In palms having crownshafts, small holes with gummy exudates are present near the bottom of the leaf bases (Figs. 1 and 2). When the outer leaf is peeled off, the younger leaf bases may be scarred with galleries dug by feeding larvae (Fig. 3). In palms without crownshafts, older living leaves may hang down against the trunk and are easily detached (Fig. 4). Closer examination will reveal small holes near the base of the petiole (Fig. 5). If these leaves are pulled off, small cocoons of wound fibers will often be visible within the chewed up leaf bases.
Damage from Metamasius hemipterus could be confused with that of Rhynchophorus sp. although cocoons of the latter species are much larger than those of Metamasius hemipterus. The two species are often found together within the same palm tissue.
Damage is caused by feeding of Metamasius hemipterus larvae within the leaf bases.
Metamasius hemipterus is widespread throughout Florida, the West Indies, and Central and South America. In Florida, it is most commonly encountered on Phoenix canariensis and Ravenea rivularis. A related species, M. inaequalis, is a problem on Elaeis guinennsis in Central and South America.