Feb. 10. I9I9 Injury to Casuarina Trees 157 



Because of its thorough establishment in the red mangrove it is evi- 

 dent that this beetle was not introduced into Florida with the casuarina; 

 in fact, specimens had been collected at Key West before the casuarina 

 was planted in Florida. 



The beetle's habitat is the West Indies, where the red mangrove tree 

 is also native. 



In India the casuarina is a common tree, but the red mangrove does 

 not occur. C. tranquebarica, despite its specific name,^ does not occur in 

 India. Tranquebar is on the east coast of Madras. 



THE ADULT 



The adult of the mangrove borer (PI. 20, D; 21) is metallic greenish 

 bronze and has two lighter-colored and one smaller basal impressions on 

 each elytron. There are also impressions on the thorax. Adults can be 

 told from those of any other speciesofChrysobothris found in the United 

 States by the fact that the eyes are nearly contiguous on top of the head. 

 The female is larger than the male, and the front of the head is green. 

 The length ranges from 13.5 to 17 mm. The smaller, more active male 

 ranges in length from 12.5 to 14 mm.; the front of the head is bright red. 

 There are other sex differences in the last ventral segment of the abdomen 

 (PI. 19, A) and, of course, in the genitalia. 



Adults of both sexes are fond of bright sunlight and are commonly 

 found flying from 10 a. m. to 3 p. m. (central time) in open places in the 

 swamps and on the casuarina trees. Oviposition takes place in either 

 morning or afternoon. 



Both male and female beetles feed on the tender, succulent bark of 

 the trees which they infest. They may be found resting on the trunks 

 of trees in the bright sunlight chewing through the outer bark to the 

 cambium. 



The beetles, owing to their rapidity of movement, strong powers of 

 flight, and shyness, are probably able to survive enemies and live for 

 two or three weeks, or possibly a month or so. They are difficult of 

 detection when resting on the bark of red mangrove, but when flying 

 in the sunlight they are conspicuous on account of the bright-green 

 color of the body. The beetles are never active unless the day is warm, 

 sunny, and not windy. 



As the beetles are strong fliers and are fond of flitting from one sunny 

 tree trunk to another, and as they lay many eggs each, it is probable 

 that one female may be responsible for the death of many trees. 



On April 13, 1918, in a mangrove swamp along Biscayne Bay, oppo- 

 site Miami, Fla., females were found ovipositing at i.io p. m. (central 

 time), and the operation observed. After a short exploration of the 

 bark, made with extended ovipositor (PI. 19, B), a proper crevice was 



' Fisher. W. S. Chrysobothris tranquebarica Gmel. vbrsus imprbssa Fabr. In Proc. Ent. 

 Soc. Wash.. V. 20, no. 8, pp. 173-177 November, 1918 (1919). 



