It’s Hairstreak Season

Mid June to mid July is Hairstreak season. A single generation of five hairstreaks (genus Satyrium) found in the state fly only in that time period. They get the name hairstreak from the threadlike extensions on the bottom of their hindwing. It is thought that the orange spot and hairstreak on the hindwings are meant to convince (or confuse) predators into thinking that is the insects’ head and to direct their attack there. At which time the butterfly escapes, cosmetically damaged but still alive. The five Nebraska hairstreaks are the Coral (S. titus), Acadian (S. acadicum), Banded (S. calanus), Hickory (S. caryaevorum), and Striped (S. liparops). Of the five Banded and Coral and Hairstreaks are usually found every year. Acadian Hairstreaks about every other year, Striped Hairstreaks about every five years, while Hickory Hairstreaks are seldom reported. Of the five species Coral, Hickory, Striped and Banded are all NENHP Tier 2 species (see June 14 post).

Banded Hairstreak – Satyrium calanus

Larvae feed on oaks and their range in Nebraska largely coincides with that of native bur oaks. Adults often perch on their host plants with males flying out to investigate passing butterflies. They can be highly localized, often being found exclusively on the same tree or two for multiple years while being absent from other trees nearby. Several personal observations – I’ve seen this hairstreak in the morning (as early as 7:00 am) on east facing oaks. Tapping oak branches puts them into flight (perched in the trees they are not easily located). Checking flowers in the vicinity of oak trees can also be productive. The Band in the common name refers to the band of white markings on the underside of the hindwing.

Coral Hairstreak – Satyrium titus

Larvae feed on Chokecherry and Plum (Prunus sp.) While in the same genus as the other hairstreaks it actually lacks a tail on the hindwing. Instead this butterfly can be identified by the “coral” colored markings on the outer margin of the ventral hindwing. While wild plums are larval hostplants most are found on/near chokecherries. Finding milkweeds in bloom in close proximity to chokecherry plants increases your odds of locating this butterfly. They are found statewide.

Acadian Hairstreak – Satrium acadicum

Larvae feed on willows (Salix sp.) and adults are usually found in riparian areas on or near their hostplants. Adults are lighter colored than other members of this genus. Maculation on the interior of the ventral hindwing consist of a row of dots. They appear to be less common south of the Platte River valley but otherwise can be found statewide.

Striped Hairstreaks – Satyrium liparops

While Striped Hairstreak larvae feed primarily on Chokecherry (P. virginiana) locating adults seems to be completely haphazard, with individuals often showing up randomly at unexpected locations (you can’t go looking for them, they just “happen”). The ventral hindwing is subtly marked with white striping. Distribution is statewide.

Hickory Hairstreak – Satrium caryaevorum

Hickory Hairstreaks are seldom reported and their range is restricted to southeast Nebraska where native hickories (shagbark and bitternut) occur. Most sightings are of single individuals. However, as is always the case, there are exceptions. Jim Reiser and I stumbled onto a population in a “ravine” west of Lincoln in 1994 where they were everywhere. Knowing we would never see this again we collected a couple dozen, mostly males (sadly for us males in the insect world we are largely disposable). They just kept floating out of the trees. When we left it seemed like there were more than when we arrived. Every once in a while the stars line up and normally small populations explode. Enjoy those moments when you come across them. I’ve driven Highway 34 west out of Lincoln several times (as an alternative to the Interstate madness) in recent years and cannot say for sure where that location is. Landscapes change, sadly it seems, hardly ever for the better.

There is one historic record of Edwards Hairstreak from Cherry county from about a 100 years ago but for the sake of brevity I won’t cover it here. So the hairstreaks are out. They’re small (fingernail sized) and very similar but with good pics can be identified. Or just enjoy them being there. Happy Hunting!

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