The cucumber beetle is so named because it feeds off cucumber plants (among other vining fruits) and can seriously damage or even kill the plants.
Its body is even shaped like a cucumber even though it is significantly smaller. It also feeds off the plants and fruits of watermelon, muskmelon, pumpkin, squash and gourd.
The stripes on the back of one type of cucumber beetle resemble the stripes on some varieties of watermelon and some cucumber rinds. The other type of this beetle has spotted backs.
Cucumber Beetle Damage
The cucumber beetle comes out of hibernation every spring in southern states when the soil temperature reaches about 65 degrees, Farenheit. In states further north, the beetle migrates from the south and arrives in June.
Whether it migrates or hibernates, it is looking for food to eat about the same time that sprouts of these vining plants are just pushing up through the soil’s crusty surface. The sprouting seedlings provide a tender, succulent meal for the hungry cucumber beetle.
This insect also causes damage through the bacteria it carries inside its body that comes in contact with the plants and the soil through the beetle’s feces. If the bacteria gets inside the plant’s system, it can cause its leaves to wilt.
The bacteria multiply rapidly and can move from an infected plant to healthy plants. The larvae of the cucumber beetle feeds off the plants’ roots and stems, and the adult cucumber beetle feeds off the larger plants’ leaves and blossoms. This insect also eats the rinds of the cucumber, muskmelon, watermelon, pumpkin, gourd, and squash.
Results of the Damage
If the beetle has infected the internal systems of the cucumber, watermelon and muskmelon plants and caused the leaves to wilt, the plants cannot be saved, cutting into crop yields and profits. Yields are also affected negatively when the beetles have eaten sprouts, blossoms, roots and stems of the plants.
Infested plants will not produce as much as healthy plants. Beetles that feed off the rinds of watermelons, cucumbers and muskmelons ruin the appearance of those fruits, making it impossible to sell them at farmers markets and to retailers. Profits take a direct hit.
Prevention both Natural and Artificial
Inspect the soil to look for eggs prior to planting. Introduce lacewings and ladybugs, which feast on the eggs, into your garden at the site.
Plant your cucumbers, squashes and melons a little later in the season than your neighbors so any beetles in the area will be attracted to their gardens. As soon as you plant your seedlings, or if you plant seeds in your garden, as soon as they sprout, cover the seedlings with screens, cones or garden row covers.
Constant inspection of your plants from the minute they begin to poke up through the soil is essential. As the plants grow, be sure to inspect the undersides of leaves and stems because the beetles are shade loving insects.
Gardeners can buy a device to place near their plants that serve to lure beetles into them and trap them on a sticky surface similar to fly paper.
Sprays are available made from pyrethrum, which is an extract of the chrysanthemum painted daisy flower. If any of the plants indicate evidence of bacterial wilting, pull them up and destroy them immediately before the healthy plants around them are infected.
Do not put infected plants into your compost pile, which is another way bacteria is spread, perpetuating the problem. Destroying them also prevents them from attracting more of these pests into your garden.
Any covers place upon the plants squash, pumpkins, melons, cucumbers and gourds must be removed as soon as blossoms appear so the plants can pollinate.