294 



But considering the damage that various insects do and tlie cost of 

 sitraying taken from accurate figures for different groves of ages 

 varying from one to five years, it is clear that spraying pays directly, 

 apart from the indirect benefit of preventing the establishment of a 

 number of fungus diseases in the trees themselves. 



Newell (W.) & O'Byrne (F. M.). Should Cottony Cushion Scale 

 be allowed to spread unrestricted in the State of Florida ? — 



Florida State Hortie. Soc. Qtrly.. De Land. Proceedings 32nd 

 Ann. Meeting, 1919, ])p. 152-159. [Received 8th May 1920.] 



The Florida Plant Board, which was created in 1915, attempted to 

 make a regulation which would keep the cottony cushion scale {Icerya 

 purchasi) confined to the parts of Florida it then occupied, chiefly 

 the central portion of the State. The regulation requires every 

 nurseryman in this territory to scrub any food- plant of this scale 

 that he sends out with an insecticide under the personal supervision 

 of an inspector, for whose time the nurseryman pays. This results 

 in a very heavy tax on the industry and some of the nurserymen are 

 in favour of the repeal of the rule, considering that Icerya purchasi is 

 quite sufficiently controlled by the Australian Coccinellid [Novius 

 cardinalis]. But if this were done, apart from the fact that in certain 

 years the scale outstrips the Coccinellid, individuals outside would 

 not be willing to buy stock from the infested territory, while other 

 States might very well set up a quarantine against Florida, and this 

 would be a greater handicap to the industry than the present regulation. 



In the discussion that followed this paper attempts were made to 

 suggest an alternative regulation, but no conclusion was arrived at. 



Berger (E. W.). Work of the Entomological Department, State 

 Plant Board. — Florida State Hortie. Soc. Qtrly., De Land, Pro- 

 ceedings 32nd Ann. Meeting, 1919, pp. 160-170. [Received 

 8th May 1920.] 



Some account is given of the method of introducing AscJiersonia 

 alewrodis (red fungus) and A. flavocitrina (yellow fungus) against the 

 common and cloudy-winged whiteflies of citrus [Dialeurodes citri and 

 Aleiirodes iwbifera] [R.A.E., A, vii, 215]. The spores are produced 

 in enormous numbers in the cultures furnished by the State Plant 

 Board, and it is only necessary to spray a mixture of them with water 

 on to the whitefly larvae in the infested trees. The storing, mixing 

 and application of the fungus, together with the best spraying 

 machines to use are described in detail. 



The Entomological Department is almost always able to supply 

 colonies of the Australian CoccineUid [Norivs cardinalis] for use 

 against the cottony cushion scale [Icerya purchasi]. In the control 

 of camphor thrips [Cryptofhrips floridensis] the results of cutting back 

 the trees to 10-inch stumps and dipping them in double strength oil 

 emulsion was so successful that a ruling in the Nursery Department 

 was made that camphor trees so treated, provided they did not show 

 thrips lesions, might be sold from thrips infested nurseries. 



Other work has included the placing out of colonies of Cryptochaetuni, 

 an Agromyzid fly parasitic on the cottony cushion scale in its immature 

 stages, which had been sent from Cafifornia [R.A.E^, A. vii, 20]. 



