Alfalfa Weevil

Common Name: Alfalfa Weevil

Genus: Hypera

Species: postica

Identification: The beetles are grayish-brown to nearly black. They are about 1/8- to 1/4-inch long with a medium-sized beak projecting downward from the front of the head.

Lifecycle: The weevils overwinter as adults. In the spring the females lay eggs on the alfalfa stem. There are 3 to 4 larvae instars over a period of 29 to 58 days. The larvae become full grown about the first cutting and drop to the soil where they spin a cocoon and emerge as adults in 10 days. The adults can live for 10 to 14 months. There is one complete and sometimes a partial second generation per year.

Geographic Distribution: In all alfalfa-growing areas in West, midland and eastern United States.

Damage and Treatment: After feeding in the stems for 4 to 5 days, larvae emerge and feed in the terminal buds, severely stunting the crop. Treatment should be made when insect populations and/or damage levels reach economic thresholds. Refer to local University Extension Pest Management Guidelines for specific state thresholds.

Alfalfa

Fruits Nuts Trees and Vegetables

Alfalfa Caterpillar Colias

Amaranthes Amaranthus palmeri, Amaranthus hybridus, Amaranthus spinosus

Aphids Therioaphis maculata, Dysphis plantaginea, Acyrthosiphon kondoi, Acyrthosiphon kondoi, Acyrthosiphon pisum, Aphis gossypi

Armyworm, Beet Spodoptera

Cabbage Looper Trichoplusia

Codling Moth Cydia

Colorado Potato Beetle Leptinotarsa

Common Cocklebur Xanthium

Cutworms Agrotis ipsilon, Agrotis orthogonia, Peridroma saucia

Fall Armyworm Spodoptera

Grasshopper Melanoplus sanguinipes, Camnula pellacida

Green Peach Aphid Myzus

Kochia Kochia

Lambsquarters Chenopodium

Leafminer Liriomyza trifolii, Liriomyza sativa, Liriomyza huidobrensis

Leafroller Archips rosanus, Archips argyrospila, Argyrotaenia velutinana, Choristorenra rosaceana

Lygus Bug Lygus

Nightshades Solanum americanum, Solanum nigrum, Solanum ptycanthum, Solanum saccachoides

Panicum, Fall Panicum

Pear Psylla Cacopsylla

Pennsylvania Smartweed Polygonum

Pigweed, Redroot Amaranthus

Silverleaf Whitefly Bemisia tabaci, Bemisia argentifolii

Stink Bug Nezara viridula, Chlorockroa say, Euschistus consperus

Sweet Potato Silverleaf Whitefly Bemisia tabaci, Bemisia argentifolii

Tarnished Plant Bug Lygus

Tobacco Budworm Helicoverpa

Velvetleaf Abutilon

Venice Mallow Hibiscus

Wild Mustard Brassica

Mustang Learn more...

Mustang Max EC Learn more...

Stallion Learn more...