A Chrysopid Larva That Cloaks Itself in Mealybug Wax

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 Eugenia (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 inspection 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 independently by Miller and Denno (1977), it was assigned to a new genus by these authors and named Plotococcus eugeniae. The holotype is from a series we collected at our Lignumvitae site. The main features of P. eugeniae are evident from Figure 1 A. Most conspicuous are the long lateral wax filaments, present in mature and developing 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 filaments 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. 1B, C), had initially escaped our detection. We eventually learned to spot it at close range, by the oval shape of its packet, and its occasional mobility. It proved surprisingly abundant. We located dozens of individuals amidst the mealybugs in a few hours of observation.