Ips Bark Beetles of the World

Dichotomous and matrix-based keys to the Ips bark beetles of the World (Coleoptera: Curculionidae: Scolytinae)

CJAI 38 — June 27, 2019

doi:10.3752/cjai.2019.38

Hume B. Douglas, Anthony I. Cognato, Vasily Grebennikov, and Karine Savard

Results

Key to Ips adults

The illustrated dichotomous key presented here and interactive LUCID keys developed both include multiple routes to identification of one or both sexes of many species at the following internet URL: https://keys.lucidcentral.org/keys/v3/ips_de_geer/.

In some cases multiple identification paths were necessary because of observed intraspecific variation. In other cases species were scored as having additional character states because observed morphology was too close to the dividing line between character states to assign specimens reliably to one state or the other. Although these divergent interpretations of morphology sometimes contradict published descriptions they do not necessarily imply that those descriptions are incorrect. Identification of some Ips specimens remains difficult despite these steps. Users should compare identifications carefully to the fact sheet for that species or other taxonomic literature where indicated to maximize identification quality. Both keys are intended for use with single specimens (or partial specimens) of unknown origin for use with samples from traps or international plant quarantine interceptions. However, morphological information from both sexes, tree host species and geographic origin can all help improve accuracy of identifications.

Subspecies included in the key are defined partly based on morphology and partly on geography. Their taxonomic validity and limits remain under investigation. The morphological key to species may not produce accurate subspecies-level identifications when used without added locality-based inference. Entries were made for Orthotomicus and Pseudips using characters from multiple species to assist users who may have confused members of these genera for Ips species.