Identification of bee and wasp taxa relevant in systemic allergic reactions to Hymenoptera stings in Central Europe

Abstract

Background

Correct identification of the Hymenoptera that was responsible for stinging a patient is crucial when establishing the indication for specific immunotherapy (SIT) using Hymenoptera venom immunotherapy (VIT), advising the patient on allergen avoidance, and in terms evaluating accidental stings or sting challenges during VIT. There are around 15 species of social bees and wasps that most frequently cause stings in Central Europe. Even lay people are normally able to correctly classify causal insects into their respective families, i. e., Apidae or Vespidae. On the other hand, a more precise taxonomic classification and distinction within the subfamily and the genus is often imprecise or incorrect; for example, within the family Apidae (true bees), Apis (honeybees) is often mistaken for Bombus (bumblebees), while within the family Vespidae (folded-winged wasps), there is confusion between Polistes (paper wasps), Vespa (hornets), Dolichovespula (yellow jackets, long-cheeked wasps), and Vespula (yellow jackets, short-cheeked wasps).

Results

The morphological characters used for the typing of relevant genera are described and illustrated. A redetermination of wasps used at university hospitals for sting challenge tests revealed that 7% did not belong to the desired genus Vespula, but mainly to Dolichovespula instead. However, sting challenge tests using Dolichovespula species elicit approximately the same percentage of systemic allergic reactions as do Vespula stings.

Conclusion

With training, even nonentomologists are able to distinguish between taxa using simple techniques. The fact that a similar number of systemic allergic reactions are seen with sting challenge tests using Dolichovespula as with challenge tests using Vespula may be due to the high allergen affinity between the venoms. Another possible explanation for this could be that allergic reactions are more commonly triggered by Dolichovespula venom compared with Vespula venom than originally assumed.