Gregson, J. D.

English

Journal of the Entomological Society of British Columbia

22 ENTOMOLOGICAL SOCIETY OF BRITISH COLUMBIA, PROC. (1951), VOL. 48, AUG. 15, 1952 upshot will be remains to be seen and it might he of interest to maintam blocks of orchard trees under the spray programme used in, we will say, 1940 or thereabouts. Some valuable information might be forthcoming af-fording as it would, a direct compari-son on insect populations. A remark made by the president of the British Horticultural Socie ·~ y a few months ago gives one food for thought. He drew attention to the fact that, most of our leading types of livestock, cattle, horses, sheep, poultry, etc., were produced by the efforts of ordinary farmers, with little, or no assistance from Science as we know it today. He also put forward the idea that Science may, at times, actua lly delay discoveries by spliHing too many hairs. There is a good deal of truth in these statements, but it will be for the younger men to ponder them. THE HISTORY OF THE STUDY OF EXTERNAL ARTHROPODS AFFECTING ANIMALS AND MAN IN BRITISH COLUMBIA ]. D. GREGSON Livestock Insec t Laboratory, Kamloops, B.C. The earliest observations of insects 'lffecting man and animals date back to records made by early explorers on the voracity of some of these pests. In Dr. Cheadle's diary of his trip across British Columbia in 1863 are such comments as "Fearful amount of gadflies. Horses half mad . . . tormented to death by flies. Sandflies and musquitos terribly annoying ... musquitoes murderous." Remarking on the terrible "musquitoes" at the plains o f Sumas, he states that "In-deed men from all countries agree that the musquitoes of B.c. are un-matched for numbers and ferocity." Tn the early nineties the mosquito still occurred in millions in the Fraser Valley, rendering work a "purgatory" from early July until September. Re-lief was obtained when the area was dvked. The first economic studies of a~imal insect pests were undertaken by Dr. Seymour Hadwen, Animal Pathologist at Agassiz in 1912. From his pen arose publications covering ticks, warble flies and other livestock pests, and under joint authorship with Dr. E. A. Bruce, he published his ob -servations of the migration of warble lavae through the tissues of cattle. In a la ter bulletin he treated compre-hensively the control of insects affect-ing livestock. In 1919, under the di-rection of the Dominion Entomologist, Dr. Hewitt, Mr. Eric Hearle com-menced his studies of mosquitoes in the Fraser Valley. This was follow-ed by his 1927 publication of the "Mosquitoes of British Columbia." The study of insect and ticks affect-ing animals and man was placed on a firm footing with the official estab-lishment of a Dominion Insect Unit at Kamloops in 1928. Eric Hearle was transferred from Indian Head, Sas-katchewan, to act as Officer in Charge -and staff. His wire to the Domin-ion Entomologist, Mr. Arthur Gibson, that he had "located a place that is admirably suited to our needs" referred to an old shack that was located in the centre of town and which had served in its time various purposes from a funeral parlour to a bootlegging joint. Once established, he set himself, singlehandedly, to the terrific task which lay before him. Not only was he treading on virgin territory as far as his work was concerned, but he was working in a province that con-tains a richer supply of biological ma-terial than all the rest of Canada. This is readily evidenced in later taxonom-ic studies of various insects. During the first summer he studied and collected all data and specimens he could lay his hands on. This in-cluded mosquitoes, blackflies, sandflies, horseflies, ticks, mites and lice. His ENTOMOLOGICAL SOCIETY OF BRITISH COLUMBIA, PROC. (1951), VOL. 48, AUG. 15, 1952 23 surveys covered the whole o f lower British Columbia. Thirteen districts were examined for warbles, which were causing 75 per cent. warble dam-age in hides. Half a dozen addresses were given during the first month alone. Questionnaires on tick paralysis were sent to all doctors in the Interior and a display was set up at the Van-couver Exhibition. During most of this period he lacked a stenographer. Within the next two years, mos-quito controls had been inaugurated at Kamloops and Kelowna. Tick studies had advanced to include life-history studies of th~ more important species , including observations of their effect on both domestic and game animals. This brought to light many tick paralysis cases, including an out-break at Douglas Lake involving 100 head o f cattle, out o f which 30 were lost. Tularaemia was first recorded for British Columbia in rabbits at Vavenby. In 1931, the fi rst of a series of large-scale warble control measures were undertaken at Tranquille. From this work it was demonstrated that the grub incidence in cattle could be brought successively from 19 per cent. tn 0 . .1 per cent. within four years. During 1932 and 1933 Hearle spent several months in the vicinity of Jasper Park Lodge making a detailed survey of biting fly conditions. Over 1400 blackllics alone were pinned and determined. Following this work, at the age of 41, his health broke and he was confined to bed. There he continued with the classification of ticks, mosquitoes, blackflies and horse-flies, practically completing manu-scripts on the ticks and blackflies of British Columbia, before his untimely dea th in the spring of 1934. His paper "The Ticks of Western Canada" and his bulletin "Insects and Allied Parasites Injurious to Livestock and Puultry in Canada" were published posthumously. Immediately following He a r Ie's dea th, Professor G. J. Spencer took charge of the laboratory during the summer months. On the staff a t that time were two assistants, T. K. Moil-liet and the writer, and a stenog-rapher. It was during the same year that the original working quarters burned down. While much of the laboratory equipment had been trans-ferred to the Post Office Building, this fire resulted in a loss of field facilities. Steps were taken to