Black Widow Spider

Black Widow Spider

Common Name:

Black Widow

Scientific Name:

Latrodectus spp.


Adult female body length about 1/2″ (12 – 13 mm) including an almost spherical abdomen about 1/4″ – 3/8″ (7.2 – 9.6 mm) in diameter. Overall length with legs of about 1 1/2″ to 1 3/8″ (38 – 43 mm). Males about half the size of females. Female color typically black, abdomen on ventral (underneath) side with 2 reddish triangular markings usually joined to form an hourglass shaped marking. Markings may be yellow or orange in color. Males usually black with color pattern on dorsal and upper surface; pattern variable but typically consists of a median row of red spots with white lines radiating out to sides. Young spiders primarily orange and white but acquire typical color and patterns as they mature.

Places Most Commonly Found:

Females deposit their eggs in silken egg sacs which are about 3/8″ to 1/2″ in diameter. Most of the spiders overwinter as immature individuals, develop into adults in the spring and die in late July. Females avoid light in sheltered spaces and tend to work their webs only at night. Female normally shy and retiring but aggressively attacks aft egg laying and when guarding the egg sacs. Female venom is a neurotoxin. Major symptoms of a bite are increased body temperature and blood pressure, profuse sweating, nausea and sever pain in the bite area radiating up the affected limb.

Most Active Period:

Early spring to late summer. Juveniles overwinter in protected areas.

Difficulty of Control:

Moderate to control with proper inspections and perimeter pesticide applications.

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