WV Farm Bureau Magazine August 2014 | Page 15

Spotted wing Drosophila are a growing insect concern in small fruit plantings W est Virginia small fruit growers need to be on the lookout for a new invasive insect pest, the spotted wing Drosophila (SWD). SWD have become a challenging problem for fall-bearing berry crops throughout the state. SWD flies look similar to native vinegar (fruit) flies whose larvae typically infest over-ripened fruits. However, unlike these native vinegar flies, SWD can infest ripening and ripe fruit. Determining SWD infestation To determine whether SWD are present in fruit plantings and if action is needed to control populations, monitor SWD weekly before fruit begin to color and continue monitoring until the end of harvest. Homemade monitoring traps can be constructed from clear plastic deli containers. Make several holes 1/8 inch in diameter in the upper half of the containers. These small holes allow Homemade monitoring traps access for can be constructed SWD and from clear plastic other vinegar deli containers. flies, but keep out other larger insects. Fill containers with approximately 1 inch of apple cider vinegar (this acts as the lure) plus one drop of unscented dish soap. The dish soap breaks the vinegar’s surface tension, so the flies sink into the vinegar and drown rather than escape. To hang a trap, thread a wire or string through two opposite holes near the top of the container and close with a lid. Hang traps in the fruit zone; make sure the holes are not blocked. longer and more pronounced than other vinegar fly species; however, the ovipositor may be diffi