Gregson, J. D.

English

Journal of the Entomological Society of British Columbia

-i4 THE T ICK REFERENCE LIBRARY AT KAMLOOPS, BRITISH COLUMBIA, AND ITS APPLICATION TO TICK STUDIES IN CA NADA J . D. GREGS ON' The tick refer ence library at Kam-loops consists of a bout 5000 refer ences on 5 x 8 cards, together with more th a n 1200 r eprints. Because th ere is no comparable library elsewhere in Canada and because it may be of ser vice to those en gaged in rela ted fi elds of study, pa rticularly those of zoonosis, it is timely to draw a ttention to its m a in headin gs. Its role in a id -in g present s tudies on ticks is exem-plified by references to current and future problems on these pa rasites. The ticks of Canada receiv ed th eir first r ecognition through C. G . Hewitt, when, as the Dominion Entomologist at Ottawa, he publish ed "A contribu-tion to the knowled ge of Canadian ticks" (Hewitt, 1915) . He cited sixteen species a nd emphasized the import-anr.e of ticks as carri ers of serious cliseases to man and a nima ls. Only seven of the names then listed r emain unchanged in the present lis t of over thirty species record ed in Canada (Gregson, 1956). On the other hand, the cause of the disease, tick paraly-sis, which had been recognized then only for three years, is still little understood . Proj ected research on ticks did not begin un til 1928 when Eric Hearle , Officer-in-Charge of the newly-estab-lish ed Dominion Entomologica l La-boratory at Kamloops, co mmenced his studies on insects a ffectin g live-s tock a nd man in British Columbia. K a mloops h as since remained the center for tick studies a nd a ttention has acco rdingly been pa id to the com-pilation of r eferences pertinent to this work . At first th ese were ma inly confined to North American publica-tions on taxonom y, with li ttle re gard 1 H escarcll St a t ion , l30x 210, I'<lmloo ps. B.C. to tick- borne diseases south of the forty-ninth parallel. As knowledge of bird mi grants and parasites increased a nd as world-travel became a n every-day occurrence it became increasin gly importa n t to r ecogn ize species of ticks a nd diseases transmitted by th em th at were of potentia l import-a n ce to Ca nada. Similarly, as litera-ture On ticks increased , it beca m e desirabl e to refer to a ny fundamental research bein g done elsewhere on species simila r to those in Canada. Thus the r efer ence library now covers every aspect of tick research that has come to the writer 's attention, includ-ing publica tions on tick-borne dis-eases, for these frequently contain information on the vectors and their hos ts . Reprints have been secured wherever possible. However , complete works of for eign publications and t.heir translations a r e often difficul t to obtain . A third of the references to ticks and tick-borne d iseases, for example, are in fore ign languages; more than half of th ese are in Rus-sian. An a rbitra ry filing system was adopted to include the main sections on systema tics, morphology, tick-borne diseases, and control. However , beca use ma ny of the references referred to data on more tha n one of these subj ects, priority was given to the fir st category. References to spe-cific t icks a r e fil ed according to their respective genera; those containing severa l gen era a re fil ed under a "groupecl" h eadin g. For co nvenience Nearctic references a r e filed separ-ately. When th e emphasis is on morphology, disease, or control, th ey a re filed und er these h eadings or P':<l(. i<: .'T ' ,II()I. . S", R i:IT. ('''1. , ' .11,:1 .1. ''", .. ;)~I (lH6 ~ ). DIT 1. 1 9ti~ subheadings thereof. To da te no at-tempt has been made to cross index the individual references for su bj ect matter , or to make an a uthor index of the whole series. Both are desir-able. 1. Systematics Over 1500 separate references are in this category. The vas t amount of Il1formation in many of th e foreign works, Russian in particula r , can be extracted only as the publications a r e acquired and studied. Such pa pers on Old World species, their hosts and habits , have much to offer when com-pared with our own studies, for in Canada we a re in a favourable posi-tion to a ppra ise our north-western species in terms of Holarctic origins. Considered in this light, it is import-ant to speculate on their capacity to transmit tick-borne diseases at pres -ent confined to Asia a nd Eu rope. Looking southwards, an observant eye must be kept on a ll Nearctic records and descriptions of ticks , par-ticula rly those which may be trans-ported on bird or bat migrants . Recent taxo nomic studies of certain argasids in this group h ave cast doubt on th e id entity of at least one species tha t is pres umed to h ave been brought in on a bird . Past record s of ticks from caves, seashore retreats , beaver houses, burrows, and 11uma n dwel-lings, have shown that th ey may well extend their normal range in such protected conditions; the biology and epizootic significance of south ern s pecies cannot be ignored . Amo ngst species occurring in Canada are tax-onomic problems of variation in size, host specificity , a nd distribution which can profita bly be compa red with simila r findings in th e U.S . a nd other pa rts of th e world . 