G . H. F. Nuttall 
435 
Nymph to adult: an exceptionally long time is required for meta¬ 
morphosis at this stage. When the nymphs have fully gorged themselves 
they moult after 6 months at 15-25° C., some may, however, require 
10 months, and incompletely fed specimens are found to be still active 
after 16 months. 
Observations relating to oviposition. 
Oviposition usually begins on the 5-6th week (at 18° C.) after the 
replete and fecundated female has abandoned the host. The eggs are 
large, dark salmon coloured, and only number about 200 per female. 
Season. 
From the table on p. 433 which contains Brnmpt’s observations on 
H. inermis and H. concinna, we learn that the adults of H. inermis 
occur on deer in France during the six months November to April 
inclusive. Observations for the four months May-August are lacking. 
The ticks were not found in September-October. 
Remarks upon the exceptional behaviour of H. inermis. 
H. inermis offers an exception to all the ticks whose life-histories 
we know in that it gorges with remarkable rapidity both in the larval 
and nymphal stages. It is the rule in Ixodid ticks for all stages to 
remain attached to the host for several days. In Argasidae we do not 
know of a species where the larvae feed as rapidly as does the larva of 
H. inermis although the nymphs are rapid feeders. Whilst this habit 
of rapid feeding may favour the survival of the species, the long time 
required for the process of oviposition and for metamorphosis from egg 
to larva and from nymph to adult must exert a contrary effect. The 
phenomenon observed in H. inermis by Brnmpt is very interesting 
and worthy of attention. 
Insect parasites of H. inermis. 
A chalcidid called Ixodiphagus cmicurtei du Buysson, 1912 (p. 246) 
was discovered by Brumpt in the nymphs of Ixodes ricinus in France 
and raised by him to the seventh generation in the laboratory. This 
insect attacks the nymphs of H. inermis. Whereas scarcely 1 % of 
these nymphs become infested, all of the nymphs of I. ricinus, Dernia- 
centor venustus, D. reticulatus and Rhipicephalus sanguineus in which 
the parent I. caucurtei deposits her offspring, die and yield imagines of 
Ixodipltagus. 
