Gregson, J. D.

English

Journal of the Entomological Society of British Columbia

4 ENTOMOLOGICAL SOc. OF BRITISH COLUMBIA, PROC. (1950), VOL. 47, JULY 15, 1951 gave excellent control of the two-spotted spider mite and the Pacific mite. (3) EPN 300 has a high human toxicity rating and a medium phyto-toxicity rating. When applied in the pink stage at 0 .75 pounds it gave good control of the European red mite al-though it w'as somewhat inferior to I pound of parathion . At 1.5 pounds it gave considerably better control of the Willamette mite than I pound of para-thion . C 4) KARA THANE applied at the rate of 1.5 pounds was not so effective as 1 pound of 15 per cent parathion when used as a pink application for control of the European red mite , or when used in summer applications for control of the two-spotted spider mite and the Pacific mite, When applied in the summer by an automatic sprayer at 12 pounds per acre. however. it gave excellent control of the Willamette mite. Although it caused a very slight amount of damage to Newtow'n apple trees in August . it has a low phytotoxicity rating. (5) R-242 has a low human toxicity rating and a low phytotoxicity rating. At 1. 5 pounds. it was slight! y less effec-tive than 1 pound of parathion (15 per cent ) when used as a pink application for control of the European red mite, When used in the summer at 2 pounds it was not so effective as 1 pound of parathion for control of the two-spotted spider mite and the Pacific mite. When used at 12 pounds per acre in a concen-trate sprayer. however. it was slightly more effective against the Willamette mite than 8 pounds of parathion. (6) ARAMITE has a low human toxicity rating and low phytotoxicity rating . When applied in the summer at 2 pounds, it gave excellent control of the two-spotted spider mite and the Pacific mite. Also. when applied by a concentrate sprayer at 12 pounds per acre. it gave excellent control of the Willamette mite. NOTES ON THE SPRING ACTIVITY OF THE ROCKY MOUNTAIN WOOD TICK, DERMACENTOR ANDERSONI STILES (ACARINI: IXODIAE)l J. D, GREGSON L ivestoc k In sect Labo rato ry , Kamloops, B. C. One of the remarkable features in the dry -belt they disappea r regularly in life-cycle of the Rocky Mountain wood May, regardless of how moist or cool tick. Dermacentor andersoni Stiles. in the preva iling atmospheric conditions British Columbia is the annual appear- are. It is suggested that some form of ance of adults at the beginning of spring diapause must take effect. releasing its and their regular disappearance about hold only after another winter has the middl e of May. Such seasonal passed. periodicity is natural for most insec ts , In the Interior of British Columbia of which the adult stage is generally of the Rocky Mountain wood tick is dis -short duration. However. ticks usually tributed throughout the greater part of live longer than insec ts . and it would the dry bunch-grass open-land, Its be expected that adults of the Rocky peak abundance may vary. depending on Mountain w'ood tick, which are here- the locality . from sparse populations to with shown to be capable of living for heav y concentrations. The latter occur at least 1 year. w hich continue to be in scattered parts of the Province where active as long as the weather remained host and climatic conditions are appar-favourable. Such is not the case. how- ently particularly ideal for tick develop-ever. and though in Alberta and in the ment and survival. One such site is at damper regions of British Columbia Rayleigh. 10 miles north of Kamloops. adults of this species may be active as B , C. where there is an extensive talus late as June, in the British Columbia slope backed by a rocky bluff 200 feet 1 Contribution \"0. 271 i. nh' i~ioIl of Entomology. Seiellf'e Sen'ice, Department of AgIicu1tul'e, Otta wa, ('<tHada. high. The narrow belt of vegetation at the base of the cliff. besides harbour-ing a variety of rodent life. seems regu-ENTOMOLOGICAL SOc. Of' BRITISH COLUMBIA. PROC. (1950). VOL. 47. JC:l- Y ! 5. 1951 5 220 5 III 200 >C 180 4 6 u 7 8 f= IbO "'-0 a: w 100 OJ ~ 80 => 60 z 40 MA RCH MAY Fig. 1. \\"eekl,v collectiolls of the Rocky \IOllllLJi 11 \\'ood t.iek. Dermacentor andersoni Stiles. at Hayleigh. H. C., during the !'