508 MEDICAL ENTOMOLOGY 



seen rotundattis during the day time biting patients in an Indian hospital 

 about the face, legs and arms. The swelling and irritation caused by the 

 bites of lectularius on the face are now not so familiar as they were many 

 years ago when the bug was common in houses in Europe. In Indian 

 houses, where the occupants sleep on the floor with only a loin cloth 

 the bug bites those parts of the body which are ordinarily covered. 



In captivity both lectularius and rotiindatus will feed on almost 

 any animal ; the authors have fed them on rats, cats, dogs, monkeys, rab- 

 bits, guinea pigs and calves. Both sexes are blood-suckers, though the male 

 does not feed as often as the female. It is well known that the bed bug 

 will live for a long time without any food ; in Madras rotiindatus has been 

 kept alive in a test tube for four months. This fact, together \vith many 

 observations made on the occurrence of lectularius in uninhabited houses 

 where it was not possible for it to obtain blood, has led to the erroneous 

 belief that the bed bug is able to subsist on the juice of moistened wood, 

 and even on dust ; such statements have even appeared in modern books 

 on parasitology. Reference to the structure of the mouth parts and 

 biting apparatus of the bed bug will show that it is impossible for it to 

 ingest solid particles or to obtain moisture from wood. No food 

 other than blood has been found in the alimentary tract of the large 

 numbers of rotiindatus and lectularius which the authors have dissected. 



It has several times been stated that bed bugs will feed on each other 

 in the absence of blood ; during the course of hundreds of experiments 

 this has never been observed in Madras, either in the case of rotiindatus 

 or lectularius. Bugs replete with blood have been placed in the same 

 test tube with large numbers of starving adults and nymphs, but 

 they have never been attacked, nor have starving bugs been observed 

 to insert their proboscides into the excreta of full-fed ones. 

 . Two very curious habits, apparently purposeless but very striking on 

 account of the regularity with which they may be observed, are to be 

 noted with regard to the feeding of the bed bug. Like most other 

 blood-sucking insects it defaecates immediately after a feed, but unlike 

 the majority, it does not pass out red blood, but only the remains of the 

 last meal, a semi-solid sticky material ; this black fluid is passed out just 

 after the proboscis is withdrawn, and the bug has a very characteristic 

 habit of turning round and moving backwards, in such a way that the 

 excreta falls in the neighbourhood of the wound made by the proboscis. 

 The second peculiarity lies in the persistence with which individuals, 

 particularly the young stages, will return to feed after they are apparently 

 gorged to repletion. 



