Don't Pet It

Josh Starry and I were working on my fruit trees, and on the inside of the garage door the sharp-eyed MRFC Secretary spotted an unusual-looking spider guarding some of her eggs. The eggs looked like those of a black widow, but this spider was brown.

Josh took this picture of it on his phone and sent it to entomologist and MRFC member Dr. Craig Welch. Back came an instantaneous ID: Latrodectus geometricus, the brown widow.

Not so distinctive as the black widow Latrodectus mactans, the browns vary in coloration from light brown to almost black. The underside of the abdomen exhibits the characteristic hourglass marking, but it may be orange or yellow orange, and not so easy to see.

L. geometricus has spread throughout Florida, joining the Southern black widow, northern black widow, and red widow on our venomous spiders list. Its venom is twice as strong as the black widow's, but its bites inject less and consequently are no more dangerous than those of the better-known cousin. Like all the widow spiders, it's not aggressive and prefers to retreat when disturbed. Bites usually occur when the spider is trapped against the skin, in clothing or reaching a hand into a dark place. And I wouldn't count on a retreat when Mom is guarding her eggs.

Craig's ID message also contained the excellent advice, “Don't pet it.” According to the Mayo Clinic, most bites cause only pain and swelling, and can be treated with ice, over-the-counter pain relievers, and elevating the bite if it is on an arm or leg. But if more serious symptoms develop, such as intense pain, limb rigidity, nausea, or vomiting, or if the victim is a child, elderly person, or in poor health, medical attention is required. And some authorities recommend it for all cases. Your call.

Now I hate, just hate to kill spiders. Inside the house, I lobby on their behalf as part of our strategy against insect invaders, and they usually get to stay a while before their webs are dusted away. With a bit of luck, they can scurry off and start building again. Outdoors, I cheer them on. But venomous spiders can't be tolerated, and Craig advised us to kill the brown widow and burn the eggs.

A plastic mallet was a quick, though probably unnecessarily messy approach to the first step. The sticky eggs were well-adhered to the garage door, and these 10 and 12-inch bromeliad tweezers were handy for removing them.

We put the eggs on a flat stone and ignited them using some of the alcohol I keep for sterilizing pruning gear. As the flames burned away, it dawned on me that I should have checked the garage for more of the unacceptable inhabitants. Of course there turned out to be several, for which the disagreeable procedure had to be repeated. I'm learning.

As ever, prevention is far and away the best approach, but there's rarely a need to go toxic. The widow spiders like man-made structures, such as entryway corners, eaves, garages and sheds, mailboxes, hand grips of trash bins, undersides of outdoor furniture, and even cars. Just monitor these areas and keep them clear whenever suspect residents start to appear. Keep outdoor work areas free of clutter, and wear gloves when you grab on to something you can't fully see. And learn which are the friendlies--- that is, almost everyone--- and which need to live elsewhere.