P.J. Silk and E.G. Kettela
SERG Project # 2000/06
A new microencapsulated spruce budworm (Choristoneura fumiferana) sex pheromone formulation was field tested to determine its effect on the mating efficiency of this insect.
The formulation was aerially applied using a Cessna 188 and Micronair AU 4000 atomizers to a 4ha plot of naturally regenerated spruce/fir containing caged moths (2 males/2 females per cage).
Preliminary data shows that the formulation deposited in the plot had a profound effect on the mating efficacy of female moths in that little or no mating occurred in pheromone-treated areas compared with controls.
Preliminary lab release rate studies show that this formulation could last 25-30 days; field observations confirm this although adherence to foliage (i.e., sticker) appears to require further work.
Modeling of the deposit using the AgDISP (v 7.0) model indicated that only some of the intended deposit entered the block (5 %). A maximum deposit of only 10% of the target application was predicted on the down-wind side of the block.
In order to achieve better deposit, the model suggests that aircraft height should have been lower (as low as 15 m) and that block widths need to be much larger.
In conclusion, although little deposit appeared to have occurred within the block, the pheromone, by aerial application, had a profound effect on the mating success of spruce budworm. It is recommended that this project proceed to phase 2 so that an isolated population of feral insects can be treated with this formulation to determine the effects on mating. Larger blocks are recommended. It is also recommended that formulation development work by 3M be required to improve adherence to foliage of this microencapsulated product.