Identification: red hourglass on otherwise<unk>  spider. Females tend to be larger and deliver more venom 
Genus: Latrodectus<unk><unk> s live in southern Canada and every U.S. state except Alaska. Bites are more common in warmer months 
Aptly named because of their sexual cannibalism (but only occurs approximately 2% of the time)
Most venomous spiders in North America
Venom several times more potent than rattlesnake venom
Most people who are envenomated have no serious damage due to the low volume of venom delivered.
Rarely bites can be fatal
High risk are the young, very old, and the infirm.
Venom several times more potent than rattlesnake venom
High risk are the young, very old, and the infirm.

α-Latrotoxin envenomation causes massive release of neurotransmitters (norepinephrine, dopamine, acetylcholine, glutamate and GABA) from the nerve terminals → muscle cramps, tachycardia, hypertension
This clinical envenomation syndrome is known as latrodectism
Black widow spider bite
Hymenoptera stings 
Octopus bite
Mammalian bites
Armed spider bite
Closed fist infection 
Funnel-web spider bite
Dog bite