Snowberry clearwing, Hemaris diffinis . The caterpillars of this moth feed upon snowberry and Tartarian honeysuckle, and are called hornworms because each has a horn on the tail like other sphinx moth caterpillars. There are two generations each season and the insects overwinter as pupae in the ground. The moths soon emerge and lay eggs for the second generation of larvae. The caterpillars vary from dark green with lighter green on the back to brown or purplish, with spiracles very prominent.
All wings are transparent with dark brown margins.
The body is black marked with golden pubescence. If needed, spray with Bacillus thuringiensis var. Malathion or spinosad can control larger larvae. The first generation larvae are found in May or early in June, while the second generation is active in July. These products are registered for use against this pest in Connecticut.