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Desert Roaches articleHEllo ALl,
Here is an article on some Desert Roaches.
DESERT COCKROACHES
Article and photos by Ivan Huber and Emile Fiesler
Ivan, as a specialist in cockroaches, has long been interested in the desert cockroaches found in the Southwestern part of the United States. They belong to the family Polyphagidae in the order Blattaria. Members of this non-cosmopolitan family are not nearly as well known as other cockroaches.
The North American desert cockroaches, also called sand cockroaches,
belong to the genus Arenivaga, meaning 'wanderer on/in the sand'. In the Old World a similar, or maybe congeneric group, is the genus Polyphaga.
The male genitalia of the two groups, which are a primary distinguishing
feature, appear virtually identical. Many years ago, Ivan was able to
collect some specimens from the El Segundo Dunes in Los Angeles
County. This area on LAX property is now inaccessible. Ivan was
unable to keep the few specimens he collected alive on the usual
food for cockroaches in the laboratory (commercial dog food), though Cochran [Cochran 1979] succeeded with another species. The wingless females and nymphs can be sieved out of the sand; sometimes a few centimeters below the surface, sometimes as deep as 60 cm. Occasionally, they can be seen "swimming," identified by a little sand bump moving on the surface. Males are winged, can be found on the surface, and are reportedly attracted to lights. They are said to feed on decaying leaves and roots of desert shrubs.
An interesting adaptation this genus possesses is a swollen clypeus ('lip-shield') beneath which are hypopharyngeal pouches from which moisture from the air is extracted.
We include two photos taken by Emile in T e x a s .
Figure 1 is a female desert cockroach in her native habitat.
Figure 2 is a space alien trying to communicate in sign language. Correction: figure
2 is the same female specimen as seen from the ventral side.
Also included is a photo (figure 3) taken by the late Louis M. Roth of a female carrying an ootheca (eggcase). She appears to be dragging it by her flange.
Because the phylogeny of the order is based largely on how the female handles the ootheca, this is an important piece of evidence. In primitive cockroaches, the egg-case, which somewhat resembles a ladies' clutch purse, is produced and carried with the
seam upright. It is dropped or buried soon thereafter. In Roth's opinion, the egg-case carried by its flange is a step toward the more advanced condition in which the ootheca is produced and then retracted into a brood pouch until development is completed.
We very much welcome your assistance in identifying localities where desert cockroaches are found, as well as specimens, photos, documents, or other information
you might have on these interesting animals.
Reference:
[Cochran 1979] D. G. Cochran, A
method for rearing the sand cockroach,
Arenivaga tonkowa
(Dictyoptera: Polyphagidae).
Proceedings
of the
Entomological
Society of
Washington.
Volume 81,
pages 580-582,
1979.
Related bibliography:
"Cockroaches:
E c o l o g y ,
Behavior, and
Natural History." William J. Bell,
Christine A. Nalepa, and Louis M.
Roth; foreword by Edward O.
Wilson. Johns Hopkins
University Press, June 30, 2007.
ISBN: 9780801886164; 230
pages.
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