Note: The "abstract" is actually the entire paper

Gregson, J. D.

English

Journal of the Entomological Society of British Columbia

JOURNAL E NTOMOL. SOC. BlnT. COIX .\WU. VOL. 63 (1966), DE('. 1. 1966 13 cocoons between the rocks under the double layer of fabric, On April 16 a pupa could be seen in the cocoon under the curtain fabric. It was 27 mm long, black and shiny. A female emerged on June 1, after six weeks pupation, A male emerged from a cocoon between th e rocks on June 11. The third pupa was killed by mildew. The moths em erged 10 days earlier than those observed in nature, a sign that th e hibernation place was too warm and the a mbient air too dry. None of the larvae reared was para-sitised. Reference Jones, J, R. J . L. 1951. An annotated check list of the Macrolepidoptera of British Columbia , Entomol. Soc. Brit. Columbia Occasional Paper No . 1. RECORDS OF TICK PARAL YSIS IN LIVESTOCK IN BRrTISH COLUMBIA J. D. GREGSON1 ABSTRACT Reports of 189 outbreaks of tick paralysis in livestock in British Col-umbia are tabulated with regard to distribution, the kind and number of animals involved, the annual inci-dence of paralysis, and the dates and sizes of the major outbreaks. The disease is most prevalent in the west-ern half of the interior dry belt where there have been apparent peak years of cases. The recorded totals are in excess of 2010, 1849, 9, and 13 for cattle, sheep, horses, and dogs, re-spectively. Most of the loss from the disease results from the extra man-power needed to care for affected ani-mals, reduced animal condition, and disuse of otherwise valuable pasture. Almost every year since its incep-tion in 1928, the entomology labora-tory at Kamloops, B.C., has received word of cases of tick paralysis in live-stock and humans in this province. Since the published records refer only to 11 out of some 190 outbreaks of the disease in livestock, it is felt that more information should be made available from data in this labora-tory's files. I Research Station, Research Branch, Canada Department of Agriculture, Kamloops, B.C. Tick paralysis was first recognized as a dis ease in North America when Todd, in 1912, accumulated case his-tories of the effects a ssociated with tick bites in humans and differenti-ated the symptoms from those of Rocky Mountain spotted fever. Had-wen (1913) associated the disease with a condition observed in the Vicinity of Keremeos, where for three years a farmer had up to 300 of his sheep affected by a form of paralysis. Hadwen proved experimentally that the disease was caused by the bite of Dermacentor venustus Banks ( = D . andersoni Stiles) . His theory that a toxin caused the symptoms remains unchallenged. Other than Bruce's (1920) warn-ing to ranchers of tick paralysis, there are no further references to outbreaks until Bruce's publication in 1922. In this, h e r ecords witnessing an out-break at Vavenby where Moilliet had 200 sheep affected out of a band of 400. Subsequent unpublished refer-ences to this rancher indicate that up to 1928 as many as 10% of his flock of 1300 were sometimes paralysed. In 1928, at the request of the B .C. ranching industry, a laboratory was established at Kamloops for the study 14 JOUI{ .'.\I. EY[()\IOL. SO". BIUT. COU ;1\lnJ\, VOL. 63 (1966). DEC. I, 1966 of insects affecting livestock. After this date all records of tick paralysis appear in the laboratory 's files and unpublished monthly reports. These have been the source of most of the figures presented here . Concerning the validity of these records, it must be noted that only occasionally have instances of paral-ysis in livestock been fully and offi-cially verified. The symptoms are so well known to the stockman that his first thought is for his animals, and only after they have been "de-ticked" does he trouble to report the occur-rence, and not always then. Frequent-ly the information trickles in sec-ond-hand a year or more later. Nev-ertheless, because the symptoms are not likely to be confused with other illnesses, there is usually little doubt of the authenticity of