NATURAL CONTROL OF CITRUS MEALYBUG IN FLORIDA. 6 



INSECT ENEMIES OF THE MEALYBUG, AND INSECTS ASSOCIATED 

 WITH THE MEALYBUGS AND SOMETIMES CONSIDERED AS 

 BENEFICIAL. 



During the past two summers, 1920 and 1921, three insects have 

 been found associated with mealj^bugs: Pyroderces rileyi Wlsm.,^ 

 Laetilia coccidivora Comst.,^ and a species of Chrysoplatycerus.^ 



The larva of the tineid moth Pyroderces rileyi^ known as the 

 pink cornworm or scavenger bollworm, is conspicuous in mealybug 

 clusters, occurring abundantly between clustering grapefruit, par- 

 ticularly if dead leaves are pinioned in the cluster. It is perhaps the 

 most common of all insects frequenting mealybug clusters, and many 

 growers are of the opinion that it feeds upon the mealybug. The 

 larvae are deep pink or "wine red" (Busck*) in color, about three- 

 eighths of an inch long, and more or less cylindrical in form. Just 

 back of the head a rectangular, almost black area is to be noted, 

 which, though common to other lepidopterous larvae, serves at once 

 to distinguish the common Florida form from other larvae occasion- 

 ally found in similar situations. The insect is without doubt a scav- 

 enger, playing no economic role as far as the mealybug is concerned. 

 Busck* reported it as a trash feeder. The writer, unaware of this 

 or similar publications, performed some experiments to determine its 

 relationship to the mealybug. A few larvae brought into the labora- 

 tory were confined with live mealybugs in a glass vial for several 

 days, but none of the mealybugs were eaten. On the other hand, an 

 old dead leaf found sandwiched between two grapefruit, covered 

 with the larvae, was brought into the laboratory and confined in a 

 pill box in a moist chamber. On this the larvae grew to maturity in 

 the complete absence of mealybugs. 



The second insect, the pyralid moth, Laetilia coccidivora^ is much 

 less common than Pyroderces rileyi, but, like it, occurs in the larva 

 stage associated with mealybugs. The writer performed no experi- 

 ments with this insect, but it is looked upon generally as predacious 

 in habit, feeding upon the mealybugs. In the Winter Haven grove, 

 where the observations of the past season were made, however, it was 

 1 ot abundant, and among the thousands of mealybugs that were 

 collected for experimental purposes only 12 of these larvae were ob- 

 seiv^ed. The full-grown larva is somewhat larger than that of 

 Pyroderces rileyi and is grayish green in color. It forms a silken 

 web, beneath which it lives and feeds. 



The third insect, new apparently in Florida, is a chalcid, an un- 

 known species of Chrysoplatycerus. The specimens submitted for 



^ Determined l>y Carl Heinrich, of the Bureau of Entomology. 



3 The writer is indebted to A. B. Gahan, of the Bureau of Entomology, for the generic 

 identification of this insect and for the information regarding C splendens Howard. 



* Busck, August. The pink bollworm, PectinopJiora gossypielJa. In Jour. Agr. Res., v. 

 9, no. 10, p. 362, 366, 1917. 



