Abstract

LARA G., JUAN CARLOS; LOPEZ N, JUAN CARLOS  and  BUSTILLO P, ALEX E. Effect of entomopathogenic nematodes on populations of the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae), in berries on the soil. Rev. Colomb. Entomol. [online]. 2004, vol.30, n.2, pp.179-185. ISSN 0120-0488.

The effect of two native entomopathogenic nematodes Heterorhabditis sp. (Rhabditida: HeteroRhabditidae) and Steinernema sp. (Rhabditida: Steinernematidae) was studied in doses of 125.000, 250.000 and 500.000 infective juvenils (U) per tree base on populations of the coffee berry borer, llypothenemus hampei. During the first coffee harvest of 2001, there were no statistical differences between treatments for infestation level in the tree due to the high variability of the number of fruits with which the experiment began. For the second coffee harvest of 2001, percentage of mortality of the coffee berry borer with the two species was 53 and 88%, a month after their application, statistically different (p<0,05) in relation to the control (6%). Five of the six evaluated treatments had average percentages of borer infestation in the tree (PPIA) lower than the control 9,93 ± 1,81 (mean ± S. E), particularly the applications of Steinernema sp. (500.000 U/plate) with a PPIA of 4,17 ± 0,57 and Heterorhabditis sp. (250.000 U/plate) with PPIA of 5,62 ± 1,24. This reduction is equivalent to 58 and 43,4%, respectively, in relation to the control. This reduction can be explained by observing the mean percentages of mortality of coffee berry borer life stages in fruits on the ground (PMB), which fluctuated between 13,64 and 42,27% for each species of nematodes. Thirty days after application, this difference is well established, with significant differences compared to the control (p<0,05). In conclusion, these nematodes penetrate the fallen fruits on the ground, mainly parasitize immature stages and reproduce in these insects within the fruit to reduce the populations of coffee berry borer in coffee plantations.

Keywords : Steinernema; Heterorhabditis; Infective juvenile.

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