16 - Friday, February 4, 1994 — North Shore News iE & GARDE! On TVs, VERs, CAMCORDERS & | STEREO SYSTEMS | Sale ends Sunday NEWS photo Mike Wakefield BUILT IN 1907, this heritage home at 257 East Keith Rd. in North Vancouver, is being brought back to its original splendor. The home will be the centrepiece of a new town- house complex that was designed using the house as a guideline. DhM thact Sony, Hitachi, RCA, JVC PhD thesis suggests novel y | Toshiba and AIWA — Daacoar: way to control caterpillars | New Open Sundays 12 to Spm | LISA POIRIER is used to people laughing at her PhD thesis project. _ After all, how many people would .' choose to study caterpillars that-spit at each other when they meet? It sounds absurd, .but Poirier’s work, which won the best student paper award at the Entomological Society of Canada conference last September, is reaily no laughing: Matter.” _ _.. The results could, in the long run, be. of use in the ongoing battle lo contro] one of Canada’s major forest insect pests. ‘Poirier, a graduate student in Simon Fraser University’s centre for pest management, is studying the larval, or caterpillar. stage of the western spruce budworm, The insect, along with its more wide- Spread eastern cousin, defoliates millions of hectares of North American coniferous forest every yeur. The adult budworm is actually a small dullish-brown moth, but it is the larval stage that causes all the damage. In spring. the young caterpillars burrow into the young buds of fir and spruce trees, where they each form a protective silken tunnel and start lo feed. They Iter emerge to eal mature needles. Currently. budworm outbreaks are controlled by aerial spraying with a naturally occurring, bacterial pesticide. But another weapon would be very useful, says Poirier. That's why something she noticed as a child stuck in her mind. “As a kid in northern Ontario, I used to collect budworm caterpil- lars and I noticed when | handled them that they'd leave a tittle drop of brown liquid on my finger. I always wondered what that was. “Years later when | saw twa caterpillars spit this liquid at cach other, something clicked. } had to know more.” She soon did. Her research has already shown that this spit is prob- ably regurgitant, or gut contents. The caterpillars, which are solitary by nature. apparently use it to wam others of their kind to stay away from their food supply. “It's a crucial part of their defence repertoire.” says Poirier, as she deftly removes a budworm caterpillar from a rearing jar. She gently pokes it, and it instantly Keep your tires properly inflated, You'll increase the life of the tires. You'll save on fuel and lower harmful emissions. rears up, flailing and snapping with its tiny mandibles. “They're like little bulldogs.” she grins, as the annoyed caterpillar deposits a tiny droplet of spit on her finger. . The droplet is about about two” microlitres — the size of a pinhead. As part of her study. Poirier placed spit samples at the mouths of budwornt caterpillar tunnels. “At first, nothing happens,” she says. “The resident caterpillar goes through its usual threat behavior and then retreats into jis tunnel. But later on in the day it comes out and stars moving around, sometimes spinning down from its twig to the ground. This is very unusual behav- ior. “This gave me the idea that we can use the spit to fool them into thinking @ tree is too crowded. so that they leave their tunnel or drop to the ground, That’s when they're vulnerable to predators — and pes- licides. Greater Vancouver Regional District 20" 10 50" oF ano HO GST Made in Germany and Italy MAIN STORE ; VANCOUVER — 1148 Homer St., Tel: 682-1483... OTHER STORES RICHMOND — 4411 No. 3 Road, Tel: 276-2252 HOURS: Monday - Saturday 10 a.m. - 5 p.m. Sunday 12:30 p.m. - 5 pm. NEW STORE PARKER PLACE, RICHMOND 4330 No. 3 Road, Tel: 224-0888 HOURS: Sunday - Thursday, 11 a.m. - 6 p.m. Friday & Saturday 11 a.m. -9 p.m.