COLEOPTERA

beetles and weevils

COLEOPTERA

• Coleos: sheath

• Ptera: wing

• Complete

• Chewing

• Wings:– Front: hardened (elytra), not for flight– Back: membranous

• Larva are grubs

WHITE GRUBS

• C-shaped larva

• Several different species are a pest

WHITE GRUBS

• Identify species by rastral pattern

WHITE GRUBS

• Identify species by rastral pattern

WHITE GRUBS

WHITE GRUBS

• Weevils are legless white grubs

WHITE GRUBS

HOST

Turf

• Lush, high irrigation and fertilization

Many are harmless, feed on OM

WHITE GRUBS

DAMAGE

• Consume roots in late summer

• Water stress spots in mid-August

WHITE GRUBS

MONITOR

• Direct sample (8 to 12 grubs / sq ft)

• Pull water stressed spots in August– Mole crickets?

WHITE GRUBS

CONTROL

• Milky spore, Japanese beetle only

JAPANESE BEETLE (98)

• Larva: white grub

• The grub was introduced in 1916 from Japan on Iris roots

JAPANESE BEETLE (98)

JAPANESE BEETLE (98)

JAPANESE BEETLE (98)

HOST

• Larva: turf roots

• Adult: rose, Prunus, maple, other woody plants…

JAPANESE BEETLE (98)

DAMAGE

• Larva: feed on turf roots

• Adult: June to September

JAPANESE BEETLE (98)

DAMAGE

• Tissue between veins (young leaves)

• Lacey symptoms

JAPANESE BEETLE (98)

DAMAGE

• Also eat fruit and blossoms

JAPANESE BEETLE (98)

MONITOR

• Pheromone traps

• Branch beating adults

JAPANESE BEETLE (98)

CONTROL

• Larva: Milky spore disease, nematodes, insecticide

• Established woody can tolerate

WEEVILS (92)

• Snouts beetles

• Many flightless (elytra fused)

• Larva: legless grubs

WEEVILS (92)

HOST

• Whitefringed beetle: Azalea

• Palmetto weevil: Palms

• Other weevils, most other woody plants…

WEEVILS (92)

Whitefringed beetle

WEEVILS (92)

DAMAGE: Whitefringed beetle

• Adults: notched symptoms on foliage in July

WEEVILS (92)

CONTROL: Whitefringed beetle

• Plants tolerant in Lowcountry

WEEVILS (92)

Palmetto weevil

WEEVILS (92)

DAMAGE: Palmetto weevil

• Dying or weak palm gives off scent

• Male locates susceptible palm, releases pheromone

• It’s all over after that

WEEVILS (92)

DAMAGE: Palmetto weevil

• Larva feeds on crown

• “Breaks” the neck

WEEVILS (92)

CONTROL: Palmetto weevils

• Insecticides no good once infested

• Cut down before adult emerges

• Mass trapping and sanitation

BARK BEETLES (173)

• Size of rice

• Dark, red, brown, or black

• Southern Pine Beetle

BARK BEETLES (173)

• Vectors blue stain fungus

BARK BEETLES (173)

• Larvae tunnel called galleries (packed with frass)

BARK BEETLES (173)

HOST

• Pine, spruce…

• Plants in weakened state (predisposed)

BARK BEETLES (173)

DAMAGE• Larvae tunnel through the phloem • Pitch around boring holes• Sawdust below• Further weaken host

BARK BEETLES (173)

DAMAGE• European Elm Bark Beetle

– 1904 in Boston• Attacks American Elms and introduces spores

of the Dutch Elm Disease (DED)

BARK BEETLES (173)

BARK BEETLES (173)

BARK BEETLES (173)

BARK BEETLES (173)

MONITORING

• Declining branches– Break open

• Pheromone traps

BARK BEETLES (173)

CONTROL• Avoid unseasoned firewood storage near

hosts– Cover with plastic for several months

• Destroy infected branches• Systemic insecticides do NOT work once

there are symptoms• Some resistant varieties, such as Valley

Forge American elm

BORERS (179)

Flathead borers

• Legless grub

BORERS (179)

Flathead borers

• Metallic adults (copper, blue, green)

• Steamlined, bullet shaped

• Grooved wings

BORERS (179)

Flathead borers

BORERS (179)

Roundhead borers

BORERS (179)

Roundhead borers

• Long antennae (long horn beetles)Long antennae (long horn beetles)

BORERS (179)

HOST

• Predisposed trees

• Mostly deciduous

• Rarely attack healthy host

BORERS (179)

DAMAGE

• Larvae bore throughout tree

• Finish off dying host

BORERS (179)

MONITOR

• Limb dieback

• Boring holes wet or oozing

BORERS (179)

MONITOR

• Limb dieback

• Boring holes wet or oozing

BORERS (179)

CONTROL

• Avoid unseasoned firewood storage near hosts

• Destroy infected branches

• Systemic insecticides do NOT work

TWIG BEETLES

Twig borer

• Lay eggs in twig and introduce Ambrosia fungus

• Larva feed on fungus

• Pupate in twig before winter

TWIG BEETLES

Twig borer

HOST

• Southern Magnolia, redbud, dogwood…

TWIG BEETLES

Twig borer

DAMAGE

• Small branches wilting and dying

• Hole located at base

• Does not harm the health on host

Red Bay Ambrosia Beetle

• Decimating red bay trees

• Red bay wilt (closely related to DED)

• http://okeechobee.ifas.ufl.edu/News%20columns/Red.Bay.htm

Red Bay Ambrosia Beetle

• Discoloration of outer sapwood

Red Bay Ambrosia Beetle

• May push out “stick” as it feeds