NEUTRALIZING THE ASH LEAF CONE ROLLER by GAIL GRAVELINES A moth that transforms lush urban ash trees into sickly looking stands may soon be a pest of the past thanks to research underway at the University of Alberta. The ash leaf cone roller moth -- known to most urban dwellers as the nasty caterpillar that hangs in droves from silken threads on city trees -- doesn't kill the ash trees it infests. Its annual appearance however, provokes thousands of concerned calls to nurseries and local government offices. The moth also damages younger nursery trees. "Ash trees are a favourite urban tree used by many municipalities for their shade and aesthetic appeal," says Dr. Maya Evenden, Assistant Professor of Biological Sciences at the University of Alberta,pictured left,. Now, most of Edmonton's ash trees are affected by the ash leaf cone roller moth that was first found in Edmonton in 1999. This tiny moth gets its name from the way it rolls the leaf around itself for protection during its the caterpillar stage . This inside the leaf strategy makes pesticide spraying ineffective as well as harmful to other species. Dr. Evenden, is leading research into how the chemicals the moth sends out to attract mates can be used to control its population. She's also looking at how the chemical signals an infested ash tree emits can be used to more effectively attract the tiny wasp that is the ash leaf cone roller's natural enemy earlier in the pest's life cycle. Her research is funded by both the Alberta Crop Industry Development Fund (ACIDF) and the Landscape Alberta Nursery Trade Association (LANTA). "Using semiochemicals to control the ash leaf cone roller is part of an integrated, more environmentally friendly pest management approach that doesn't rely on spraying pesticides," says Evenden ,an insect chemical ecologist. Semiochemicals are the chemical substances organisms emit to communicate. Pheromones, sent out to attract mates at the right time in the reproductive cycle, are one such semiochemical. Dr. Evenden's research is focusing on isolating two semiochemical combinations -- the sex pheromone the female moths use to attract males and the ash tree volatiles, or signals, used by both male and female ash leaf cone rollers to find their host. The goal? To duplicate the message system and lure the moth to an attracticide laced with insecticide. Though this is a well established means of controlling pest populations, the ash leaf cone roller is presenting some challenges. "This moth has a long and complex reproductive cycle. If you were to dissect a female in September she would be packed with fat to make it through the winter. Around March or April she will fly around and mate. Then she will deposit her eggs in the ash tree leaf some time later. The challenge is to formulate the attractant and use it at exactly the right time in the reproductive cycle." Dr. Evenden and her research team use a wind tunnel and an adult ash leaf cone roller moth to gauge the attractiveness of various mixes of semiochemicals. The semiochemicals are suspended on the upwind end