;Causse et al, 1988), codlemone has a dominant behaviour-modifying effect on male moths, inducing the complete behavioural repertoire associated with mate finding (McDonough et al, 1993) and precopulatory events (Castrovillo & Cardé, 1980;Ebbinghaus, 1998). The importance of optimising the pheromone release rate for the attractiveness of the formulation is clearly demonstrated by behavioural tests in wind tunnel and cage bioassays in this study.…”

Short‐chain alkanes synergise responses of moth pests to their sex pheromones

“…A male moth was presented on a stand (25 cm high) placed in the centre of the wind tunnel and 25 cm from its downwind end. Moth behaviours recorded were (1) no activation, (2) activation, (3) take-off, (4) casting, (5) lock-on, (6) passing the midline of the wind tunnel, (7) close in within 10 cm of the source and (8) contacting the source, as well as the time to each behavioural step, by means of the OBSERVER software package (v.5.0; Noldus Information Technology, Wageningen, The Netherlands). Behavioural responses of Responses are normalised with respect to a source dose of 10 g of (Z)-3-hexen-1-ol as reference (100%); n is the number of antennae tested.…”

“…Products that increase the range of action of a dispenser are therefore at a premium. The addition of secondary sex pheromone components from female sex glands to the principal pheromone component, for example, has already been shown to increase dispenser efficacy …”

“…The addition of secondary sex pheromone components from female sex glands to the principal pheromone component, for example, has already been shown to increase dispenser efficacy. 7 Efficient mating disruption is in demand because the codling moth has become resistant to most conventional insecticides, especially in areas under intensive fruit production, 8 and the European grapevine moth, which has recently invaded the Americas, 9 is already showing resistance to different products. 10 Protection of high-value-added crops such as apples, pears and grapes can also be achieved by using a sex pheromone released as an aerosol in ethanol from puffers at a precise time each day.…”