Leucaena psyllid trial at Waimanalo, Hawaii.
Six- and twelve-month results are reported from this trial in Hawaii, which is part of the International Leucaena Psyllid [Heteropsylla cubana] Trial Network established in 1987 by the NFTA. Each trial had a standardized design in which trees were managed as hedgerows for fodder production (in order to maintain high psyllid populations). Details are given of the psyllid count and damage rating scales used, and of factors influencing the accuracy of ratings. Species tested were L. leucocephala (6 varieties), L. diversifolia (3), L. pallida (1), L. leucocephala × L. diversifolia (2; KX2 and KX3) and L. diversifolia × L. pallida (1; KX1). The hybrids KX1 and KX2, the varieties K376 (L. pallida), and K784 and K785 (L. diversifolia) all showed high psyllid resistance under hedgerow management for fodder and green manure production, and warrant further investigation. It is noted that site (as well as management) can affect results. For example, the hybrid KX3 performed poorly at Waimanalo but has been shown to perform better at Mealani (a cooler site). Also, although the L. leucocephala varieties K584 and K636 were classified as psyllid tolerant (as uncoppiced trees), this was inadequate for management as fodder. A brief report is given of psyllid predators observed (Curinus coeruleus, Olla abdominalis [O. v-nigrum] and species of Anthocoridae).