Psenocerus supernotatus
(Say, 1823)
Currant-tip Borer
Psenocerus supernotatus, commonly known as the Currant-tip Borer, is a small longhorned beetle ( Cerambycidae) notable for its remarkable -mimicry. At only 4 millimeters in length, it is the sole in the Psenocerus. The exhibits , with white markings on its creating the illusion of a constricted "waist" that resembles ant body segmentation. Despite its suggesting currant as a , it has been reared from multiple hardwood species including Green Hawthorn, Tulip Tree, and Black Willow.
Pronunciation
How to pronounce Psenocerus supernotatus: /ˌpsɛnəˈsɛrəs ˌsuːpərnoʊˈteɪtəs/
These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.
Identification
Distinguished from true ants by the presence of (hardened forewings) rather than the membranous wings or wingless condition of ants, and by having only six legs (ants have six legs but with distinctly different proportions). Separated from other -mimicking cerambycids by its extremely small size, downward-directed nearly concealed by the pronotum, and specific pattern of white markings. Differs from Cyrtophorus verrucosus (9 mm) and Euderces pini (7-8 mm) by being substantially smaller. Can be distinguished from Molorchus and Tilloclytus by head orientation and specific elytral markings.
Images
Appearance
Very small , approximately 4 mm in body length. Dark coloration with distinctive white streaks or bars on the that create the illusion of body segmentation, mimicking the constricted waist of ants. The is relatively small, directed downward, and nearly hidden by the pronotum. The overall body form is slender and -like. Earthtone colors provide cryptic camouflage.
Habitat
Associated with hardwood trees and shrubs, particularly in areas where plants occur. have been found on man-made structures such as air-conditioning units, suggesting they may wander from host vegetation. The has been reared from Green Hawthorn, Tulip Tree (Liriodendron tulipifera), and Black Willow, indicating a preference for deciduous woodland and riparian where these trees grow.
Distribution
Widespread in North America east of the Rocky Mountains. Documented from Canada (Manitoba, New Brunswick, Nova Scotia, Ontario) throughout the eastern and central United States. GBIF records confirm presence across this broad range.
Seasonality
are active from April to June, with peak activity in early spring. This seasonal pattern aligns with the flowering period of many hardwood trees.
Host Associations
- Green Hawthorn - larval reared from this plant
- Tulip Tree - larval also known as Tulip Poplar or Yellow Poplar; reared from this plant
- Black Willow - larval reared from this plant
- Currant - larval source of , though other are more commonly documented
Life Cycle
Larval development occurs within the wood of trees and shrubs. emerge in spring and are active during daylight hours. Specific details of -laying, larval instars, and are not documented in available sources.
Behavior
are active, running rapidly, and capable of . They are frequently found on flowers, with one record from ninebark (Physocarpus opulifolius). The -mimicking appearance likely provides protection from that avoid ants. Adults may be found on man-made structures, suggesting some tendency to wander from plants.
Ecological Role
As a wood-boring , larvae contribute to the decomposition of dead and dying hardwood branches and stems. The 's -mimicry represents a case of , where a harmless gains protection by resembling ants that are defended by formic acid and aggressive . Not considered a pest species.
Human Relevance
Not considered an economic pest. The does not affect crops or orchard trees. May be encountered by entomologists and naturalists during spring insect surveys. Its -mimicry makes it an interesting subject for studies of and protective mimicry.
Similar Taxa
- Cyrtophorus verrucosusAnother -mimicking cerambycid, but substantially larger (9 mm vs. 4 mm), with different elytral markings and orientation
- Euderces pini-mimicking cerambycid in same size range but slightly larger (7-8 mm), with more slender body and frequently found on flowers feeding on pollen and nectar
- Molorchus bimaculatus-mimicking cerambycid with different pattern of markings and different associations
- Tilloclytus geminatus-mimicking cerambycid with oblique and transverse markings creating different illusion of ant body structure
More Details
Taxonomic history
Originally described by Thomas Say in 1823 as Clytus supernotatus, later transferred to the Psenocerus. The has undergone taxonomic revision but remains the sole member of its genus.
Discovery and documentation
Despite its small size and cryptic appearance, the has been documented 588 times on iNaturalist as of 2025, indicating it is not rare but is frequently overlooked due to its -like appearance.