But the calls, and the number of spiders we are finding, have decreased quite a bit. An official from Iwakuni City's Environmental Safety Department said employees are searching outside the base fences for signs of black widows. Wallace said three black widow spiders were found in a hangar in 1997. In 1999, base officials found about 10, and so far in 2000, more than 270. Black widow spiders are usually found in warm areas around the world, but they are not native to Japan, the entomologists said.
Females are poisonous, while males and juveniles are harmless.
The normally passive spiders deliver a poisonous bite when disturbed. Less than 1 percent of black widow bites are fatal. Putting hydrogen peroxide on a black widow spider bite can protect against infection. In some cases, an antidote is used. Most adults recover completely from the poisonous bite in two to five days.