378 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



Besides the ticks which are known to transmit diseases, there are 

 many others which attack domesticated animals. Among these may 

 be mentioned Ixodes pilosus Koch, which attacks sheep, goats, oxen, 

 horses, etc., and is supposed to be the cause of a paralysis of sheep 

 in Cape Colony; and Hyalomma cEgyptium Linn., the Bont leg tick, 

 the adult of which may be found on all domestic animals, and is thought 

 by some to cause abscesses on the animals. Other ticks whose injury 

 may only amount to tick worry, are Ixodes rubicundus Neumann, R. 

 oculatus Neumann, R. sanguineus (Lat.), R. lunulatus Neumann, 

 R. duttoni Neumann, R. bursa Canestrini & Fanzago, R. niiens Neu- 

 mann, Amblyomma variegatum (Fabr.), and sometimes A. marmoreum 

 Koch. 



The Life History of Certain Species. With this formidable array 

 of ticks and diseases that they transmit, it can readily be seen that 

 their destruction is not so simple as the control of B. annulatus 

 is in the Southern United States. The problem is made more difficult 

 by the fact that the life history of the various ticks differs considerably 

 and in some cases is such, that destruction is impossible or next to 

 impossible. Due to the work of Doctor Theiler, C. P. Lounsbury 

 and C. W. Howard, the life cycle of many of the common ticks has 

 been worked out. B. decoloratus has a very simple life cycle. In 

 about five days or more from the time the engorged female drops 

 from the host, the eggs are laid. These hatch in from three to six 

 weeks — or in winter a longer period is required. The larvse may live 

 for six or eight months without feeding. B. decoloratus seeks but one 

 host in its life time, i. e. the moult from larva to nymph and from nymph 

 to adult is performed without leaving the host animal. The period 

 spent on the host is about three to four weeks. The eggs of R. evertsi 

 hatch in about 30 daj^s, and the larvae can exist for seven months 

 without feeding. R. evertsi differs from B. decoloratus in that two 

 hosts are attacked in its life time. The moult from larva to nymph 

 is performed upon the animal, but the engorged nymph drops from 

 the animal and moults on the ground, seeking a second host for its 

 adult existence. The time spent on the first host is about ten to 

 fifteen days, but the adult tick may live for as much as a year, should 

 it not find a suitable host. The adult tick remains on the host animal 

 from six to ten days. The life cycle of R. appendiculatus is typical 

 for R. capensis, R. nitens, and J^. simus and is given for the group. 

 The eggs are laid by the engorged female in about six or more days 

 from the time she drops from the host animal. These hatch in from 

 28 days to several months, depending upon the temperature. The 

 larva remains on the animal for about three to eight days, after which 

 it too drops to the ground to moult — which is accomplished in about 



