On a typical day, they greet farmers bringing them ticks, real estate agents with mysterious roaches and anxious homeowners ...

John E. Woodmansee Photo: Tobacco hornworm on a tomato plant that has been attacked by a parasitic Braconid wasp. The white capsules on its back are the pupal stage of the tiny wasp. Braconid larvae ...

A few dark specks on a sheet, windowsill, or skirting board can make an ordinary room feel suddenly suspect. The reaction is ...