Are your cucumbers infested with striped or spotted insects? It’s probably cucumber beetles.
Don’t worry. Here is the guide on how to get rid of cucumber beetles naturally and chemically.
Cucumber beetles
Before we get started, let’s first know about this insect.
The cucumber beetle is a bright yellow striped or dotted plant pest that is a specialist in feeding cucurbits crops including cucumber, watermelon, pumpkin, and squash.
The striped cucumber beetles mostly feast on cucumbers whereas spotted or dotted beetles will also feed on additional plants.
Cucumber beetles have a yellow cover back with black stripes or spots. They are nearly one-half inch long, with two antennae.
They are easy to spot due to their bright color; however, they mostly hide underneath the leaves and return to their roots at night. You can spot them in the early morning.
You can identify cucumber beetle presence by seeing your plant’s leaves and stems.
If your plants’ stems are eaten up and leave become yellow and wilt. Then probably your cucurbits are infested by cucumber beetles. To confirm, look for them in the early morning besides cucurbits or under leaves.
These beetles are a bit hard to get rid of, they resist organic and chemical methods when they become adults. So the best way to tackle them is when they are at an early stage of life or just started to infest.
For this, we have to learn about the cucumber beetle’s life cycle.
Cucumber beetle’s life Cycle
Adult Cucumber beetles first infest plants, mainly cucurbits. They leave the hibernating site early in the season (mid-April to early June), and feed on vegetables and seedlings, eating all leaves and stems.
Then female cucumber beetles start laying eggs underside of the leaves, laying around 25 eggs each time. These eggs get hatch within weeks and produce larvae. The larvae start eating up the roots of the plant.
Larvae grow into adult beetles from mid-July to September, the beetles once again feed on the leaves, stems, and fruits of the plant and destroy it. They hibernate in the winter season and come next season.
Cucumber beetles can damage the whole vegetable garden, if not stopped in time. It spreads bacterial diseases and viruses from plant to plant, such as mosaic virus and bacterial wilt that will destroy the whole crop.
How to Identify Cucumber Beetles
Cucumber beetles are small plant pests about ¼ inches long with a yellow-black striped abdomen, a blackhead, and two antennae. Spotted cucumber beetles are also the same size but they have 12 black spots on their yellow abdomen. Its eggs are too tiny, very hard to see from the eyes, and its larvae look like worms – black head, white or brown body with 3 pairs of legs on the thorax.
How to Identify Cucumber Beetles Damage
Though cucumber beetle larvae feed on plants’ roots, adult beetles do more damage to crops. They eat up leaves and stems, making small holes that stunt the plants’ growth. Identify them if cucurbits’ leaves become wilting and yellowish.
Adult beetle’s flowers and leaves feeding reduce fruits productivity, and direct eating of fruits will cause unattractive marks and scars on the fruits.
However, cucumber beetles alone cannot damage a whole plant. But, they spread bacterial diseases among plants that can destroy crops. The bacterial diseases and plant viruses can spread even if a decent amount of cucumber beetles are present.
Adult cucumber beetles overwinter in weeds, woody areas, and garden debris. The diseases also overwinter with them internally and can spread onto plants in the next spring through fecal matter.
How to Get Rid of Cucumber Beetles Naturally
Cucumber beetles mainly infect the seedling stage of the plant. Be watchful of plants when they are seedlings.
Neem oil
Coat the infested parts of the cucurbits crop with Neem oil. It is capable of deterring cucumber beetles. Neem oil is a natural pesticide that has chemical compounds that kill pests.
Soapy water
Wipe infested leaves or stems of cucurbits with soapy water to remove cucumber beetles. This solution is helpful to remove eggs and larvae from cucumber beetles. Wipe the plants with soapy water and after one hour wash with water. Soapy water does contain chemical compounds that are not good for crops and cause damage.
Yellow trap
You can use yellow sticky traps to collect cucumber beetles and other pests. It is found that insects get attracted to yellow, bright colors. Put strong glue like petroleum jelly on yellow paper or board and place it near seedlings.
Use high-density glue to trap. Ordinary glue will evaporate within minutes, use petroleum jelly or honey for effective results. Pests come and will get stuck. This is a housemade simple way to trap plant pests.
Use vacuum cleaner
Vacuum cleaners are capable to suck eggs, larvae, and cucumber beetles. It might not help to get rid of them totally but will prevent infesting them. Take vacuum clear closer to plants’ part where they infested (stem or underside of leaves). It will suck the majority of the pest population in.
Then collect these pests in an airtight bag and throw or burn the burn, so they do get back. For this there is a ‘bug vacuum’ available on the market, however, the household vacuum cleaner can also be used.
Hand-Pick
Adult cucumber beetles are fairly easy to spot due to their bright yellow color with black spots or stripe combination. You can spot them early in the morning, on the cucumbers. There usually hide the underside of leaves and lay eggs there to prevent predators. Hand-pick them and collect them in an airtight bag, then throw or destroy them.
Cover the plants
You can cover cucurbits crop with row cover to protect them from plant pests. This is an easy way to prevent them. Though, you must remove row cover during the blooming season for several hours every day to promote pollination.
Insecticides
There are some non-reactive insecticides that you can apply to the cucurbits to get rid of cucumber beetles. But, there are only a few insecticides that can be used on cucurbits because they are very sensitive. Spread them on plants when they just get pop from the soil.
Contact the cooperative extension for approved insecticides for your area.
Apply B. bassiana spray when cucumber beetle eggs hatch. This insecticide will effectively kill all cucumber beetle larvae. However, if they are infested heavily for quick action and control, spray a pyrethrin or azadirachtin insecticide into the infested parts.
Companion plants
Planting marigolds and nasturtiums along with cucurbits will help to deter cucumber beetles. Do not plant all cucurbits in one garden bed, plant nasturtium or marigold between them. You can also spread around the base of the cucurbits, this is effective against cucumber beetles.
How to Prevent Cucumber Beetle
Getting rid of this pest is difficult once they infest heavily on plants. So, we should first try to prevent cucumber beetles. Below are some methods you can use to deter them from plants.
- Transplant cucurbits in new garden beds every two years. Planting in the same area continuously will increase the chance of diseases and cause faulty crops.
- Rather than seeding, transplanting young plants can protect seedlings from damage.
- Plant, trap crops around harvesting crops, and many cucurbits varieties attract cucumber beetles. The pests will keep eating these trap crops and your harvesting crop gets saved.
- Spread natural predators in the garden. Many insects predate cucumber beetles, such as soldier beetles, braconid wasps, and some nematodes. You can order these beneficial insects online and spread a few of them in the garden, they will help to keep the plant pests population in balance.
- Plant, companion plants along with cucurbits to keep away pests from your crops. Read companion plants for cucumbers.
Hey! I’m Madhuresh, a passionate content creator, and a Plant lover. I created Shiny Plant to explore and learn about new plants. The purpose is to provide simple and effective Gardening Tips. Hope you’ll find this informative.