Just lately a grower from the UK despatched us a photograph of injury to a pumpkin plant and needed to know what it was and whether or not it could possibly be managed. This pest had apparently been an issue for a very long time, to the extent that it was questionable whether or not it was worthwhile planting pumpkins or squashes once more.
Like all greens, pumpkins and squashes are not any strangers to ailments and bugs. Squash Vine Borer ( Melittia cucurbitae ), which is what was affecting our grower's pumpkins, is barely one of many vary of pests that impacts members of the cucurbit household (members of which embrace pumpkins, squashes, zucchinis, cucumbers, melons and so on). Moreover the UK Squash vine borer lives in most temperate areas of North America, though not on the Pacific Coast. This pest is famend for the truth that you can not see it till it’s too late (when the plant is wilted and doesn’t get better when watered). Shut examination will reveal that the stem has been severed simply above floor degree.
Once you study the bottom of affected crops, you’ll discover a small gap and a few frass (sawdust-like droppings). The outlet is an indication of the presence of the Squash Vine Borer. If there are a number of numbers of borers, these pests can truly trigger the stem to interrupt – particularly whether it is windy – or to rot, relying on the climate. The damage will even forestall the plant from taking over water and vitamins, which is able to in the end trigger it to die.
The Squash Vine Borer is the larvae of a species of black moth that assaults each wild and cultivated kinds of squash. The moth seems to be like a bee or wasp due to its actions, and the brilliant orange scales on its hind legs. It has a wing span or round 25 to 37mm (1 – 11/2 in). The females often lay reddish-brown eggs on the leaves, and once they hatch the larvae bore their approach into the bottom of the stem; the larvae develop and feed contained in the stalk, finally killing the leaf. From the leaf, the caterpillars migrate to the principle stem, and with sufficient feeding injury to the stem, your entire plant could die.
Squash Vine Borers can have an effect on hubbard squash, pumpkins, zucchinis, gourds and different squashes. It’s not widespread to seek out them on melons or cucumbers. Management Gardeners discover Squash Vine Borer a tough pest to fight. Some attempt to keep away from it by timing the manufacturing season to reap earlier than the pests can construct up, or after they’ve peaked. Nevertheless, there are cultural management measures that may be carried out.
As Squash Vine Borers overwinter within the soil as larvae in cocoons, eradicating and destroying outdated vines after harvesting will assist. Tilling the soil will even assist to destroy any cocoons that could be there. Birds will even help you with this job as soon as the soil is tilled.
As soon as your crop is planted, in case you are vigilant, you might be able to take away eggs once they seem. Because the larvae often bore into the stem near floor degree, a paper or different wrapping on the base of the stem could help as a barrier. If you happen to discover the plant wilting or a gap on the base of the stem, it’s doable (in case you are very cautious) to slit open the stem and take away the larvae, after which cowl the stem with moist soil in order that it may develop extra roots. The truth is when you discover a gap, you possibly can even simply pile some moist soil over the affected space to try to promote new root progress in order that the plant won’t die.
An outdated trick for rising pumpkins and squash is to cowl the vine with earth at varied factors alongside its size, inducing rooting at a number of factors, thereby persevering with to feed the growing fruit regardless of the lack of the unique stem. After the vine has taken root at a number of factors, the contaminated portion of the plant may be minimize off, together with one other inch the place the larvae is consuming into wholesome tissue, with out vital injury to the plant. Row covers are another choice that can be utilized up till bloom.
Some gardeners use pesticides, however these are ineffective after the larvae are contained in the plant. It is usually not really useful as these pesticides used to kill the grownup moth could contaminate the flowers and thus kill pollinators by way of poisoned nectar or pollen.