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Braconid Wasp
Photo by  Joseph Berger

Parasitoidal wasps
(Ichneumonidae, Braconidae, Chalcidae) are solitary wasps that lay their eggs on or in a host insect. The host then provides sustenance for the growing parasitoid through its life cycle.

Most parasitoids are tiny wasps that are easily overlooked. Adult parasitoids range in size from 0.3 mm to 35 mm long.

Species Affected

A local example is the Birch Leafminer Sawfly (Fenusa pusilla & Profenusa thomsoni), which damage local birch trees.

 An imported parasitoidal wasp (Lathrolestes spp.) has suppressed local sawfly populations, making chemical products unnecessary to prevent the brown foliar damage characteristic of birch leafminer attacks.

Ichneumonid Wasp Photo by Edward H. Holsten   


Development of parasitoid populations usually lags behind that of the prey. This will result in a period of time where pest populations are high.  When considering pest control operations, keep in mind that parasitoid populations may become adequate within one or two seasons to control the pest without the use of chemicals.

Last updated: 12/6/2012 7:55:06 AM