Natural Oil Lure Outperforms Trimedlure in Capturing Males of the Mediterranean Fruit Fly, Ceratitis capitata (Diptera: Tephritidae).

Females of certain tephritid fruit fly species (Diptera: Tephritidae) pose an enormous agricultural threat, as they oviposit in commercially important fruits and vegetables. Trapping networks are often operated in fruit fly-free areas to detect incipient infestations. Trapping relies largely on male attractants, so-called male lures, with trimedlure (TML) being used to detect invasive Ceratitis spp. Operating large-scale surveillance programs incurs substantial costs for both supplies and labor, and the problem is exacerbated by the fact that trimedlure (as well as other male lures) is effective for relatively short intervals in the field (6-8 weeks). Because frequent servicing increases costs, there is considerable interest in modifying existing lures or developing new formulations to extend their effective field longevity. Here, we present results of a field study in Hawaii on a wild population of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), that compared male captures in traps baited with (i) fresh liquid TML, (ii) TML plugs, (iii) a novel controlled-release TML sachet, and (iv) a novel natural oil blend dispensed from a sachet. Catch was recorded weekly for 12 weeks and then at 16 and 20 weeks, with 12 traps deployed per treatment. The natural oil formulation, which contains the natural plant product α-copaene, was as effective as the fresh liquid TML even after weathering for 20 weeks. Future work will focus on developing a dispenser for this formulation that is compatible with standard trap design and deployment.

Economic Benefits from the Use of Mass Trapping in the Management of Diamondback Moth, Plutella xylostella, in Central America.

The diamondback moth, Plutella xylostella (L.), is a worldwide pest of brassica crops, resistant to a large number of insecticides. As an alternative, the use of pheromone-baited traps has been proposed but farmers are yet to be convinced. In the present study, we aimed to validate the benefits of the use of pheromone-baited traps for monitoring and mass trapping in cabbage production in Central America as means of Integrated Pest Management (IPM) in comparison to calendarized insecticide sprays, which are the farmers' current practices (FCP). Mass trapping was established in nine selected plots of cabbage in Costa Rica and Nicaragua. Average captures of males/trap/night, plant damage and net profits of these IPM plots were compared to simultaneously evaluated or historically reported FCP plots. The results indicate that in Costa Rica, trap captures did not justify the application of insecticides and average net profits increased by more than 11% when the trapping methods were implemented. In Nicaragua, IPM plots were able to reduce insecticide applications to one third of those in FCP plots. These results confirm the economic and environmental benefits of pheromone-based management of DBM in Central America.

Mating disruption of Guatemalan potato moth Tecia solanivora by attractive and non-attractive pheromone blends.

The behavioral mechanisms of mating disruption in Guatemalan potato moth Tecia solanivora were studied using the sex pheromone components, (E)-3-dodecenyl acetate, (Z)-3-dodecenyl acetate, and dodecyl acetate, formulated in a 100:1:20-ratio mimicking the female-produced blend, and in a 100:56:100 off-blend ratio. The mode of action of these two blends was tested in mating disruption experiments in the field and in a greenhouse, as well as in a laboratory wind tunnel. Field treatments with both blends at 80 g pheromone per ha reduced male attraction to trap lures baited with 100 µg of female sex pheromone. In mesh-house treatments, these two blends were equally effective at reducing male attraction to traps baited with live females and mating of caged females. Subsequent flight tunnel tests corroborated that both blends reduced attraction of naive males to calling females, and pre-exposure of males with either dispenser blend for 24 hr resulted in a strongly reduced response to calling females. The pre-exposure effect was reversible, with males again responsive after 24 hr in clean air. The two dispenser formulations produced a similar effect on male behavior, despite the differences in blend composition. One mating disruption dispenser formulated with either the female-blend or off-blend elicited the same rate of male upwind attraction in a wind-tunnel bioassay. Sensory overload and camouflage, therefore, are contributing mechanisms to mating disruption using either blend. The off-blend, which is more economical to synthesize, is a valuable tool for further development of mating disruption against this major pest of potatoes in Latin America.

Reduction in an almond moth Ephestia cautella (Lepidoptera: Pyralidae) population by means of mating disruption.

Pheromone-based mating disruption of the almond moth (Ephestia cautella) (Walk.) (Lepidoptera: Pyralidae) was carried out in a chocolate factory in Sweden. Population monitoring was conducted with pheromone-baited traps and water traps. Pheromone traps showed a 94% catch reduction, and monitoring with water traps showed a significant decrease in total catch (5.0 and 1.6 individuals per trap per week before and during treatment respectively). The significance of the results was tested by fitting the observed data to a first-order autoregressive model. This made it possible to test the data with a 95% confidence interval, comparing trap catches before mating disruption treatment with trapping data during the experiment. It is suggested that this statistical approach may be used more frequently in mating disruption experiments where it is extremely difficult to control external factors and therefore equally difficult to use a comparable control plot to evaluate the treatment.