io MEDICAL ENTOMOLOGY 



bee will serve as a representative species. Examine mounted 

 specimens of mouthparts as well as complete heads. The 

 labrum, above, is narrow and quite simple. The mandibles are 

 easily distinguishable and are useful wax implements. In ants 

 the mandibles are highly efficient carrying organs and weapons 

 of defense. The maxilla form the lateral conspicuous wings of 

 the suctorial parts; the lacinia and galea are fused into one 

 piece, and the maxillary palpi are quite minute. The labium is 

 represented by the long structures to the right and left of the 

 middle tube, which is probably the hypopharynx. The hypo- 

 pharynx terminates in a spoon or bouton, which completes the 

 lapping character of the type. 

 Draw and label parts. 



EXERCISE 2 



INSECT MOUTHPARTS (cont.) 



C. Hemipteron type. 



A very different sort of organ than the above described types 

 is found in the Hemiptera. Here the labium forms a prominent 

 beak, which is usually three (rarely one or four), jointed, and 

 telescopic. Examine mounted specimens of mouthparts of a 

 cone-nose, Reduviidae. The beak encloses a pair of mandibles, 

 often provided with cruel barbs at the distal end, and the 

 maxilla, all bristle-like, and of great efficiency in piercing the 

 skin. The maxillae are more or less completely joined, forming 

 a tube, so that often only three bristles or stylets can be seen on 

 examination. The labrum is quite short and inconspicuous. 



Draw side views of the head of the cone-nose, showing the 

 proboscis and stylets. Label the parts. 



D. Lepidopteron type. 



This type, represented by the commoner butterflies and moths, 

 is typically a coiled, sucking tube, capable of great elongation. 



