均翅亚目亚目

生物特性

豆娘的稚虫水虿生长于水中，身体侧扁长形，尾端有叶片状的尾腮，具有呼吸与运动的功能。隐匿于水草或石块缝隙。

由于豆娘的体态优美、颜色鲜艳，且其翅膀颜色多变，故很多爱好者喜爱观赏。

而蜻蜓与豆娘的主要差别有以下：

眼睛的距离：蜻蜓的复眼大部分是彼此相连或只有小距离的分开；豆娘的两眼有相当大距离的分开，形状如同哑铃一般。

翅膀的形状：属差翅亚目的蜻蜓，其前后翅形状大小不同，差异甚大；属均翅亚目的豆娘，其前后翅形状大小近似，差异较小。

腹部的形状：蜻蜓的腹部形状较为扁平，也较粗；豆娘的腹部形状较为细瘦，呈圆棍棒状。

停栖方式：蜻蜓在停栖时，会将翅膀平展在身体的两侧；一般豆娘在停栖时，会将翅膀合起来直立于背上。

Damselflies are flying insects of the suborder Zygoptera in the order Odonata. They are similar to dragonflies, which form the suborder Anisoptera, but are usually smaller and have slimmer bodies. Most species fold the wings along the body when at rest, unlike dragonflies which hold the wings flat and away from the body. Damselflies have existed since the Late Jurassic, and are found on every continent except Antarctica.

All damselflies are predatory insects: both nymphs and adults actively hunt and eat other insects. The nymphs are aquatic, with different species living in a variety of freshwater habitats including acidic bogs, ponds, lakes and rivers. The nymphs moult repeatedly, at the last moult climbing out of the water to undergo metamorphosis. The skin splits down the back, they emerge and inflate their wings and abdomen to gain their adult form. Their presence on a body of water indicates that it is relatively unpolluted, but their dependence on freshwater makes them vulnerable to damage to their wetland habitats.

Some species of damselfly have elaborate courtship behaviours. Many species are sexually dimorphic, the males often being more brightly coloured than the females. Like dragonflies, they reproduce using indirect insemination and delayed fertilisation. A mating pair form a shape known as a "heart" or "wheel", the male clasping the female at the back of the head, the female curling her abdomen down to pick up sperm from secondary genitalia at the base of the male's abdomen. The pair often remain together with the male still clasping the female while she lays eggs within the tissue of plants in or near water using a robust ovipositor.

Artificial fishing flies that mimic damselfly nymphs are used in wet-fly fishing. Damselflies are sometimes represented in personal jewellery such as brooches.