Feb. lo, I9I9 Injury to Casuarina Trees i6i 



middle of April to the ist of June, but a few stragglers are found as late 

 as August. Most of the eggs are probably laid from the middle of April 

 to June. The larvae seem to be full grown by August, and the majority 

 form the pupal cells before winter. The species probably passes through 

 a dormant period, or one of comparative inactivity, during the months 

 of December, January, and February, as mature larvae under the bark 

 or in the pupal cells. On March 19, 191 7, such mature larvae, together 

 with pupae and immature adults, were found in infested trees at Miami 

 Beach. On April 4, 191 7, many pupae were changing color, indicating 

 that they would soon transform to the adult stage. In 191 8, on April 8, 

 mature larvae, pupae, and adults were in pupal cells in infested trees at 

 Miami Beach. The first eggs were found on April 13, 1918, and the 

 first young larvae on April 23, at Miami Beach, in infested red mangrove 

 trees. 



PREDATORY ENEMIES AND PARASITES 



The flicker {Colaptes auratus) and the red-headed woodpecker (Melan- 

 erpes erythrocephalus) pick out larvae and pupae from infested trees, and 

 often obtain a high percentage of the insects infesting a few trees. Pre- 

 dacious beetle larvae account for other borers. On April 3, 191 7, larvae 

 of a predacious trogositid beetle (Tenebroides sp.y were found under the 

 bark of a red mangrove tree infested by C. tranqueharica, in a swamp 

 near Miami Beach. 



On April 9, 191 8, in the same general locality, larvae of an elaterid 

 beetle (Adelocera sp.)^ were found under the bark of a red mangrove tree 

 infested with the beetle. Presumably they were predacious enemies of 

 the mangrove borer. 



Two species of hymenopterous parasites have been found. One 

 species, Atanycohis rugosiventris Ashmead,^ was found to be fairly com- 

 mon at Miami Beach in 191 7 and 191 8. Its cocoons occur in a mass at 

 the end of the larval burrow of the beetle. Adults were found emerging 

 from the cocoons on March 19 and April 10, 1917, and on April 9, 1918. 

 The other species, A. lahena n. sp.,^ constructs a single cocoon in the 

 pupal cell of C. iranqtiebarica, in infested casuarina trees. 



Notwithstanding the numerous natural enemies of Chrysobothris tranque- 

 harica it is evident that reliance can not be placed upon them to control 

 this borer without help from man. 



CONTROL OF THE BORER 



In view of the large number of casuarina trees which have been and 

 are being planted in southern Florida and the varied uses to which they 

 are adapted, it will be seen that the problem of controlling this injurious 

 borer is important. Since 191 6 owners of these large plantations have 



' Detennination by Dr. Adam G. Bbving, Bureau sf Entomology. 

 ' Determination by Mr. J. A. Hyslop, Bureau of Entomology. 

 « Determination by Mr. S. A. Rohwer, Bureau of Entomology. 



