Squash Borers
Fresh vegetables are the ultimate goal of any gardener, but pests such as squash borers can “squash” those hopes of reaping those delicious specimens. Learning to control these destructive insects can save your harvest.
Hubbard squash, zucchini, gourds, pumpkins and other squash varieties are all at risk of attack by squash borers, also known as squash vine borers. The word “vine” is added to their name because of their habits of attacking that location of the plant. It is the larvae that cause the damage to the flourishing plants, as they bore into the plant stem. Their tunnels cut off the supply of nutrients absorbed into the plant through the stem system, creating the plant to suddenly wilt and eventually die away.
The squash borers begin life as eggs laid upon squash leaves; tiny ovals that appear flat and reddish. Within hours after hatching from the eggs, the larvae work their way to the plant’s stem, where they proceed to bore tiny holes into the stem to find their food source. The holes are evident, usually near the ground surface, by a small amount of frass protruding from the spot of entry. Often, many larvae will be present within the same plant stem. The larvae of squash borers appear grub-like, with wrinkly bodies and brownish colored heads.
These larvae will remain within the plant stem for as long as six weeks. They will ultimately reach about 1 inch in length. These squash borers will eventually form a cocoon, where they will stay protected over the long winter months. In the early summer, the adult moth will emerge. A member of the clear-wing moth family, this particular moth is unusual in appearance. Possessing a wasp like body shape, the moth is black with reddish orange markings. Metallic green front wings and clear hind wings are identifiers, as well as the orange and black hairs on the hind legs. Flying during the day, these moths mate; with the females then going from host plant to host plant, depositing as many as 250 eggs in total.
Controlling the squash borers can begin with harvest; removing any spent vines, leaves and plants from the garden area and destroying them will eliminate the larvae presence. Plow in the early spring to destroy any cocoons possibly in the soil from the previous year. Chemicals can be applied to growing plants, but may not be effective after the eggs have hatched. Hand picking of the larvae from the plants can be effective as well.
Closely monitoring the stems of your garden plants may help to avoid the invasion of the destructive squash borers. Keeping your plants free of insects will save your harvest; providing you with the fresh, delicious vegetables you planned for.