Black Soldier Fly larvae and pupae

Description:

Larval/prepupal/pupal stages of Hermetia illucens. Dark brown, segmented exoskeleton, 17-22 mm long and 5-7 mm wide, with elliptical cross-section. The longer axis of the ellipse is horizontal.

Habitat:

Suburban neighborhood on an insular tropical upland plateau.

Notes:

Spotted in the back yard worm bin. Most individuals were buried in soil and worm castings. Those individuals did not appear as dark in color as did the two outside the "mud", on the underside of the bin lid. The ones in the "mud" were likely larvae, the two on the underside of the lid probably pupae or prepupae. Those two were removed and measured. They were capable of locomotion, "inch-worm" style, with a noticeable wave traveling from front to rear, expanding the distance between the exoskeleton segments as it went. There were a few hairs on each exoskeleton and a probe-like structure on the front end that emerged from a hole in the exoskeleton, and which could be withdrawn into it. Observations suggest these creatures have distinct dorsal and ventral sides. The pictures show: 1. a pupa/prepupa on the underside of the worm bin lid, alongside a worm; 2. several individuals--likely larvae--in situ; 3. a pupa/prepupa after it was removed from the bin and placed on a cement slab; 4. a close-up of its forward-facing "probe"--it takes very little imagination to see eyes on either side; and 5. a close-up of a pupa/prepupa with its probe withdrawn into its exoskeleton.