Lm National LibrarY Bibliothèque nationale rÉ of Canada du Canada Canadian Theses Service Service des thèses. canadiennes Ottawa, Canada K1 A ON4 The author has granted an irrevocable non- L'auteur a accordé une licence irrévocable et exclusive licence allowing the National Library non exclusive permettant à la Bibliothèque of Canada to reproduce, loan, distribute or sell nationale du Canada de reproduire, prêter, copies of his/her thesis by any means and in distribuer ou vendre des copies de sa thèse any form or format, making this thesis available de quelque manière et sous quelque forme to interested persons. que ce soit pour mettre des exemplaires de cette thèse à la disposition des personnes intéressées. The author retains ownership of the copyright L'auteur conserve la propriété du droit d'auteur in his/her thesis. Neither the thesis nor qui protège sa thèse. Ni la thèse ni des extraits substantial extracts from it may be printed or substantiels de celle-ci ne doivent être otherwise reproduced without his/her per- imprimés ou autrement reproduits sans son mission. autorisation. IqEÍ-¡ ú-11"5-54855*x Canad?d SEASONÀL ABUNDANCE, PHYSTOLOGICAL AGE, AND DAILY ACTIVITY OF HOST.SEEKING HORSE FLIES (DIPTERÄ: TABANIDAE) AT SEVEN SISTERS, MÀNTTOBA, WITH AN EVALUATTON OF PERMETHRIN SPRAY TREATMENTS AS À MEANS OF INCREASTNG THE PERFORMANCE OF GROWTNG BEEF HETFERS SU&fECT TO HORSE FLY ATTACK. by PauI Edward Kaye McElligott, B.Sc. A thesis presented to the University of Manitoba in partial fulfillment of the requirements for the degree of Master of Science !{innipeg, Manitoba June, l-989 c PauL E.K. McElligott, l-989 SEASONAL ABUNDANCEI PHYSIOLOGICAT AGE, AND DAILY ACTIVITY OF HoST-SEEKING HoRSE FLIES (ITpInne' TABANIDAE) RT snVsN SISTERS, MANIToBA, WITH AN EVALUATION OF PERI'ÍETHRIN SPRAY TREATMENTS AS A MEANS OF INCREASING THE PERFORMANCE OF GROI.IING BEEF HEIFERS SUBJECT TO HORSE FLY ATTACK BY PAUL EDWARD KAYE McELLIGOTT A thesis submitted to the Faculty of Craduate Studies of the u¡riversity of Manitoba in partial fulfillment of the requirenrents of the degree of MASTER OF SCIENCE o t9B9 Pernlissior: has been granred to the LIBRARy OF THE UNIVER- SITY OF MANITOBA to Ie¡rd or sell copies of this rhesis. to the NATIONAL LIBRARY OF CANADA to microfilnr rhis thesis and to le¡ld or sell copies of the film, and UNIVERSITy lvf ICROFILIvf S to publish an abstract of this tlìesis. The author reserves other publication rights, and neither the thesis nor extellsive extracts froln it may be prirrted or other- wise reproduced without the author's wrjttelr pernlissjo¡r. I1 ABsTR.ACT Effects of biweekly permethrin treatments on the weight gain performance of growing beef heifers subject to attack by large numbers of blood-feeding tabanids was evaluated. In 1987 and L988 respectively, groups of 55 and 72 heifers (of similar age and weight) r¡rere divided into two herds. Animals in one herd received biweekly whole-body sprays of permethrin (aqueous emulsion, 0.5t permethrin, applied at l- L/aninal), while the other herd was left untreated. Animals in both herds were weighed biweekly and those in one herd r.rere treated concomitantly f rom early June through nid JuJ-y. Permethrin spray treatments did not effectively reduce the impact of horse flies on the animalst weight gains. No consistent trend was apparent in differences between the average daily weight gains of animals in untreated and treated herds, and animals in both herds gained, oD averagie' from 35.38 to 44.82 kg over the 6-week experimental period in both years. Tabanj-ds were trapped frorn dawn until dusk using four Manitoba Horse Fly Traps (MIIFT!s) at Seven Sisters, from mid May until rnid JuIy in L987, and f rom rnid l,Iay until mid August in 1988, to determine the seasonal activity patterns of the various species present. Thirty one tabanid species in four genera (Hvbornitra (L5 spp. ) , Tabanus (4 sPP. ) , I].I Chrysops (11 spp. ) , Haematopota (f- sp. ) ) , of which ten Hybornitra spp. were abundant, were present in MIIFT catches. Hvbornitra lurida (Fa11en), and H. nitidifrons nuda (McDunnough) peaked in abundance in late May to early June; H. illota (Osten Sacken) and H. lasiophthalma (Macguart) in early June; H. affinis (Kirby), H. arpadi (Szilady), and H. zonalis (Kirby) in nid June; and H. epistates (O.S.) and H. pechumani Teskey & Thomas in late June to early August. Hybomitra trepida (McD. ) peaked in abundance twice, in late June and early August. labanid density and diversity was greatest during June, and few flies were present at the site after nid JuIy. Subsamples (L0-30 flies) of daily trap catches were dissected to determine seasonal changes in the per cent parity of ten abundant Hybomitra species. At the beginning of the flight season, 80 to L00å of flies dissected were nulliparous. As the flight season progressed, however, ân increasing proportion of flies captured were parous. After approxinately one month of flight activity, parity in all- but three species reached levels approaching 100å, and remained high thereafter. Hybornitra lurida and H. nitidífrons nuda were 1-008 parous within two v¡eeks of their first appearance in trap catches, and parity of H. trepida increased to l-008 after four weeks, declined to 4OZ two weeks later, and rose again to l-003 after a further 2 weeks. 