Harmful
Pentatomidae
Stink Bugs
(Family: Pentatomidae)
Like other pest Hemipterans, these insects feed on plant sap with their piercing-sucking mouthparts. They can greatly weaken plants especially if the population is large.
Entomology
Harmful
Galerucinae
Flea Beetles
(Family: Chrysomelidae)
These little cuties are unfortunately a huge issue for many tomato growers.
Harmful
Caelifera
Grasshoppers
(Suborder: Caelifera, grasshoppers and relatives)
Grasshoopers generally have wings and large back hopping legs. You can differentiate them from crickets by looking at their antennae—cricket antennae are usually long, since they’re nocturnal insects, so they use those long “feelers” to help with walking around.
Harmful
Sphingidae
Hornworms
(Family: Sphingidae)
These large caterpillars often reach 5 inches in length and are most easily identified by the “horn” protruding from the tip of their abdomen.
Harmful
Pseudococcidae
Mealybugs
(Family: Pseudococcidae)
These unarmored scale insects damage tomatoes by feeding on their plant saps and secreting a sweet concoction known as “honeydew,” which encourages the growth of sooty molds. They also are known to transmit diseases.
Harmful
Thysanoptera
Thrips
(Order Thysanoptera)
A thrips (no, that’s not a typo—there’s no such thing as a thrip!) is a bizarre, minute insect. They are typically less than 1 mm long with slender bodies, fringed wings and weird lopsided mouth parts.
Harmful
Noctuidae
Cutworms
(Family: Noctuidae)
These caterpillars are the larvae of some moths in the family Noctuidae. They get their name from their behavior of cutting small plants at the base of the stem. Since there are so many species, they come in a variety of colors and patterns, so damage is the best way to identify them.
Harmful
Noctuidae
Fruit Worms
(Species: Helicoverpa zea)
This moth species belongs to the dreaded family of moths called Noctuidae. Within this family, you can find other agricultural pests often referred to as cutworms.
Harmful
Cabbage Looper
Loopers are easily identified in their larval stage because they crawl by arching their backs, creating a “loop.”
Harmful
Tetranychidae
Spider Mites
(Family: Tetranychidae)
Spider mites are not insects but arachnids (think spiders, scorpions, etc.) that damage plant cells by piercing them to feed. These are VERY SMALL and are often not noticed until their population has exploded.
Harmful
Diaspididae
Armored Scale
(Family: Diaspididae)
Armored scale insects are known as one of the more frustrating pests and often don’t look like insects at all. These tiny sap-suckers create protective, waterproof coverings to fend off the elements and predators.
Harmful
Aphididae
Aphids
(Family Aphididae)
This is one bug I think most people can identify immediately.
Harmful
Liriomyza
Leaf Miners
Leaf-mining flies
(Genus: Liriomyza)
The larva create tunnels in the mesophyll, leaving the epidermis intact. This will resemble light colored “squiggles” on the leaves.
Harmful
Coreidae
Leaf-Footed Bugs
Leaf-footed Bugs get their common name from the leaf-like extension found on the hind legs of many species.
Harmful
Wireworms
Though the larvae are known as wireworms, adult insects in the family Elateridae are known as click beetles.
Harmful
Aleyrodidae
Whiteflies
(Family: Aleyrodidae)
Whiteflies (Family Aleyrodidae). Despite their name, whiteflies are not actually true flies but rather closely related to aphids and mealybugs.
Harmful
Green June Beetle
Green June beetles are well known and hated by many gardeners; their other aliases are June bugs or June beetles. Though considered pests in both larval and adult stages, the grubs are known to be more destructive in most settings.
Harmful
Coccidae
Soft Scale
(Family: Coccidae)
Soft Scale is a very diverse family of insects so there is often exceptions in physical appearance. Though they may not look like insects, these Hemipterans are related to aphids, whiteflies, and mealybugs.