cases witnessed and reported by ranchers. The size of ar outbreak is often more question a tJ : ; a distraught rancher tends to exaggerate his loss-l"; . Compensating this in the overall pictme is the fact that many in-.s ta nces of tick paralysis never are re-corded. Indeed, herders have fre-quen tly been reticent in reporting their troubles even to their employers for fear of reprisals for negligence. TABLE I-Number of livestock and humans paralysed annually in British Columbia by tieks as reported to th e Kamloops laboratory since 1900. Year to 20 20-28 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Totals Cattle 13 22 * 4 101 2 2 2* 29 200 15 22 10 20 32 25 16 491* 34 3 70 1 58* 103 .. 1 30 385* 1 23 1 1 263* 30 2010 Sheep 385" 375 130 26'" 24 20 20* 22 1'" 13 103 2* 211 2* 1 16* * .. 50 341 100 3 4 1849 Horses 2 1 1 1 1 3 9 Dogs 1 5 2 2 3 13 Totals 398" 399 130* 30* 125 24 22'" 24'" 30* 218 119 24'" 221 22* 34 2 41* 17* 494'" 34 o 3* 70 1 108'" 444 o o 101 30 o 385" 1 23 o o 6 1 267" 33 3881 Reports 6 7 2 6 5 5 3 5 5 12 7 5 8 4 4 2 4 4 11 4 o 2 2 1 7 21 o 1 2 1 o 10 1 3 o o 4 1 19 5 189 * "several" cases. These are not entered in the totals. Humans ±80 +80 6 9 11 5 1 4 4 1 4 7 1 1 2 2 3 2 4 4 1 8 7 2 2 2 1 1 3 1 7 5 3 2 276 JOURNAl. El'no:\roL. SOC. BRIT. CO r.I : ~IBL\, YOI.. 63 (1966 ), Dr.\,. 1 , 1966 1ii Human cases are well documented in the Kamloops files since 1928, but prior to t h at date t h e records are ob-scure and there are possibilities of duplication. In this paper the 189 single and multiple records of tick paralysis in livestock are tabulated in three ways. Fig. 1 illustrates their distribution and the kind and approximate num-bers of animals involved. Table 1 lists, separately and together , the annual totals of paralysed cattle, sheep, horses and dogs, and a l.so the annual incidence of paralysis as re-corded from separate reports, either single or grouped cases. Human cases have been included to give an overall picture of tick activity. Table 2 lists those outbreaks which exceeded 20 paralysed animals. Reference to these tabulations, with d etails in the original reports, p ermits s ome speculation regarding the frequ ency and distribution of tick paralys is as it affects livestock. How-ever, in dealing with a disease as enigmatic as this one (Gregson, 1962) caution must be taken not to be mis-led by false interpretations for it will be appa r ent that to evaluate properly anyone aspect, the whole picture must be considered. Since the main r urpos e of this paper is to list the incidence in livestock , other aspects 01 the di sease will not be di sc ussed. The distribution of tick paralys is in livestock , with the exception of two known outbreaks, a ppears to be con-fined to the western half of the inte-rior dry belt. The largest outbreaks TABLE 2-0utbreaks of tick paralysis in B.C. since 1911, invo lving more than 20 head of livestock. No. ex posed Date Locality Posi t ions' Cattle Sheep to ticks P3ralysed Died 1911 Keremeos 49°N 119°W x 900 46+ 46 1912 Keremeos 49 119 x 900 :334 90 1920 Vavenby 51 119 x 400 300 1927 Similkameen 49 119 x 40+ 40 1929 Vavenby 51 119 x 1300 10% yr few 1929 Blackpines 50 120 x 350 20 / day few 1930 Douglas L. 50 120 x 900 100 65 1930 Stump Lake 50 120 x 10-151 day 1931 Copper Cr 50 120 x 700 20+ 20 1932 Falkland 50 119 x 180 35+ 35 1935 Quilchena 50 120 x 638 200 26 1936 Wolf Cr. 49 120 x 1000 100 1938 Pinantan 50 120 x 1700 90 12 1938 Jaffray 49 115 x 100+ 100 1940 Scheidam Fl. 50 120 x 200 26 5 1944 Merritt 50 120 x 40 12 1944 Quilchena 50 120 x 1230 400 50 1944 Douglas L. 50 120 x 42 + 42 1948 Big Creek 51 122 x 2000 50 several 195') MerritL 50 120 x 40 3 1950 Pritchard 50 119 x 300 50 1 1951 Quilchena 50 120 x 800 30 3 1951 Penticton 49 119 x 20+ 1951 Barnhartnle 50 120 x 700 270 7 1954 Barnhartvale 50 120 x 100 1955 Douglas L. 50 120 x 400 30 2 1957 Stump Lake 50 120 x 118 32 7 1957 Douglas L. 50 120 x 700 320 30 1964 Alkali L. 51 122 x 300 22 7 1964 Dog Cr. 51 122 x 650 ± 90 3 1964 Farwell Can. 51 122 x 250 ± 60 13 1964 Copper Cr. 50 120 x 400 30 1965 Chimney Cr. 52 122 x 250 28 * According to 1953 Gazetteer of Canada; B.C. Co-ordinates the geographical quadrilaterals. given at S.E. corners of 16 J OU RN A L E i\ TOMO L. So('. B IUT. C O l. e .