A CHRYSOPID LARVA THAT CLOAKS ITSELF 
IN MEALYBUG WAX 1 
By Thomas Eisner and Robert E. Silberglied 2 
Section of Neurobiology & Behavior, 
Cornell University, Ithaca NY 14853 
While doing field work on Lignumvitae Key, Monroe County, 
Florida, on May 18-20, 1974, we noted a widespread mealybug 
infestation, on the underside of leaves of a shrub of the genus Euge- 
nia (family Myrtaceae). The colonies, which sometimes extended 
over entire branches of the plant, were easily detectable from a 
distance by the white waxy covering of the mealybugs. Close inspec- 
tion showed the mealybugs to be of unusual appearance, and to be 
associated with a chrysopid predator that seemed itself to be 
cloaked in wax. 
The mealybug turned out to be undescribed. Discovered inde- 
pendently by Miller and Denno (1977), it was assigned to a new 
genus by these authors and named Plotococcus eugeniae. The holo- 
type is from a series we collected at our Lignumvitae site. The main 
features of P. eugeniae are evident from Figure 1 A. Most conspicu- 
ous are the long lateral wax filaments, present in mature and devel- 
oping females, which impart upon these forms a distinct stellate 
appearance. Younger individuals, including “crawlers,” which have 
fewer and shorter filaments, are often partly hidden beneath the 
overlapping filaments of females. Microscopic examination of fila- 
ments showed these to consist of central shafts, densely beset with 
powdery wax (Fig. 2). The surface of infested leaves typically bore a 
loose coating of this wax. 
The chrysopid, camouflaged by the wax packet on its back (Fig. 
IB, C), had initially escaped our detection. We eventually learned to 
spot it at close range, by the oval shape of its packet, and its occa- 
sional mobility. It proved surprisingly abundant. We located dozens 
of individuals amidst the mealybugs in a few hours of observation. 
'Paper no. 85 of the series Defense Mechanisms of Arthropods. 
2 Deceased, January 13, 1982. 
Manuscript received by the editor March 9, 1988. 
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