I'OKTO RICO EXPERIMENT STATION. 448 



the eradication of the white ants, which, due to the semiabandoncd 

 state ot" the i)hico, had hocoine thoroutrhly o,stal)lished in the out]>uild- 

 ini^s, fence posts, and all mango and "jobo" trees in the vicinity. 

 Over seventv-tivo nests were destroved wnthin 100 yards of the office 

 buildino-. As the arsenic treatment proved too slow and uncertain, 

 recourse was had to burning- with kerosene. A few ounces of the oil 

 usually sufficed in dry weather to effect the entire destruction of a 

 nest and all the insects therein. In a few cases the individuals which 

 had been outside the nest at the time of its destruction returned and 

 formed a small nest near the site of the old one. As many as eight 

 queens were discovered in one nest, though four was an unusual num- 

 ber. The num])er of workers in a large colony was estimated to be 

 from 50,000 to 100,000. The species has been determined as Eutermes 

 inor'io (?). The winged form migrates from April to Jul3^ Live 

 wood is very seldom attacked. 



A smaller species, having Inaline instead of sooty wings, swarms in 

 vast immbers in April, but no nest has been located yet. 



It is recommended that all fence posts be well tarred before setting. 

 The "poma rosa" {^Eugenia {Jamhom) jamhos) is especiall}'^ liable to 

 the attacks of white ants. The following kinds of woods ma}' be used 

 for posts in a "live"' fence: Algarrobo {Hymenxa courhariP)^ jobo 

 {S2>ondiax lufea), bocare {^Erythrina microjyteryx)^ almacigo {Bursera 

 Kimaruha), guaj'abo {Psidlum guayaljo)^ and molinillo or havilla {Ilura 

 crepitans). Of course some of these species will not take root in dry 

 soil, but with a little care an ant-proof fence ma}' be had which is 

 practically permanent. The sprouting branches should be lopped off 

 two or three times a year. 



Thechanga has done more or less damage in the vegetable beds and 

 nurseries. Kepeated applications of the poisoned bait, as recora- 

 nuMided \n Bulletin No. 2, have served, however, to keep this eneniy 

 in check. Trai)s made by sinking 5-gallon kerosene tins just below 

 the surface of the soil and lightly covering the open tops of same with 

 small sticks, grass, and earth proved utterly useless. 



CUTWORMS. 



Comparatively little damage has been done by these insects, though 

 a species of Prodenia has been quite numerous and hand-picking of 

 the larva? had to be kept up for some weeks in the Central American 

 rubber-seed beds. Larvte of an undetermined species were sent in 

 from the coffee sul)station and reported as doing considerable injury 

 in the coffee-seed beds. 



The cotton bollworm {ireliotJiia armiqer) destroyed a field of corn in 

 November and December, Dropping or spraying Paris green in 

 water into the heart of the young plants resulted in killing great 



