UNIVERSITY PARK, Pa. — The songs that crickets and katydids sing at night to attract mates can help in monitoring and mapping their populations, according to Penn State researchers, whose study of Orthoptera species in central Pennsylvania also shed light on these insects' habitat preferences.
"We were surprised to find more species in suburban areas than in either urban or rural areas," said the study's lead researcher, D.J. McNeil, postdoctoral fellow in Penn State's Insect Biodiversity Center and the Department of Entomology.
The study was the first to show that the use of aural point count surveys — a method commonly used by wildlife biologists to study birds and other vertebrates by listening to their songs — can be effective in exploring the population dynamics of night-singing insect species, the researchers said.
"Insect populations are showing declines globally, and several studies have indicated that Orthopterans, such as grasshoppers, crickets and katydids, are among the most threatened insect groups," said study co-author Christina Grozinger, Publius Vergilius Maro Professor of Entomology, Penn State College of Agricultural Sciences. "Having a nondestructive way to monitor and map these species is vital for understanding how to conserve and expand their populations."
McNeil explained that Orthoptera species — such as those in suborder Ensifera, which consists of crickets and katydids — are known to be highly sensitive to variation in habitat conditions. Since they feed on plants, these species also can be affected negatively when insecticides and herbicides are applied to vegetation.