The only indigenous neurotoxic insect in the state of Maryland and found through many states in the US
The "bite" often not visible and does not cause a necrotic lesion like the brown recluse
Causes Acetycholine release from post-synaptic motor and sensory nerves
This leads to intense muscle contraction and pain. There have been reports of a black widow spider on the leg and the patient undergoes ex lap surgery for suspected acute abdomen only to find out the abdominal muscles were fasciculating due to envenomation
Treat with aggresive analgesia and benzodiazepines.
Not often lethal with approximately 60-70 deaths in the US over 30 years
Take a look at a picture of the black widow on the following attachment