{"id":9741,"date":"2018-10-02T10:19:51","date_gmt":"2018-10-02T15:19:51","guid":{"rendered":"https:\/\/uwm.edu\/field-station\/?p=9741"},"modified":"2018-10-03T10:29:47","modified_gmt":"2018-10-03T15:29:47","slug":"maple-spanworm-2","status":"publish","type":"post","link":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/maple-spanworm-2\/","title":{"rendered":"Maple Spanworm 2"},"content":{"rendered":"

Howdy, BugFans,<\/p>\n

Another week, another Maple Spanworm. This one, the Large Maple Spanworm<\/strong> (Prochoerodes lineola<\/em>) is also in the family Geometridae<\/em>. The BugLady didn\u2019t have to play her usual game of Identification Roulette because, of the seven New World species in this primarily tropical genus, this is the only one that occurs in eastern North America.<\/p>\n

\"Maple<\/a><\/p>\n

Like last week\u2019s Maple spanworm (Ennomos magnaria<\/em>), the adult is a fall-flying, nocturnal leaf mimic, and the caterpillar is cleverly disguised as a twig (here\u2019s a \u201cfrosted\u201d<\/a> and an \u201cunfrosted\u201d version<\/a> of the caterpillar). It\u2019s a nice-sized moth, about 1 \u00bd\u201d to 2\u201d across, with a few small points on the edges of the wings. There\u2019s a lot of variation in color,<\/a> but the dark line that bisects the front wing (the post-medial line) is diagnostic; it has pale edges and a sharp angle near the tip of the wing.<\/p>\n

Wagner, in Caterpillars of Eastern North America<\/em>, tells us that \u201cSeasonal phenology remains unclarified in the Northeast, where there seems to be a single principal generation, with mature caterpillars from June through August; southward with two to three generations.\u201d Both Wagner and Sogaard, in Moths and Caterpillars of the North Woods<\/em>, say that it overwinters as an egg, but other sources say that it overwinters as pupa. Here\u2019s a nice series of pictures of its life cycle.<\/a><\/p>\n

A publication by the North Carolina Parks Department says \u201cWe suspect that few individuals overwinter in North Carolina and that we get annual migrations in the spring that are able to establish temporary, but recurrent breeding populations throughout the state.\u201d The 2018 \u201cChecklist of Wisconsin Moths\u201d (Ferge, Balogh and Johnson), though, lists it as a resident here<\/a>.<\/p>\n

Like last week\u2019s Maple spanworm, the caterpillar does not limit its diet to maple; it\u2019s also found on woody plants like birch, willow, tamarack, aspen, blueberry, cherry, and dogwood, and on herbaceous plants like soybeans, sweet-fern, and members of the geranium family.<\/p>\n

\"Maple<\/a><\/p>\n

The Large maple spanworm was one of a number of moths studied by researchers Amanda Soutar and James Fullard in an effort to find out more about how moths avoid predators at night. They say that:<\/p>\n