Baculovirus-based Products: Ideal Tool for Sustainable Fall Armyworm Control

Usted puede encontrar la versión en español de este artículo aquí. 'Productos en base a Baculovirus: Herramienta ideal para el control sustentable del Gusano Cogollero'

AgroPages recently interviewed Dr. Fernando Hercos Valicente, researcher from Embrapa Maize and Sorghum to talk about Baculovirus-based product for the control of Fall Armyworm. Dr. Valicente graduated from Purdue University USA, he has been working at Embrapa Maize and Sorghum since 1984 with Bacillus thuringiensis and Baculovirus based biopesticides, production, formulation of bioproducts and GMOs (Bt derived). He is also the professor at the Federal University of Lavras, MG, in the area of Plant Biotechnology with emphasis on Plant Resistance Management.

 

 

The fall armyworm, Spodoptera frugiperda, (Smith) is responsible for significant losses in corn production, and may account for 34% to 52% in losses in the final production of grains. This insect pest can attack more than 100 types of crops.  Its life cycle is completed in 30 days under laboratory conditions and the number of eggs it lays may vary from 100 to 200 per posture/female, and a total of 1,500 to 2,000 eggs can be placed by a single female. So, there is great potential for damage that this insect can cause to maize and other crops.

 

 

The biggest challenge in controlling this pest is its habits during its life cycle. In the specific case of corn, the larvae start to attack very early, depending upon the region, weather conditions and crop management, and in the more advanced stages, the larvae only remains in the whorl of the corn plant. So, it is very difficult to reach the caterpillar inside the whorl of the corn plant with either chemical or biological pesticides. The most important part of armyworm management is the timing of the first control action using biological pesticides. This timing varies from region to region and country to country. Usually, the first action should be taken between (V1 and V3) or, at most, 10 days after seed germination. 

 

 

There are many solutions and products that are currently used, or may be used, to control fall armyworm. In those countries where armyworm recently arrived, it is important to monitor the presence of pests in the field, for each region and country. Larvae should be observed in the laboratory for the presence of parasitoids (important biological control agents) reaching up to 50% of parasitism. During a survey, it is important to separate larvae with baculovirus symptoms. Cultural control includes the exposure of pupae to high temperatures, because damage can be caused to pupae during plowing. Transgenics are an option and part of the IPM (Integrated Pest Management) and different genes (proteins expressed) can be used, and also Insect Resistance Management (IRM) that includes refuge areas plus high doses of protein. Chemical insecticides are useful for pest outbreaks and should not be discarded. Finally, Biological control is one of the most important tools to maintain equilibrium in the ecosystem. It may be achieved using parasitoids (Trichogramma sp.) and pathogens, such as fungi, Bacillus thuringiensis (Bt) and Baculovirus. 

 

 

Embrapa Maize and Sorghum has launched, in agreement with private companies, baculovirus based products and will introduce a Bacillus thuringiensis based product this semester (it is already registered). 
 

Baculovirus based biopesticides are developed using healthy larvae, from artificial rearings of fall armyworms to multiply the virus. The most important factors in the large-scale production system are: incubation temperature, age of the larvae and baculovirus concentration. Quality control is extremely important. 
 

Bacillus thuringiensis (Bt) is a bacterium that produces a crystal protein during the fermentation process. This protein is toxic to insects and it is also specific. The fermentation process is made using fermenters and a medium composed of carbon and nitrogen sources, as well as mineral salts. The whole process must be autoclaved and sterilized.
 

Baculoviruses and Bt are biological control agents that do not harm the health of applicators, do not kill natural enemies of pests, do not contaminate the environment, or leave residues in products to be sold on supermarket shelves.
 

The effect of biological products on pests is the same as that of chemicals when applied efficiently. Chemicals generally kill faster than baculovirus-based products. However, when a caterpillar ingests pulverized baculovirus in the leaves, it decreases feeding by 93%. Bt-based products kill insects quickly, when well positioned. The cost is expected to be similar to traditional chemical products.

 

CartuchoVit - Baculovirus based (VR Biotech^®)

VirControl Sf - Baculovirus based (Simbiose^®)

Crystal - Bt based (Farroupilha/Lallemand^®) -  to be launched later this semester. 

 

Baculomip-Sf - Baculovirus based (Promip^®)