Bugs & Eggs

Insects, eggs, cocoons, and webs you can't place

Most of the insects, eggs, and cocoons you find in a yard are harmless — and plenty are actually working for you. But a cluster of yellow eggs under a tomato leaf, a web tent in a tree crotch, or a line of white bugs on a stem is worth identifying before you decide to act, because the right response ranges from "leave it alone" to "remove it today." These guides cover the finds American homeowners photograph most, with clear pointers on which ones are beneficial, which are pests, and which deserve a professional look.

Bugs & Eggs guides

Tiny Yellow Eggs Under Leaves: Pest or Friend? Tiny yellow eggs on the underside of leaves usually belong to squash bugs, ladybugs, Colorado potato beetles, or whiteflies. Identify them before you do anything — ladybug eggs look almost identical to pest eggs, and crushing them destroys one of the best aphid killers in your garden. Read the guide → Brown Egg Sacs on Branches: Mantis, Lanternfly, or Moth? A brown egg case on a branch is either very good news or very bad news: praying mantis egg cases (oothecae) are beneficial and should be left alone, while spotted lanternfly and spongy moth egg masses are invasive pests you should destroy — and in many states, report. Texture and shape tell them apart, so identify before you scrape. Read the guide → Clusters of Orange Eggs on Leaves: Crush or Leave? Clusters of orange eggs on leaf undersides most often belong to Colorado potato beetles on potatoes and tomatoes, or squash bugs on vine crops — both worth removing. But ladybugs lay very similar-looking yellow-orange clusters, and theirs should stay. Check the host plant and the egg shape before you crush anything. Read the guide → Green Caterpillars on Plants: Which One Is Eating Yours? The green caterpillar on your plants is most likely a cabbage worm if it's on broccoli or kale, a tomato hornworm if it's large and has a tail spike, or a sawfly larva if it's on roses. Which plant is being eaten narrows it down fast, and handpicking plus row covers handle most of them — no spraying required. Keep in mind that some green caterpillars grow up to be butterflies worth keeping around. Read the guide → Red and Black Bugs on Your House: What Are They? Red and black bugs clustered on your house are most likely boxelder bugs, which gather by the hundreds on warm, sunny walls in fall while looking for winter shelter. Milkweed bugs, firebugs, and tiny red velvet mites are the usual look-alikes. None of them bite, sting, or damage the structure — the real nuisance is the ones that slip inside, and the ones you squash can leave stains. Read the guide → Shiny Green Beetles on Plants: Japanese Beetles or Friends? Shiny metallic-green beetles clustered on your plants are most often Japanese beetles, especially if they're piled on roses, grapes, or linden leaves in early summer and the foliage is turning to lace. Green June beetles, iridescent dogbane beetles, and quick-running tiger beetles are the usual look-alikes — and two of those are actually good news. Which beetle you have decides whether you act or leave it be. Read the guide → Small White Cocoons on Plants: Don't Destroy Them Yet Small white cocoons on your plants could be braconid wasp cocoons, mealybugs, spittlebug foam, or ordinary moth pupae — and the difference matters, because braconid cocoons are one of the best things you can find in a garden. If the white capsules are riding on the back of a fat green caterpillar, leave everything exactly where it is: tiny parasitic wasps are already destroying that pest for you. Read the guide → Swarm of Flying Insects in Yard: Termites, Ants, or Gnats? A sudden swarm of flying insects in your yard is most often flying ants, termite swarmers, mating clouds of midges or gnats, emerging ground bees, or mayflies near water. Most swarms are harmless and gone within days — but a termite swarm coming from the soil near your house means you should schedule an inspection right away, so the first job is telling termites apart from everything else. Read the guide → Tiny White Bugs Under Leaves: What They Are, What to Do Tiny white bugs on the undersides of leaves are most often whiteflies, mealybugs, woolly aphids, or spider mites. The quickest test is to disturb the plant: whiteflies scatter into the air instantly, while mealybugs and woolly aphids stay put in cottony patches. All of them respond to gentle controls — a hard spray of water and insecticidal soap — so there's no need to reach for harsh chemicals. Read the guide → Webs on Tree Branches: Tent Caterpillars or Webworms? Silky webs in your trees are most likely eastern tent caterpillars if it's spring and the web sits in a branch fork, or fall webworms if it's late summer and the web wraps the tips of branches. Both look alarming but rarely do lasting harm to a healthy tree — and whatever you do, never try to burn a nest out of a tree. Read the guide → White Fuzzy Bugs Flying Around? Meet the 'Fairy Flies' Tiny white fuzzy bugs drifting through the air are usually woolly aphids — sometimes nicknamed 'fairy flies' or 'fluff bugs' — riding the breeze between host trees. Whiteflies that billow up when you brush a plant, hackberry woolly aphids, and waxy planthopper nymphs are the other common sources. Nearly all of them are harmless to you and only a minor stress on healthy plants. Read the guide →

Not sure where to start?

Answer four quick questions about what you found and we'll point you to the most likely guides.

Identify a clue