Subject: Weird bug
Location: Pennsylvania
July 20, 2014 12:02 pm
Found this bug on my house in northeast Pennsylvania in the summertime. Any idea what it may be?
Signature: Shannon

Ailanthus Webworm

Ailanthus Webworm

Dear Shannon,
This pretty native Ermine Moth is commonly called an Ailanthus Webworm.  It is one of the few insects known to feed on the invasive, exotic Tree of Heaven,
Ailanthus altissimus, which is recognized on the government website Weeds Gone Wild as being a major threat with this statement:  “Tree of heaven is reported to be invasive in natural areas in 30 states across continental U.S. and Hawaii. It is highly adaptable to disturbance and a huge range of soil types and conditions, grows best in full sun and is tolerant of drought.  Ecological Threat  A common tree in urban areas where it causes damage to sewers and structures, ailanthus poses a greater threat to agriculture and natural ecosystems. It is a vigorous growing tree and prolific seeder that establishes dense stands that push out natives. Tree of heaven contains chemicals, including ailanthone, that have been found to have strong allelopathic (herbicidal) affects on the growth of other plants which help it establish and spread.”  Though the native Ailanthus Webworm has adapted to feeding on an invasive plant, it is doubtful that the Ailanthus Webworm will have much of an impact on controlling the spread of the scourge.

Location: Pennsylvania

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