67 
THE CATTLE GRUBS OR OX WARBLES 
emergence of the adults was 16 to 25 days. All of these records were 
_made in midsummer, and the specimens reared in New York were 
kept in a building in which the temperature was warmer than out- 
doors, hence the periods shown are probably shorter than would 
| occur normally. 
TABLE 9.—Duration of prepupal and pupal stages of Hyupoderma bovis 
Adults emerged Temperature 
: during period from 
Date Duras Dura-|Per!04| dropping to adult 
dropped yah how cian com 
< or ex- ate (0) 3 rop- 
Locality tracted | pupated | pre- Nua Num re al| Pine ree 
from pupal} Date of |offe-| stage to } age 
host stage minlesimales adult | Max.) Min. daily 
mean 
1918 1918 Days 1918 Days-| Days \ °F. | OF. | OF. 
Dallas, Tex__...--- May 15 | May 16 IL JM bene B20) eee 5 if 14 15 | 98.4 | 54.0 | 78. 28 
1D 0.3 SS ea May 24 | May 25 1| June 8 1 1 14 15 | 96.0 | 63.1 | 81. 62 
DOs esse ee May 27 | May 28 Tt diwnoyey 119) 1 15 16 | 97.0 | 65.0 | 81.37 
4 1921 1921 1921 
Herkimer, N. Y_-_-| June 24] June 24 aA! Apoubig. uly coe if Gp AL sc Le el teaee ee he eet oa 
De. ees July 14] July 15 il 4) dhbdbiee BO) gos 1 15 1 Ghee oe ees eae 
IDOLS. Sees July 17]| July 17 TG AU ee nb) ees 1 TUE Ou eee eee ees SA 
IDS aS ee Aug. 3/| Aug. 4 1 | Aug. 28 a al Ppa 24 PA ya | See rea Senet 
1922 1922 1922 
| Middletown, N. Y_} Apr. 20| Apr. 27 7 | June 4 | Pages 38 45 | 85.0 | 28.0 | 58.6 
IDOS SS Bes Sales GS PAL ses 55e Geie=donse 1 1 38 44 | 85.0 | 28.0 | 59.1 
ID) Obs Sess 3s oa PAV a2 ed Oe Arey |e Cl Ose 1 1 38 42 | 85.0 | 32.0 | 60.0 
DD) OMe Se te Auprs 26) 22-002 52 eed oree. 1 3 38 39 | 85.0 | 32.0 | 60.9 
DOM eee ke Apr. 28| May 1 Saeed omens 2 1 34 37 | 85.0 | 33.0 | 61.4 
IDS ees = OO Me 2k aes Se ikedoe Hillmen 34 37 | 85.0 | 33.0 | 61.4 
IDO) 5 eee ee Atpr 429) 22=d0n 224 Dred @ ses s8 1 3 34 36 | 85.0 | 33.0 | 61.9 
1D YG) 5 ae ea re Pek Ose Ow eee 2 | June 5 il 2 35 37 | 85.0 | 33.0 | 62.1 
1D) Oe ee Apr. 30 |_--do____-| 11%] June 4 1 1 3344 35 | 85.0 | 33.0 | 62.1 
]DY0)-es = See eg May 4] May 8 4 | June 6 11s ie ee 29 33 | 85.0 | 40.0 | 62.8 
ID) SS eee SECON ee PaCS ea 4 | June 7 Gules ee 30 34 ; 85.0 | 40.0 | 63.2 
TD gee 4k gi ae Bacon! SB BG lout Oe Bo (oyuRnane 4 | June 8 1 2 31 35 | 89.0 | 40.9 | 63.6 
IDXO)s 5 eis ee May 8| May 9 14%) June 7 Hei int ess 28% 30 | 85.0 | 40.0 | 63.8 
LD) Qe et 2aCOs 232) IMleiy a0) Deere: 19 nouns 2 30 32 | 91.0 | 40.0 | 64.6 
DOR ae May 12) May 13 1 | June 8 Oi eee oe 26 27 | 89.0 | 40.0 | 64.5 
DO ess eS ed Ose ae i O(0 (oye iL June 9 3 4 27 28 | 91.0 | 40.0 | 64.9 
1D) OSE ESTE OK ayattae FNS (0 Ko) eee 1 | June 10 1 1 28 29 | 92.0 | 40.0 | 65.3 
ID Yaya) eae ah May 14 | May 15 14%) June 9 3 1 241% 26 | 91.0 | 41.0 | 65.0 
1D) OR Sh > PedOse ee med Ose 14%) June 10 1 i see i 2514 27 | 92.0 | 41.0 | 65.5 
IDOE Se seer ee SeGOus =a dom see 1144) June 11 |_____- 1 26% 28 | 92.0 | 41.0 | 65.8 
ID) Qe May 17 | May 19 1Y4)__-do___- ifs | Utena 234% 25 | 92.0 | 41.0 | 66.5 
ID oy nee elem Se dOea (2 aedoLene 14%| June 12 |_____- 1 24% 26 | 92.0 | 41.0 | 66.8 
IDO) aaa May 20 | May 21 1 | June 11 dial ean 21 22 | 92.0 | 41.0 | 67.8 
1DY0)s Saree eG Ova een | ean Omens dihare) WA eee 1 22 23 | 92.0 | 41.0 | 68.2 
ID Oa ae May 25 | May 26 1 | June 16 Pe See a 21 22 | 92.0 | 41.0 | 68.3 
WORE Ee oye tl May 27 | May 29 2 | June 19 | IH (eke 21 23 | 92.0 | 41.0 | 68.1 
1 Half days are given to approximate more closely the time required for transformation. 
At Middletown, N. Y., during 1922, a large number of adults were 
reared from larve which emerged normally from the backs of cat- 
tle. These pup were kept in a screened, roofed insectary out of 
doors. The prepupal period ranged from about 10 hours to 7 
days, with an average of 1.7 days; the pupal period, from 21 to 
38 days with an average of 29.4 days. The time from leaving the 
host to emergence of adults varied from 22 to 45, with an average 
based on 167 records of 31.34 days. The longest period (Table 9) oc- 
curred in the spring. As some larve left hosts in 1922 about April 1, 
it is probable that some periods longer than the maximum shown 
might have occurred among the larve dropped earlier in the spring. 
_ In Canada, Hadwen (34) observed a period of 30 to 40 days to 
intervene from the emergence of the larve to the appearance of 
