Versione Italiana

YELLOW SACK SPIDER

Luciano Schiazza M.D.
Dermatologist
c/o InMedica - Centro Medico Polispecialistico
Largo XII Ottobre 62
cell 335.655.97.70 - office 010 5701818
www.lucianoschiazza.it

Ragno
  www.acremar.it

August 2006 : a spider terrorized Austria. Do not disturb it. It gets angry: it is the commonly called yellow sack spider, or precisely, Cheiracanthium punctorium.

Let’s get acquainted to it:

Does it also live in Italy ? Certainly, in particular in the country side and the mountains of Veneto, Emilia Romagna, Calabria. Tuscany. Sicily and Sardinia.

It is 2 cm long, easy to spot because its front (prosome) is orange-red, the back (opisthosoma) pale color, with a brown-reddish longitudinal dorsal stripe. In the front are well evident two well developed chelicerae, especially in the male. It has eight long and strong legs that allow it to easily move within its environment.

What environment ?

During the summer when there's plenty of food the yellow sack spider prefers to live on trees, shrubs, and in low vegetation close to open expanses, such as fields.

This spider does not produce webs. Instead it construct sacs in protected areas. The idea of creating sacs instead of webs has given the Yellow Sac Spider its name. It becomes aggressive when disturbed.
Sundown is the most active period. They wait for their prey on the sheet portion of their sacs, used for hunting and mating.

The male loves to wonder around during the night, but at sunrise it searches for a retreat. This might be a house, so better check your shoes prior to wear them!
Yellow sac spider bites occur most frequently when the very defensive spider is trapped in clothing.

Why should we fear it? Because it produces a neurotoxic and cytotoxic venom. The bite is similar to a wasp sting: the skin becomes red-bluish, swollen and necrotic.

The pain may extend to the stung limb, that might get swollen as well as the lymph nodes. Itch and numbness may also occur.

Some patients develop chills, fever, headache, nausea, anorexia and sometimes shock. It takes a few days to get rid of the symptoms.

The “souvenir” of the bit is often an ugly scar.

Symptomatic therapy is recommended.