Andre CampbellThese pests are accurately described as squash vine borers (SVB) because their larvae most often attack squash plants.
These pests, whose larvae resemble fat white grubs, feed on vine crops such as pumpkins, winter and summer squash, zucchini, and gourds.
They may also go after cucumbers and melons. Wilting is usually the first sign of an attack [1].
Adults are often mistaken for bees or wasps because of their movements and orange-and-black markings. They lay eggs at the base of plants.
After about a week, the larvae hatch and quickly bore into stems, where they feed on internal plant tissues.
How to Get Rid of Squash Vine Borers Naturally
1. Bacillus Thuringiensis (Bt)
BT is widely used as a biological pesticide in agriculture worldwide. It is a soil-dwelling bacterium that produces a protein that is toxic to certain insects and related pests.
Buy Bt for squash vine borers and spray it on the leaves and stems of your squash plants. You can also inject it directly into the plant’s vine.
Bacillus thuringiensis (Bt) can kill newly hatched squash vine borer larvae before they tunnel deeply into stems. It does not kill the eggs, so applications are most effective when timed around egg hatch.
2. Row Covers
This is a popular method of protecting plants from many garden pests. Row covers made of a special lightweight material are suspended over the growing crops and supported by hoops.
These coverings keep moths out, preventing them from laying eggs on the plants. However, the material will still allow light and air to reach your crops.
Apply row covers immediately after planting. Remove them during flowering if pollinators need access to the blossoms, or hand-pollinate the flowers if the covers remain in place.
3. Yellow Sticky Traps
Yellow sticky traps may help monitor adult squash vine borer activity and capture some moths. However, they should not be relied upon as a standalone control method.
4. Parasitic Wasps
Some parasitic wasps attack squash vine borer eggs. Others lay their eggs on or inside the larvae.
After hatching, the developing wasps parasitize the SVB larvae, devouring them as they feed and develop. Therefore, attract parasitic wasps to your garden to help control a vine borer infestation.
5. Trap Crop
Utilizing trap crops as companion plants can help draw these pests away from your main crop. One such crop is the blue Hubbard squash.
Squash vine borers are often more attracted to Blue Hubbard squash than many other squash varieties, making it a useful trap crop.
For that reason, plant it at the corners of your garden to help keep squash borers away [2]. The blue Hubbard is also used as a trap crop for squash bugs.
6. Remove by Hand
Removing squash vine borer larvae by hand may be unpleasant, but it is an effective way to control vine borers organically.
You should also check thoroughly for eggs and remove them. They are tiny but orange-brown in color, and you will spot them at the bases of target plants.
7. Crop Rotation
Rotating crops is another way of controlling pests. Try not to plant squash in the same spot for two consecutive years.
If an alternating crop is planted, overwintering larvae will be unable to find suitable food in the following season.
8. Diatomaceous Earth (DE)
This is a naturally occurring substance composed of fossilized diatom remains. Diatomaceous earth is very sharp, causing irritation for soft-bodied insects and related pests.
It may help reduce the number of newly hatched larvae before they enter plant stems. However, its effectiveness is limited once the larvae start feeding inside the vines.
Sprinkle DE around the base of the plants. You should also use it to dust the entire plant.
9. Aluminum Foil Wrap
Another squash vine borer control home remedy is an aluminum foil wrap. To protect the plant’s main stem, wrap it in foil.
This can make it more difficult for squash vine borer moths to lay eggs on the lower stem.
10. Neem Oil
Neem oil is another remedy to help prevent these pests from damaging your crops.
It can help prevent egg-laying and affect newly hatched larvae before they bore into stems. However, it tends to be less effective against larvae that are already inside the vines.
Make a homemade squash borer spray by combining 2 tablespoons of neem oil with a gallon of water. Use it to spray all the surfaces of your plants.
11. Beneficial Nematodes
There are harmful and beneficial nematodes. The helpful ones can be bought from specialist suppliers for use in the soil.
Beneficial nematodes seek out squash vine borer larvae and pupae in the soil, infecting them with bacteria that kill the pests.
12. Grow Resistant Squash Varieties
Squash vine borers prefer some squash species over others.
- Most vulnerable: zucchini, pumpkins, yellow squash.
- More resistant: butternut squash (Cucurbita moschata), tromboncino squash.
13. Plant Late
In regions where squash vine borers have a single generation per year, planting later in the season may help crops avoid peak egg-laying periods. Timing varies by climate and region.
Therefore, consider planting a second crop near the end of the laying period. The crop will likely mature after the pests stop laying eggs.
14. DIY Yellow Trap
These creatures are attracted to the color yellow. To make a homemade squash vine borer trap, fill a yellow container with soap and water.
The yellow container may attract some adult moths, which can then become trapped in the soapy water. Change and refill the soapy solution every few days.
15. Pest-Repelling Plants
Some gardeners report fewer squash vine borer problems when growing aromatic herbs such as mint, basil, onions, and parsley nearby. However, scientific evidence for their effectiveness is limited.
16. Stem Surgery
After finding the entry hole:
- Slit the stem lengthwise with a sterile knife.
- Remove or destroy the larva.
- Cover the damaged section with moist soil.
Many gardeners successfully save plants this way.
17. Spinosad
Spinosad can help control newly hatched squash vine borer larvae before they enter the stems. You can also use it to control thrips, caterpillars, leafminers, and many other garden pests.
Spinosad is commercially available as a spray. Use it according to the instructions on the label.
Takeaway
Squash vine borers can quickly destroy healthy squash plants, but early detection and prevention are key.
Row covers, crop rotation, beneficial nematodes, and Bt treatments can significantly reduce damage. Regular egg inspections are also important for minimizing damage.
Combining several of these methods often gives the best protection against these destructive pests.
Sasha Campbell
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