23 



result 0(1 in the almost complete destniction of the coffee leaf-miner, 

 ulthouiijh one year previous each coffee ])lant at the station grounds 

 carried on an average something like twenty-five larvae of the leaf- 

 miner. Unfortunately, the good results of the parasites' work were 

 not so much in evidence in other sections of the island. 



The several insects injurious to cotton were studied during the year 

 and a large cotton plantation was visited in the vicinity of Aguadilla, 

 where great damage by a caterpillar had been reported. It was found 

 that although the cotton caterpillar {Alabama argillacea Hbn.) had 

 been somewhat destructive in small areas through the plantation the 

 pupae were nearly all parasitized. Chalcis annulata Fab. was reared 

 from a few pupae which were obtained in the plantation. 



Ten species of mosc[uito-eating dragon-flies were studied on the 

 station grounds. 



The principal fungus disease not mentioned in last year's report, 

 which deserves much study and which should be carefully guarded 

 against in all the orange plantations of the island, is the Florida leaf- 

 spot fungus (Colletotrichum gloeosporioides). This fungus appeared 

 during the last year in the station's citrus nursery, especially on rough 

 lemon stock. It had been previously noted in several districts of the 

 island, and it is doubtful whether this disease, which appears to be 

 recently introduced, can be checked in its spread over the island. 

 The peculiar root rot of the roselle {Hibiscus sabdariffa) attacked a 

 few of the plants of this species. It is said to be common throughout 

 Florida, and it appears to be of bacterial origin. 



The exchange of seeds and plants with other stations in the Tropics 

 has become a very important part of the station's work. 



REPORT OF THE HORTICULTURIST. 

 By H. C. Henricksen. 



Horticulture is yet in its infancy here, and it has been found neces- 

 sary to do much pioneer work of a practical nature in order to form 

 a basis for more scientific work. This has been especially didicult 

 on account of the unskilled help, which has made it necessary for 

 the horticulturist to attend to practical details which could and prop- 

 erly should be left to the gardener. It is hoped that it may be pos- 

 sible to secure the services of a trained man within a short time. 



The climatic conditions of Porto Rico are such that results can be 

 obtained in much shorter time than is required in the Temperate 

 Zone. This is especially true when experimenting with annuals, 

 but even perennials yield quick results. While this is an advantage in 

 time saved it must not be imagined that it is work saved; on the con- 

 trary, it often requires the work of three or four years condensed into 

 one. On that account it has been found necessary to take up one line 



