. The life history and bionomics of some North American ticks . iod of 4 femalesdropped in April and May was 7| days. The average preovipositionof 17 lots of females collected during the period from March to June,inclusive, was days. During April and May, 4 ticks showed adeposition period of from 27 to 39 days, with an average of 31J mean temperature during the shortest period was ° F. andduring the longest period it was ° F. These females died infrom 1 to 7 days after deposition was completed. The averagenumber of eggs deposited by the 4 females was 3,210 and themaximu
. The life history and bionomics of some North American ticks . iod of 4 femalesdropped in April and May was 7| days. The average preovipositionof 17 lots of females collected during the period from March to June,inclusive, was days. During April and May, 4 ticks showed adeposition period of from 27 to 39 days, with an average of 31J mean temperature during the shortest period was ° F. andduring the longest period it was ° F. These females died infrom 1 to 7 days after deposition was completed. The averagenumber of eggs deposited by the 4 females was 3,210 and themaximum number deposited by an individual was 4,555. The minimum incubation period under laboratory conditions was21 days. This record was made during June, 1910. The total effect-ive temperature required for embryonic development appears to beat least 842° F. The last two lots of eggs, the hatching of which is THE PACIFIC COAST TICK. 183 recorded in the following table, were kept in an incubator duringincubation and removed therefrom when hatching was Fig. 15.—The Pacific Coast tick, Dermaccntor occidcntalis: Distribution in the United States. The togadots show localities where the species has been collected in our investigation. The small dots showthe probable range of the tick. (Original.) The incubation period was reduced to 16 days in these two instances,during which time the mean temperature was about 90° F. 184 LIFE HISTORY OF NORTH AMERICAN TICKS. Table LXXXII.—Preoviposition, incubation, and longevity of larvx of Dermacentor occidentalis. Deposi-tion be-gan. Hatchingbegan. Mini-mumincu-ba-tionpe-riod. All larvae dead. Larvallongev-ity. Temperature during incu-bation. Date engorged femaledropped or collected. Maxi-mum. Mini-mum. Aver-agedailymean. Totaleffec-tive. 1910. Apr. 2 (collected) Do 15Apr. 14Apr. 21Apr. 26Apr. 27May 10May 13May 16May 20May 23May 24June 4June 24Dec. 12 Dec. 16 1910. May 19May 17May 25May 26May 28June 16June 7June 10June 12
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Keywords: ., bookauthorhunterwd, bookcentury1900, bookdecade1910, bookyear1912
