Letters

Science News, July 8, 2000

Two bugs with one bomb

Cornell University entomologist Jeffrey G. Scott sees a cockroach contraceptive as still being a long way off ("Birth control for male cockroaches," SN: 4/15/00, p. 255). He may wish to investigate such a product that has been very effective and on the market for years. I can personally attest to its effectiveness. The common "flea bomb" that one gets from a veterinarian--the kind that you put in the middle of a room, close the door on, and let go--also sterilizes any resident cockroaches. (You get two nuisances eliminated for the price of one.) The lifetime of the roach apparently is about 30 days, because after that time, their population disappears.

John D. Shotzbarger Minneapolis, Minn.

Too cool

The article "It's high tide for ice age climate change" (SN: 4/15/00, p. 246) may be confusing to readers who don't know the quantitative difference between an ice age and a little ice age, as referred to in the story. During the last ice age, the average cooling in the Northern Hemisphere was about 5 [degrees] C, but the cooling during the last little ice age was only about 0.2 [degrees] C. During the last little ice age, montane glaciers advanced in both hemispheres. However, during the last ice age, much of North America and Europe were covered by glacial ice. This should all be compared with global warming of about 0.6 [degrees] C during the 20th century. Too bad that the next little ice age isn't expected until the 22nd century.

Paul Damon Tucson, Ariz.

Blast the zappers

In doing your usual excellent job of presenting information in interesting and lighthearted ways, you implied that bug zappers control mosquitoes ("Mosquito magnets," SN: 4/22/00, p. 268). In fact, bug zappers don't attract mosquitoes and therefore kill very few of them. They do kill large numbers of harmless and even beneficial insects, including pollinators and insects such as the crane fly, which would be out there eating mosquitoes if they weren't zapped.

Merle Hetley Bangor, Maine

I found the article "Mosquito magnets" interesting. Perhaps the researchers could confirm or refute the old saying "swat a mosquito (or blackfly), and 100 will come to the funeral." My father used to say he was quoting his father. That would put the saying back to the mid-1800s at least.

Alden Gray Ashfield, Mass.

Moms and quiet time

I've never been a baboon, but I have been a mom, and consequently a mother baboon's failure to call out to a separated youngster emitting distress sounds is not a bit puzzling to me ("Cries and greetings," SN: 4/29/00, p. 280). If I heard my toddler wailing on the other side of the road, would I call and say, "Don't worry, mummy's coming," even if the child were capable of understanding language? Nope. I'd listen carefully to the sounds I recognize as my child in trouble and move purposefully and quickly in that direction. A child sitting in one place crying is more predictable than one who hears Mom's voice and reacts to it.

M. Lou Mongan Sausalito, Calif.