Preliminary exploration for potential biological control agents for Psidium cattleianum

Abstract

Psidium cattleianum is a weedy tree introduced to Hawaii from Brazil. Two forms of the species are known in Hawaii, a red-fruited form commonly known as strawberry guava, and a yellow-fruited form commonly known as waiwai. The red-fruited form is usually considered the more common, troublesome of the two in Hawaii. Strawberry guava aggressively invades and forms dense thickets in native forests from about 2500 to 4000 feet elevation, replacing native vegetation. As part of the National Park Service's biocontrol program, an exploratory trip was made to Brazil during April, 1988, in search of potential biocontrol agents, both insects and diseases. Except for limited plantings of the red-fruited form, the yellow-fruited form was the form found throughout the trip and was the form associated with the name P. cattleianum in the areas of Brazil visited (Parana and Santa Catarina states). The red-fruited form was largely unknown even to botanical scientists in this region. Although no diseases which appeared to be of significance in control were found, several insects, causing a variety of types of damage were found. In addition to P. cattleianum, some observations were made on lantana (Lantana camara) and Christmasberry (Schinus terebinthifolius), also troublesome weedy species introduced to Hawaii from Brazil.