254 EXPERIMENT STATION RECORD. 



is the most serious orauge pest. Oviposition continues over a period of from 8 

 to 11 days, from 40 to 80 eggs being deposited. Tlie incubation period is shorter 

 than the period of oviposition, the first egg hatching before the last is laid. 

 Incubation has been found at times, however, to require as many as 18 days. 

 The adult males appeared in 5 weeks, while 7 weeks are required for the develop- 

 ment of the females. The life cycle of the female is said to i-equire from 8 to 

 9 and in some cases 10 weeks. 



Infestation by the white scale (Chionaspis citri), which is generally found 

 on the trunks and branches of old trees, usually starts at the base and gradually 

 works up among the branches and often into the young twigs. The black 

 fungus that parasitizes this scale is said to be rather slow in spreading in 

 cultivated groves. Life-history studies at the station show that this scale 

 requires the same length of time to develop as does the purple scale. "The 

 most effective emulsions are kerosene with carbolic acid, 1 part of the mixture 

 to 5 of water, and crude oil with carbolic acid, 1 part of the mixture to 15 or 18 

 of water." 



The Florida red scale {Chrysomphalus aonidum), which is quite prevalent 

 in citrus groves, is generally found on the leaves and fruit of the orange and 

 lemon. It does not spread as rapidly as the purple and white scales but when 

 found on the fruit is very difficult to remove. About 8 or 9 weeks are required 

 for its development. The red-headed fungus {Sphwrostilbe coccophila) has been 

 found preying upon It. The treatment is said to be the same as for the purple 

 scale. 



The hemispherical scale, generally found on the small branches and leaves 

 and occasionally on the fruit, attacks many ornamental plants but is not con- 

 sidered a serious pest as it is readily held in check by one or two sprayings 

 of kerosene emulsion. It is attended by ants which distribute the young from 

 place to place. It is preyed upon during the rainy season by a white fungus 

 ( Sporo trich um, sp. ) . 



Brief notes are presented upon beneficial fungi and methods of their intro- 

 duction in combating scales. The red-headed fungus appears in the Bayamon 

 district and is more prevalent thei'e than the white-headed fungus. In the 

 Pueblo Viejo district, however, the white-headed fungus has been observed in 

 greater numbers than the red-headed fungus. It is said that the species that 

 prey upon the purple scale spread very rapidly, whereas those which prey upon 

 the white scale do so very slowly. 



Windbreaks are discussed at some length, attention being called to the fact 

 that there is not a grove on the island that does not need in some part more 

 protection from wind than it has at the present time. The several causes 

 of scarred fruit are discussed. Chafing by wind is shown to be an important 

 factor ; in one case the windy side of a tree showed 23 scarred and 234 unscarred 

 fruit, while the leeward side showed 7 scarred and 210 unscarred. 



Notes on spraying and spraying machinery and an extended discussion of 

 insecticides and fungicides follow. 



Notes on some coconut pests, P. L. Guppy (Proc. Agr. Soc. Trinidad and 

 ToMgo, 11 (1911), No. 2, pp. 164-171). — The data here presented relate to 

 Brassolis sophorce, the spiny coconut caterpillar (Hyperchiria sp.), a rhinoceros 

 beetle, and Rhynchophorus palmarum, the larva of which is the well-known 

 " gru-gru worm." 



Insects injurious to shade trees, J. B. Smith (Ami. Rpt. Forest Park Reserv. 

 Com. N. J., 4 {1908), pp. 85-100. pis. 3, figs. 4).— A brief account of the more 

 important insect enemies of shade trees in New Jersey. 



Insects of the greenhouse and their extermination, J. J. Davis (Trans. III. 

 Mart. Soc, n. ser., 44 (1910), pp. d^-^i). — The author here considers a few of 



