The unusual forked tail on the White Furcula caterpillar may be the first thing one notices, but it is not the last unusual feature on this larva.
Furculas are a type of nocturnal moth with a lovely mop of hair by the head and 'shoulders'. The furry crest has ribbons of metallic blue and dark yellow color in it. The White Furcula is not completely white, but those parts that are have a clean, snowy brightness. A dark gray, almost salt-and-pepper colored band crosses the middle of the wings, with smaller corners of dark color by the tips. A border of the same metallic blue and yellow separate the dark from the light regions. The white areas have a line of black dots that follow their curvy boundaries, and a row of these black dots hug the bottom edges of the wings. Black legs are loaded with long, white tufts of hair.
The caterpillar of the White Furcula is yellow or green with a dark brown diamond at the center of its body. This brown color also covers the head and runs a line down through a long, thin, forked tail. Furcula actually means 'forked' and this tail is about half as long as the caterpillar itself, and may be sticking straight up in the air or stretched behind the rear, extending the overall length of the larva. The segments behind the head may be swollen and come to points on either side, or they may be rounded, depending on maturity. The function of its coloring and pattern is to mimic the leaves, both alive and dried up, that it feeds on.
Look for adults and caterpillars on cherry trees, but also on willow and poplar trees. Two broods are produced each year and adults can be seen from spring through the end of summer.
Scientific Name: Furcula borealis
Butterfly or Moth
Size (Adult; Length): 30mm to 42mm (1.17in to 1.64in)
Colors: white, black, gray, orange, blue
Descriptors: metallic, shiny, patches, salt-and-pepper, grey, furry, flying, black dots
Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.
Butterfly and Moth Anatomy
Antennae: Butterflies and Moths have a pair of antennae on the head used as sensors.
Head: The head is home to the insect's eyes, antennae, and proboscis.
Thorax: Home to the three pairs of legs as well as vital internal organs.
Abdomen: Contains vital internal organs such as the heart(s) and reproduction facilities.
Forewing: The upper, forward wing pair used for flying.
Hindwing: The lower, rearward wing pair used for flying.
NOTE: Butterflies and Moths are part of the Lepidopteran order as they share many similarities.