Animal Diversity Web

Ge­o­graphic Range

Gray hair­streaks can be found in South­ern Canada to Cen­tral Amer­ica and North­west­ern South Amer­ica. They occur from coast to coast and in a va­ri­ety of al­ti­tudes rang­ing from sea level to nine thou­sand feet. (Carter, 1992; Tveten and Tveten, 1996)

• Biogeographic Regions
• nearctic
  • native
• neotropical
  • native

Habi­tat

Un­like most but­ter­flies, gray hair­streaks do not pre­fer one spe­cific habi­tat. They are wide­spread in trop­i­cal forests and open, tem­per­ate wood­land areas. They can also be found in mead­ows, crop fields, ne­glected road­sides, and res­i­den­tial parks and yards are often homes of this fas­ci­nat­ing but­ter­fly. (Carter, 1992; Milne and Milne, 1980; Scott, 1986; Tveten and Tveten, 1996)

• Habitat Regions
• temperate
• tropical
• terrestrial

• Terrestrial Biomes
• forest
• rainforest
• mountains

• Other Habitat Features
• suburban
• agricultural

• Range elevation

  0 to 2745 m

  0.00 to 9005.91 ft

Phys­i­cal De­scrip­tion

In the ear­lier stages of the life cycle, gray hair­streaks are straw, pur­plish-white, pink, red­dish-brown, or green lar­vae with var­i­ous other paler marks. The head is yel­low­ish-brown. Throuhout Texas, how­ever, the lar­vae have been noted to be en­tirely green and cov­ered with short hairs. The pupae hi­ber­nate and are usu­ally brown­ish in color. In the adult stages of the life cycle the but­ter­fly's upper wings are dark gray­ish brown with a promi­nent or­ange spot lo­cated at the outer mar­gin close to the shorter of the two black­ish tails. The con­spic­u­ous or­ange spot is larger than most Stry­mon species. The hind wing is gray (darker in males and spring adults than in fe­males and sum­mer adults). It too has a black-eyed or­ange spot at the bases of the hind­wing tails. There is a small patch of blue be­fore the tail, and two bro­ken cross­bands of black and white spots. The male ab­domen is or­ange. The wingspan varies from 2.6 to 3.65 cm. (Carter, 1992; Milne and Milne, 1980; Scott, 1986; Tveten and Tveten, 1996)

• Other Physical Features
• ectothermic
• heterothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes colored or patterned differently

• Range wingspan

  2.6 to 3.65 cm

  1.02 to 1.44 in

De­vel­op­ment

After about six days the eggs hatch, and over the next twenty days the cater­pil­lars grow and de­velop. They then form a chrysalis and after about ten days emerge as adults. Sil­very-blues spend the win­ter as pupae and can have three or more gen­er­a­tions per year. De­vel­op­ment time can vary greatly de­pend­ing on ge­og­ra­phy and the dif­fer­ent hosts. (Drees and Jack­man, 1998; Scott, 1986; Tveten and Tveten, 1996)

• Development - Life Cycle
• metamorphosis
• diapause

Re­pro­duc­tion

Mat­ing and egg-lay­ing occur in early spring. Adult males perch on small trees and shrubs from early af­ter­noon to dusk to await fe­males. They usu­ally perch at a level where they can catch cooler breezes, lower to the ground in the spring and higher as the year goes on. Males back dor­sally. Mat­ing pairs are nor­mally spot­ted at night, and fe­males oviposit dur­ing the midafter­noon. The fe­males then lay their pale green eggs on hosts' buds or newly opened flow­ers of the host plant. (Drees and Jack­man, 1998; Scott, 1986; Tveten and Tveten, 1996)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• oviparous

• Breeding season

  early spring

There is no parental in­volve­ment once eggs are laid.