\lB I " , 1 ] 96G VOl.. 63 (196fi ), DI':I'. , 0 0 0 ~ ~ 8 0 ~ 0 "l 0 0 0 ';'I 52 ~ 0 ..!.. .., 0 0 ~ ~ 0 ~ 0 (} 0 0 (l-I .., ~-~~ jI if 0 <)0 .. :.' . 1-0ccurrences FIg. , I I i. ~~ J '\ ~ 0 -0 \~ . . -h Co lumbia I Bntls south-cent ra . ra lysis in of tIck pa 1900 to 1965. fr om i - ! ~ I i JOURNAL ENTOMOL. S OC. BRrr. COl.umJ.\ , VOL. 63 (1 96 6 ) , DEC. 1 , 1966 17 occur in the best areas for ranching, in the vicinity of Keremeos, Prince-ton, Nicola , Kamloops and Vavenby (Hearle, 1933 ; MOilliet, 1937 ; Gregson , 1958). Smaller, more localized out-breaks h ave been recorded at points along the Fraser River trench from Lillooet to Macalister and up the Chilcotin River to Alexis Creek. Oth-ers have appeared at Mamette Lake, Upper Bonaparte, Chase, Falkland and Kelowna. The paucity of cases in the Koo t -enay district may partly be due to the fact that only about 15% of the beef cattle industry is in that area. Nevertheless, there are enough ani-mals and ticks for a paralysis poten-tial. Of interest is the fact that since 1928, 25% of the human cases in B.C. have occurred in this region. Con-versely, there is only one human rec-ord in the vicinity of Nicola Lake where a total of more than 1000 cattle have been paralysed. Host denSity is obviously a factor in the incidence of paralysis but presumably not the only one . Ticks east of the Rocky Moun-tains produce paralysis rarely, if at all. Besides the apparent distribution-al variation in tick virulence, there is the possibility of seasonal variation , resulting either from tick activity or their feeding habits. Ranchers are often heard to say that there are "bad tick years." One sheepman believed that extremes in spring temperatures made the ticks "hungrier and dead -lier." Whether or not there are such variations in tick virulence, Table 1 shows that some years such as 1935, 1944, 1951, 1957 and 1964 are worse than others fo r livestock infestations. Not only were there major outbreaks of paralysis durin g these years, but also there were more than the aver -age number of separate outbreaks. A questionnaire solicited much of th is information in 1951 , but question-naires were sen t out also in. 1939, 1955 and 1965. It is perhaps SignifIcan t that the incidence of human paral-ysis is noc appreciably highe" during years of b eavy livestock paralysis. Human exposure to ticks would be ex-pected to be less variable than that of lives tock and may thus indicate that variations in the livestock rec-ords are more or less determined by movements of the cattle . During years of hay shortage speCial advantage is taken of wa rm, tick-infested hillsides for early spring grazing; this might furth er coincide with a year of high tick activi ty . When conditions of a pa rticula r year force this practice upon many ranchers, there may be a high incidence of paralysis, often in new areas. Such was the situation in the Fraser River trench in 1964. Changing ranching practices such as the decline in sheep populations, or avoidance of tick-infested areas fol-lowing an outbreak of para lysis, are also responsible for annual fluctua-tions of this disease . One often hears that ticks are on the increase, or that they were orig-inally brought in on livestock. Dr. L. Guichon, pioneer rancher in the Nic-ola valley from before 1890, was of the latter opinion and did not become aware of ticks as a pest until after 1920. Parks, of Cache Creek, saw ticks for the first time in 40 years in 1928 ; Lees, at Hanceville since 1913, noticed ticks there first in 1916, then further west at Alexis Creek in 1937 ; Cotton, of Riske Creek, reported in 1941 that ticks were the worst in the 43 years of his ranching experience and that h e had had no ticks at first ; Collett, of Merrit t , had h is first tick trouble in 40 years during 1945; Davis, of Mamette Lake, had his first trouble in 13 years during 1957; Cordonier re-ported ticks in 1950 for the firs t time during his 30 years of ranching a t Barnhartvale. Although the first pub-lish ed records of paralysis are those appearing along the B.C.