Subject: Large bluish beauty
Geographic location of the bug: Outside Sackville, New Brunswick, Canada.
Time: 11:38 AM EDT
Your letter to the bugman: Walking near my parents’ trailer, I nearly stepped on this rather beautiful creature and couldn’t help but wonder what it is. It was generally inclined to stay still, but once I put it down, after lifting it for closer inspection, it was happy to race over very course gravel in order to get back to the tall grass.
How you want your letter signed: Parker
This is a Blister Beetle in the genus Meloe, commonly called an Oil Beetle because the iridescent surface of the beetle looks like oil on water. Blister Beetles should be handled with caution, as many species are able to exude a compound called cantharidin that is known to cause blistering upon contact, especially in sensitive individuals. The “crook” in the antennae indicates this is a male Oil Beetle.
Blister Beetles as a family tend to have complex life cycles. Of the genus Meloe, the Oil Beetles, BugGuide states: “Larvae feed on eggs and other food in bees’ nests” and “In some species, triungulins [see definition below] aggregate and use chemical signals to attract male bees to which they attach themselves. This allows transport (and transfer) to a female bee who carries them back to her nest (Saul-Gershenz & Millar 2006). First-instar larvae climb to the top of a plant as a group, clump together in the shape of a female solitary ground bee, exude a scent imitating the female bee pheromone. When a male bee comes and tries to mate with the clump of larvae, some of these clamp onto his hairs and eventually get to female bees when he mates for real. Impregnated female bees fly off and build nests in burrows; triungulins move to the new nests and feed on honey and pollen stocked by the bee for her own young. –Jim McClarin’s comment.” Of the family, BugGuide notes: “Life cycle is hypermetamorphic. Larvae are parasitoids. Eggs are laid in batches in soil near nests of hosts, sometimes in nest of bee host, or on stems, foliage, or flowers. Larvae undergo hypermetamorphosis–first instar larvae (usually called triungulins) are active, have well-developed legs and antennae. These typically search for hosts. Later instars tend to have reduced legs and be less active, having found hosts. There is a coarctate (pseudopupal) stage, which is usually how the larvae overwinter. Life cycle may be as short as 30 days, or as long as three years. It is typically one year, corresponding to that of host.