se-cure 32 acres of land three miles west of Kamloops, and a plea issued for the construction on it of rt laboratorv, wherein the expanding problems ;)f ticks and their diseases could he undertaken with greater safety to the public. It was shortly after 1'.1r. Allen Mail's arrival, in 1937, from Montana, to take over his duties as Officer-in-Charge, that these plans went into effect, and a $21,000 two-storey building was erected . The occupation of the building was fol-lowed by the co-operative inclusion of members of the Dominion Range-land Department and of the Depart-ment of Pensions and National Health. The presence of the latter marked the commencement of Western Canadian studies of plague and spotted fever, and surveys of ticks and fleas for their testing were first made by members of the entomological staff. Quaran-tine quarters and animal housing were added for this disease work, which is still in progress under the supervision of Dr. Humphreys, in what is now the Department of National Health and Welfare. The next phase o f study in livestock insect control appeared with the ad-vent o f power spraying, and extensive tests were made to determine the optimum pressures and derris mix-tures for warble control under Brit-ish Columbia conditions. The pres-ence of wartime shortages in additioll necessitated comparisons being made with derris and pyrethrum suhsti-tutes. Along with these studies came those pertaining to the protectio n of armed fo rces from the attacks of bit-ing flies, and in this connection, many tests were made to determine the effectiveness and practical value of mosquito repellents. In 1943, Mr. Mail resigned his post at this laboratory to accept work in 24 ENTOMOLOGICAL SOCIETY OF BRITISH COLUMBIA, PROC. (1951), VOL. 48, AUG. 15, 1952 the United States, leaving as his suc-cessor, J. D. Gregson. At this time chemical advances in the production of synthetic insecticides were creat-ing a new aspect in insect control. Before long DDT and thiocyanates re -placed pyrethrum fly sprays; citron-ella and other aromatic oils were cast aside for such superior compounds as 612, dimethyl phthalate and indalone. Gammexane was discovered to be a long-awaited acaricide and mosquito and blackfly oil larvicides were dis-carded fo r those embodying DDT. These and other discoveries shed a new light on insect control and, of course, provided much room. for new research to meet our conditIOns. In tick control it has been necessary to discover dosages of BHC that will give maximum protection to cattle and sheep from ticks and keds, yet not prove injurious or objec!ionable in any way to the host or to Its con-sumer. This has involved numerous field tests each year using arti~cially infested animals. These expenments have progressed from the deliberate application of over?oses on labora -t ory animals to cau~IOus recommenda-tion and finally Widely accepted use on ;ange stock. During recent ye~rs attention has been devoted to the 10-triguing study of systemic insecti-cides where it has been found pos-sible'to rid an a nimal of its external parasites by a single oral dose of ma-terial. Mosquito control, the administra-tion of which has long passed to. ~he hands of some two dozen commumtles in British Columbia, has likewise undergone a great transformation, and since the establishment in 1949 at Kamloops of a Household and Medical Unit laboratory, its Officer-in-Charge, Mr. L. C. Curtis, has been engaged in perfecting modern control methods. These include air-spraying and fog-ging. The latter method i~ .coming into popular use as an adult1C1de and can be generated by means of a gas engine exhaust adaptation. Since DDT is an effective biting-fly larvicide in such small amounts (one part in 20 million for blackflies), appropriate methods for its release in water are also being studied. Linked with the economic progress of livestock insect control has been the advance of academic knowledge. Here may be included taxonomic studies, such as have stepped up the known number of British Columbia ticks from 12 to 20 within the past 20 years. The number of flea species known to exist in the province in 1907 was six. During the next 30 years Jordan and Rothchild of the Zoological Museum, Tring, England, described many additional species and by 1936, G. ]. Spencer of the Universi-ty of British Columbia had built this number up to 61. G. P. Holland, now Chief of the Systematic Unit, Ottawa, in his monograph of the fleas of Canada, lists over 90 as now occurring in British Columbia. Spencer's check lists in our proceedings have similarly demonstrated our increased knowl-edge of pediculous and dipterous para-sites. Ecological observations made at Kamloops have shed much light on tick behaviour, have shown tick life-cycles as long as 21 years, and indi-cated the gradual increase and de-crease of such economic tick species as Dermacentor andersoni and Ixodes pacificus as apparently a~ected .by civilization. Such outstandlOg speCies as the southern spinose ear tick Otobius megnini and the relapsing fever carrier, Ornithodoros hermsi, have in recent years been taken a number of times during field collections. Par-ticular attention has been paid to the life-history of the warble fly, and by the use of specially constructed girdles on infested cattle, some 400 grubs have been ' collected for fly studies each spring. In retrospect, the study of insects an.d allied pa rasites affecting man and animals in British Columbia has ad-vanced rapidly and fully. With a staff of twelve now at the Ka mloops la-boratory, and with the increasing co-operation of Provincial, Dominion and University departments, the future should hold even greater progress. 

The history and study of external arthropods affecting animals and man in British Columbia

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The history and study of external arthropods affecting animals and man in British Columbia

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Journal of the Entomological Society of British Columbia