Ailanthus Webworm

Atteva punctella

September 2, 2004

So, the Ailanthus Webworm feeds on Ailanthus altissima, or Tree-of-Heaven (you know, the tree in Betty Smith's "A Tree Grows in Brook-lyn").  The tree was introduced by a gardener in Philidelphia in 1784.  

So what did the native (and it is) 

A. punctella feed on before the introduction of this invasive plant?

A possible explaination is they originated in South Florida and the tropics south of that where they  feed on Paradise Tree, Simarouba glauca.  Both of these host plants are in the Simaroubaceae family, so the switch to Ailanthus wasn't that radical a departure in their diet. The introduction of this new food source in points further north 

(it's in 48 of our states) allowed it 

to expand its range.

They still don't do well in our Northeast winters, though.  Most of what we get are migrants from the south that get here by late summer.

This, by the way, adds a new family to the site - the Yponomeutidae, or Ermine Moths.