Effect of entomopathogenic fungi on the control of the coffee berry borer in the laboratory

Among the management and control tactics of the coffee berry borer Hypothenemus hampei (Ferrari), there is the use of entomopathogenic fungi. Due to the importance of prospecting isolates of entomopathogenic fungi for the control of the coffee berry borer, the objective of this study was to evaluate the efficiency of 26 isolates of entomopathogenic fungi in the control of this insect pest in the laboratory. The coffee berry borers were immersed in a solution adjusted to the concentration of 1 to 3 × 108 conidia/mL of each isolate and the control treatment (sterilized water). After seven days total mortality and confirmed mortality were evaluated. The isolates that caused the highest mortality and two commercial isolates were selected for evaluation of lethal concentration (LC50 and LC90) and lethal time (LT50 and LT90). Coffee berry borers were treated at different conidia concentrations for lethal concentration to assess total and confirmed mortality. For a lethal time, the coffee berry borers were treated at the concentration of 108 conidia/mL of the selected isolates, and, after two days and every 24 hours until the eighth day, the number of dead individuals was verified. Among the 26 isolates evaluated, 24 presented mortality higher than the control treatment, and three presented mortality higher than 85%. In the LC50 and LC90 assays, the IBCB 353 and IBCB 364 isolates were more lethal to H. hampei. In the LT50 and LT90 assays, the IBCB 66 and IBCB 353 isolates caused lethality in a shorter time.

Pochonia chlamydosporia e Bacillus subtilis no controle de Meloidogyne incognita e M. javanica em mudas de tomateiro / Pochonia chlamydosporia and Bacillus subtilis on the control of Meloidogyne incognita and M. javanica in tomato seedlings

O objetivo deste estudo foi avaliar o efeito da aplicação de Pochonia chlamydosporia no solo e a microbiolização de sementes de tomateiro com Bacillus subtilis no controle de Meloidogyne incognita e M. javanica em condições de casa de vegetação. Os tratamentos foram constituídos pela incorporação no solo de 20g de milho triturado colonizado ou não pelo fungo, com ou sem microbiolização das sementes com a suspensão bacteriana (DO540 = 0,5) por 24 h. O solo dos vasos foi infestado com 5.000 ovos de M. javanica ou M. incognita. Nenhum tratamento alterou a massa da parte aérea e das raízes dos tomateiros em ambos os experimentos, tampouco reduziu o número de galhas dos nematoides aos 45 dias após o transplantio das mudas e infestação do solo. A microbiolização das sementes de tomateiro com B. subtilis reduziu em 62,6% o número de ovos de M. incognita, quando comparado com as sementes não tratadas, independentemente da aplicação do fungo. A combinação entre microbiolização de sementes com B. subtilis e a aplicação de P. chlamydosporia reduziu em mais de 80% o número de ovos de M. javanica em comparação com a adoção de apenas um dos tratamentos isoladamente.

The aim of this study was to evaluate the effect of the application of Pochonia chlamydosporia into the soil and tomato seeds soaked in Bacillus subtilis cell suspension on the control of Meloidogyne incognita and M. javanica under greenhouse conditions. The treatments were incorporation into the soil of milled corn (20 g) colonized or not by the fungus, with or without seeds treatment with bacterial suspension (OD540 = 0,5) for 24 h. The soil of each pot was infested with 5,000 eggs of M. javanica or M. incognita. Neither the biomass of tomato plants nor the number of galls were influenced by the treatments 45 days after seedlings transplanting and soil infestation in both the experiments. Seed microbiolization with B. subtilis reduced the number of eggs of M. incognita by 62.6%, in comparison to non-treated seeds, regardless of the application of the fungus. The combination of seed microbiolization with B. subtilis and application of P. chlamydosporia reduced more than 80% the number of eggs of M. javanica, when compared to each separate treatment.