Never Home Alone by Rob Dunn

Author:Rob Dunn
Language: eng
Format: epub
Publisher: Basic Books
Published: 2018-11-05T16:00:00+00:00

Figure 9.2 Social velvet spiders, Stegodyphus mimosarum, feeding on a house fly. (Photograph by Peter F. Gammelby, Aarhus University.)

In our nightmares, the wasps we release to control cockroaches deposit their eggs into our bodies, and the baby wasps develop in our body cavities, eat us from the inside, and then hatch from one or another of our orifices (or make a new one). This does not happen. These wasps are small, safe, and our allies. Similarly, we imagine that the spiders in our houses might bite us. Or even consume us. They don’t, either. Spiders, too, are nearly always our allies.

Each year, tens of thousands of “spider bites” are reported around the world, and the numbers seem to be increasing. Yet spiders rarely bite humans, and nearly all of these “bites” are instead actually cases of infections due to resistant Staphylococcus bacteria (MRSA) misdiagnosed by patients and doctors alike. If you think you have a spider bite, ask a doctor to test whether you have a case of MRSA. Those odds are much higher. One of the reasons spider bites are rare is that most spiders use their venom exclusively or nearly exclusively on prey rather than in defense. For spiders, it is nearly always easier to flee than to fight. One study even attempted to find out how many pokes it took to get each of forty-three individual black widow spiders to bite artificial fingers (made out of congealed Knox gelatin). But the spiders wouldn’t bite. After one poke with an artificial finger, none of the spiders tried to bite. Nor did any of them try to bite after sixty repeated pokes. The only time in the study that a black widow bit the artificial fingers was when the fingers were used to intentionally squish the spider three times in a row. Sixty percent of the spiders squished between two artificial fingers three times in a row bit. Even then, the spiders that did bite released venom only half of the time, such that half of the bites would not have been problematic, just painful.34 Venom is costly to spiders, and they don’t want to waste it on you; they are saving it for mosquitoes and house flies.35

Our use of chemistry to kill species where we live, on the other hand, comes back to bite us again and again. Spraying pesticides in houses and backyards creates what ecologists call an enemy-free space for any pests resistant to those pesticides. Our goal should be the opposite: homes full of (rather than free of) the enemies of our pests. The use of cockroach baits, for example, was supposed to be a solution to this problem. The pesticides would be consumed by the pests, but not by their predators. But then the cockroaches evolved a way around even this human innovation. Just how they evolved remained a mystery until 2011. By that point, Jules Silverman had begun to shift the work he was doing in the lab. He stopped working on cockroaches and ants and was beginning to spend most of his research time on aquatic insects.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.