• Parental Investment
• pre-fertilization
  • provisioning

Be­hav­ior

The adults are quick fliers and are seen most often be­tween the months of May and Sep­tem­ber. They like to bask in the sun with wings spread wide, un­like most hair­streaks, but they also rub their hind­wings to­gether in the typ­i­cal fash­ion of most hair­streaks. This back-and-forth move­ment makes the wings look like an­nten­nae, ap­par­ently to fool preda­tors into at­tack­ing a less vital part of their body. They are best seen when at rest and their wings are folded to­gether over the back, one hind wing some­times raised while the other is low­ered. (Drees and Jack­man, 1998; Milne and Milne, 1980; Tveten and Tveten, 1996)

• Key Behaviors
• flies
• diurnal
• motile
• hibernation

Food Habits

Just as in many other char­ac­ter­is­tics of gray hair­streaks, their food habits are gen­eral. Nei­ther the cater­pil­lar nor the but­ter­fly are spe­cific to any cer­tain plant or flower, but rather feed on a va­ri­ety of plants. The lar­vae eat from at least twenty dif­fer­ent fam­i­lies of plants, in­clud­ing the pea and mal­low fam­i­lies. Nor­mally they can be found eat­ing fruits and flow­ers. They can also be found on maize, cot­ton and a va­ri­ety of shrubs and trees. The but­ter­fly feeds on nec­tar from a wide va­ri­ety of flow­ers. (Carter, 1992; Milne and Milne, 1980; Scott, 1986; Tveten and Tveten, 1996)

• Primary Diet
• herbivore
  • folivore
  • frugivore
  • nectarivore

• Plant Foods
• leaves
• fruit
• nectar
• flowers

Ecosys­tem Roles

These gen­er­al­ists feed on (and likely pol­li­nate) a wide va­ri­ety of plants. They also may be eaten by a wide va­ri­ety of preda­tors.

• Ecosystem Impact
• pollinates

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Gray hair­streaks ben­e­fit hu­mans just as so many other but­ter­flies, bees, and small birds do. The but­ter­fly par­tic­i­pates in a mu­tu­al­is­tic re­la­tion­ship with many flow­er­ing plants by re­ceiv­ing nu­tri­ents (nec­tar) and act­ing as a pol­li­na­tor. (Milne and Milne, 1980; Tveten and Tveten, 1996)

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

The lar­vae of gray hair­streaks, when abun­dant, can be­come pests to com­mer­cial crops, in­clud­ing cot­ton, beans, corn, and hops. Habits such as these have earned the cater­pil­lar the com­mon name of "cot­ton square borer" and "bean ly­caenid". (Milne and Milne, 1980; Tveten and Tveten, 1996)

• Negative Impacts
• crop pest

Con­ser­va­tion Sta­tus

Gray hair­streaks are not cur­rently en­dan­gered or threat­ened.

• IUCN Red List

  No special status

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Other Com­ments

This but­ter­fly is so abun­dant across the United States that some sug­gest that be­sides the monarch it should be named the na­tional but­ter­fly. (Tveten and Tveten, 1996)

Con­trib­u­tors

Matthew Wund (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Lau­ren Ro­driguez (au­thor), South­west­ern Uni­ver­sity, Stephanie Fab­ri­tius (ed­i­tor), South­west­ern Uni­ver­sity.

Ref­er­ences

Carter, D. 1992. But­ter­flies and Moths. New York: Dor­ling Kinder­s­ley.

Drees, B., J. Jack­man. 1998. A Field Guide to Com­mon Texas In­sects. Hous­ton: Gulf Pub­lish­ing Com­pany.

Milne, L., M. Milne. 1980. The Audubon So­ci­ety Field Guide to North Amer­i­can In­sects and Spi­ders. New York: Al­fred A. Knopf, Inc..

Scott, J. 1986. The But­ter­flies of North Amer­ica: A Nat­ural His­tory and Field Guide. Cal­i­for­nia: Stan­ford Uni­ver­sity Press.

Tveten, J., G. Tveten. 1996. But­ter­flies of Hous­ton and South­east Texas. Austin: Uni­ver­sity of Texas Press.