Life cycle

In Denmark, there is one generation of harvest mites a year. The mites overwinter in the nymphal stage and evolve into adults in the early summer. The adult mites lay eggs in the ground. The larvae hatch in late July – early August. The active larvae are six-legged. They are 0.2-0.3 mm long, but because of their red or reddish-yellow color, they can easily be seen. When a larva has had a blood meal, it has almost doubled in size. It lets go of the host and fall to the ground. It finds a hiding place where it can molt and become a free-living nymph.

The older stages of the harvest mites are almost never seen. They hunt other small animals and are without particular interest to us. Adult harvest mites are red and approximately 2 mm long and 1 mm wide. On bare peat soil, big, bright red mites are often seen. These are is the so-called velvet mites. They are related to the harvest mite, but are harmless to humans.