Garden Guru: Whitney Cranshaw
"I was more into dinosaurs and reptiles as a kid but insects were easier to find," wryly recalls Whitney Cranshaw, author and entomology professor at Colorado State University in Fort Collins. Cranshaw grew up in Massachusetts, spending hours observing and collecting insects in a field near his house. "Praying mantids have a special place in my heart," he says. "I used to bring them home and feed them grasshoppers, which they ate like corn on the cob. I liked their prehistoric appearance and how they'd tilt their heads to look at me."
Cranshaw is still collecting insects and wrote a book about it to help other bug-lovers: Bagging Big Bugs: How to Identify, Collect and Display the Largest and Most Colorful Insects of the Rocky Mountain Region. In his work, however, he often finds himself trying to engender respect for insects in people who might not fall into the category of "bug-lover."
According to Cranshaw, many so-called "pest problems" are simply a lack of public understanding about the natural cycles of insects. For example, he describes a harmless local June bug that generates numerous phone calls to his office for the 2 to 3 weeks that it's active. "It's a quarter-pounder with stripes and funny antenna, and it hisses. People are afraid it will eat their kids," he laughs. "Once they know the beetle is just part of Colorado wildlife, their anxiety levels drop."
Often called upon to bridge the gap between the interests of insects and the interests of humans, Cranshaw uses Integrated Pest Management's premise of working with the natural life cycles of insects to control pest problems with less pesticide. In one project, he worked with national food companies that processed canned peas and other vegetables. The processing system occasionally allowed insects ? a pupal case of a caterpillar, for example ? to slip by and end up in a can, drawing consumer complaints. "They probably taste better than the canned peas, although they may be higher in cholesterol," jokes Whitney. There were no pathogens involved so it wasn't a health issue, but he researched different spraying times or harvesting techniques that would reduce the chance of insect contamination.
Insects in canned food is one thing, but Cranshaw has a low tolerance for the public's obsession with cosmetically perfect produce. "Two-thirds of all spraying on crops is to prevent a bit of chewing injury because the public won't accept any blemish," he remarks.
This summer Cranshaw is helping gardeners with myriad insect problems brought on by the drought. Trees and shrubs are stressed, and as a result they are more susceptible to attack by borers and bark beetles. Thrips are usually controlled by rain, which traps nonfeeding pupa stages of the insect in the soil, but the drought has allowed them to thrive. Spider mites also are frolicking in the dusty soil, and dry lawns are more welcoming to chinch bugs, largely because their natural enemies are inhibited by the arid conditions. Honeydew from aphids and soft scales is building up in tremendous amounts on some plants because there's no rainfall to wash it off.
"Also, in isolated areas we are seeing a bit of an 'oasis effect' where the irrigated landscapes concentrate the activity of insects," says Cranshaw. In these areas flea beetles and leafcutter bees are having a heyday.
He also forecasts a big yellow jacket year. The lack of rainfall has allowed good nesting sites, and the high temperatures have accelerated population growth. "They'll run out of food in August and get grumpy," he predicts. "I'll be receiving a lot of calls."
When Cranshaw isn't conducting pest management research, teaching, or working with the public through the Cooperative Extension Service, he squeezes in time for writing. He's now working on a new book, Garden Insects of North America, to be published by Princeton University.