Recently a UK grower sent us a photo of the damage to a pumpkin plant and wanted to know what it was and if it could be controlled. Apparently this pest had been a problem for a long time, to the point where it was questionable whether it was worth replanting pumpkins or zucchini.
Like all vegetables, pumpkins and gourds are no strangers to disease and insects. Pumpkin vine borer (Melittia cucurbitae), which is what was affecting our grower’s pumpkins, is just one of the range of pests that affect members of the cucurbit family (including pumpkins, zucchini, zucchini, cucumbers, melons, etc.). In addition to the UK squash vine borer, it lives in most temperate areas of North America, though not on the Pacific coast. This pest is known for the fact that it cannot be seen until it is too late (when the plant withers and does not recover when watered). A close examination will reveal that the stem has been cut just above ground level.
When you examine the base of the affected plants, you will notice a small hole and some droppings (sawdust-like droppings). The hole is a sign of the presence of the pumpkin vine borer. If there are multiple borers, these pests can cause the stem to break, especially if it’s windy, or rot, depending on the weather. The injury will also prevent the plant from absorbing water and nutrients, ultimately causing it to die.
The squash vine borer is the larva of a species of black moth that attacks both wild and cultivated varieties of squash. The moth looks like a bee or wasp due to its movements and the bright orange scales on its hind legs. It has a wingspan of around 25 to 37 mm (1 – 11/2 in). Females usually lay reddish-brown eggs on the leaves, and when they hatch, the larvae work their way to the base of the stem; the larvae develop and feed inside the stem, eventually killing the leaf. From the leaf, the caterpillars migrate to the main stem, and with enough feeding damage to the stem, the entire plant can die.
Squash Vine Borers can affect hubbard squash, squash, zucchini, squash, and other squash. It is not common to find them in melons or cucumbers. Control Gardeners consider squash borer to be a difficult pest to control. Some try to avoid this by scheduling the production season to harvest before pests build up or after they have peaked. However, there are cultural control measures that can be implemented.
As squash vine borers overwinter in the soil as larvae in cocoons, it will be helpful to remove and destroy old vines after harvest. Tilling the soil will also help destroy any cocoons that may be there. The birds will also help you with this work once the land has been tilled.
Once your crop is planted, if you are vigilant, you may be able to remove the eggs when they appear. As the larvae generally pierce the stem near ground level, a paper or other wrap at the base of the stem can help as a barrier. If you notice that the plant is wilting or has a hole at the base of the stem, it is possible (if you are very careful) to open the stem and remove the larvae, and then cover the stem with moist soil so it can grow more. estate. In fact, if you notice a hole, you can simply pile some damp soil over the affected area to try to promote new root growth so the plant doesn’t die.
An old trick for growing squash and zucchini is to cover the vine with soil at various points along its length, inducing rooting at various points, and thus continue to feed the developing fruit despite the loss of the original stem. Once the vine has taken root at various points, the infected part of the plant can be cut off, along with another inch where the larvae are eating healthy tissue, without significantly damaging the plant. Row covers are another option that can be used until flowering.
Some gardeners use pesticides, but these are ineffective after the larvae are inside the plant. It is also not recommended, as these pesticides used to kill the adult moth can contaminate the flowers and thus kill pollinators through poisoned nectar or pollen.