Project Number: 1931-21000-015-08
Project Type: Reimbursable

Start Date: May 15, 2005
End Date: May 14, 2008

Objective:
The objectives are to evaluate mass trapping as a management option for dogwood borer by comparing the effects of two trap densities with conventionally managed and untreated control plots in commercial apple orchards in three states, to determine trapping efficiency within commercial apple orchards and the potential for immigration of dogwood borer into commercial apple orchards from native forest, and to compare the relative abundance and seasonal flight activity in apple orchards, managed urban landscapes and native forest in four states within the southern portion of its range.

Approach:
To evaluate mass trapping as a management option, one commercial apple orchard (ca. 12-20 acres) will be selected in each state and will consist of young trees on size-controlling rootstocks. Orchards of square dimensions will be selected and divided into four, square plots of equal area (ca. 3-5 acres). Treatments in each orchard will include Lorsban 4E (conventional control), a low density trapping regime with two traps per acre, a higher density trapping regime using eight traps per acre, and an untreated control. The two trap density treatments will be deployed in opposite plots so that each borders the control and conventional plots on one side. Lorsban 4E at 3.0 pt/acre will be applied as a dilute spray at petal-fall to drench the lower 2¿ of trunk, including the graft union and rootstock. Delta style sticky traps baited loaded with 1 mg of pheromone will be deployed in all plots. In plots comparing the effect of mass trapping according to trap density, traps will be uniformly distributed. In conventional and control plots, 3 traps will be deployed in a diagonal line from plot corner to corner, with the middle trap in the plot center. Traps will be deployed prior to the onset of dogwood borer emergence and flight and the number of males captured in each will be monitored weekly until flight ends. Outside each orchard, 3 traps baited with the pheromone lure will also be deployed 50 m into adjacent forest, providing an indication of potential moth 'pressure' from immigration. The effect of two mass trapping treatments and conventional insecticide treatments on infestation levels will be evaluated against an untreated control plot. determined from measurements of head capsule width. Trapping efficiency will be in a commercial apple orchard (5 acres). In the center of the orchard, an experimental plot will be established, consisting of 10 rows of trees with 100 trees per row. Treatments will include a single trap baited with a 1 mg pheromone lure and a single trap baited with a 10 mg pheromone lure. After the plot has been prepared by removing old males and pupal exuvia over a 48h period, a single trap baited with a 1 or 10 mg lure will be deployed from 7:00-11:00 p.m. in the center of each experimental plot. This will be done on alternating evenings over 4 nights during two periods of peak dogwood borer emergence and flight activity. Trapping efficiency will be based on the number of captures per trap and the number of fresh pupal exuvia recovered from all trees within the plot during each 24 h period. Flight phenology of male dogwood borer will be monitored using pheromone traps deployed in commercial apple orchards, managed urban landscapes (e.g. municipal park, cemetery, arboretum) and native, deciduous forest. Two Delta style pheromone traps per site will be baited with the pheromone lure, suspended at ca. 2 m in the canopy of trees, and deployed prior to the onset of flight activity. Traps will be spaced 100 m apart, and the number of dogwood borer captured will be recorded at weekly intervals until flight has ended.