}Hing of l~Uf). The hatched pOl'tioll~ rrpn~sellt the !lumbers of marked ticks ref'aptured, the lIumerals inrlictltillg tlto~{' of the yarions weekI';. The dark horizuntal Jines inrIieate thf' Ilumhers of mah~s. larly to have a copious supply of adults of andersoni, despite large annual col-lections for laboratory use. For the past 6 years their earliest appearance has been recorded on the following dates: 1945, Feb. 24: 1946, Feb. 26: 1947, Feb. 19: 1948, Mar. 17: 1949, Feb. 25: 1950, Feb. 27. During 1949 and 1950 an attempt Was made to show their rise, peak and decline of activity by counting and re-leasing all specimens as soon as they were collected on the drag, i.e., a square yard of flannelette that is swept over the vegetation in the manner of a flag. In addition, to determine whether the earli-est ticks would be the first to disappear. each week's collections in 1949 were marked with a different colour of Fleet-X automobile enamel. a slow-drying Duco-Iike paint. The results of these observations are illustrated in Fig. 1, in which the number of marked ticks for each week is indicated. The activity of the ticks is shown to be equally late, regardless of when they appeared. It must be noted that the data for the weekly periods of activity cannot be entirely accurate. for only a fraction of each week's marked specimens was re-captured. The recoverable portion ap-peared to be rather constant and in the neighbourhood of 40 per cent. Ac-cordingly it is reasonable to assume that some 60 per cent of each week's active ticks, both old and new, are not recov-ered, and that the following week's un-marked specimens have not all recently hatched or emerged from hibernation. This incomplete recovery is explained by the fact that the ticks do not con-stanty present themselves in favourable positions for transference to a host or may have already attached themselves to hosts. Casual observations during sunny days have revealed that they very ac-tively run about on the ground, and climb up twigs, only to descend again. Such individuals would not be readily available for capture on the drag and would account for the fact that often when one sits for a few minutes he or his drag picks up several specimens not otherwise detectable. This activity, which is contrary to the impression gained from the usual appearance of ticks waiting motionless at the tops of grass stems, leads to a certain amount of dispersaL and marked specimens were recovered near! y 20 feet from their pain t of liberation 2 weeks previously . Other individuals showed no tendency to roam, and week after week were ob-served at the same clump of grass. Collections of ticks in the same area the following spring (Fig. 2) have shown nearly 8 per cent of the previous season's marked ticks still active, this figure being the percentage for the greatest n urn ber (40) of marked ticks taken at one time (April 17, 1950) of the total number (530) of ticks marked in the previous year. Since no attempt was made to re-mark the 1950 captures . it is not known how many orDers were collected on other days and it is likely that this percentage is even higher. T~e 6 ENTOMOLOGICAL SOc. OF BRITISH COLUMBIA, PROC . (1950). VOL. 47. JULY 15. 1951 560 540 520 500 480 460 440 420 400 380 '" 360 :<: 340 u ... 320 u. .300 0 280 a:: UJ 260 '" 240 ~ ::J 220 z 200 180 160 140 120 100 80 60 40 20 MARCH APRIL MAY Fi g· ~. \\' l'c'kl.\ ('oll~~d i ()lls o f the Hocky "-,f ollntaill \\'o()(1 t il'k at Rayleigh , B. C., dur ing' the s pring of 1 95 0. Tlte dark hOl- i :~Ollla l li lle:i indi cale the lJuud.)(! rs o f ] V 4~1 TII ;.trkl'd ti c k !; J'N:ap l-ll red. Th e halched a n~as represe llt l h e IJUlni>crs o f llJ i.lil's. year-old ticks were virile enough to persist to the end of the tick season. That the remaining 1950 adults w ere new stock moulted from nymphs that had fed during the previous summer is sugges ted by the early appearance of the males , a phenomen on common in the first appea rance of va rious species of insec ts. Tbe nea rly equal ratio of tbe se xes and the ea rl ier appearance and disap-pearance of the mal es are shown in Figs. 1 and 2. The peak of tick activity fell approximately at the end of March in 1949 and on April 10 in 1950. This is in keeping witb tbe relative ea rliness of the two seasons. the spring of 1950. as indicated by phenological observa-tions . being approximately a week later than tbat of 1949. The main period of tick activity lasted from the height of tbe flower season of the common dry-belt buttercup. Ranunculus glaberrimus and of the johnny-jump-up. Fritillaria pudica. to tbe appearance of blossoms of saskatoon. Amelanchier sp. and of Oregon-grape. Mahonia neruosa. Ac-tivity ceased with the blooming of the chokecherry, Prunus demissa. The rea-son for the apparent great increase in the tick population at Rayleigh in 1950 is unexplained. What causes the ticks to disappear toward tbe middle of May is not kno wn. A study of the temperature and humidity fluctuations recorded dur-in g their activity reveals no striking cbange that could account for their sud-den decline. Disappearance due to a gradual aging or depletion of energy is ruled out by tbeir reappearance tbe fol-lowing yea r without having had a meal in tbe interim. Observations were made to determine the fate of these ticks after activity. A number of adults w ere enclosed in a cage over talus 3 feet deep from the time they became active in 1949 until the following spring. All tbat were recov-ered (15 per cent) were found dead in ENTOMOLOGICAL SOc. OF BRITISH COLUMBIA, PROC. (1950) , VOL,4 7 , JULY 15 . 