BRN 9-2 (uncompressed) - Flipbook - Page 73
Giant Water Scavenger Beetle
(Hydrophilus species)
Oviposition/Reproduction/
Foraging Notes - by James Von Loh
On July 25, 2024 I photo-documented an oval
mystery structure (egg case) submerged at the
surface of the Dripping Springs Visitor Center, Organ
Mountains, Desert Peaks National Monument
stormwater retention pond, near a mating pair of
beetles. The mysterious ~3.0 cm ball of silk and
Green Sprangletop grass leaves had a hard tube-like
structure (mast [scale and siphon]) protruding above
the waterline.
The pair of Giant Water Scavenger Beetles appeared
to be mating/fertilizing eggs, immediately adjacent
to the egg case. Initially, I wondered if they might be
using this existing structure to deposit their eggs (at
this writing, I believe the lower beetle is a female and
that she is secreting her own protective egg case
during/following the mating behavior).
Note that there appears to be a small, round hole in
the egg case wall (see arrow in image below)
perhaps a place to deposit new eggs? or from which
larvae have already emerged?
I sought assistance from the iNaturalist online
community to determine its origin and use, under
the 'construction' category for entry.
A year later, Kylie Wirebach provided an ID and
support images (https://www.inaturalist.org/
observations/46057143 from a July 09, 2009
cocoon observation (21268, Lietuva; Vilniaus County,
Lithuania) which described the observation as Òhydrous
species cocoon on water surface. Thanks to entomologist,
Dr. Eduardas Budrys, for object identiÞcationÓ. That
observation is shown at the bottom right.
The online AI Query via the Google search engine, resulted
in the following information and points; it appears that
much of this information is from The New Field Book of
Freshwater Life by Elsie Klots:
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