Population Dynamics of Lepidoptera Pests in Eucalyptus urophylla Plantations in the Brazilian Amazonia

José Zanuncio,Pedro Lemes,Carlos Wilcken,Marcus Soares,José Serrão,Germi Santos

doi:10.3390/f5010072

Abstract

Forestry companies study the population dynamics of insect pests in Integrated Pest Management for cost effectiveness. The objective of this study was to obtain qualitative and quantitative information on population fluctuation of the Lepidopteran defoliators of Eucalyptus urophylla plants in the Brazilian Amazon rainforest. In all, 402 species were collected, of which 10 were primary pests, nine were secondary pests, and the remaining bore no definite relevance to eucalyptus. Primary pests formed a low percentage of the total species, although they recorded a high percentage of the total number of individuals. The abundance of secondary pests, except in Caracuru, was less than 150 specimens annually. Primary pests showed higher population peaks during periods of low precipitation. The small number of species and the high abundance of primary and secondary pests could be due to the availability of food, or a deficiency in natural biological control. This suggests the possibilities of population outbreaks in the eucalyptus plantations. The period of highest occurrence for insect species in these crops must be identified so that suitable strategies can be developed for Integrated Pest Management.

Highlights

Eucalyptus accounts for about 62% of the 5.4 million hectares of Brazilian forest plantations, mainly Eucalyptus grandis, E. urophylla, and E. saligna [1]
Lepidoptera in eucalyptus plantations are distinguishable into three types: (I) primary pests, (II) secondary pests, and (III) the species with undefined importance, that may or may not feed on eucalyptus [7,9,10,11]
The number of primary pest species was similar in all the locations; Ponte Maria had eight secondary pest species, one less than the other locations

Summary

Introduction

Eucalyptus accounts for about 62% of the 5.4 million hectares of Brazilian forest plantations, mainly Eucalyptus grandis, E. urophylla, and E. saligna [1]. These species are grown for essential oils, charcoal, cellulose, and wood production [2,3], which reduce the pressure on native Brazilian forests [4]. Eucalyptus hybrids are important to forestry in the tropical regions, but seem to be more susceptible to pests than the pure species [5]. The increase in food supply for phytophagous insects, the low diversity of natural enemies, and the expansion of eucalyptus plantations are factors that contribute to the adaptation of new pests in these systems [6,7,8]. Lepidoptera in eucalyptus plantations are distinguishable into three types: (I) primary pests (which can reach population outbreak levels), (II) secondary pests (which feed on eucalyptus but without outbreaks), and (III) the species with undefined importance, that may or may not feed on eucalyptus [7,9,10,11]

Objectives

Results

Conclusion