Biology of H. eoncmna ^42 



Time the tick remains upon the host. 



The Larvae, a few days after emergence, attach themselves quickly 

 to a variety of hosts (deer, hedgehog, dog, guinea-pig, rat, mouse) and 

 gorge themselves with blood or lymph in 3-10 days ; nearly all of them 

 abandon the host in 3-5 days. 



The Nymphs, a few days after emerging, attach themselves to the 

 same hosts as do the larvae and feed to repletion in 3-12 days, mostly 

 abandoning the host in 4-5 days. 



The Adults, after fasting for weeks or months, attach themselves to 

 the host whereon they copulate, probably after 4 days, for the sexes are 

 then found attached close together with their venters juxtaposed. The 

 fertilized female becomes replete in 8-10 days ; she is then slate- 

 coloured and ■ weighs on an average, when fully gorged, 0*35 g. 

 Unfertilized females may stay for several weeks upon the host 

 remaining about a third gorged. 



Time required for metamorphosis. 



Egg to Larva : the larvae emerge some weeks after the eggs are 

 laid and they are capable of living for a long time unfed. 



Larva to Nymph : nymphs emerge 17 days after they abandon the 

 host as gorged larvae when maintained at 25-30° C. From 64 gorged 

 larvae found upon a hedgehog, 64 nymphs emerged. 



Nyviph to Adult: adults emerge after 22 days at 25° C. From 4 

 gorged nymphs found on a stag at Chantilly there emerged 4 J' after 2 

 months: from 15 gorged nymphs found on a hedgehog there emerged 

 15 adults. Certain incompletely gorged nymphs undergo metamorphosis 

 to adults very slowly and they often die before it is completed. H. con- 

 cinna differs in this respect from certain species of ticks, for instance 

 Amblyomma cayennense (as seen by Aragao, 1912, p. 96), Rhipicephaliis 

 appendiculatas and R. sanguineus (Nuttall, 1913, p. 195 ; Cunliffe, 1914, 

 p. 372), Dermacentor reticulatus (as seen by Brumpt), wherein im- 

 perfectly gorged nymphs were found to give rise to small adults. 



Oviposition. 



At a temperature of 18° C, oviposition occurs in about the second 

 week. The eggs are larger than those of Ixodes ricinus, they are dark 

 salmon coloured. Each female usually lays upwards of 1000 eggs. 



