Species: Ram's-horn Gall Wasp (Andricus aries)
Family: Gall Wasps (CYNIPIDAE)
Category: Insects (Other)
Location: One Sighting
A. Insects (Other)
More extensive information on insects can be found in a separate blog post.
B. Gall Wasps (CYNIPIDAE)
Gall wasps are wasps that induce galls on plants, which aid the development of their larvae. They are generally small insects.
Galls develop in the tissue of plants after the female insect lays eggs. After the eggs hatch into larvae, the galls provide nourishment for them and protection of them.
C. Ram's-horn Gall Wasp (Andricus aries)
Andricus aries wasps were first spotted in England in 1997, in Berkshire. Their appearance has become more common since then.
Little is known about the wasp that produces these galls, just that they have two generations in the same year on the same host tree. Galls form in May from eggs laid in the leaf bud of the host earlier in the year. Adult wasps emerge from the swollen galls in late summer. The second generation remains in the gall and emerges the following spring. The adult wasps appear to choose oak trees as their host, including the Pedunculate Oak.
This species - along with mites - are exceptions to the species listed on this website in that we cannot show their photographs directly, but we know that the galls that they have created are proof of their earlier presence.
Images
Ram's-horn Gall Wasp
The adult wasps appear to choose oak trees as their host, including the Pedunculate Oak, on which these galls were spotted in September 2022.
(Photo credit: Stuart MA Ball.)
Ram's-horn Gall Wasp
Galls form in May from eggs laid in the leaf bud of the host earlier in the year. Adult wasps emerge from the swollen galls in late summer.
This photograph shows the galls shown above some four weeks later, starting to turn brown.
(Photo credit: Stuart MA Ball.)
