Though the adult Western Grapeleaf Skeletonizer Moth does not bite or sting, its caterpillar does both, hurting leaves and people.
It may be completely black with shiny wings, or it may have a bright yellow or orange collar, but either way, an observer might take this insect for a fly or bee, but the Western Grapeleaf Skeletonizer Moth is neither. That said, it is still quite a nuisance in its own way.
Lemony colored eggs are laid in groups of 10 to 100 on the bottom of grape leaves. They hatch in about 7 days. The caterpillar is yellow and tubular. It may have a blue ring near its head and another near its rear. Its ten yellow bands of color are broken by eleven black hairy rings that can cause painful stings to humans. The spines can cause an allergic reaction that may require medical attention. Like every type of caterpillar, it has a voracious appetite and this species devours the fleshy green parts of leaves of grapevines harming the plant and its fruit production. All that remains of the leaf after the caterpillar is finished with it are its veins, still in leaf shape, giving it a skeleton-like appearance. Look for them, with gloved hands and long sleeves, under grape leaves. They chew through them from the bottom. They are a major pest to California grape-growers and wine producing industries. To further aggravate the situation, many generations can be produced in one year making it possible to see a vineyard decimated by the caterpillars in one growing season. They pupate after 40 days of feasting and emerge two weeks later as winged adults, ready and able to reproduce.
A variety of methods are used to control the larvae of the Western Grapeleaf Skeletonizer Moth: introduction of granulosis virus and species-specific parasites, the use of insecticidal spray, removal of leaf litter and debris away from plant bases, and destroying infested leaves.
Scientific Name: Harrisina metallica
Butterfly or Moth
Size (Adult; Length): 22mm to 30mm (0.86in to 1.17in)
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.