ART. 5. LARVAE OF CALENDEINAE COTTOISr. 5 



Spiracles l?tteral except on the eighth abdominal segment, where 

 they are placed dorsally. Spiracular opening oval. 



Both thoracic and abdominal spiracles located anteriorly and in 

 a separate corner area. The area containing the mesothoracic spir- 

 acles, however, is epipleural, while the areas with the abdominal 

 spiracles are derived from the alar area. With the exception of 

 Rhynchophorus^ where the spiracles are bilabiate, they belong in all 

 genera to the bifore type. 



Only one pair of thoracic spiracles are present, the mesothoracic 

 pair; no vestige of a metathoracic spiracle found. All spiracles of 

 same size except the mesothoracic and eighth abdominal; the meso- 

 thoracic being about twice as large and the eighth abdominal spiracle 

 considerably larger than the average abdominal spiracle. 



The air tubes of the bifore spiracles distinct but varying in size 

 according to the genera; those of mesothorax and abdominal seg- 

 ments 1-7 point dorsad but those of the eighth abdominal segment 

 are directed caudad. 



The closing apparatus of the spiracle is similar to that found by 

 Boving in the larvae of the Donaciinae, a detailed description of 

 which appears in his Natural Histor}?^ of the Larvae of Dona- 

 ciinae.^ 



As shown in plate 7, figure 4, h and c, the apparatus consists of 

 a constriction of the walls at the beginning of the trachea, formed 

 by a chitinized, wedge-shaped ridge or fold that projects into the 

 lumen of the trachea, and an opposing soft fold that, by the action 

 of a muscle between two hollow arms at the fold, may be forced 

 against the chitinized ridge, thus effectually closing the entrance 

 to the trachea. 



KEY TO GENERA.2 



1. Mala with simple setae or with not more than one branched seta 2 



Mala with branched setae 4 



2. Mala dorsally with longitudinal row of eight setae one of which is branched. 



Distal end of palpifer dorsally with a tuft of hair Cactophag-us, p. 6. 



Mala dorsally with longitudinal row of six or seven setae none of which 

 are branched. Distal end of palpifer naked 3 



3. Mala with seven dorsal setae. Body elongate, more than 5 mm. in 



length Rhodobaenus, p. 6. 



Mala with six dorsal setae. Body almost globular, not more than 3.5 mm. 

 in length Sitophilus, p. 6. 



4. Dor.sal (or buccal) side of ligula setose ,5 



Dorsal (or buccal) side of ligula not setose L__ 7 



» Internationale Revue der Gesamten Hydrobiologie und Hydrographie. 1910 Pp 50- 

 .^1, 60-62. 



' Leng's catalogue has been followed in the use of generic names with the following 

 exceptions : Calendra of Leng's catalogue is replaced by Sitophilus, and Sphenophorus of 

 Iveng's catalogue by Calendra. 



94987—24 2 



