Bug FAQKarner Blue
Plebejus samuelis · Order: Lepidoptera · Family: Lycaenidae
The Karner blue is a tiny butterfly with a wingspan of about 2.5 cm and forewing lengths of 1.2 to 1.6 cm, differing slightly between males and females. It lives in dry, sandy habitats like oak savannas and pine barrens that support wild lupine, needs periodic disturbance to stay open, and its larvae feed only on that plant.
Source: Wikipedia
How to get rid of it
If burning isn’t possible, mowing at a height above 4 in (10 cm) in autumn or winter, leaving clippings, can keep the area open with little harm.
Source: Wikipedia
Where it lives
Found in dry, sandy ecosystems such as oak savannas, pine barrens, dunes, and early-successional woodlands that host wild lupine. These habitats need disturbance to prevent tree and shrub canopy closure.
Source: Wikipedia
Life cycle
Produces two generations each year; eggs from the second brood overwinter and hatch in mid- to late April.
Source: Wikipedia
When you see it
First-brood adults are on the wing from late May through late June.
Source: Wikipedia
Where it comes from
Native to the Great Lakes region and the northeastern United States and Canada. Historically formed a narrow band from the western Great Lakes eastward to New England and southern Ontario.
Source: Wikipedia
Lookalikes
Melissa blue can be told apart by orange banding on the female forewing, and Nabokov's blue prefers different habitats and host plants.
Source: Wikipedia
Where it is found in the US
Recorded in 9 of 51 states and DC. Most records: Wisconsin, New York, New Hampshire, Michigan, Minnesota, Ohio, Pennsylvania, Indiana.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Same family (Lycaenidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Karner_blue
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.