第 0631 号，共 1 402 张

Western black widow

Latrodectus hesperus

需要看医生很少致命，但被咬了要去看医生。

咬伤吃：肉

The western black widow is a venomous spider that lives in western North America. The female is black, often with a red hourglass mark on her belly, and her webs are tangled and irregular. Her venom is strong, so it is worth knowing what she looks like.1

生活在

Western North America: south-western Canada (British Columbia to Manitoba), the Pacific Coast, Texas, Oklahoma, Kansas, and Mexico1

北美洲

首页

It builds tangled webs low above the ground. It is commonly found near the Canada-US border and less commonly across the grasslands of the Canadian Prairies.1

长度

1.4 cm到1.6 cm (0.6 in到0.6 in)1

最高速度

约 0.98 公里/小时（0.61 英里/小时）

在陆地上, 粗略估计

它吃什么？

It hangs upside down near the centre of its web and waits for insects to land in it. It bites the prey, injects venom, and wraps it in silk. Beetles and ants, wasps and bumblebees make up most of its prey.1

Western black widow的照片 — Western black widow。照片：Luke Padon。 CC BY 4.0, iNaturalist.

怎样认出它

The female is about 14–16 mm long and black, often with an hourglass-shaped mark on the lower abdomen.1
The hourglass mark is usually red, but it can be yellow and, very rarely, white.1
The male is about half the female's length and is generally beige, with lighter striping on the abdomen.1
Its webs are irregular or tangled, with no obvious overall pattern.1

常被误认为： It was once described as a subspecies of Latrodectus mactans and is closely related to the northern species Latrodectus variolus.1

毒液之力

咬伤

它咬的时候，毒液通过毒牙或牙齿出来。

它的毒液会造成什么？

The female's venom contains a neurotoxin called α-latrotoxin, which attacks the nerves. In humans, its symptoms include pain, nausea, vomiting, goosebumps and localised sweating.1

它对人有多危险？

对人的危险: 严重被咬了要去看医生。死亡非常罕见。

Historical reports gave fatality rates between 0.5% and 12%. However, recent studies have not been able to confirm any deaths from the U.S. species of Latrodectus, including zero deaths among 23,409 documented bites from 2000 through 2008.1

它害怕时会做什么？

Juveniles and females can fling a sticky ball of silk at predators, which can stop most of them.1

如果它咬人

清洗咬伤处，用冰袋冷敷止痛。如果疼得厉害、疼痛扩散或感到不适，就去看医生。

一定先拨打你的急救电话（112、000、911）。这里是一般急救指导，不是医疗建议。急救基础

注意安全

永远不要摸、抓或逗弄野生动物，即使是很小的，即使它看起来在睡觉或已经死了。
给它留出空间。如果遇到它，保持冷静，慢慢后退，让它走自己的路。
如果被它咬了：保持冷静，保持不动，拨打你的急救电话（112、000、911）或尽快去医院。记住它长什么样，拍张照片会有帮助。

它不是冲着你来的。它用毒液捕猎或保护自己，而且它更愿意躲起来。更多安全知识

在世界哪里？

非洲亚洲欧洲北美洲南美洲澳大利亚和大洋洲

它有多大？

它有多长？

比你的小指还短

Western black widow和你比起来有多大？

只是在你的浏览器里算一算。什么都不会被保存或发送到任何地方。

它有多快？

一只陆龟 约 0.3 公里/小时 (0.19 mph)

Western black widow 约 0.98 公里/小时 (0.61 mph)

一个在走路的人 约 5 公里/小时 (3.1 mph)

值得了解

事实

When prey hits a gumfoot thread, the thread breaks and creates tension that pulls the line and prey up to the spider.1

This spider is an opportunistic cannibal, and it may eat other members of its own kind when prey is scarce, when it is very hungry, or in self-defence.1

The silk is strongly sticky, and its strength is similar to that of silk from orb-weaving spiders.1

Males can be preferred by females based on the webs, with well-fed females chosen over starved ones.1

Males may mate several times during their relatively short lives.1

谣言粉碎机

谣言： A black widow bite is usually deadly.

真相： Recent studies have not confirmed any deaths from the U.S. species of Latrodectus, including zero deaths among 23,409 documented bites from 2000 through 2008.1

给毒液专家

学名: Latrodectus hesperus
类别: 蜘蛛
家人: Theridiidae2
排序: Araneae
大洲: 北美洲
宝宝: Females produce egg sacs, and the young are born in the months from May to October.1
对人的危险: 3 / 5: 严重3