ECONOMIC ZOOLOGY ENTOMOLOGY. 253 



some seasons and localities it does noticeable injury and may stunt young 

 Irees to some extent. 



Insects injurious to citrus fruits and methods for combating them, W. V. 

 Tower (Porto Rico Sta. Bui. 10, pp. 7-3o, pis. 5). — In this bulletin the author 

 deals with 12 of the more important insect enemies of citrus fruits in Porto 

 Rico, and their natural enemies, Including methods of propagation and insecti- 

 cides, with directions for their preparation and application. 



The orange leaf weevil (Dinprepes spenglcri) appears during May, June, and 

 July, and again in November, there being two broods annually. The larvae 

 feeds on the roots of the oi-ange, in a few cases having been found damaging 

 the trees to such an extent that the leaves turn yellow and drop off. The 

 guava, avocado, mango, and rose are also food plants of the adult. " When 

 this insect appears spraying should be resorted to with arsenate of lead, 4 

 pounds to 50 gallons of water. If there is a great d6al of scab in the groves 

 it is recommended that a fungicide be applied with the insecticide." 



The small orange leaf weevil, a ravenous feeder on orange leaves, especially 

 the new growth, is a pest that was first noticed in January and February, 1908, 

 in the San Juan district and near Arecibo in groves planted in sandy soils. 

 In 1908 all thie beetles disappeared by March 1, but reappeared again in June 

 and during the blossoming period were seen scarring the fr^iit. The eggs, which 

 vary in number from 6 to 24, are deposited in clusters between the leaves. 

 On hatching the larvae soon fall to the ground and feed on the roots of the 

 orange trees. The treatment is the same as for the orange leaf weevil. 



The May beetle {Lachnos'terna sp.) is the source of injury more particularly 

 noticeable in young groves, especially where the ground has been broken for 

 the first time. It generally appears during April, May, and June and is a 

 Aoracious leaf feeder. The caculo, the common name by which the larva of this 

 beetle is known in Porto Rico, feeds on the roots of orange, sugar cane, and 

 a number of common grasses, causing considerable destruction, often as many 

 as 50 having been taken from about the base of a single young orange tree. 



The orange dog, a papilionid caterpillar which has been found at the station 

 during July and October, feeds on the leaves of the orange and when present 

 in large numbers causes considerable damage as it is a ravenous feeder. Satis- 

 factory results have been obtained in combating this pest by spraying with 

 arsenate of lead, 3 pounds to 50 gallons of water. 



The brown ant (Solenopsis gcminata), which attends the white fly and the 

 Lecanium scale, attacks the young, tender shoots and leaves of the orange when 

 its natural food supply is cut off. The ants carry sand up about the base of 

 the trees and when the food supply is scant they gnaw the bark where it is 

 covered by their sand houses. Often when pineapples have been removed from 

 between rows of orange trees the ants attack the latter in great numbers, 

 scarring the trees, eating young, tender shoots, and cutting holes in the fruit. 

 Carbolic acid emulsion is said to be the simplest and most inexi)ensive spray 

 to be recommended in combating them. 



The woolly white fly (Aleyrodes howarcU) feeds upon the guava and orange 

 and is attended by ants. A red spider feeds upon the essential oils of the 

 orange, preferably on the under or shady side of the fruit or leaf, causing them 

 to become rusty in appearance. The adult is readily held in check by sulphur 

 sprays or by soap or kerosene emulsion. A rust mite closely resembling the 

 Florida species and probably identical with it was first discovered on orange, 

 grapefruit, and lemon in Porto Rico during the spring of 1909. 



A preliminary account of the four species of scale described as the source of 

 injury to citrus on the island has been previously noted (E. S. R., 22, p. 252). 

 The purple scale which is present in all cultivated and wild groves on the island 



