356 EXPERIMENT STATION EECORD. 



It is said tlmt in fiold oporntions luivnin.c; results to some extent from in- 

 creased dosages, due to tlie lieated gas being more injurious tlian cooler gas. 

 From the experiments conducted it is evident that the largest amount of gas is 

 availal)le when 2 parts of water are used with one each of cyauid and acid. 

 It is said to be impracticable, however, to use 2 parts of water in field work and 

 3 parts are recommended. 



Preliminary experiments for the control of the purple scale are reported. 

 These lead to the conclusion that for normally shaped orange trees from 11 to 

 14 ft. in height exi)Osed to the gas for 1 hour, when situated in a region with 

 conditions comparable to those at Orange, Cal., a d(»sage rate of lA oz. of 

 cyanid per 100 cu. ft. will destroy the purple t^cale in all its stages on the 

 leaves and wood. If the tree ccmtain fruit infested with this scale it will be 

 necessary to slightly increase the dosage. The author believes that a period 

 between 50 minutes and li hours, while producing satisfactory results will at 

 the same time be most economical. The cost of the extra cyanid required to 

 kill the eggs on the fruit above that necessary for the destruction of the eggs 

 on the leaves and branches is said to be more than the scaly fruit is worth. 



Under the heading of "general considerations," many important lujints are 

 taken up, including leakage of gas during the operation, time of the year for 

 fumigation, fumigation during the blossoming period and while the fruit is of 

 small size, anil other information of value to the fumigator. An improved 

 system of fumigation, which was introduced into California in July, 190S, is 

 described at some length. This is said to have decided advantages over the old 

 method. A dosage schedule is also included. 



Parasitic fungi of the white fly, H. S. Fawcett {Florida Hta. Rpt. 1908, pp. 

 LXVn-LXX\ , pi. /).— In addition to the fungi previously noted (E. S. R., 20, 

 p. 55G), the cinnamon fungus {}'vrtirilliinii iKfcrochidnin) and the white-fringe 

 fungus (Microccra sp.) have been found to be parasitic ui)on the white tly. 

 The cinnamon fungus, which was found on white tly l.-irva^ at Palmetto, was 

 also found to attack several scale insects. 



The white-fringe fungus, which was found killing large numbers of white fly 

 larvae at Sutherland, is now thought to be a. species of Fusarium, but until the 

 perfect stage is discovered the name Microccra sp. will be retained. The growth 

 of this species in culture is said to have been much more rapid than any of the 

 other white fly fungi. Experiments indicate that the fungus requires favorable 

 conditions of moisture for its growth and that it is probably even more 

 dependent upon moisture than are any of the othei' white fly fungi. 



The work with pure cultures of the rod and yellow Aschersonias has been 

 continued and is here briefly reported upon. 



Insect pests of cacao, H. A. Ballou (Imp. Dept. Agr. WQSt Indies Pamphlet 

 58, 1009, pp. 26, figs. 12). — Cacao thrips {Physopus ruhrocincta) and the cacao 

 beetle (Stcirastoma depressiim) are said to be the insect pests chiefly found in 

 cacao orchards. Aphids, mealy bugs, the akee fringed scale {Asterolccanium 

 pustulans), and the root borer of the sugar cane {Diaprcpcs abbrcviatus) 

 are also mentioned as pests. Spraying machines and insecticides are briefly 

 considered. 



Cryptorhynchus lapathi, J. Vanhoudenhove {Bui. Soc. Cent. Forest. Belg., 

 16 {1909), ho. 1, pp. 2.'{-21). — Attention is called to the importance of this 

 curculionid, which was not included in the account of the enemies of the willow 

 previously noted (E. S. R., 20, p. 857). 



The occurrence of the larvae of a parasitic fly (Protocalliphora chrysorrhoea) 

 in bird nests in the vicinity of Shawnee, Pa., C. W. Miller {Worthington 

 -Soc. Study Bird Life Bill. 2, pp. 8, pU. 7/). — The author reports the occurrence 

 in "Pennsylvania of the immature stages of this fly iu nests of the wood thrush, 



