42 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 1 



access to the ear. These species furnish what evidence we now have 

 of the adaptation of habits to the habits of the host, but I have no 

 doubt that similar habits will be discovered in other species when they 

 have been given sufficient study. 



It seems probable that in the species which drop to pass their molts 

 greater resistance to high and low temperatures and the power to with- 

 stand long periods of fasting have been acquired. Again the species 

 which have acquired the habit of molting on the host has probably 

 lost in this power of resistance. 



As related to protection, the adaptation of habits may be considered 

 under accelerated engorgement, attachment to favorable part of body, 

 and nocturnal habits. Of accelerated engorgement we have several in- 

 stances among the ticks. This is best illustrated by Argas persicus 

 and miniatiis in their engorging within a few hours at the most. 

 Lounsbury argues that they are descendants from forms which re- 

 mained for days at a time on the host. That this is the case is shown 

 by the larva, which still remains upon the host for days to engorge. 

 In the Cattle Tick, Margaropxis annidatiis, after it has become about 

 one third engorged, which requires a number of days, complete en- 

 gorgement takes place and the ticks drop within a comparatively few 

 hours. In this way the chances of destruction due to the removal by 

 enemies such as birds and the attack by parasites have been reduced 

 to the minimum. 



Again we find species which have adapted their habits for protec- 

 tion in attaching to favorable parts of the body as have Ornithodoros 

 megnini and Derniacentor nitens in attaching to the inside of the ears. 

 The species of Haemapliy salts found upon quail, field larks (and other 

 ground- feeding birds) in Texas, Lousiana and Florida, appear to at- 

 tach only to the head, a place from which they are not easily removed 

 by the fowl. Perhaps the most highly developed habit acquired by 

 ticks for protection is that found in the nocturnal habits of the genus 

 Argas. Through this habit of resting during the day time, they escape 

 detection by the fowls, which, upon discovery, devour them with great 

 avidity. At night the fowls come to their roost near by and the 

 ticks have little trouble in finding the host and engorging at a time 

 when the fowl is inactive, and thus largely escape detection and de- 

 struction. 



Mating. — In the Argasidce mating takes place after the final en- 

 gorgement has occurred and the tick has left the host, but few observa- 

 tions having been recorded. In Ornithodoros megnini the nymph 

 leaves the host, molts, and without further feeding is fertilized and 

 commences oviposition. 



In the Ixodidce the mating appears normally to take place upon the 



