296 ELEMENTARY ENTOMOLOGY 



SECTION XV. SUCKING MOUTH-PARTS 

 (TYPE, BUTTERFLY) 



Material. The commonest type, and one of the best for this work, is the 

 monarch butterfly (Anosia plexippus}. These may be collected and dried and 

 the scales carefully removed from the head with a stiff earners-hair brush. 

 Part of the specimens should be boiled in caustic potash (KOH) and the head 

 mounted in balsam. The remainder of the specimens should be placed in the 

 moist chamber for a day or so before they are wanted. The mouth-parts of the 

 Lepidoptera are greatly modified, and only careful study reveals the relation 

 between them and the biting mouth-parts of the locust. 



1. Labrum. This is a very short, quadrangular piece, almost or 

 entirely indistinguishable in some species, as it is immovably joined 

 to the clypeus. 



2. Mandibles. The mandibles are almost entirely wanting in the 

 monarch butterfly, although they are represented in some forms 

 by two triangular pieces which are of little or no use to the insect. 

 In some of the moths they are more highly developed. 



3. Maxillae. The maxillae are the most conspicuous part of the 

 mouth, the two together forming a long, coiled sucking tube used 

 in drawing up nectar. Each maxilla is deeply grooved on the 

 inner side, the two fitting together, forming a complete tube. The 

 maxillary palps are wanting in this form, although present in some 

 of the lower forms. 



4. Labium. The labium consists of a small, triangular flap 

 almost completely fused with the base of the maxillae. Extending 

 out from either side of the labium are the large labial palps, which 

 form two prominent, plumelike projections from either side of the 

 head. They are three-jointed and covered with scales. 



Exercise 42. Make a drawing of the mouth-parts of the monarch butterfly, 

 showing the above in detail. 



SECTION XVI. SUCKING AND BITING MOUTH-PARTS 



(TYPE, HONEY-BEE) 



Material. The honey-bees for this section's work may be preserved in 75 

 per cent alcohol. It may be found advantageous to substitute the bumble-bee, 

 as the mouth-parts are larger and more easily dissected. In either case it is 

 desirable that the students be provided with prepared slides. The mouth-parts 



