Photo details: Canon 100mm macro lens on Canon EOS 50D, ISO 100, 1/250 sec, f/18, MT-24EX flash 1/2 power w/ diffuser caps.

While searching the hilltop prairies for Cylindera celeripes (swift tiger beetle) at McCormack Loess Mounds Natural Area in northwestern Missouri, I ran across a species of cicada that I’d not yet encountered in the state – Beameria venosa.  Cicadas as a rule are quite large insects, but with a body measuring only 16 mm (well under an inch) in length, B. venosa is one of – if not the – smallest species of this group in all of North America.  Had it not been for its distinctly cicada-esque call I might have thought it was some sort of fulgoroid planthopper (albeit a rather large one).  But a cicada it is, and a beautiful one at that despite its small size.

Beameria venosa is a prairie obligate species occurring from Nebraska and Colorado south to Texas and New Mexico.  To my knowledge, it has not been formally recorded from Missouri, although it is certainly already known from the state (it is listed in the 2009 issue of Missouri Species and Communities of Conservation Concern Checklist as “vulnerable” due to the restricted occurrence in Missouri of the prairie habitats in which it lives).  Froeschner (1952) listed 14 species of cicadas from Missouri but did not include this species even among those of possible occurrence in the state.  In my younger days, I managed not only to find all 14 of those species, but also a fifteenth species – the magnificent Tibicen superbus – in the southwestern corner of the state (formally recorded from the state some years later by Sanborn and Phillips 2004).  The occurrence of B. venosa in Missouri now brings to 16 the number of cicada species known from Missouri.

Despite its small size, the calling song of B. venosa is quite audible.  In fact, it was only due to its call that I noticed and began looking for this individual.  This brings up an interesting point regarding conspicuous insect songs and their role in enhancing predation risk.  Many predators are known to orient to the calls of cicadas (Soper et al. 1976), which in turn exhibit a variety of predator avoidance behaviors such as high perching, hiding, fleeing, and perhaps even mass emergence in the periodical cicadas.  Beameria venosa appears to avoid predators by producing its continuous train of sound pulses at a very high frequency.  Although audible to humans, the high frequency call apparently is not audible to birds and lizards – their chief predators (Sanborn et al. 2009).  In the open, treeless prairies where B. venosa lives, high frequency calling appears to provide the selective advantage for predator avoidance that fleeing, hiding, and high perching cannot.

REFERENCES:

Froeschner, R. C.  1952. A synopsis of the Cicadidae of Missouri. Journal of the New York Entomological Society 60:1–14.

Sanborn, A. F., J. E. Heath and M. S. Heath.  2009.  Long-range sound distribution and the calling song of the cicada Beameria venosa (Uhler) (Hemiptera: Cicadidae).  The Southwestern Naturalist 54(1):24-30.

Sanborn, A. F. and P. K. Phillips.  2004.  Neotype and allotype description of Tibicen superbus (Hemiptera: Cicadomorpha: Cicadidae) with description of its biogeography and calling song.  Annals of the Entomological Society of America 97(4):647-652.

Soper, R. S., G. E. Shewell and D. Tyrrell. 1976. Colcondamyia auditrix nov. sp. (Diptera; Sarcophagidae), a parasite which is attracted by the mating song of its host, Okanagana rimosa (Homoptera: Cicadidae).  The Canadian Entomologist 108:61-68.

Copyright © Ted C. MacRae 2009