Caurinus dectes  Russell, 1979

This species is tiny, males in alcohol that have been mascerated (and expanded) in KOH are only 1.9 mm long.  They have almost no rostrum, and the male forewings extend only to the end of the first abdominal segment and have only five bristles.  Tarsal claws are absent.  There are no long bristles nor thick pilosity covering the body.  The basal abdominal segments are fused, but the male eighth abdominal tergite and sternite are not fused laterally.  Male ninth tergites are very elongate and dististyles reduced to tiny, flat sclerite.  The female has no ovipositor.


Distribution – Geographical: At this time, known only from the Coast Range of Oregon.  This is a relatively mild climate for a species of boreid.


Distribution – Temporal: 11 October until 4 April at 185 m to 600 m elevation (Russel, 1979).


Ecology: This species lives in moist forested sites with abundant epiphytic and terrestrial bryophytes.  Most specimens have been recovered by heating mossy stems of vine maple, Acer circinatum  Pursch.  The most common mosses associated with these stems are:  Rhytidiadelphus loreus (Hedw.) Warnst. (Rhytidiaceae), Metaneckera menziesii (Hook.) Steere, and Neckera douglasii (Hook.) (Neckeraceae).

The favored food and oviposition site for adults is the epiphytic liverwort Porella navicularis (L. & L.) Lindb. (Porellaceae) and Caurinus dectes appears to breed in these epiphytes .


Biology: Eggs hatch in February to March.  Larvae are almost legless and go through three instars.  Larvae feed in mines or galleries of leafy liverworts (Jungermanniales).  Pupation takes place in a silk-lined cell or cocoon from July until August.  This species is univoltine, but successive generation can overlap through egg diapause, and enough adults have been collected during spring and summer to suggest that some adults may survive for a full year (Russel, 1982).


Notes:  The name Caurinus dectes is derived from the Latin word for northwest wind, caurinus, and biter, dectes, for the geographical location of the species and the large, strong mandibules.


The primary type was never deposited in the California Academy of Sciences Collection and today cannot be located.




Russell, L.K. 1979. A new genus and a new species of Boreidae from Oregon (Mecoptera). Proceedings of the Entomological Society of Washington,81(1):22-31.


-----. 1982. The life history of Caurinus dectes Russell with a description of the immature stages (Mecoptera: Boreidae). Entomologica Scandinavica, 13(2):225-235.



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