The strawberry bud weevil (Anthonomus signatus), “clipper,” is an invasive pest to northeastern U.S. strawberry and raspberry crops. Strawberry is the primary host of clipper, but it has been observed damaging raspberry crops as well. The first objective for this research is to determine the importance of clipper as a pest on raspberries in the northeastern U.S. Raspberry plantings were scouted weekly on 13 grower-cooperator farms in Maine during the late spring and early Summer 2005 for the adult insects and bud injury (clipped or not). 10 canes from each site were then collected and the number of total buds and clipped buds were taken. This data will be correlated with the bud injury data to determine interrelationships between clipper populations and bud injury levels on different varieties of raspberries. The first year of this research has determined that clipper is a pest of raspberry in the northeastern U.S. Up to 55% clipper damage was found on raspberry plants in 2004 and up to 22% clipper damage was found in 2005. The other objective for this research is to develop integrated pest management (IPM) strategies for clipper on raspberry crops in the northeastern U.S. While scouting the farms this past summer, some different scouting techniques were tested for their efficiency and effectiveness at predicting the population levels of clipper on the crop. The scouting method of white sticky traps were hung in the field and provided the most accurate method of scouting for clipper in the field. In addition to this research, the importance of clipper as a pest of raspberries was tested using greenhouse-grown plants. They were analyzed for the ability of raspberry fruit yield to compensate for the loss of flower buds due to clipper damage. The research showed that plants with any clipped buds yielded significantly lower and the mean number of berries is significantly lower than the control plants with no clipped buds. The results also showed that the mean berry size was highest if there were no primaries clipped and significantly lower if primaries or secondaries were clipped concluding that there is little or no compensation in Killarney red raspberries when buds are clipped. This is a thesis project in progress with one more season of data to collect. Concluding the research, this work should improve grower awareness of clipper as a pest of raspberries and provide an IPM program to manage clipper on raspberries in the Northeast.
If the inline PDF is not rendering correctly, you can download the PDF file here.