The Cottony Maple Scale. 24 7 



become dormant as cold weather sets In, pass the winter in tliis st-ite, 

 start growth again as spring opens, and produce their eggs when 

 jnature. 



NATURAL ENEMIES AND REMEDIES. 



Fortunately the cottony maple scale is beseiged by a great number 

 of natural enemies, both paracitic and predaceous, which commonly 

 keep it from increasing sufficiently to become harmful. Among the 

 former the most efficient ones in the destruction of the pest are the 

 foui'-winged chalcid flies. The importance of this group in forestalling 

 the ravages of the scale is best shown by quoting what Dr. L. O. 

 Howard,* U. S. Entomologist, has to say in regard to Coccophagiis 

 lecanii (Fitch), a parasite belonging to the above named group. 



"This species, which has been reared from a number of differen:; 

 scale insects of the Lecaine group, is very widespread and appears 

 frequently in astonishing numbers. It was due to this parasite that 

 it was found almost impossible to carry the scale insects through 

 the season at Washington in 1S98; of the many thousands of scale 

 Insect larvae which settled upon the trees under observation it is 

 safe to say that much less than one per cent reached full growth. 

 During the months of July, August and September they were stung 

 by this little parasite, which laid its eggs in their bodies; soon after- 

 wards they turned black, the adult parasites issuing from lioles ciit 

 through the backs of their bodies. The development of the jjav isite 

 was plainly seen to be very rapid, occuping certainly not more than 

 two or three weeks, and there was therefore a succession of genera- 

 tions, with an increase in numbers in geometrical progression, until 

 really the wonder is that a single scale insect escaped. 



"The writer had under close observation a branch of a largo ?\or- 

 way maple tree growing in the Smithsonian grounds, which in June was 

 fairly plastered with the egg-sacs of the Pulvinaria, whilo in July 

 its leaves were thickly spotted with newly settled young; in August 

 he spent an entire morning trying to find a living scale insect, but 

 without exception all which were found had been killed by this im- 

 portant parasite. The little Coccophagus even gained access to the 

 Insectary. Potted maple trees stocked with the scale insects were 

 . discovered by them, and the scale was exterminated, although the 

 little trees had been swarming with these scales, and although daily 

 an assistant had picked off and crushed those which through a change 



♦Bulletin No. 22, New Series, U. S. Dept. Agr.,Dic. Ent., pp. 13. 



