MECHANISM OF FEEDING IN HEMIPTERA 



By M. a. H. QADRI 



Professor and Head of Department of Zoology 



University of Karachi 



Pakistan 



Among the old works dealing with the mouth parts of Hemiptera 

 are those of Davidson (1914), Grove (1919), Muir (1926), Myers 

 (1928), and Becker (1929). Among the recent workers, the more 

 important ones are Weber (1928-54), Rawat (1939), Snodgrass 

 (1944), Butt (1943), and MacGill (1947). 



The present studies were conducted in order to find out the indi- 

 vidual and joint activities of the mouth parts and the processes in- 

 volved in sucking the juices and injecting the saliva in the host tissue. 

 This obviously necessitated the study of the skeletomuscular struc- 

 ture of each mouth part and the related areas of the head capsule as 

 well as that of the endoskeleton of the head known as the tentorium. 

 It was originally contemplated to select a large number of forms for 

 such study so as to exclude the possibility of error of judgment. But 

 as it was found that the fundamental makeup of many forms is 

 identical, the author mainly devoted himself to the intensive study 

 of the Indian mango hopper Idioccrus niveosparsus (Leth.) (Jas- 

 sidae) and the Indian sugarcane leaf hopper Pyrilla perpusilla Walker 

 (Fulgoridae). The results were also checked by the study of the 

 sugarcane white fly Aleurolohiis barodensis Maskell. These studies 

 are obviously important because Homoptera are vitally concerned in 

 the spread of various plant diseases. They are also serious pests of a 

 host of plants of extreme economic importance. 



In Heteroptera the following types were studied : 



1. Sphaerodema annulatum Fabr. (Belostomatidae). 



2. Belostoma indicum Lep. Serv. (Belostomatidae), 



3. Anisops niveus Fabr. (Notonectidae). 



4. Agraptocorixa hyalinipennis Fabr. (Corixidae). 



5. Corixa promontoria Distant (Corixidae). 



HOMOPTERA 



Head capsule. — The head capsule of Homoptera is characterized 

 by a considerable development of the facial region as a result of its 

 elongation due to opisthognathous mode of attachment. The labrum 



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