Squash bugs can cause wilting and stunted growth in garden plants such as squash, cucumbers, melon and pumpkin. They feed by puncturing through the outer layer of leaves and sucking out sap from plants.
Adult nymphs measure 5/8 inches long with long legs and antennae, while younger nymphs are much smaller.
1. Diatomaceous Earth
What kills squash bugs is a natural pesticide that can be used both indoors and outdoors. It works on various pests, especially those with hard shells like cockroaches.
Diatomaceous earth (DE) is a white powder made up of fossilized shell remains of micro-organisms known as diatoms. These organisms, which were once alive with bodies composed primarily of silicon dioxide, were once microscopic algae.
DE is used for a range of applications, such as water filtration and pest control. It’s mined from the bottoms of rivers, lakes, and oceans then ground into powder form for ease of handling.
DE, when applied to a bug, causes it to dry out and succumb. This occurs because the fine particles of powder cut through its exoskeleton, ultimately leading to death.
Furthermore, it irritates the bugs’ skin and eyes; therefore, wearing a mask when using this poison to kill pests is recommended.
For outdoor use, you can sprinkle DE on affected plants and leaves or create a spray by mixing one part DE with four parts water. It is best to use food-grade DE for this purpose and it should be reapplied after rain or irrigation.
Squash bugs are a particular nuisance in garden beds, feeding on the leaves of your squash plants and other cucurbits like carrots. To eliminate them, apply a thin layer of detergent around their roots and foliage to kill them off.
Another way to use DE is to make a homemade spray for squash bugs. Add two or three drops of lemon oil to the DE and shake it up before spraying on affected plants or leaving it on soil and leaves to eliminate pests.
When gardening or using DIatomaceous Earth in your home, it is imperative to only purchase and use food-grade DE. Other grades of DE, like pool grade and garden grade, can be hazardous for your health since they contain high amounts of crystalline silica which is more toxic to lungs than amorphous silica.
2. Neem Oil
Neem oil is an effective solution for eliminating squash bugs. It’s organic and non-toxic, meaning it won’t harm pets or other wildlife.
It’s a plant-based insecticide that can kill insects at various stages of development and prevent their emergence from eggs or larvae. Additionally, it helps control fungi, thrips, and root-knot nematodes.
Neem oil can be beneficial when treating certain pests, but for optimal effectiveness it should be combined with other chemicals. You can find neem oil products at most garden supply stores and many organic food stores.
Some neem oil pesticides are ready-to-use and come in a spray bottle; others require some preparation prior to application. Always read the label instructions before applying neem oil onto your plants.
Neem oil can also be used to prevent weeds in your garden. Apply the oil around plants during spring and summer for effective weed control. Note that it takes time for the oil to penetrate into the ground, so apply it every three weeks.
Another way to use neem oil is to spray a foliar treatment on your plants. It has the power to eliminate various fungi, such as powdery mildew, leaf spot, rust and scab. Not only that but this oil works on both ornamental and vegetable plants alike!
Neem oil is an effective fungicide for controlling fungal diseases in your garden. You can use it to spray vegetables and fruit trees outside their blooming season to prevent infections from spreading and eliminate existing ones.
When spraying your plants, be sure to wet the undersides of their leaves thoroughly with the spray. Some insects hide beneath leaves and can be difficult to spot, so this step is essential for success.
You can also make your own pesticide by mixing liquid soap and water. Spray the solution onto any leaves affected by squash bugs.
You can spray neem oil on squash bugs during the spring and summer to kill them and prevent them from hatching into adults. It works on both new nymphs as well as mature adults.
3. Tachinid Flies
Tachinid flies are parasitic insects that live among plants and arthropods. They comprise one of the largest families of flies.
They feed on a variety of hosts, from plant-eating insects like true bugs and beetles to spiders and centipedes. Some are generalists while others specialize in one host species.
Tachinid fly larvae feed on hosts’ organs, often entering through their mouthparts to chew and consume. Additionally, these pests chew through skin in order to insert their spiracles for breathing purposes.
Tachinids may consume their host during the first instar or overwinter as mature larvae inside an insect. After pupating in or around their host, these predatory wasps will exit to seek a mate and emerge to pupate.
Tachinid flies are diverse, but most have an affinity for certain hosts. Common examples include forest tent caterpillars, tiger moths, prominent moths, corn earworms, army worms, tomato fruitworms and squash bugs.
Some flies are commonly encountered in gardens, while others only occur in certain regions. It’s essential to be aware of these differences because they can disrupt your garden’s balance and make it difficult to maintain a pest-free zone.
Trichopoda pennipes, the Tachinid fly, can help keep your squash bug problem under control without the use of chemicals. It lays its eggs on nymph and adult squash bugs’ undersides where they hatch into maggots that burrow into their bodies and eventually kill them.
Squash bugs are an effective and natural pest control option if you take preventive measures by planting vegetables that provide nectar and pollen, and keeping a watchful eye out for them on your garden plants. This method works best if you partner plants that provide this nutrition, as well as keeping an eye out for these pesky pests in general.
Another method is to manually remove nymphs and adults. It’s simple enough, without the use of insecticides: just scrape the eggs off leaves then deposit them in a glass of water with some dishwashing liquid.
4. Bacillus thuringiensis
Squash bugs are one of the most destructive pests for cucurbits such as squash, pumpkins and cucumbers. Feed on plant juices, they feed off plant nutrients which causes wilting and stunting of plant growth while spreading diseases like bacterial wilt and mosaic virus.
These pests have the capacity to live in a variety of places, such as beneath leaves and in soil. Fortunately, there are several natural ways to eliminate squash bugs and prevent infestations from taking hold.
Bacillus thuringiensis (Bt) is a soil-dwelling bacterium that produces an effective insecticide known as Bt. This safe and efficient pesticide has become popular in gardens worldwide.
Commercially available products with Bt as the active ingredient can be used for controlling squash bugs and other garden pests. These sprays are especially efficient when used as a preventative measure to avoid infestation.
Some Bt products come ready-to-use, so all you have to do is attach the hose end adaptor and spray directly onto affected plants or areas. Others come as concentrates that you mix with water before applying as a broadcast spray.
To effectively utilize Bt as a preventative measure, inject it into vines and stems before larvae enter the plant. Once administered, the Bt proteins will eliminate these pests before they cause any harm or spread disease to your plants.
If your squash vine borer infestation is severe, injecting Bt directly into the plant stems may be an effective and environmentally friendly solution to control these pests. Not only is this cost-effective and environmentally friendly, but it’s also highly effective at eliminating larvae before they even get close to your plants.
Another solution is to spray your garden with an organic insecticide containing Carbaryl, an effective squash bug killer. These products can usually be found at most retailers.
You can use insecticidal soap to control and eliminate these pests. It’s an eco-friendly approach that will kill bugs on contact without leaving any residual effects on plants, so you only have to apply it every couple of weeks or so.