Population dynamics of Hypothenemus hampei (Coleoptera: Scolytidae) in agroforestry and monoculture systems of conilon coffee in the southern portion of the state of Amazonas, Brazil

Abstract

Hypothenemus hampei is the main coffee pest in the Amazon and worldwide. Although coffee cultivation exists in the State of Amazonas, there is no information regarding the behavior of this species population in this region of Brazil. Since the Amazon region is a favorable environment for H. hampei, the present study aimed to investigate this insect population in the following cultivation systems implanted in the municipality of Humaitá, Southern Amazonas: i) coffee in native forest (CNF), ii) coff ee intercropped with cupuaçu and açaí (native Brazilian fruits) (CCA) and iii) coffee in monoculture (MC). Also, the climatic and phenological parameters of the plant were used in relation with the population dynamics of the insect. For that, ten baited traps were installed in each field for the monthly sampling of the H. hampei population from July/2018 to June/2019. The highest population abundance of the insect was observed during the coffee flowering season, mainly in monoculture crops, when compared to the other intercropped fields. The total mean value of the insect population observed in the three environments evaluated was highest in August/2018, with a recorded value of 1749. The increase in rainfall indexes occurred simultaneously with a decrease in the insect population; this coincides with the end of the flowering season (October/2018, 161.8 mm) and the beginning of grain formation (November/2018, 234.8 mm). The lowest abundance of the insect observed in the coffee fields in native forest, with an abundance of 83 (CNF), indicates that the local biodiversity disfavors the population size of the pest in the environment. These results suggest that phenological phases of conilon coffee and the influence of climatic conditions can result in changes in the population dynamics of the H. hampei. Coffee agroforestry systems are more promising to maintain this population at low levels.