The presence of two species, Contarinia pseudotsugae and Contarinia cuniculator is suspected in the Netherlands
In the Netherland, the presence of a new Douglas fir needle midge, tentatively identified as Contarinia pseudotsugae (Diptera: Cecidomyiidae – EPPO Alert List) was detected in November 2015 (EPPO RS 2016/008). The pest was observed on numerous forest trees of Pseudotsuga menziesii (Douglas fir) in the provinces of Gelderland, Limburg and Noord-Brabant. During the yearly national specific survey of forest stands (conducted for Bursaphelenchus xylophilus, Gibberella and Mycosphaerella), further insect specimens were found in five provinces (Gelderland, Limburg, Noord-Brabant, Overijssel, and Utrecht). Based on gall and larval characteristics, the presence of two species, C. pseudotsugae* and C. cuniculator*, is now suspected. Relatively mild wilting symptoms on lower branches were observed on multiple trees (at least 10 per location) at 8 locations in natural forest stands (totalling thousands of P. menziesii trees). Considering the wide distribution of these Douglas fir needle midges and the fact that they probably have been present for several years, no phytosanitary measures were taken.
The pest status of Contarinia cuniculator and C. pseudotsugae in the Netherlands is officially declared as: Present, in specific parts of the areas where host plants are grown.
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* The identity of these pests remains to be confirmed on adult specimens as only larvae were collected.
Sources
NPPO of the Netherlands (2016-04).