Status of Biological Control as a Management Tool for Leucaena psyllid, Heteropsylla cubana, Crawford (Homoptera: Psyllidae) in Eastern Tanzania

Abstract

Biological control offers economic and environmental solutions against insect pests. Two Biological control agents Tamarixia leucaena and Psyllaephagus yaseeni were introduced from Trinidad to Tanzania for the biological control of the Leucaena psyllid (Heteropsylla cubana Crawford) which attack agroforestry fodder called Leucaena. We investigated status of biocontrol agents of H. cubana and indigenous predators of H. cubana in Morogoro and Tanga regions.  Terminals of infested growing shoots were collected and treated to remove indigenous predators associated with H. cubana.  Mean abundance of mummies, indigenous predators and parasitism percentage of H. cubana were quantified. The mean number of T. leucaenae and P. yaseeni mummies were 2.33 and 1.68 in Tanga and 2.64 and 2.10 in Morogoro per terminal shoot. Parasitism rate of P. yaseeni and T. leucaenae were 0.16% and 0.11% in Tanga and 0.15% and 0.14% in Morogoro respectively. The dominant indigenous predators were spiders followed by ladybird beetles. Therefore, introduced biological control agents and indigenous predators play a vital role in controlling H. cubana. However, there is a need to understand the interactions between indigenous predators and H. cubana in order to advice farmer on appropriate biological control measures.