Cimicidae - Cimex incrassatus
Size: 4.04 mm (female)
Group Guild Status
Trogloxene Parasite Rare
A single adult cimicid (“bed bug”) was retrieved from the Maternity Roost guano deposit in the Big Room on August 13, 2011. This animal was apparently groomed off one of the cave myotis that were still present in the cave in August. Larvae of the ischnopsyllid fleas (bat fleas) were also observed and sampled from the guano in the monthly guano sample taken that same day. Cimicids are blood-feeding parasites of mammals and birds. C. incrassatus is a nearctic species that is recorded from southern California, Arizona, and Mexico. The species has been recorded from the following vespertilionid bats: pallid bat (Antrozous pallidus), big brown bat (Eptesicus fuscus), fringed myotis (Myotis thysanodes), cave myotis (M. velifer), Yuma myotis (M. yumanensis), and western pipistrelle (Parastrellus [Pipistrellus] hesperus) (Usinger 1966).
They are apparently uncommon in the bat population at Kartchner Caverns since two guano deposits were examined and sampled nearly every month for two years with only this single observed occurrence of the species. It is possible that they are more common and are simply not often groomed off of the bats, but this seems less likely.
The individual specimen is somewhat anomalous due to two morphological variables that do not completely follow the key in Usinger (1966), as follows: the spermalege is intermediate in form between C. incrassatus and C. antennatus, appearing more asymmetrical, and more closely resembling that of C. antennatus; and the hind femora are considerably longer, with a ratio of 2.85 (length to width) compared with either C incrassatus or C. antennatus, the latter of which is the longer of the two with a typical ratio of 2.5. In spite of these discrepancies we place the specimen within C. incrassatus. We consider it unlikely that this is an undescribed species, but rather represents a morph within a variable species. Future studies by a specialist could resolve the question. This species was not recorded during the initial study
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