Burrowing Webworm or Tubeworm Moths Acrolophinae
Tubeworm moths of Acrolophus are remarkable for their hairy nose cones (palpi) Males often have very long palpi thrown over their heads like elephant trunks. Females have hairy, shorter nose cones that project outward from the head, not curved. Females are seldom seen.
Four have a lion mane-like thoraxes. The other two have thin, erect hair (spiked). Antennae are bright yellowish-brown. Length 9 to 16 mm. All except one fly from mid-June to the end of July.
Very little is known of their life cycle. Most larvae feed on roots and leaves of grasses and clover, building silk-lined tubes in tunnels underground and appearing at night to feed. They over-winter in larvae stage, continue feeding in spring and pupate inside their silk-lined tunnels to emerge as adults in summer. Ontario has 6 species of Acrolophus (2 of them new) and one that could possibly expand it’s range from Ohio into Ontario. One other one, Amydria effrentella is common in Ontario.
Acrolophus arcanella New
Acrolophus morus (mora)
Acrolophus plumifrontella Possible
Acrolophus propinqua New
All Acrolophus species fade quickly. New, freshly emerged species with large manes often have a line or two of iridescent white dashes, a scattering of iridescent white spots, or both.
Explanation of the term ‘triangle pattern’. Inner margin yellowish to white with two yellowish/white triangles and with a dark triangle before and between the yellowish triangles.
Quick ID Acrolophus males
Lion mane thorax:
Acrolophus arcanella – the only one with short, hairy nose cones (palpi), pointed; extend only to top of head, not curved. Triangle pattern. Dark brown-black, fading to light brown. New for Ontario.
Acrolophus popeanella – cream to yellowish diagonal stripe from wing base to inner margin. No triangle pattern. Dark brown or reddish-brown fading to almost entirely yellow. This is the most common species in s. w. Ontario and also has the most extreme colour changes.
Acrolophus plumifrontella – mostly brick red, usually maintains red along outer (costal) margin when old. Overall it appears shorter (smaller) because wings are very wide (6 to 7 mm) and wing tip is straight or squared. In Ohio and expected in Ontario. (No photos).
Acrolophus texanella – dark slanted patch near hind margin close to inner margin, usually with a white slanted line before patch. Long, thickly scaled antenna to mid-wing. Faint triangle pattern. Dark brown fading to light brown. A smaller species with two found at Point Pelee National Park in 2012, and one in Norfolk (not date). No photos.
Hair spiked thorax:
Acrolophus morus (mora) – Variable. Large with pointed wings. Triangle pattern. Palpi short, reaching to base of thorax. Antenna long, to mid-wing. Legs hairy. Best ID’d by fly date of September to October, long after all other Acrolophus in Ontario. A more northern, rare species; not in s. w. Ontario. (No photos).
Acrolophus propinqua – Entirely brownish-gray with purplish iridescent sparkles; no pattern. Wedge shaped; narrow wing base and wide wing tips. Palpi long, darker on fresh individuals, fading to entirely bright orange-yellow on older individuals. New for Ontario.