Microterys nietneri

Microterys nietneri: (former name: Microterys flavus)

Females of Microterys nietneri are about 2 mm in size; they are yellow-brown in color with clearly visible black and white bands on the wings and antennae.

Males are black and smaller than the females. Microterys nietneri is a gregarious species which means that a female may lay one to several eggs within a host. These eggs may all develop into new parasitoids, depending on the size of the host insect.  Brown soft scales that are parasitized by Microterys nietneri can be identified by presence of one or several dark rings underneath the scale cover. The rings are the excrements produced by young parasitoid instars that grow within the scale body. Within this ring sits the larva or pupa of the wasp. When development is completed the young wasp hatches by gnawing  a hole through the scale cover.

Mode of action:

The parasitic wasp can parasitize small as well as larger stages of the brown soft scale. Depending on the size of the host a female may lay one or more eggs within the scale body. A total of up to seven young wasps can be born out of one scale insect. The new generation of wasps starts again looking for brown soft scales to lay eggs and in this way the cycle repeats inself. The soft scale is killed by the parasitic wasps that are growing within their body. The dead scale will remain on the plant for some time and finally will fall off. Adult wasps feed by puncturing younger stages of brown soft scale and suck them empty. This feeding behaviour kills young soft scales (host feeding).


Microterys can be used in greenhouses and in plantations against the brown soft scale (Coccus hesperidum). Some other soft scale species are parasitized as well but to a much lesser extent. The temperature for Microterys to be effective must be at least 18 ⁰C. Consider repeated introductions. The product is sensitive to various chemical pesticides.

effect of Microterys nietneri

  • 1 to 7 eggs per scale insect depending on size of scale
  • parasitizes small as well as larger stages of brown soft scale
  • Host feeding: small scale stages are killed in this way

The product Microterys nietneri

transparent tube of 40 ml with 25 or 100 adult parasitoids.

Shelf life:
maximum 2 days at 10-15°C.

Effective between 18 and 30oC, optimum at 25 ° C, tolerant to low humidity level

Targets Microterys nietneri: