Researchers in Canada and the UK have found that the blueberry stem gall wasp, a Dutch plantation pest, is unlikely to cause significant damage due to the short production cycle of blueberries and the insensitive varieties grown in Western Europe. The wasps, only 2.7 millimeters long, lay their eggs in new vegetative shoots, leading to the development of galls where the larvae grow. These galls can limit growth and usually develop best in warm, dry summers.