Performance of the beneficial entomofauna in Leucaena leucocephala (Lam) de Wit areas

The performance of biol egulator populations in two areas of leucaena (3 an d 15 years of establishment) was studied for two years. Insect population w as characterized and possible natural biological control agents of Heterops ylla cubana were studied to maintain the biological equilibrium within the agroecosystem. A monthly representative sample of 60 catches was used. The tables of risks and comparison of proportions were used for the analysis. T here was a higher incidence of the H. cubana psyllid in the leucaena area o f 3 years of establishment, without economical damages for the plants. It i ncreased at the end of the rainy season and at the beginning of the dry sea son with averages of 1242.5 and 995.5 individuals in the areas of 3 and 15 years, respectively. October showed the maximum psyllid population in both areas. The study demonstrated that among the beneficial entomofauna the Chi locorus cacti coccinelidae had the highest incidence and stability reaching 84.6% while the other biological agents remained at low proportions. It is concluded that under our conditions the active presence of bioregulators p revents the psyllid from causing economical damages to leucaena, among them : Chrysopa sp. Cycloneda sanguina and Zelus longipes. Further bioecological studies of these predators are needed for their mass production and releas e in leucaena areas. Also, it is necessary to define the Ch. cacti as a pos sible psyllid bioregulator, giving an alternative to a more efficient pest control under safe ecological conditions.