i6o 



Journal of Agricultural Research 



Vol. XVI, No. 6 



finally packed with coarse boring chips. In some large, heavily infested 

 red mangrove trees as many as three pupal cells per linear 2 inches were 

 found. 



THE PUPA 



The pupa is white and of the shape characteristic of buprestid pupae 

 (PI. 20, C; fig. 2). It is of the common Chrysobothris type, with the head 

 resting on the breast and the legs and wings folded on the ventral surface. 

 The developing insect gradually acquires characters of the adult beetle. 

 The size varies with the individual and there is also a sex difference; 

 the length ranges from 15 to 20 mm. 



KiG. 2. — Chrysobothris tranquebarica: a, Female pupa, ventral view; b, same, dorsal view. 



The average duration of the pupal period is about two weeks. When 

 the adult becomes mature it chews its way out through the plug of 

 wood fiber, cuts an oval hole through the bark, and escapes. This hole 

 is often mistaken by property owners for the point of entrance of the 

 borer. 



SEASONAL HISTORY 



One year is required for the development of the mangrove borer from 

 egg to adult. Adult beetles first begin to emerge about the ist of April. 

 The period of maximum activity of th^ beetles on the wing is from the 



