in Chicago that the egg-contents of 80 to 85 per cent of the cottony 

 ovisacs had been destroyed by the white mealy larvae of Hyperaspis. 

 These larvae enter and devour the entire contents of one ovisac after 

 another without destroying its form, so that only an examination will 

 reveal the empty ones. 



The predaceous caterpillar of Lcetilia coccidivora Comst. has been an 

 efficient ally in controlling the pest in the vicinity of Washington, D. C. 

 It is particularly effective where the cottony masses are in close prox- 

 imity, because of its habit of eating its way through the masses, spin- 

 ning a strong web about itself, and forming a gallery as it progresses. 

 The caterpillar is very active and moves about freely within its web. 



Several specimens of Leucopis nigricornis Egger, a common dipterous 

 parasite of aphides, were reared from cottony maple scale collected in 

 Chicago, 111., on Jul}' 21, 1905, by the writer, and 

 from other specimens sent to the Bureau from 

 Crystal Lake, 111. This parasite is considered to 

 be a European species, and although aphides seem 

 to be its favorite host, it is occasionally reared from 

 nondiaspine Coccidse. 



Several species of chalcid flies (Chalcidoidea) 

 are truly parasitic upon the cottony maple scale 

 as well as upon others of the Lecaniina^. There 

 is no doubt that many more Pulvinarias are killed 

 by these interesting little fellows than by all other 

 enemies. Goecophagus lecanii Fitch, G. flavoscu- 

 tellum Ashm., Atropafes collinsi How., Aphycus 

 pulvinarice How., Gomys fusca How., and Eunotus 

 lividus Ashm. have been reared from the cottony 

 maple scale. 



REMEDIES. 



Fig. 3. — Pulvinaria innu- 

 merabilis: gravid fe- 

 male, greatly enlarged, 

 before commencing to 

 secrete egg sac in the 

 spring ( Erom Howard). 



In dealing with an infestation by the cottony 

 maple scale, the most important matter to be 

 considered in each case is the advisability of artificial means of control 

 under (lie existing conditions. The natural enemies of this pest have 

 done and are still doing such effective work in its control, that it is a 

 question whether remedies should be applied when the infestation is 

 not serious. Nature always maintains a balance, and this pest can not 

 be in the ascendency for any great length of time. On the contrary its 

 parasites will eventually multiply so rapidly as to completely check its 

 progress, and it may even narrowly escape extermination. 



Insecticides applied for a pest always kill its parasites and often- 

 times predaceous enemies are also destroyed. Hundreds of larva' of 

 Hyperaspis binotata were found to have been destroyed by a summer 

 treatment with kerosene emulsion for the cottony maple scale in parks 



