128 LIFE HISTORY OF NORTH AMERICAN TICKS. 
host dropping on the eleventh day. Upon a cold-blooded host the 
period of engorgement will undoubtedly be found to be much longer, 
as was found to be the case with Ambylomma dissimile. Attempts to 
get nymphs to attach to a horned toad were unsuccessful. 
TABLE XLVI.—Engorgement of nymphs of Amblyomma tuberculatum. 
Nymphs dropped engorged—days following 
application. Total 
Date nymphs applied. Host. ee 
Pho | Bo) a [ep Tegel eal) oat ge | ton ater abet 
PARTS 1411908 2 ober eee bi cleeieiereree Bowine ==.) 0) Ov OnlenOsly (Ons Ob S0n|e OntaOblbeou lead a 
ee 15, MONS Fo mercies cee an cteeoa| sees doeie.: OA OS) BOE MO Wap Oeliee@eai ie ah tei) Spe & 8 
BV 20 5 AOOR NS a atrae lene siete stores ett yaal| jaar GOsrsee OF OM On Oss Ol) SOM On ela een wee 10 
May: (5 1909S 2 Act clase cumiaes oa -ee =| Seer donee... On OR SOR ORO On| Oh ienttn | iO)n On| pO) 1 
Mary. lil’, 1909) Ooi so ee oe Were wa eres cee ae GOn acer OF SOR Ose OF SO SOR Onis On esOn ies |e? 3 
At a mean temperature of 81° F. nymphs which dropped the last 
of May commenced to molt in 29 days, a total effective temperature 
of 1,104° F. having been required. The molting period of nymphs 
which become males and females is about the same. It was found 
that when the engorged nymphs were placed in tubes on moist sand 
they at once burrowed into it out of sight. When examined they 
were found an inch or more beneath the surface, in which position 
molting took place. This habit was not observed in engorged larvae, 
but is probably the same. Although observations on this habit have 
not been made in other species of ticks, owing largely to the fact that 
it was necessary to keep them on an impenetrable surface in order 
that the exact dates of molting could be observed, it seems quite 
probable that some of them may do so also. Such a habit is of great 
advantage to the tick in protecting it from enemies during the 
quiescent period, as well as in preventing drying out. 
TasLteE XLVII.—WMolting of engorged nymphs of Amblyomma tuberculatum engorged 
on bovine. 
Temperature from 
Engorged nymphs molted—days following drop- | Number dropping to date 
ping. molted. | frst tick molted. 
Date engorged 
nymphs \"ber. Aver 
TO 3 ! a ver- 
-| || Maxi-| Mini-| age 
29) 32] 36] 37) 38] 39] 44) 46] 48] 49) 51] 53] 66/203/207 é 8 "3 | mum. |mum. | daily 
g 2 = mean. 
Apr. 23,1908] 1] of of of of o| of of of of of of lta] of of a] of 3] 91.8) — 47] 76.29 
Apr. 24,1908} | of of of of of of of ofofedts|ig] of of of 2 4) 6 89 47| 74.72 
Apr. 25,1908/ | o of ol of of of otabeol ono] of of of of a] af al 80 47| 74.73 
Apr. 26,1908} 2] o| of o| of of of of o| og] Of of of of of of a] a} 91.8) 47] 75.11 
May 28,1908] i] 0! o| oc of of o| of of Of of of of of of a] Of i} 91-5] 69) 80.50 
May 29,1908] 4] 0] of19] 1g 19119] Of of of of of O| of of 3] 3| 4} 91.5] 69) 80.61 
May 30,1908}  3lig] cl O| of of of o| of of of 0} of of of of 3) Of a] 91-5] 69) 81.08 
May 31,1908} 2] 0 oct} o| of of o| of of o| of of of of 3 a] 2} 91-5 69) 81 
Nov.24;1908| i] 0] of of 0| of of of ol of of of | 0| 019] of 3 i} 100 17| 67.15 
Dec. 2,1908| 1 o| of o| of of of of o| of cl o| of og] of 3] Of 3} 100 17| 67.89 
May 21,1909] —1{19] of 0} of of of of o| of of 0 of of of of of | 4} 100 47| 86.17 
May 22,1909] 1 0| 1] | of o| O| of o| of of of of of Of O..¥...- ee 47| 86.56 
Total .. 7:1 meee | ame (ae | Mv | ei Has Pa Ps) Flee) NE |S le Te call CM OTA zs 
