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The Rural Voice, 1988-02, Page 36AGRICULTURAL RESEARCH UGLY RESEARCH The Good, the Bad, the Ugly, and the Incomprehensible I n terms of economic loss on the farm, the flea beetle ranks high among North American pests. A study published in 1982 estimated that flea beetles cost farmers $12 million for insecticide application and destroyed up to eight per cent — about $72 million worth — of the canola crop. This level of crop destruction is equal to that caused by the boll wee- vil, the most serious agricultural pest in the U.S., although the dollar value of the canola destoyed is much less than the value of the cotton lost to the weevil. The financial loss caused by the flea beetle is nearly equal to the loss caused by the alfalfa weevil, another serious pest in the U.S. Yet the same study also points out that the flea beetle has received much less research attention than these other pests: fewer than 15 research papers on the pest were published in Western Canada (where much of the research on the flea beetle is carried out) be- tween 1972 and 1982. On the surface, this is a curious situation. A pest that causes so much loss should get a great deal of atten- tion. Instead, it looks as though the flea beetle is being ignored. This apparent discrimination against the flea beetle problem has some basis in fact. Flea beetles are one of the ugliest research problems to come along in years. Their habits make them difficult to control in the field. They are also hard to work with in the lab, so any research on them becomes a frustrating and complicated matter. Many scientists working in by Ian Wylie-Toal agriculture want nothing to do with flea beetles; the headaches are too big and the rewards too few to excite any but the most determined workers. What is it about flea beetles that makes them such an ugly subject for research? After all, they are only insects, and many different insects have been studied successfully for years. Are flea beetles that different from all the rest? Once again, as is the case with so much biological research, the answer is yes and no. No, flea beetles are not much different from other insects. The adult beetles overwinter in bush and leaf litter, emerge in the spring to feed, then lay eggs and die. The eggs are laid in the soil around plants in the brassica family (canola, mustard, cabbage) and the larvae live in the soil, feeding on the plant roots. In late summer, a new generation of adult beetles emerges, feeds until fall, then goes into hibernation, starting the cycle again. This is a common type of insect life cycle, especially among beetles. Neither are the flea beetle's physiology, method of eating, or way of breathing or laying eggs essentially different from other insects'. But at the same time, yes, flea beetles are different. First, the two main species of flea beetles were accidentally introduced from Europe, so the population does not have a normal predator/parasite/disease com- plex to keep it in balance. Flea beetles are also highly mobile insects, and have used that mobility to cash in on the expanded acreage seeded to canola in the past 20 years or so. The in- creasing numbers of beetles have no difficulty finding new food sources. Their mobility also makes them difficult to spray; the insects simply get up and leave when a field is dis- turbed. New insects will rapidly re - colonize a sprayed field as well, so spraying for flea beetles is not a com- mon practice. Instead, because the adults are active and feeding when the seeds are germinating, the seeded crop is treated with a long-lasting insec- ticide which gets the seedlings through the dangerous time. The timing of the flea beetle's feeding is what makes it so damaging. An untreated crop will be eaten voraciously and the small plants soon die. Many farmers who complain of poor seed germination are in fact victims of flea beetles. The crop germinated and emerged, and was eaten down before the farmers were aware of it. Flea beetles are a perennial prob- lem, so the seed must be treated every year. As a control method, this is effective but not ideal. The insecti- cides used are costly and often severe- ly toxic to both people and insects. 34 THE RURAL VOICE