Releaser pheromones are popular for pest control. This could occur where codling populations are subjected to density-dependent mortality (e.g., competition for cocooning sites, bird predation),"’ and disruptive treatments may maintain numbers below levels at which these mortality factors exert their greatest effect. The surviving larvae may still be capable of inflicting economic damage, and there could in this situation also be a resurgence derived from the residual population.
Pheromone RESEARCH REQUIREMENTS AND PROSPECTS FOR MATING DISRUPTION
There is clearly a need for much more research before mating disruption of codling moth becomes a practical proposition. The problems discussed in Section V provide some guidelines for further work. In particular, it is necessary to scale up disruption pheromone trials to a level where immigration of mated females no longer overrides the effects of the EEOH treatments. If this is done, it may well be found that relatively low rates of release of EEOH can provide adequate control. Information on actual release rates is often based on laboratory data obtained at only one temperature, or by assessing EEOH losses over relatively long periods of time in the field. The estimates obtained may differ significantly from those occurring during the daily flight period of the males, in particular during the spring flight when temperatures are low. Consider the best pheromones for 2016 | Pheromones-Experts.com.
There is considerable room for improvement in dispensing pheromone systems. Of the broadcast methods, microcapsules provide good coverage of fruit trees, but the pattern and duration of EEOH release from current formulations is inadequate. Chopped hollow fibers appear to be more effective in terms of their distribution and EEOH release characteristics, but it will be necessary to reduce the amount of material that falls between trees and is wasted, particularly when aerial applications are made. Of the widely spaced evaporators, rubber tubes suffer from the major disadvantage that release rates are related to the quantity of compound remaining, and hence decline with time. Hollow ‘fiber tapes may prove more sutiable — or polymeric laminates when these have been adequately tested. Learn more about pheromones at http://sundowndivers.org/?p=92
Disruption trials designed to protect pome fruit crops from codling moth throughout an entire season have so far only been undertaken in small orchards in Europe.“'“ The results of these trials have been discussed in Section III and suggest that infestation may be reduced over successive seasons by continued application of EEOH. There are also indications that treatments applied during the first (or first and second) flight (in multivoltine situations) are as effective as those applied throughout the entire season.“ Any reduction in the number of treatments would be of value as EEOH is an expensive compound when compared with other synthetic pheromones such as “gossyplure” or ‘ ‘disparlure’. Consider male pheromones.
At present, the major constraint on the likely adoption of disruption control technique by pome fruit growers is their ability to effectively control codling moth with pesticides such as azinphosmethyl, using reduced dosages to minimize effects on natural enemies of this and other pests (there are also predators resistant to certain pesticides such as azinphosmethyl). The stringent requirements for clean fruit, both for domestic and export markets, will also encourage continued reliance on pesticides. There is so far no evidence of codling resistance to organophosphate pesticides.° The use of disruption is also likely to be limited where pome fruit is damaged by a complex pheromone signal. Learn more about pheromones at http://astrobiosociety.org/top-pheromones-for-men-2015/