Insects in Greater Vancouver
by Mark L.Winston
Many of Vancouver’s most important insects are similar to its human inhabitants: they came from somewhere else. Honey bees, gypsy moths, cockroaches and crane flies all originated outside of North America, and were carried here by wagons, boats, cars, planes and trains.
Honey bees were deliberately imported to British Columbia by European settlers in the mid- 1800s, and have become an important part of our urban environment. Beekeeping is technically not permitted within the city limits of Vancouver, but numerous colonies are comfortably hidden by beekeepers in backyards and gardens, and on rooftops and apartment balconies. These insects pollinate a wide variety of homegrown produce, including fruit trees, squashes, peas, beans and many other garden crops that would not bear fruit without the work of this useful insect. Honey bees do well in the city, and can produce copious honey harvests in addition to performing their crucial pollinating role.
Gypsy moths have been a more recent immigrant, and are Vancouver’s most publicized insects. These forest-eating moths originated in Europe and Asia, and regularly arrive today from two directions, eastern North America and Siberia. They may do minor damage to our forests if they become established, but present a major threat to our lumber export industry: importing countries would require fumigation of all B.C. wood products if gypsy moths were declared resident. Vancouver and the surrounding area are the major provincial regions that repeatedly become infested with new moths, because of our port facilities and frequent traffic with Eastern Canada. Thus annual spray programs are conducted to eliminate these incipient infestations. The largest of these was conducted in 1992, when much of the city was sprayed by air with a moth-killing bacteria, and all of Vancouver’s residents were media-sprayed with a deluge of newspaper, radio and television stories about gypsy moths.
Cockroaches are another familiar imported resident, in this case originating from various tropical countries. These insects thrive in urban environments because of warm buildings and abundant food they scavenge from garbage bins, unclean cupboards and floors and food processing sites. These most cosmopolitan of insects share Vancouverites’ love of restaurants, and can be found dining out in many of our finest food emporiums.
Crane flies came from Europe, and the long-legged, very large adult flies are a noticeable resident in late summer. The adults do no damage, however. It is their larvae, commonly called leatherjackets, that feed underground on roots and stems of lawn grass, and can devastate a homeowner’s proudly tended lawn in the spring.
Not all of Greater Vancouver’s insects came from somewhere else; we can be proud of our local carpenter ants that share many of our homes. These ants burrow in wood to make their nests, and colonies can reach huge sizes if untreated. There probably is not a single home made out of wood that has not been, or will not be, infested with these large ants, and the flights of the winged king and queen reproductive ants are a prominent and sometimes spectacular part of our urban scene. Termites also can be found living in our homes, and can be differentiated from ants by their soft bodies and whitish appearance. Termites also differ from carpenter ants in being truly home- grown; they feed on wood, using bacteria and other organisms living in their guts to digest the tough wood fibres.
Wasps and fleas are two other groups of insects in addition to cockroaches, carpenter ants and termites that provide an excellent business for the abundant population of pest control companies. Wasps are most problematic in late summer, when their nests become large and populous. Wasps are considered harmful because they sting and love snacking on our picnic food, but they actually are beneficial because they eat the larvae of other pest insects. Not much can be said in favor of the flea, however. The local fleas that bite people feed primarily on dogs or cats, but are not averse to a human meal if that becomes available.
One group of Canadian insects is significant for its absence--we have few biting flies and mosquitoes. Our spectacular terrain and heavy rains are responsible for making the Lower Mainland one of the few regions in Canada that are relatively free of these blood-sucking pests. The larvae of these flies require standing water in which to feed and mature, and the area surrounding Vancouver has mostly swiftly flowing streams in which the larvae do not thrive.
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