SYMPTOMS
You find large, irregularly shaped holes in leaves. The main veins remain intact. Leaves may be partly skeletonized (soft tissue eaten away, leaving veins). Leaves may be rolled into a tube and sewn together with silk. A caterpillar hides inside the tube. Look for tiny, black, or green pellets of caterpillar poop.
DIAGNOSIS
leaf-eating caterpillars and budworms: European corn borer (Ostrinia nubilalis); hemp borer, leaf roller, or hemp seed eater (Grapholita delineate); cotton bollworm (Helicoverpa armigera); corn earworm (Helicoverpa zea); flax noctuid (Heliothis fireplace); hemp bagworm (Psyche cannabinella); silver Y moth (Autographa gamma); dot moth (Melanchra persicaria); cabbage moth
(Mamestra brassicae); garden tiger moth (Arctia caja); common hairy caterpillar (Spilosoma obliqua); beet webworm (Loxostege sticticalis); hemp dagger moth (Plataplecta consanguine)
SYMPTOMS
You find large, irregularly shaped holes in the leaves, or entire leaves are missing. Main veins are eaten. Look for tiny, black pellets of caterpillar poop. Caterpillars in soil are curled into C shapes.
DIAGNOSIS
cutworms and armyworms: black cutworm (Agrotis epsilon), paddy cutworm (Spodoptera litura), beet armyworm (Spodoptera exigua), playback cutworm (Agrotis gladiatorial), common cutworm (Agrotis segetum), bertha armyworm (Mamestra configurator)
SOLUTIONS
• Weed
• Use screens on doors, vents, and windows
• Use cutworm collars
• Turn off lights at night
• Remove pests by hand
• Use beneficial insects
• Use beneficial nematodes
• Use beneficial bacteria
• Use beneficial protozoa
• Use insecticidal viruses
• Use hot-pepper spray
• Use garlic spray
• Use insecticidal soap
• Use neem
• Use spinosad
• Use pyrethrin
• Do not plant near corn (maize)
• Rotate crops
SOLUTIONS
• Use cutworm collars
• Remove pests by hand
• Use beneficial insects
• Use beneficial nematodes
• Use beneficial bacteria
• Use insecticidal viruses
• Use hot-pepper spray
• Use garlic spray
• Use insecticidal soap
• Use neem
• Use spinosad
SYMPTOMS
You find numerous small holes between leaf veins. Leaves may be skeletonized (soft tissue eaten away but veins remain). Look for tiny beetles that hop like fleas on leaves.
DIAGNOSIS
flea beetles: hemp flea beetle (Psylliodes attenuate), hops flea beetle (Psylliodes punctulata), striped flea beetle (Phyllotreta nemorum), others (Podagrica spp.)
SOLUTIONS
• Sanitize
• Weed
• Use traps
• Use beneficial nematodes
• Use beneficial bacteria
• Use hot-pepper spray
• Use garlic spray
• Use insecticidal soap
• Use neem
• Use spinosad
• Rotate crops
• Do not plant near eggplant
SYMPTOMS
You find large, ragged holes in leaves; leaves may be skeletonized (soft tissue eaten away but veins remain). Look for copper-colored, metallic green beetles or beetles that resemble brown ladybeetles.
DIAGNOSIS
large leaf-eating beetles: Japanese beetle (Popillia japonica), Indian bean beetle (Epilachna dodecastigma)
SOLUTIONS
• Weed
• Use row covers
• Remove pests by hand
• Use beneficial fungi
• Use hot-pepper spray
• Use garlic spray
• Use insecticidal soap
• Use neem
• Use spinosad
SYMPTOMS
You find holes in the middle, or notches on the edges, of leaves. Holes and notches have yellow halos. Look for black beetlelike insects with long snouts, which often hide in the soil. When disturbed, they drop to the ground and play dead.
DIAGNOSIS
weevils and curculios: hemp weevil (Rhinoncus pericarps), cabbage curculio (Ceutorhynchus rapae)
SOLUTIONS
• Sanitize
• Weed
• Use row covers
• Remove pests by hand
• Use traps
• Use beneficial nematodes
• Use hot-pepper spray
• Use garlic spray
• Use insecticidal soap
• Use neem
• Use diatomaceous earth
• Use spinosad
SYMPTOMS
Ants swarm over plants, cutting large pieces from leaves, usually from edges. They carry leaf pieces to their nest.
DIAGNOSIS
leaf-cutter ants
SOLUTIONS
• Use traps
• Use diatomaceous earth
SYMPTOMS
You find large, round, smooth-edged holes in leaves. Plants may be stripped of leaves. As you walk among plants, these significant pests leap away from you.
DIAGNOSIS
grasshoppers: two-striped grasshopper (Melanoplus bivittatus), sprinkled locust (Chloealtis conspersa), clear-winged grasshopper (Camnula pellucid), elegant grasshopper (Zonocerus elegans), citrus locust (Chondracris rosea)
SOLUTIONS
• Weed
• Use row covers
• Use screens on doors, vents, and windows
• Remove pests by hand
• Use beneficial fungi
• Use beneficial protozoa
• Use neem
• Use diatomaceous earth
SYMPTOMS
Leaf edges have ragged holes, or leaves are skeletonized (soft tissue eaten away but veins remain). Look for pale green, ½-inch- long (13 mm) caterpillar-like larvae.
DIAGNOSIS
hemp sawfly (Trichiocampus cannabis)
SOLUTIONS
• Use row covers
• Use screens on doors, vents, and windows
• Remove pests by hand
• Use neem
SYMPTOMS
You find holes in the middle of tender new leaf blades. Look for ½- inch-long (13 mm), dark red-brown, flattened, segmented insects with two large pincers on their rear ends.
DIAGNOSIS
common earwig (Forficula auricularia)
SOLUTIONS
• Use traps
• Use insecticidal soap
• Use diatomaceous earth
• Use spinosad
SYMPTOMS
You find large, irregularly shaped holes in leaves, with glistening trails of dried slime. Look for slugs or snails on or near plants.
DIAGNOSIS
slugs or snails: slugs (Deroceras spp., Limax spp., Agriolimax spp.,
Arion spp.), brown garden snail (Helix aspersa)
SOLUTIONS
• Weed
• Use row covers
• Use copper tape
• Remove pests by hand
• Use traps
• Use beneficial nematodes
• Use iron phosphate
• Use diatomaceous earth
SYMPTOMS
You find leaves bitten in half or completely eaten. Whole plants may be missing. Stems may be gnawed close to ground level. Look for telltale deer prints or rodent burrows.
DIAGNOSIS
mammals: deer (Odocoileus spp.), rabbit (Sylvilagus spp.), rat (Rattus spp.), vole (Microtus spp.), mouse (Mus musculus), pocket gopher (many genera), woodchuck or groundhog (Marmota monax)
SOLUTIONS
• Use fences
• Use netting
• Use traps
• Use hot-pepper spray
• Use garlic spray