FIELD STUDIES OF THREE SPECIES OF APHIDS ON PECAN: AN IMPROVED CAGE FOR COLLECTING HONEYDEW AND GLUCOSE-EQUIVALENTS CONTAINED IN HONEYDEW¹

Cages were designed for isolating single aphids and for collecting honeydew excreted by aphids. The cages were easy to construct and use and protected the aphids and honeydew from rainfall and predators. The cages did not cause condensation of leaf transpiration within. Glucose-equivalents in honeydew excreted by each instar of Monellia caryella (Fitch), Monelliopsis pecanis Bissell, and Melanocallis caryaefoliae (Davis) were measured. Honeydew of M. caryella contained 9 and 13 times more glucose-equivalents than M. pecanis and M. caryaefoliae, respectively. All instars of each aphid species produced similar levels of sugar; however, successive instars tended to produce slightly more honeydew. Monellia caryella was found to be the most detrimental to the energy reserve of pecan trees, assuming equal numbers of each species.