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Dangerous Insects That Damage Gardens

Looking at a blooming and ripening garden hijacked with destructive insects is the worst nightmare to any gardener. Fortunately, such a calamity can be overcome with timely interventions and vigilance. Hence, learn to identify these harmful insects to maintain the harmony of your garden.

Flea Beetles

Flea beetles are pitch black beetles with a dark greenish metallic coat that mimic the fleas by their flying. These are native to North America and love to feed on the vegetable crops by protruding into the vegetables and the young leaves. However, if they attack the plant in large numbers, all that stays is the skeleton of the leaves. To protect your crops from flea beetles, it is advised to either provide biting protection, such as a plant cover that acts as an insect barrier, or prepare garlic spray as its smell and taste will keep the beetles at bay.

Japanese Beetles

There are two versions of these beetles: the adults are black with a metallic bluish-green tint below bronze-colored wings and larvae with brown heads and white grubs. These beetles are localized to regions east of the Mississippi River. These beetles primarily feed on the leaf foliage, leaving just the veins of the leaves. Then engulf in the flowers, and the larvae feed on the roots, obstructing and taking away all the soil nutrients these plants require. Handpicking is one of the traditional methods to curb their numbers; people also use floating row covers to keep their gardens safe.

Colorado Potato Beetle

These beetles are easy to identify due to the black strips on their wing cover under a yellowish-orange exterior color. These beetles are fond of vegetables such as cherry tomatoes, potatoes, eggplants and relish their leaves. As a result, they attack vegetables and clear almost all of their foliage. Tomatoes and Potatoes are commercial crops that are always in demand. Hence, proper protection is required for their healthy growth. The best way to keep these beetles at bay is by spraying the plants with neem oil. Neem is an organic insecticide that protects plants and seeds from insect attacks.


These intruders are very active at night. This is the main reason why you tend to notice their existence in your yard or garden. They’re around an inch long in size with a grayish-black segmental larval body. Cutworms are localized to North America. They survive on early vegetables, stem, flower seedlings, and even an entire small young plant. These cutworms are primarily visible on the soil surface, and hence they can be easily handpicked. Look out for these tiny creatures during the day while they are mostly confined to the surface. Handpicking at night will need you a good torch or a flashlight.

Mexican Bean Beetle

These beetles have versions as well. The adults are oval and yellow, with almost 16 black spots on their wing covers. The larvae incorporate a dark yellow grub with spines that are long and branched. They are predominantly localized to the east Mississippi regions, including Texas, Arizona, Colorado, and Utah. They grind on leaves of soybeans, cowpeas, and snap beans. TMostardeners apply floating covers to control their population, while others construct a trap with insecticide luring ingredients. You can even spray neem oil to have a check on their numbers.

Tarnished Plant Bug

This bug is easy to distinguish from the rest due to its yellow triangles with black tips present on its forewings. Predominantly localized to North America, they target all the fruits and vegetables native to North America. Apart from treating the leaves, fruit, and vegetable foliage, they suck the plant juice filled with nutrition. This devoid the leaves and the fruits from the supply of juices, causing them to distort. Though the bugs can be handpicked, they are fast-moving ones, making them jiggle from one plant to another. The best way to reduce their numbers is by applying floating row covers or spraying with neem oil.


Scales come in three versions: a male with tiny flying insects, females confined to the stem and leaves, Larvae resembling a white spider due to their thread-like mouthparts. These three forms relish the plant sap of all fruits, trees, and ornamental shrubs found in North America. When scales attack plants, their color changes to yellow, and the leaves drop, indicating that the plant will not survive for long. If you notice the attack early, you can chop off the infested part of the plant. If indoors, then spray your shrub with neem oil, summer oil, or even soapy water.


Caterpillars are larval forms of the butterfly species. They’re squashy with a hard head capsule, segmented body, and pseudo fleshy legs near the segments. Caterpillars are very evident on fruits, vegetables, plants, shady trees, and ornamental shrubs. They primarily resemble a feed on the leaf foliage, but some even dig holes into fruits and vegetables, damaging the plant. The best way to have a check on their number is by encouraging the growth of native predators. Caterpillars can also be handpicked, or a floating cover can be inserted as a barrier.

Take A Home Message!

The goal here is to protect your garden from these harmful insects and not kill the insects in your garden. Please be careful with the type of protection you use. It would be best to go the organic way because the chemical insecticides will kill beneficial and harmful insects. Also, there has to be a balance between prey and predators. Take action only if their numbers go exponentially high. Nature has its way of maintaining a balance, and hence if there are harmful insects, there will be predators to these insects. The concern arises when the number of predators declines due to anthropogenic activities.