1V Hourly trapping was carried out between O53O hr and 2230 hr for four days weekly throughout the sunmers of t987 and 1988, to determine the patterns of daily activity of nine tabanid species at Seven Sisters. One MIIFT was used in L987; four traps in L988. Temperature and light intensity lrere recorded at hourly intervals in 1988 on1y. Hvbomítra epistates and H. pechumani v¡ere most active during late morning or rnidday; H. arpadi and H. zonalis in early afternoon; H. affinis, H. i1lota, and H. lasiophthalma in late afternoon; and H. nitidifrons nuda and H. lurida in early evening. The norning onset of tabanid flight activity stas usually temperature related, while the cessation of flight activity in the evening was either temperature or light related, depending on whether temperature or light intensity vras first to faII below threshold leve1s. Tabanid flight activity was generally low at temperatures below 2Oo C, although H. lasiophthalna and H. affinis r{ere caught at ternperatures as low as Lzo c. Little flight activity occurred at light intensity levels below 1000 Iux. At Churchill, Manitoba, where hourly trapping vras carried out in L988, tabanid (H. affinis and H. frontalís (Walker) ) activity was low below L4o c, aÌthough tinited activity occurred down to 60 c. TABLE OF CONTENTS ÀCKNOWLEDGEMENTS ....viii LIST OF TABLES ....x LIST OF FIGURES ..xi FOREWARD ...xiv GENERAL ÏNTRODUCTION ...1 LITERÀTURE REVIEW fmpact of Tabanids on Livestock Production ......3 Control Measures .......8 Clirnatic Factors and Tabanid Host-seeking Activity ..L4 Seasonal Trends in Horse FIy Populations .......L7 CHAPTERS: r. THE EFFECT OF PERMETHRIN TREÀTMENTS ON THE WEIGHT GAINS OF BEEF HEIFERS SURTECT TO STRESS CAUSED BY BITTNG HORSE FLIES. A. INTRODUCTION ......2O B. MATERIALS AND METHODS 1. Study Àrea ....22 2. Tabanid Populations .....22 3. Study Animals ......23 C. RESULTS L. Tabanid Populations .....26 2. Weight Gains .......27 D. DISCUSSION ...28 vi IÏ. SEÀSONÀL DISTRTBUTION AND PHYSIOLOGICAL ÀGE OF HOST- SEEKTNG HORSE FLIES (DIPTERÀ: TABANIDAE: HYBOMTTRA sPP. ) AT SEVEN SISTERS, MANITOBÀ. A. INTRODUCTION ......39 B. MATERÏALS AND METHODS L. Study Area ....41- 2. Collection Technigues ...41 3. Physiological Age Grading ....42 C. RESULTS 1. Seasonal Abundance .... ".43 2. Seasonal Changes in Physiological Àge . .48 D. DISCUSSION 1. Seasonal- Succession of Species ....49 2. Seasonal Changes in Per Cent Parity ....51- ITI. DÀTLY ACTIVTTY OF SEVERAL IiIANITOBA HORSE FLY SPECTES (DTPTERA: TÀBANIDAE: HYBOMITRA SPP. ) . A. ÏNTRODUCTION ......86 B. MATERTALS AND METHODS l-. Study Areas and Data Collection ...89 2. Daily Àctivity Patterns ......91- 3. Esti¡nation of thresholds .....92 4. Frequency Distributions ......92 C. RESULTS l-. Daily Patterns of Tabanid Activity .....93 2. Temperatures, Light Intensities, and Times of onset and Cessation of Tabanid Activity .....95 3. Freguency Dist.ributions ......96 vt l- D. DTSCUSSTON 1-. Daily Activity Patterns ......99 2. Threshold Estimates ....L00 GENERÀL CONCLUSIONS . .139 LITER.A,TURE CITED .....L42 APPENDICES: A. Producer, breed, birth date, and initial weight of beef heifers used in iveight gain study at the Seven Sisters Grassland Project in L987 . .150 B. Producer, breed, birth date, and initial weight of beef heifers used in vreight gain study at the Seven Sisters Grassland Project in 1988 ..L52 c. Principal characteristics of 9 predictive models of daily variation in numbers of tabanid captures as a function of meteorological factors . ..154 D. Mean hourly percentages of total daily tabanid catches for eight tabanid species at Seven Sisters, Manitoba in L987 . L56 viii ACKNOTÍLEDGEI.ÍENTS I take this opportunity to thank aII who helped ne throughout my M.Sc. program. In particular I thank rny supervisor, Dr. Terry D. Galloway for his gluidance, encouragement, humour, and accessability. I also thank the other members of my committee: Drs. Reinhart A. Brust, Garth K. Bracken, and Gary H. Crow, for their hèlpfu1 advice and critical review of this manuscript. I an greatly indebted to Robert Currie and Shelley James who, âs sunmer students, slaved on this project for many hours in the field and laboratory, and Ervin Bachmann who, âs manager of the Seven Sisters Grassland Project, witlingly shared with me his knowledge and expertise of livestock. Dr. Herb J. Teskey, Biosystematics Research Centre (Ottawa) provided invaluable taxonomic assistance. This research was funded in part by an Manitoba Department of Agriculture Àgri-Food grant through the Eastern Grassland Society. I thank the Society and its members, particularly Fraser Stewart, for their support and the use of their cattle.