Mediterranean black widow

At a glance

Key facts in one look

Human interaction: The spider has venom for prey; it contains latrotoxins. A bite can cause latrodectism — severe, lasting pain and systemic symptoms. At species level Nentwig et al. write: pain is severe and long-lasting in about two-thirds of cases; in more than half it increases in the first hour and often radiates into the limbs or abdomen; sweating is common; nausea, raised temperature, neuromuscular signs, and hypertension occur in a smaller share. Pain usually lasts 1–2 days, other symptoms 1–4 days. This is not a viper bite and not an Argiope bite. Death is rare in modern European material; that does not make a bite “mild”. If bitten, call 112. Do not handle it, cut, suck, or burn the bite. This is educational text, not a medical protocol. An allergic reaction to any bite is possible.

Gallery

Mediterranean black widow in photos

Identification

How to identify Mediterranean black widow

A small glossy black spider with a globose abdomen. The female often has red dorsal spots, sometimes none. The web is an irregular cobweb, not an orb.

1. 01

   At species level female body length is about 7–15 mm (Nentwig et al.); male about 4–7 mm. Legs are not included. There is no separate Georgian measurement series on this page.

2. 02

   The female cephalothorax (prosoma) is black and glossy; the legs are black. The abdomen (opisthosoma) is globose. The back often has three longitudinal rows of red blotches — tredecimguttatus means “thirteen-spotted”. Spots may be yellow or orange, or absent so the abdomen is entirely black. Ventrally there is a red blotch behind the epigastric furrow; this is not always the American L. mactans hourglass. The male is smaller; Nentwig et al. describe its blotches as whitish.

3. 03

   Seropian et al. 2024 write that in local populations the thirteen red spots of adult females are often reduced or lost, leaving thin white margins. A fully black female in Georgia does not rule this species out.

4. 04

   The web is irregular (Theridiidae), usually near the ground. It is not an Argiope orb with a white zigzag. An adult female often sits in a retreat, not in the web centre.

5. 05

   The same genus was confirmed in Georgia in 2024 as Latrodectus pallidus (Seropian et al.; Chachuna, Dedoplistskaro, about 648 m) — the abdomen is creamy-white, not black. That is the first Caucasus record of that species. Latrodectus dahli is in Otto 2022 for Azerbaijan, not from a named Georgian record. The false black widow (Steatoda paykulliana) also occurs in Georgia; it is usually brown, often with a red or yellow band at the front of the abdomen, not a glossy black globose abdomen with red spots. This atlas has a separate profile for the false black widow; not yet for L. pallidus.

6. 06

   This atlas has separate profiles for the wasp spider (Argiope bruennichi) and the lobed argiope (Argiope lobata). Those are larger orb-weavers with banded or lobed abdomens — not this widow.