Contarinia found in Dutch Alstroemeria greenhouse

The Dutch Plant Protection Organization found Contarinia in a Dutch Alstroemeria greenhouse. Findings were triggered by the observation of severely malformed flowers and flower buds. Gall midge larvae were present inside these flower buds. Identification of these larvae as Contarinia was based on morphological and DNA analysis. Identification is limited to the genus level as the finding likely concerns an undescribed species.

The origin of the finding is unknown. The organism is not listed as a harmful organism in the EU directive 2000/29/EC and is not listed on the EPPO A1 or A2 list.

The pest has been found in two greenhouse compartments in which large numbers of Alstroemeria plants were infected which displayed malformed flowers and flower buds. The gall midge has a significant impact on marketability of the product.

Decision on whether official phytosanitary measures will be taken is pending. The grower is taking measures in order to eradicate the pest. The grower has volunteered to remove (and eliminate) all flowers and flower buds for a period of five weeks, thereby removing all potential sites for egg laying. Plants are sprayed weekly to eliminate adult midges. The NPPO monitors the situation during this period and will monitor again next spring when the new flower production cycle starts.

Click here to download the NPPO report.