Pityogenes chalcographus L. Screening Aid
(Subfamily Scolytinae, Tribe Ipini)
From: Cavey, J., Passoa, S. and Kucera D. 1994, Screening Aids for Exotic Bark Beetles in the Northeastern United States. NA-TP-11-94. Northeastern Area: U.S. Department of Agriculture, Forest Service.
General Appearance in a Sample. A small species, 1.6-2.9 mm, with a moderately excavated elytral declivity bearing 3 conical teeth (males) or 3 smaller teeth (females). Color either black or often bicolored, black in front and red-brown on the latter half.
Recognizing the Genus. Similar genera of small bark beetles are Pityokteines and Orthotomicus, each represented in the NER by only one species. These taxa are distinguished from the genus Pityogenes below:
Recognizing Pityogenes chalcographus. Unlike P. chalcographus which has 3 teeth, males of most North American Pityogenes have 2 teeth on the elytral declivity, e.g. P. bidentatus (Herbst), a European species established in the NER. Only P. hopkinsi Swaine, a species common throughout the region, has 3 declivital teeth on both males and females (like P. chalcographus).
The following key will help screen P. chalcographus from NER Pityogenes. Males of P. hopkinsi are very difficult to distinguish from P. chalcographus. Unfortunately, even the aedeagi are similar and difficult to study, because of their small size. The dichotomy in couplet 5 should prove useful but relative, and should be used with caution and only with identified males of the 2 species in hand for comparison.
Key to Help Screen P. chalcographus from Pityogenes
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