helpfulbugs.com
Pest group

Beetles & grubs

Hard-shelled adults chewing leaves and flowers, or C-shaped white grubs in soil and turf.

Which one do I have?
  1. Colorado potato beetleLeptinotarsa decemlineataThe yellow, black-striped beetle and its humped red larvae strip potato, eggplant and tomato. It is notorious for developing resistance to insecticides, so rotation, hand-picking and early timing matter more than which spray you choose.Potato · Tomato · Eggplant
  2. Blister beetlesEpicauta spp. and other MeloidaeLong, narrow, soft-winged beetles that arrive in clusters in mid to late summer and feed on flowers and leaves. Their blood carries cantharidin, which raises a blister if one is crushed on the skin and can kill a horse that eats contaminated hay. Their larvae eat grasshopper eggs.Tomato · Potato · Beans · Alfalfa & hay
  3. Black vine weevilOtiorhynchus sulcatusA flightless black weevil whose adults notch leaf edges at night while its white, C-shaped grubs eat the roots. The grubs kill rhododendrons, strawberries and pot plants. Plants in containers suffer most, and insect-killing nematodes watered into the compost are the standard control.Houseplants · Azalea & rhododendron · Strawberry · Evergreens & shrubs · Succulents & cacti
  4. Bean leaf beetleCerotoma trifurcataA small, variably coloured leaf beetle with a black triangle behind its head. It chews neat round holes in bean leaves and can kill seedlings in spring, but older plants outgrow most of the damage. No beneficial is sold for it; planting later, row cover and hand collection are the garden answers.Beans
  5. Asparagus beetleCrioceris asparagi (and the spotted asparagus beetle, C. duodecimpunctata)Two small, colourful leaf beetles that are pests of asparagus. The common asparagus beetle scars and hooks the spears and, with its grey larvae, strips the ferns. The spotted species is orange and mostly harmless. Hand-picking, prompt harvest and a clean autumn clear-out handle most garden beds, and a tiny wild wasp kills a large share of the eggs.Asparagus
  6. BillbugsSphenophorus spp.Small snouted weevils whose legless larvae tunnel down grass stems and then eat the crowns and roots. Damaged stems snap off at the soil and are packed with sawdust-like frass. Purdue calls billbugs the most commonly misdiagnosed insect problem in North American turf, usually taken for drought, disease or grubs.Lawn & turf

Still not sure? Answer four questions about the damage and the picker will separate them.

macro · beetles, side by side

At a glance

Species
6 profiled
Controls
0 beneficials
Settings
Field, Garden, Indoors, Under glass
Crops
12 host crops

Beetles & grubs by crop

Each page is one species on one host: the host-specific control, rate and threshold.