Diptera 33 



A species which very commonly attacks man is Conorhinus 

 sanguisugus, the so-called "big bed-bug" of the south and southern 

 United States. It is frequently found in houses and is known to 

 inflict an exceedingly painful bite. As in the case of a number of 

 other predaceous Hemiptera, the salivary glands of these forms are 

 highly developed. The effect of the bite on their prey and, as Marlatt 

 has pointed out, the constant and uniform character of the symptoms 

 in nearly all cases of bites in man, clearly indicate that their saliva 

 contains a specific substance. No satisfactory studies of the secre- 

 tions have been made. On the other hand, Dr. Howard is doubt- 

 less right in maintaining that the very serious results which some- 

 times follow the bite are due to the introduction of extraneous poison 

 germs. This is borne out by the symptoms of most of the cases 

 cited in literature and also by the fact that treatment with corrosive 

 sublimate, locaUy applied to the wound, has yielded favorable results. 



Other Hemiptera Reported as Poisonous to Man — ^A large number 

 of other Hemiptera have been reported as attacking man. Of these, 

 there are several species ot Lygseidas, Coreidae, and Capsids. Of the 

 latter, Lygus pratensis, the tarnished plant-bug, is reported by 

 Professor Crosby as sucking blood. Orthotylus flavosparsus is another 

 Capsid which has been implicated. Empoasca mali and Platymetopius 

 acutus of the Jassidae have also been reported as having similar 

 habits. 



Whenever the periodical cicada or "seventeen-year locust" be- 

 comes abundant, the newspapers contain accounts of serious results 

 from its bites. The senior author has made scores of attempts to 

 induce this species to bite and only once successfully. At that 

 time the bite was in no wise more severe than a pin-prick. A stu- 

 dent in our department reports a similar experience. There is no 

 case on record which bears evidence of being worthy of any credence, 

 whatsoever. 



Under the heading of poisonous Hemiptera we might consider the 

 bed-bugs and the lice. These will be discussed later, as parasites 

 and as carriers of disease, and therefore need only be mentioned here. 



DIPTERA 



Several species of blood-sucking Diptera undoubtedly secrete a 

 saliva possessing poisonous properties. Chief among these are the 

 Culicidae, or mosquitoes, and the Simuliidae, or black-flies. As we 

 shall consider these forms in detail under the heading of parasitic 



