第 1069 號，共 1 402 號

Common backswimmer

Notonecta glauca

名字的由來： Its common names come from the way it swims on its back, using its hind legs like oars in a boat.1

無害對人無害。不用擔心。

毛毛蟲和其他蟲子

咬吃：肉

對人的危險: 輕微跟蜜蜂螫差不多或更輕微。對人基本上無害。

The common backswimmer is a small water insect that swims upside down, under the surface of ponds. It hunts other small water creatures and can fly between ponds when the weather is warm. It is the most common backswimmer in much of its range.1

分布在

Large parts of Europe, North Africa, and east through Asia to Siberia and China1

歐洲

首頁

It lives under the water surface in ponds, and it is also the most widespread of the four British water-boatmen. In warm late summer and autumn it flies between ponds.1

長度

1,3 cm 到 1,6 cm (0,5 in 到 0,6 in)1

最高速度

大約 0,45 km/h（0,28 mph）

游泳, 粗略估計

牠吃什麼？

It is a predator. It either waits for prey to pass by or swims and actively hunts it. It often feeds on mosquito (Culex) larvae at the surface, and mature females also dive to the bottom of shallow ponds to catch isopods (Asellus).1

Common backswimmer 的照片 — Common backswimmer。照片：ingridaltmann。 CC BY 4.0, iNaturalist.

怎麼認出牠

Swims and rests on its back1
Body length is about 13 to 16 mm1
Females are larger than males1
Hind legs are fringed with hair and held out to the sides like oars when resting1
Body is covered in hairs, except on the head and legs1

毒液力量

咬

咬的時候，毒液會從毒牙或牙齒出來。

牠對人有多危險？

對人的危險: 輕微跟蜜蜂螫差不多或更輕微。對人基本上無害。

如果牠咬人

被會螫人的毛毛蟲毛刺到時：用膠帶把毛黏起來，再清洗皮膚。不要搓揉。
被咬時：清洗並冷敷。如果傷者覺得不舒服或容易流血，要就醫。

一定要先打緊急電話（112、000、911）。這是一般急救指引，不是醫療建議。急救基本知識

注意安全

絕對不要碰、抓或捉弄野生動物，就算是很小的動物，就算牠看起來在睡覺或已經死了也一樣。
給牠空間。如果遇到了，保持冷靜，慢慢往後退，讓牠自己離開。
如果被牠咬了：保持冷靜，保持不動，打緊急電話（112、000、911）或趕快去醫院。記住牠的樣子，有照片會很有幫助。

牠不是想來抓你。牠用毒液來捕捉食物或保護自己，而且牠更想躲起來。更多安全知識

在世界上的哪裡？

非洲亞洲歐洲北美洲南美洲澳洲與大洋洲

牠有多大？

牠有多長？

比你的小指頭還短

Common backswimmer 跟「你」比起來有多大？

只是在你的瀏覽器裡做算術。什麼都不會儲存，也不會傳送到任何地方。

牠有多快？

一隻花園蝸牛 大約 0,05 km/h (0,03 mph)

Common backswimmer 大約 0,45 km/h (0,28 mph)

一個正在游泳的人 大約 3 km/h (1,9 mph)

值得知道

小知識

It breathes air but has no gills. It keeps a thin film of air around its body, which can last up to 120 days.1

It can tell prey from other backswimmers by the surface waves they make. Prey waves are between 70 and 140 Hz, while other backswimmers make waves below 40 Hz.1

Its air film reduces drag when it dives. Scientists use it as a model for reducing drag, with possible uses such as on ships.1

It can see in both day and night. Its pupil takes about 40 minutes to adjust to daylight and about 50 minutes to adjust to night light.1

給毒液專家

學名: Notonecta glauca
類群: 毛毛蟲和其他蟲子
家人: Notonectidae2
排序: Hemiptera
各大洲: 歐洲
寶寶: It reproduces in the spring, and young backswimmers, called larvae, live in the water.1
對人的危險: 1 / 5: 輕微3