CHAP. XX.] INSECTS AND DISEASE. 



Ticks the following distinct cycles of habits may occur: d/) all 

 stages drop off the host to moult and the female also drops off to 

 lay her eggs. (/») the larvae do not drop off but remain attached and 

 moult on the host, the nymph dropping off and also the females for 



position, (> ) both larvae and nymphs remain attached to tin- 

 host throughout all their stages, only dropping off ,i- replete 

 females. A knowledge of the actual life-cycle of the parti< ular 

 oncerned is of the first importance in devising measures 

 tor the control of that species. Some ticks can live tor > 

 without a meal. 



The Blister Beetles (Meloidae or Cantharidae) neither suck blood 

 nor actually invade the tissues, hut in many places various spi 

 are strongly attracted by lights at night and fly into houses. The 

 liquid exuded from the joints of the legs can raise large and 

 painful blisters if it touches the tender human skin ■. hich 



is well known to most residents in Southern India. 



of various kinds infest most domestic and w ild animals. 

 Human lice are treated more fully further on but it may be useful 

 to give here a list of the lice found most commonly in Southern 

 India ; they are : 



On pig, Hcrmatopinus suis, I... var. advent ictus, Neumann. 

 e -..it. ., stenopsis, Burm. 



., calf. .. vituli, I.. 



., buffalo, .. tuberculatus, Giebel. 



,. monkey, Pedicinus curygaster, Gerv. 



1'.. sides these, Hamatopinus spinulosus, Burm.. is found on rats (Mus 

 decumanus, M. alexandrinus and M. sylvaticus) and acts as the trans- 

 mitter of Trypanosoma kwisi from rat to rat. whilst //. stephensi, 

 Christ, and Newst., is found on the Indian Jumping Rat or Gerbille 

 (Tatera indica) and probably transmits a haemogregarine (Hamt 

 garina gerbiUi) common 1 } found in the blood of this animal. All 

 lice must be looked on with suspicion as possible or probable 

 vectors oi disease from one animal host to another. 



The animals which actually invade the tissues belong as a rule 

 to two groups, the mites and flies, the diseases which they ca 

 being known respectively under the general trrniv of Acariasi > I/.. . 

 Diseases due to Acari, or mites) and Myiases (Diseases due to flies, 

 k iftyia, a fly). Of the true mites occurring in India very little 

 is known, but a few attack man and domestic animals; sulphur 

 ointment provides th< best treatment as a rule. S, abies or itch is 



.'. i. which burrows in the skin ; 

 similar foi i on the horse in which t 1 



tau.-c a form of mange du I rubbing off of the hair by the 



