Abstract: Virus-based biopesticides are effective biocontrol agents of crop insect pests. Development of suitable formulations and production processes are necessary to obtain high-quality products easily adopted by farmers. A detailed unit operation study was carried out for the production process of a Phthorimaea operculella granulovirus-based biopesticide to control the tomato leafminer, Tuta absoluta, one of the most important pests affecting this crop. Physicochemical, microbiological, and insecticidal parameters were implemented in the process and applied to the finished product, and a scaling strategy was developed. A Quantitative Polymerase Chain Reaction (Q-PCR) technique was implemented to quantify viral concentrations in the active ingredient (5.34 ± 1.44 x109 Occlusion Bodies mL-1) and in the finished product (>1.6x109 OB mL-1), without contaminant interferences. The Q-PCR methodology was also useful to select the appropriate solid mixing time following Lacey´s mixing index (8 min). Factors and similarity principles influencing the liquid mixing process were identified in the scaling evaluation. Furthermore, the drying kinetics analysis enabled identifying a drying temperature of 35 °C, with an efficacy under controlled conditions higher than 97%. Contaminant concentration was lower than 1%, indicating controlled and aseptic formulation process conditions. A simple statistical method was used to estimate the reproducibility and repeatability of the parameters assessed in the finished product. These results enable to establish and extrapolate important parameters in the standardization, scale-up, and quality control for the granulovirus-based biopesticide.

Resumen Estructuras de resistencia como las clamidosporas producidas por el hongo Duddingtonia flagrans permiten la reducción de larvas infecciosas de nematodos gastrointestinales. El objetivo de esta investigación fue estudiar el efecto de fuentes de carbono y nitrógeno sobre la producción de clamidosporas del hongo en un sistema de fermentación en estado sólido (SSF), doce sustancias fueron estudiadas mediante una estrategia estadística, evaluando su efecto sobre la producción de clamidosporas. Finalmente, usando una estrategia de optimización se definió las concentraciones de las sustancias que favorecían la producción de clamidosporas, y se evaluó el efecto de estas sobre la capacidad predatoria del hongo. Las condiciones óptimas fueron la adición de 0.25% p/p de sulfato de amonio y 0.56% p/p de acetato de sodio al arroz partido. La concentración máxima alcanzada bajo esta condición fue de 2.27x107 clamidosporas g de sustrato seco-1, con una productividad de 1.62x106 clamidosporas g de sustrato seco-1 día-1.

Abstract Resistance structures such as chlamydospores produced by the fungus Duddingtonia flagrans allow the reduction of infectious larvae from gastrointestinal nematodes. The objective of this research was to study the effect of carbon and nitrogen sources on the production of chlamydospores of the fungus in a solid state fermentation system (SSF). Twelve substances were studied using a statistical strategy, evaluating their effect on the production of Chlamydospores Finally, using an optimization strategy, the modifications of the substances that favor the production of chlamydospores were defined, and the effect of these on the predatory capacity of the fungus was evaluated. Optimal conditions were the variability of 0.25% w / w ammonium sulfate and 0.56% w / w sodium acetate in broken rice. The maximum concentration reached under this condition was 2.27x107 chlamydospores g of dry substrate-1, with a productivity of 1.62x106 chlamydospores g of dry substrate-1 day-1.

Los agricultores colombianos utilizan productos químicos con categorías toxicológicas I, II y III para el control de insectos como la mosca blanca Bemisia tabaci (Gennadius, 1889) (Hemiptera: Aleyrodidae); pero su uso indiscriminado genera un riesgo para la salud y el medio ambiente. El control microbiológico con hongos entomopatógenos surge como alternativa de control ambientalmente sostenible. No obstante, su empleo exitoso dentro de una estrategia de manejo integrado de plagas (MIP) depende, en gran parte, del efecto de los productos químicos sobre el bioplaguicida. El objetivo del presente trabajo fue determinar la compatibilidad in vitro de un bioplaguicida con base en el hongo Isaria fumosorosea formulado como polvo mojable con cuatro fungicidas y cinco insecticidas comerciales. Para esto, se evaluó el efecto de tres concentraciones de los productos químicos: FR = dosis recomendada en campo, 0.5 x FR y 0.25 x FR sobre la germinación de los conidios y el número de unidades formadoras de colonia UFC/g de I. fumosorosea. Los cuatro fungicidas (Benlate, Carboxin Captan, Metalaxil-Mancozeb y Mancozeb) en las tres dosis evaluadas fueron incompatibles con el bioplaguicida, mientras que el insecticida Thiametoxam fue compatible cuando se utilizó la dosis de 0.25 x FR.

Colombian farmers use pesticides with toxicological category I, II and III to control the whitefly Bemisia tabaci (Gennadius, 1889) (Hemiptera: Aleyrodidae) in cotton and eggplant crops;although, its indiscriminate use offers a risk for the environment and the people. The use of biological control with entomopathogenic fungi can be an alternative to replace this is the use of biological control as the entomopathogenic fungi. However, the successful use of a biopesticide in an integrated pest management (IPM) would depend largely on the effect of pesticides on the entomopathogenic microorganism. The aim of this study was to determine the in vitro compatibility of a biopesticide based on the fungi Isaria fumosorosea formulated as a wettable powder (WP) to control the whitefly Bemisia tabaci with four fungicides and five insecticides currently used in cotton and eggplant crops. For this, the effect of the pesticides was evaluated at three concentrations (FR = Field recommendation; 0.5 x FR and 0.25 x FR). Effects of these products on conidia germination and the number of colony forming units (UFC)/g were compared. The four fungicides (Benlate, Carboxin Captan, Metalaxyl Mancozeb and Mancozeb) at the three doses evaluated were incompatible with the biopesticide, while one insecticide (Thiamethoxam) was compatible with the biopesticide when 0.25 x FR of its dose was tested.