Xylem and Seed Feeding by Two Passion Vine Leaffooted Bugs, Holymenia clavigera and Anisoscelis foliacea marginella (Hemiptera: Coreidae: Anisoscelini), with Notes on Mouthpart Morphology

Holymenia clavigera Herbst and Anisoscelis foliacea marginella Dallas (Hemiptera: Coreidae: Anisoscelini) use the same host plants (Passifloraceae), especially Passilfora suberosa L., and they have a very similar egg and nymphal morphology. This study compares the mouthparts of these coreids both intra- and interspecifically through scanning electron microscopy. Also, it determines the feeding sites for the fifth instars and for adults when offered some of their preferred structures (green fruit and mature leaves) of P. suberosa. Histological sections were performed on feeding sites, on plant pieces having the penetrated stylet in situ. Mouthpart morphologies were extremely similar between H. clavigera and A. foliacea marginella throughout ontogeny. The stylets reached the xylem, in almost all situations, followed by a low use of phloem. Nymphs and adults of both species consumed several fruit parts, including the seeds. When feeding upon the latter, endosperm and embryo were used for feeding. Feeding frequencies indicated that seeds are the main resource used by these coreids and that xylem feeding is probably related to water acquisition. Thus, H. clavigera and A. foliacea marginella are also extremely similar concerning use of host plant feeding sites and mouthpart morphology.