2. Morphology This sec tion contains over 600 re fe r-ences and is broken down to incl ud e a n atomical observations, s tud ies on behaviour and physiology, reproduc-tion. and feedin g. Histologica l and embryological studies go back little further than 1900 . Since then there h a ve been several ma j or works on th e feeding mechanisms of varions m em-bers of the Ixodoidea, the last origin-ating from this la boratory in 1960, but controversy and ignorance still exist over th e exact function of cer-tain structures of the sucking appar-a tus. Considerable study in Europe has also been m ade on the cuticle of t icks in r elation to wa ter balance; again , experience h as shown th at these researches could profitably be extended to cover local species. References to the beh aviou r of ticks cover such challenging subjects as hos t speCificity, dispause, photo-periodic rhythm in feeding, qu estin g habits, attractants, and phenological correlations. Knowled ge of anyon e of these topics can a id our search for better methods of tick control ; taken together they represent the in t rica te re la tionships th at exist between the tick, its env ironment , and its host. Studies on parthenogenesis , fertil-ity, th e egg waxin g organ, a nd other aspects of reproduction are ot specia l significance to local population re-search. This becomes apparen t when it is r ealized t hat the potentia lity of t ick popula tion is m eas ured la rgely in te rms of the several thousand eggs that a fema le lays. Because matin g causes an increase in the engorging rate of female D ermacentor ancZersoni Stiles, these studi es a r e also of inter -est at Ka mloops where attempts are being made to feed ticks by a r t ific ia l means. 3. Tick-c orne Disea ses There a re over 2000 references to tick-born e di seases, with emphasis on Texas fever , Rocky Mou nta in spotted fever , tularaemia , r ela psing fev er , tick paralysis. Q fever , and Colorado tick fever. all of wh icl1 occur in Nor th PH(H'. I'>' 1'0 .' (01. . SIl<'. B I<lT. CO l.!' .111l1.1 . \'01 .. ~!cI (1!16:!). DI·:(. I. HI62 America. Except for Texas fe ver , a ll ha ve been record ed in Ca n a da. Since British Columbia is unique in having a greater tick para lysis problem than anywhere else in the world , the 350 references to this disease a r e par-ticularly complete. In addition , th ere a re a bout one hundred references to kindred conditions of toxicity pro-d uced by t ick bite. The value of these r efer ences to disease will be not so much in their practical use as in providing data fo r a fund a m ental picture of tick-borne disease poten tialities. In Canada, par-ticularly in British Columbia, a re h eavy populations of ticks at the border of m a ny urban a r eas. The fact t h a t th ese ticks are la rgely free of virulent fo rms of disease should not be accep ted as a fortuitous circum-stance- rather, it should be studied as a phenomenum pec ulia r perha ps to our latitude, a nd correlated with records of the complex interrela tions that exist between ticks, their hosts, and their geographic position s. 4. Control Five hundred refer ences to control show that ticks h a ve been fought mainly by sprays and dips of a rsen-icals, and r ecently of chlorinated hydrocarbons . R esistance to chemi-cals has a ppeared in South Africa, Australia. Brazil, and th e United States. To date none h as occurred in Canada; t h e brown do g tick (Rhipi-cephalus sanguin eus (Lat.) ) will probably be theftrst to sh ow resist-a nce h ere. Russia n references to the control of ticks on vegetation by smokes, dusts, a nd sprays, and to their elimina tion by manipulation of either their natura l or domestic hosts are of importa nce , particularly in relation to tick-wild-life complexes in Can-a da. Althou gh tick pa rasites have been studied a nd released on m any occasions, there is a lack of informa -tion on other m ean s of na tura l con -trol. such as predation and tick diseases . Voles a nd ground beetles h a ve been ci ted as devouring t icks, a nd ther e is on e r eference to a fun gus a ttackin g the genitalia of ticks. The causes of fluctuation s in the popula-tion of ticks in British Columbia a r e largely un expla ined . In North Amer-ica the tick pa rasite, I xodiphagus texan us, h as been taken as far north as Idaho; in Africa the northward movem ent of similar parasites h as been observed in a pa rasitized tick on a migrating bird . It has not been determined whether such parasites playa part in British Columbia. Hewitt hoped that the meagr eness of his records would stimula te other s to a dd to the knowledge of a group which offered problems of unusual interest . Since his time there h ave been a bout ninety publications on ticks and ti ck - borne diseases in Can-ada; more than a third of which pertain to tick par a lysis. Although mu ch fundamental research r em a ins to be done there is little dou bt that his wish is bein g fulfill ed. References Gr egso n. J . D. 1956. The Ixodoi cle(l of Ca nada. Ca n. Dept. Agric. Pub. 930. 92 pp. Hell·itt. C. G. 1915. A con tr ibut ion to a know ledge of Ca nadian ticks. Trans. Roya l Soc. of Ca nad a. 9: 225-239. 

The tick reference library at Kamloops, British Columbia, and its application to tick studies in Canada

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The tick reference library at Kamloops, British Columbia, and its application to tick studies in Canada

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Journal of the Entomological Society of British Columbia