48 



SCIENCE-GOSSIP. 



TICKS AND "LOUPING-ILL." 

 By E. G. Wheler. 



(Continued from page y.) 



T"HE commencement this year of the attack of the 

 ticks on the sheep, occurred about March ist, 

 on which day two female ticks were found on a sheep 

 at Gowanburn Farm, in the occupation of Mr. Dagg, 

 in the North Tyne \'aUey. Professor Somerville, of 

 the Durham College of Science, Newcastle-upon-Tyne, 

 has commenced some experiments on the sheep at this 

 farm, and has received not only valuable information, 

 but also very material assistance from Mr. Uagg. On 

 April 19th, a number of adult ticks were present on 

 the sheep, consisting of young as well as distended 

 females, and some males. A distended pupa was 

 also found on the face of one of the sheep. 



These creatures are locally known as *' face ticks," 

 being usually found on the sheep's faces. They were 



without exception, Ixodes reduvius. There seems 

 little doubt this species only, attacks sheep in this 

 district. Only a few isolated specimens were found 

 on the collie dogs. These, however, suffer from 

 the attacks of a different species. The, dogs are never 

 known to have louping-ill. 



The size of individual ticks varies, and of course 

 so soon as distension commences in any stage, it 

 rapidly increases. For both these causes of variation, 

 full allowance must be made — as well as for the 

 variation of colour at different stages of distension, 

 which has been already alluded to. 



It is hoped that the following descriptions may 

 suffice to identify the species in all its stages. 



Ixodes redu-iiiiis Linnaeus = /. riiiniis Latreille. 

 c d 



h " f 



Ixodes reduvius. a, larva. /', section of larva, c, pupa, d, e,/, sections ot pupa. 



supposed to be a different species of tick, but there is 

 no doubt that they are the pupae of /. redmnns. They 

 were subsequently found in considerable numbers, 

 distended and undistended, together with larvae in 

 both conditions, on some sheep in Alnwick Deer 

 Park. These latter sheep had only been turned on to 

 tick-infected land three weeks previously, and it was 

 noticed that no fully matured females were found 

 upon them, though partially distended ones, were 

 fairly numerous. 



On June 2nd the attack was found to be nearly 

 over. Some sheep on the farm were then affected 

 with louping-ill, which curiously had become pre- 

 valent during the recent fine warm weather ; whilst 

 the district had been almost free from it during the 

 previous exceptionally wet cold weather of the previous 

 month. This was quite contrary to the experience of 

 other years and no reason for it could be suggested. 



Some of the females commenced to lay eggs on the 

 I2th of May. All the ticks found on the sheep were, 



sheep, deer, and 



mm. to 10 



when fully 



Legs and 



This species is found 

 occasionally on dogs. 



Adult Female. — Length about 3-25 

 mm. by 3'40 mm. wide, by 5 mm. deep, 

 distended. Shield and spiracles large, 

 palpi long. Rostrum long, with thirteen barbs on 

 each lateral margin, and corona, (') chelifers with six 

 hooks. Coxae of first pair of legs long, triangular, 

 and furnished with a long spine. Legs, shield, 

 rostrum, etc., dark brown to nearly black. Colour of 

 body deep orange red, showing four indistinct intestinal 

 lines, lighter underneath. Light grey in front both 

 above and beneath. Pubescent, opaque and widelv 

 margined. (Fig. 6, and mounted in balsam fig. 7). 

 When distended the colour is very variable. Light 

 red to reddish grey, or even almost pure white. When, 

 fully distended olive-green, or dark lead colour to 



{^) By "corona "' is meant the two orihree rings -of 

 embryo barbs at the end of the rostra of females, too 

 minute to be considered as barbs. 



