Subject:  Large Black Desert Wasp other than Tarantula Hawk
Geographic location of the bug:  Lost Palms Oasis – Joshua Tree NP
Date: 09/04/2018
Time: 07:03 PM EDT
Your letter to the bugman:  While hiking in J-Tree this week (Early September), I came across a small swarm of large, black wasps around a patch of milkweed. I initially thought they were Tarantula Hawks, but upon closer inspection they were distinctly different from the T-Hawks I’ve seen around Southern California.
-Black Body approx. 1.5″ in length.
-Rust-Red Abdomen
-Black wings with a subtle blueish sheen.
-Found in a small swarm on Milkweed.
I’ve encountered many different bees and wasps on hikes, but never anything this large that wasn’t a Tarantula Hawk. I couldn’t find anything online that looked like them. Any ideas?
How you want your letter signed:  Ryan Dunn – @CogArtist

Scarab Hunter Wasp

Dear Ryan,
We have identified your beautiful Scarab Hunter Wasp in the family Scoliidae as
Triscolia ardens thanks to images on BugGuide where it states the range is:  “Texas west to California, and south into Mexico.”  According to BugEric:  “Their life cycle can be generalized as follows.  The female wasps fly low over the ground, somehow divining the presence of subterranean scarab beetle grubs.  Once she unearths the grub, she stings it into paralysis.  this allows her to lay a single egg on the grub.  After she accomplishes her mission, she re-buries the grub and flees the scene of the crime (some species have been observed moving the grub deeper into the soil and fashioning an earthen cell around it before depositing an egg and sealing the tunnel).  The beetle grub apparently never recovers from its coma.  The egg of the wasp hatches, and the larva that emerges will feed as an external parasite on its host for about a week or two before spinning a silken cocoon and pupating.  Most North American scoliids overwinter in the pupal stage.”

Scarab Hunter Wasp

Location: Joshua Tree National Park

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