Call Prefix : PR-T

Call Suffix : 1992

Call Cutter : D - Ento 15

Location : SEARCA Library

Format : TD

Publisher : University of the Philippines Los Baños,

Publication Date : May 1992

Publication Place : Los Baños, Laguna, the Philippines :

Summary : A study of the population ecology of leucaena psyllid, Heteropsylla cubana Crawford was carried out at Maejo, Chomtong and Maesa-mai ecological modules in Chiang-mai, Thailand, between December 1990 and December 1991. The sampling method used for the population study of H. cubana was modified from Elder and Meyer (1991). H. cubana eggs, nymphs and adults congregated on the terminal shoots which spread over the canopy of leucaena. Populations of H. cubana at Maejo (July to April) and Chamthong (September to April) exhibited seasonal fluctuation during the sampling period. At Maesh-mai psyllid populations fluctuations over time and existed year-around but less abundant during April to June. Both density-dependent and density-independent factors were apparently regulating the population density of H. cubana. Despite the presence of leucaena shoot during May and August, the psyllid populations could not be detected in Maejo and Chomthong and the surrounding areas. Most of the indigenous predators associated with H. cubana were general predators but their role as regulating agents was not evident. No parasite was found in this investigation. Changes in the percentage of total nitrogen in the leucaena shoot during the sampling periods was not correlated with the population levels of H. cubana. Fecundity and survival rate of H. cubana populations reared on leucaena seedling with and without shoot were not significantly different. No morphological changes of female and male genitalia of the psyllids were observed throughout the sampling periods. Among the climatic factors, temperature was correlated with population changes.