It adds that at this stage, there have been no confirmed detections outside Auckland city. FAR is working with MPI, Federated Farmers and other groups to understand more about this pest, how it might impact on New Zealand red clover crops and how to manage it. A comprehensive factsheet will be available in early 2017 about this pest.

Red clover case bearer is small (about 8mm long) and is very similar to several other species of clover case bearer moth (Coleophora spp.) that are already well established in New Zealand. The moth's principal host plant is red clover, although it has occasionally been reported from other clover species (including white clover, haresfoot trefoil).

Adult moths are expected to be seen in New Zealand from October-December. Eggs are laid by the female moths at the base of florets and the larvae feed on developing seeds in the florets over summer. The moth overwinters as mature larvae typically near the soil surface or in leaf litter. The larvae then pupate and emerge as adults the following spring/summer. Experiences in Canada and the United States suggest that the red clover case bearer is more of a concern for clover seed crops, rather than having an effect on established red clover in pasture.

FAR says it is not feasible to attempt an eradication of red clover case bearer as it would not be possible to treat, nor survey all possible areas where host material occurs (pastures, roadsides, lawns, and waste areas throughout New Zealand).

Apparently, a number of parasitoids already present in New Zealand will attack Coleophora spp, including some parasitoids that were specifically introduced to control the other Coleophora spp. already established in New Zealand, which are also potential pests of clover.

FAR is consulting with Oregon State University as to how best to conduct surveillance on this pest in red clover seed crops for the future.

Source: FAR