Migrant Hawker

Appearance

"A. mixta" is a small "aeshna" which appears dark in flight. It is similar in appearance to other aeshnas but has a characteristic "golf-tee" shaped mark on the second segment of the abdommen which is diagnostic.

In flight it looks like a small Emperor dragonfly with a blue abdomen which, when seen from the side, curves down. The main identification problem in the field is distinguishing this species from "A. affinis" where the two species fly together.

The markings on the side of the thorax are different in "A. affinis" and "A. mixta". In "A. affinis" the sides of the thorax are greeny yellow with fine black lines along the sutures. In "A. mixta" the sides of the thorax are similar in colour but the yellow is separated by dark brown areas so it gives the appearance of having two broad yellow stripes.

Distribution

"A. mixta" is found throughout central and southern Europe, north Africa, the Middle East and across Asia to China and Japan. As it is a migratory species it can occur outside its normal range and in recent years it has been spreading northwards.

For example in the United Kingdom this insect was rare until the 1940s when it began migrating from the continent in large numbers. It continues to do so and is now a resident breeding species throughout England and Wales. It reached the Isle of Man in 1998 and Ireland in 2000.

Behavior

"A. mixta" has been seen on the wing in all months of the year but most commonly from July to Late October or early November.

After emergence, the immature adults fly away from water and spends their time feeding and becoming sexually mature. They are not territorial and they are often seen feeding or resting in groups, occasionally forming large feeding swarms.

They can be found around trees and bushes quite high up. Once mature, they return to water and begin mating behaviour with the males patrolling looking for females. "A. mixta" males are less territorial than other male aeshnas.

Habitat

It breeds in lakes and ponds and is tolerant of brackish water. It is also found away from water hawking high amongst trees and bushes, but often resting low on vegetation.

Reproduction

Males form a tandem pairing with a female on the wing and copulate. After mating the male and female split up and the female oviposits alone.

The eggs develop and then enter dipause and it is as diapause eggs that "A. mixta" overwinter. In spring the eggs hatch into a prolarva which only lasts from a few seconds to a few minutes, the prolarva then molts into a stadium 2 larva.

Larval development is rapid and adults emerge in summer. "A. mixta" is a univoltine species, that is to say that it completes its life-cycle in one year.