Snakeweed Insect Collection

Some Snakeweed Insects

Image of one of the most important of the insects attacking snakeweed
One of the most important of the insects attacking snakeweed is the long-horned beetle Crossidius pulchellus. The larvae of this beetle bore into the crown and tap root of the plant, usually destroying it. They attack only mature plants, however, and the adult beetle (seen here) may serve as a pollinator, as it frequents the blooming plants in the fall.
- (Photo by David Thompson)

Image of the larva attacking the root and leaving a characteristic bore hole
The larva attacks the root and leaves a characteristic bore hole through the center of the root. There is usually only one larva per root.

Image of The clerid beetle
The clerid beetle, Enoclerus coccineus, is a major predator of snakeweed root-boring insects, especially Crossidius pulchellus. The larvae of this predator are bright pink in color and on at least one year were found more offten than Crossidius pulchellus is the roots.

More Snakeweed Insects

Image of the foliage-feeding caterpillar
Some snakeweed insects can be very colorful, as is the foliage-feeding caterpillar of Cuculia sp., a noctuid moth. While these insects do not ever seem to be so numerous as to damage snakeweed stands, they do feed on the plants.

Image of the larvae of the moth family
The larvae of the moth family Geometridae are the familiar "inch-worms". This is a common geometrid that feeds on woody snakeweeds.

Image of the tortricid leaftier
The tortricid leaftier, Synnoma lynosyrana, can be responsible for up to 50% seed destruction on branches it ties up. The feeding of the caterpillar may severely stress the plants, opening them to attack by such root-borers as Crossidius pulchellus.

Image of the ichneumonid parasitoid
A major natural enemy of the snakeweed leaftier is the ichneumonid parasitoid Glypta albitibia.

Image of the red-kneed grasshopper
The snakeweed, or red-kneed grasshopper, Hesperotettix viridis, can be a major player in the natural control of woody snakeweeds. A density of only a few grasshoppers per plant can completely defoliate snakeweed and result in a total destruction of the seed crop for that year.

Image of the snakeweed grasshoppers
The snakeweed grasshoppers also has natural enemies, such as this asilid fly
- (Photo by David Thompson).

Image of the snakeweed bud weevil
The snakeweed bud weevil, Anthonomus tenuis, appears to favor broom snakeweed over the related thread-leaved snakeweed for oviposition. The larvae of this beetle can destroy a significant amount of the seeds in a flower head.

Image of the leafbeetle
The leafbeetle, Monoxia pererbula, can cause serious damage to snakeweed, under certain conditions.

Image of the the plants usually recover
Unfortunately the plants usually recover, although their seed production is destroyed for that year.