24 BULLETIN 647, U. S. DEPARTMENT OP AGRICULTURE. 



leaves were of a clear, bright green, with very little sooting at any 

 time. These trees, however, were receiving better attention than 

 the average yard trees about the city. They had been kept well 

 pruned and braced; weeds had been kept down, and the trees had 

 shown vast improvement over their condition when first taken in 

 charge. At no time during the three seasons in which they were 

 under care was there any large amount of sooting of figs due to 

 mealybugs. The fruit infestations usually were confined to one or 

 two mealybugs in the calyx depression and the collection of a small 

 group at this point on a small number of them. 



The mealybug conditions for the years 1913 and 1915 were the 

 same as described for 1914, both on fig trees and on orange trees in 

 the city of New Orleans and in the orange groves proper of Louisiana. 

 The sweet seedling trees of Cameron Parish are apparently not sus- 

 ceptible to the attacks of the citrus mealybugs at all; at least none 

 ever was found on these trees. 



Although certain groups of mealybugs may become larger because 

 of heavy ant attendance in Louisiana, the status of this insect does 

 not appear to have been changed by the protection received from 

 the Argentine ant. The mealybugs usually appear in some trees in 

 some of the orange groves as well as on fig trees during April. At 

 times they become numerous enough to attract attention for a few 

 weeks in May, June, and July, but in the last-named month they 

 rapidly disappear, while their enemies increase, and by the last of 

 July or early in August hardly any mealybugs can be found. 



The most important enemy of the mealybug in Louisiana appears 

 to be the Sicilian mealybug parasite (Paraleptomastix abnormis Gir.) . 

 Of the numerous predatory enemies, the most conspicuous were cer- 

 tain lady-beetles, larvae of the green lacewing flies, larvae of the small 

 gray fly Leucopis griseola Fallen, and lepidopterus larvae, of which 

 the most prevalent was Laetilia coccidivora Comst. The last-named 

 insect has the habit of spinning a more or less tubular web over the 

 mealybug groups and feeding under its protection through the larva 

 period, thus effectively defending itself against ants and other 

 enemies. Another mealybug enemy of less importance, but some- 

 times fairly prevalent among mealybugs and other coccids, is a 

 species of tubuliferan thrips which has not been identified. 



INFLUENCE OF THE ANT ON ABUNDANCE OF MEALYBUGS ON CITBUS IN CALIFOENIA. 



In parts of Los Angeles County, Cal., the attendance of the Ar- 

 gentine ant upon the citrus and other mealybugs has a much more 

 pronounced effect in favoring persistent, heavy infestation than in 

 Louisiana. This is especially the case with healthy trees that are 