1951 7 the upper inch of leaf mould, suggesting that the ticks do not seek protection from winter by descending to any depth in loose rock . Bec;:l1..lse of the presence of the cage, the ground surface was not protected by snow. with the result that it was exposed to a temperature of -40 0 F. However. temperature readings taken at a depth of I foot in the talus beneath the cage did not go below 32 0 F. The o nly adult found in its apparently natural site of hibernation was an un· engorged female. located by accident in November under a small rock at ground level. Careful search during summer months in the areas where concentra-tions of ticks had been liberated the previous spring has, however, revealed specimens among the decaying roots of bunch grass , Agropyron sp., substantI-ating the theory that adult aestivation and hibernation are spent at shallow levels. In conclusion. it has been shown that a portion of these ticks are capable of living more than 12 months as unfed adults. passing the winter under the protection of snow. The disappearance of all the ticks in late spring is appar-ently due not to normal aging but to some form of diapause, the cause of which is not known. RECORDS OF BEES FROM BRITISH COLUMBIA: BOMBIDAEl E. R. B UCKELL 2 Field C rop Insect Laboratory. Kaml oops. B. C. This paper records 26 species, 14 na med varieties, and 10 colour variants of Bombus and 4 spec ies of Pslthyrus from British Columbia. Of the 532 6 specimens h~re recorded , 4641 belong to Bombus. ano 685 to Psithyrus. These records have been compiled fro m the collcctions in the Dominion E ntomologica l Laboratory, Kamloops, B. C: the University of British Colum-bia. Vancouver. B. C: and the Provin-cial Museum, Vic toria , B . C ; and from the Canadian National Collection . Ottawa, Canada. as well as from some records in publications by Franklin and Frison. and some unpublisbed notes by F rison . Almost all of the records ob -tained from the Canadian Nat ional Col-lecrion were fro m specimens detcrmined by Frison. These bumble bees were collected by 97 collectors during 50 years from 142 hcalities; except F. W. L. Sladen. E. R. BuckelL and G. J. Spencer. they pai(\ little attention to taxonomy of bees, ane tbeir m aterial was obtained in the course of general collecting. Tbe localities are listed and their correspon ding numbers placed on tbe accompa n ying map. The collection points are mainl y in , Con tr ibu tiolJ \n, ~7:1 -L Diri s ion of Entomol ogy. .~ ( ·iell(·e Sen-j('e, Ih'part lll('r ll of .\ g'J'icult ul'{" Ottawa, Canada. :? Retired ?-i o\'em he r I, 1949. th~ soutbr. rn balf of the Province, and vast areas in tbe north have not yet been visited by collectors. This, of course. is due to the fact that there are no roads, railways , or o ther read y means of en tering t hese areas. There are no collection records from the Queen Charlotte Islands, but sev-eral spec ies must occur there as they have been taken on the adjacent main -land and on islands off tbe Alaskan coas t. Aft"r the name of each species the number of localities in which it has been taken, the number of each sex, and the total number of specimens recorded are indicated, e.g.: (26: 80 ~' 39 '" 83 "-202) . The author wishes to thank all tbose who bave helped in tbe preparation of this pa per. either by the loa n of materia l or in providlI1g species determina tion or localit y records. Tbanks are particularly due to Mr. K. V. Kro mbein, Division of Insect Identification, Bureau of E n -tomology and Plant Quarantine, W ash-ington. D. C, for tbe determination of material. and to Dr. O. Peck, Division of Entomology, D epar tment of Agricul-ture, Ottawa. Canada, for tbe British Columbia records II1 tbe Canadian ~ational Collection . 

Notes on the spring activity of the Rocky Mountain wood tick, Dermacentor andersoni Stiles (Acarini: Ixodiae)

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Notes on the spring activity of the Rocky Mountain wood tick, Dermacentor andersoni Stiles (Acarini: Ixodiae)

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Journal of the Entomological Society of British Columbia