Monday, May 1, 2017

Pollinator of the Week: The Colorado State Insect! by Donna Duffy

Colorado Hairstreak Butterfly, photo courtesy statesymbolsusa.org

Did you know that Colorado has a state insect? The Colorado Hairstreak butterfly (Hypaurotis crysalus) was designated the official state insect  in 1996 due to the steady lobbying of 4th graders from Wheeling Elementary in Aurora, Colorado (led by teacher Melinda Terry).

The Colorado Hairstreak is a small to medium sized butterfly with a wingspan of about 1.25-1.5 inches. The upperside of the wings is purple, with a darker border; coloration is brighter in the males. Small orange spots mark the lower outside edge of each wing. The underside of the wings is light blue with faint dark bands and orange spots at the base of the hind wing. Typical of other hairstreak butterflies, a delicate “tail” protrudes from the hind wings.

Hairstreak Butterfly
The distribution of the Colorado Hairstreak within Colorado generally overlaps that of its host plant, Gambel oak, which grows widely in the foothills areas of the state. The Colorado hairstreak is also found in several other southwestern states and northern Mexico.

Adults of the Colorado hairstreak may be seen from June through August making patrolling flights among stands of Gambel oak or occasionally resting on leaves. They are fast fliers that are often in motion, so they are difficult to observe. The butterflies are thought to feed on tree sap and honeydew, but do not visit flowers for nectar.

Winter is spent in the egg stage, attached to twigs of oak. Larvae feed on the newly emerged leaves in spring and pupate in late spring or early summer. They then pupate and subsequently emerge in the adult form. A single generation is produced annually. 

Several other hairstreak butterflies occur in Colorado. The most widespread species is the gray hairstreak, Strymon melinus. This insect has a wide host range of plants within the mallow (Malvaceae) and legume (Fabaceae) families. In areas of juniper scrub forest the juniper hairstreak, Callophrys gryneus, is a common hairstreak species. 

Check out CSU's document on the Colorado Hairstreak butterfly for more information.