(This 884th Buffalo Sunday News column was first published on March 2, 2008.)
Two Outstanding Books on Insects
I suppose you could call them bug books, but that informal designation would hardly do for two of the finest entomological publications I have come across in my lifetime association with natural history. That they were both published within the past year is quite remarkable.
The first is "Insects: Their Natural History and Diversity" by Stephen Marshall, professor of entomology at the University of Guelph in nearby Ontario. This is a huge book -- lifting it can serve as a day's exercise. Its 732 pages include over 4000 color insect photographs. Clearly this represents the life work of a fine scientist.
The other is the Kaufman series "Field Guide to Insects of North America" by Eric Eaton and Kenn Kaufman. It has now replaced my well worn copy of Borrer and White's "Insects of North America North of Mexico" of the Peterson series.
But let's back up a bit. Just what are these insects that Marshall and Eaton are summarizing here.
Scientists have described and given scientific names to over 900,000 species of insects in the world, which represents almost 85% of all known animal species. For comparison, only about 4,000 of the known animal species are mammals, man being one of these. Remarkably those known insect species are still a drop in the bucket: it is estimated that millions of insects are yet to be described. About 2000 new ones are identified each year.
And consider individual insects. A North Carolina study found approximately 124 million per acre and a similar study in Pennsylvania yielded figures of 425 million per acre. Even taking the smaller of those numbers, we find that there are 12 times as many insects per square mile than the world population of humans.
So there are a lot of insects out there.
And they are important. We need them to pollinate our field crops and orchards. Kaufman lists other values, among them: "Pomace flies and flour beetles are valuable research subjects in the field of genetics. Blow flies help forensic scientists solve homicides. Some are employed to control invasive weeds. Chemical compounds produced by insects are increasingly useful in medicine and other fields." Others produce "beeswax, silk, honey, dyes and shellac."
But there are bad ones as well. Marshall tells us how some of them "bite, carry diseases, cost us billions of dollars every year in crop losses and lead us to contaminate our environment with a frightening variety of toxic chemicals in our attempts to get the better of them. Insect-borne diseases, like plague and typhus, have periodically wiped out sizable portions of the Earth's human population, and have repeatedly turned the tides of war by killing far more people than guns and swords. Even today half the world's population is at risk from mosquito-borne malaria, and another 90 million people in 76 countries suffer from insect-borne filariasis. Chagas' disease, caused by a bug-borne protozoan, affects another 16 to 18 million people and countless millions are affected daily by fly-borne food and water contamination."
Just here in North America there are 90,000 already named insect species. How then can a field guide or even Marshall's big book hope to identify them all? Quite simply, they cannot. Others devote entire books to identification of one sub-family like ants and it takes trained entomologists to identify many individual insects. Instead Eaton and Marshal help us to decide their order -- like beetles, butterflies and moths, true bugs -- and family -- lady beetles, tiger moths, stink bugs. Then they suggest some of the common genera and species within those ranks.
Eaton helps the user with a brief introductory color key but Marshall provides a quite remarkable 52 page pictorial key. Thus I can get a general idea of an insect in the field with Eaton and if I capture it I can use Marshall's key to zero in still further.
Entomology is an extremely important and equally interesting field with a wide range of employment opportunities. Many of the entomologists I know started as youngsters collecting insects. That activity has unfortunately been discouraged, but now with digital cameras youngsters can approach this subject in a new way. With books like these they have the basis for such activities and I urge every library to make them available.-- Gerry Rising