-U.S. border, there is no reason to suppose that D . anderson i was introduced into Can -ada from the sou th o Indeed, cor r e-spondence from Moilliet of Vaven by and Johnson of Allcali Lake, report para lysis in cattle on their relatively northern ranches in 1907 and 1903 . espectlvely. It is probable that tic._ 18 J OU R:-IA L ENTO]l[OL. Soc. B RIT. COLUMBIA, VOL. 63 (1966), DEC. 1, 1966 populations have merely in creased following the introduction of live-stock into already infested areas. The incidence of paralysis in live-stock is greatest between th e 10th and 27th of April. Occasional cases occur two weeks on either side of these dates. The earliest case recorded was on February 9, 1962 ; th e latest, June 15, 1965. Since paralysis occurs only af ter a tick has been feeding for 5 or more days the dates of the initial infestations would necessar ily pre-cede the recorded periods. The ratio of paralysis in the two groups of livestock most affec ted has depended partly on which animals were being pastured on infested pas-t ures. Until 1930 , cases among sheep were more common ; during _ecent years ca t tle h ave s uperseded sheep and have been more affected (Table 2) . The recorded cases for the entire per iod are in excess of 2010 cattle, 1849 sheep, 9 horses and 13 dogs. The economic aspect of tick paral-ysis is difficult to estimate. Definite, recorded deaths over the past 50 years are not greatly in excess of 361 cattle, 251 sh eep and 6 l' '.rses, representin g a value of only a bo ut $60,000 even a t present prices. Greatly exceeding this fi g'ure a re the com bined losses of manpower required to h andle cattle during week-long outbreaks, of ani-mal condition during recovery, and of potential pasturage unused th rough fear of ticks. The use of BHC during th e past 18 years has helped to alle-viate the hazard of paralysis. Apart fro m this remedy, whenever untreat-ed s tock are pastured on tick-infested ran ges, there still remains the threat of large outbreaks of tick paralysis wi th heavy animal losses. References Bruce, E. A. 1920. Tick paralysis in British Columbia. Dom. of Can. Dept. Agric. Bull. No . 133:7 pp. Bruce, E. A. 1922. Fa talities in cattle due to the tick Dermacentor venl.lstu5. J . ArneI'. Vet. Med. Assoc . 61:537-539. Gregson, J. D. 1958. T ick paralysi s in cattle in Br itish Columbia in 1957. Proc. Entomol. Soc. Br it. Columbia 55:6-7. Gregson, J. D. 1962. The enigma of tick paraiysis in ~orth America . Proc. 11th intern . Congr. Entomol. , Vienna, 1960. 3 :92-101. Hadwen, S. 1913. On "tick par alysis" in sheep and man foll owing bites of Dermar.entor venustus. Parasitology 6:283-297. Hearle, E. 1933. Notes on a serious ou tbreak of tick pa ralysis in cattle. P roc. :F.illtomol. Soc. Br it. Col um bia 30: 11-16. Moilliet, T. K. 1937. A review of tick paralysis in cattle in British Columbia. Proc. Entomo!. Soc. Br it . Columbia 33:35-39. Todd , J . L. 1912. Does a human tick-borne disease exist ill British Columbia? Can. Med. Assoc. J. n. s. 2:686. A RECORD OF TUE BROWN-BANDED ROACH In 1960 specimens of th e brown-banded roach, Supella supellectilium (Serv. ) were sent from a New West-mins te r home. The furniture in the newly-built house h ad been shipped from California in a moving van with-in the last year and the infestation had since developed. Arrangements were made to spray the house and the roach was controlled. The roach has not been reeorded fro m Canada west of WInnipeg. Mr. C. G. MacNay, Ottawa, has reported it from eastern Canadian -cities. G. J . SPENCER, University of British Columbia. 

Records of tick paralysis in livestock in British Columbia

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Records of tick paralysis in livestock in British Columbia

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Journal of the Entomological Society of British Columbia