. Animal parasites and human disease. Medical parasitology; Insects as carriers of disease. 374 BEDBUGS AND THEIR ALLIES vary juice has already been poured, draws blood up through a tube made by the piercing organs, through a thickened " bottle neck " ring to the oesophagus and then into the relatively enor- mous stomach. The muscles for dilating the pharj^nx in order to make a suction pump out of it occupy the greater part of the head. According to Cragg, who has worked on the alimentary tract and digestive proc- ess of bedbugs, there are about 70 pulsa- ^* tions of the pharynx per
. Animal parasites and human disease. Medical parasitology; Insects as carriers of disease. 374 BEDBUGS AND THEIR ALLIES vary juice has already been poured, draws blood up through a tube made by the piercing organs, through a thickened " bottle neck " ring to the oesophagus and then into the relatively enor- mous stomach. The muscles for dilating the pharj^nx in order to make a suction pump out of it occupy the greater part of the head. According to Cragg, who has worked on the alimentary tract and digestive proc- ess of bedbugs, there are about 70 pulsa- ^* tions of the pharynx per minute in young bugs, in which this can be observed through Fig. 166. Diagram the body wall. Bugs seldom cling to the S%ot?bo'^ngback «ki^ While sucking, preferring to remain of proboscis. (After on the clothing. Since a fresh meal appar- ^^^^'y-^ ently acts as a stimulus for emptjdng the contents of the rectum, the adherence to the clothing is a fortunate circumstance, inasmuch as it precludes to some extent the danger of bedbugs infecting their wounds with excrement, as do ticks. In the course of ten or 15 minutes a full meal is obtained and the bug, no longer flat but round and distended with blood, re- treats to his hiding place, having first deposited a bit of excrement. According to Cragg, in the case of C. hemipterus (rotundatus), a single meal, much of which is temporarily stored in the stomach which acts as a food reservoir as well as a digestive organ, is not fully assimilated for at least a week, although the bug is ready to feed again in a day or two, thus having parts of several meals in the stomach at once. This is quite a different condition from that found in most blood-sucking insects, where a meal is com- pletely digested before another is sought. Observations made by several authors on C. lectularius do not indicate that this species has similar habits. As in other bugs, the digestive juices change the absorbed blood into a dense black mass, described by Mur
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