Western Europe
Common gorse (Ulex europaeus)
Eggs are pale yellow, cylindrical, and ~0.3 mm long. There are two actively feeding nymphal instars and two inactive (non-feeding) instars. Nymphs are creamy-yellow and look increasingly similar to adults as they molt between instars. Adults are tiny (~1 mm long), black, and have circular white wing pads. They are typically wingless, though some winged individuals do occur. Winged forms are more abundant when population densities are high.
Adults lay eggs in slits within young, actively growing branch tips. Gorse thrips complete multiple generations during the warmer months of the year. At cold, high-elevation sites, adults overwinter among gorse foliage. At low-elevation sites, adults are active throughout winter. The entire life cycle of a single generation is approximately 6–8 weeks. Adults and feeding nymphs puncture gorse stems and suck out the contents of mesophyll cells. This results in a mottled, blotchy appearance of attacked tissue.
At high numbers, the gorse thrips can reduce gorse growth and flowering and kill seedlings.
Andreas, J.E., J. Price, and F.S. Grevstad. 2022. Common Gorse Biocontrol Agents: History and Ecology in North America. In: R.L. Winston, Ed. Biological Control of Weeds in North America. North American Invasive Species Management Association, Milwaukee, WI. NAISMA-BCW-2022-12-GORSE-A. https://bugwoodcloud.org/resource/files/25362.pdf