Bioinsecticide for whitefly control reaches the Brazilian market

Date:02-06-2023

A public-private partnership between Embrapa and the company Lallemand Plant Care has launched the biological insecticide Lalguard Java, a sustainable alternative to control silverleaf whiteflies (Bemisia tabaci), a pest that causes losses in over 40 crops in Brazil. The insect is responsible for direct losses (by sucking sap, injecting toxins and physiological disorders) and indirect ones due to its excretion of a sugary substance that favors the growth of fungi on plant leaves. In addition, it is a vector of several virus-borne diseases in plants. The silverleaf whitefly has resistance to several synthetic chemical insecticides, which makes it difficult and expensive to manage.

Close-up photo of silverleaf whiteflies  Photo: Sebastião Araújo

Lalguard Java was formulated based on a strain of the fungus Cordyceps javanica, which has demonstrated efficiency in the control of whitefly nymphs (young stages) and adults, especially given its behavior as a ″hunter″ (it grows extensively from dead insects and infects other insects on leaves), which results in high pest mortality. In addition to that, it is harmless to humans and other vertebrates and has a low impact on beneficial insects, which are natural enemies of pests in the fields. Unlike chemical pesticides, Lalguard Java is harmless to the environment and leaves no traces in foods.

The bioproduct is the result of a study that began in 2012 and involved Embrapa specialists. The work included collecting the fungus from areas with high natural whitefly mortality in soybean, bean, corn, guava, tomato and cotton crops in the Brazilian states of Goiás, Maranhão; and in Distrito Federal.  

The fungus strains collected from whitefly nymphs and adults in the fields were isolated in culture media to initiate the research. After this step, they was conducted molecular analysis through genetic sequencing to determine which species were present in the samples, and then 11 strains of the fungus Cordyceps javanica were identified. The next step was to test those samples with regard to their effectiveness for whitefly control in laboratory, greenhouse and field experiments. The result of such work was the selection of the strain of Cordyceps javanica BRM 27666.

In addition to establishing a favorable climate zoning for the selected strain, they assessed its compatibility with over 30 commercial products commonly used in crops, including adjuvants, insecticides, fungicides and herbicides. The aim was to test whether synthetic chemicals had any toxic effect on the efficiency of the fungal component (spores or conidia) in whitefly control.

BRM 27666 has shown efficacy in environments with high or low humidity, which is a positive point for its application in croplands. In addition, this strain multiplies within the host and produces many spores, which are the fungus dissemination structures that can be spread through the wind, rain or by the insect itself, causing new infections.

Integrated management strategy

In 2015, a partnership was signed with the Canadian company Lallemand Plant Care, headquartered in Brazil in Patos de Minas, MG, which was responsible for transforming all the knowledge generated into a bioproduct. It is a wettable powder formula to be applied via leaf spray containing fungal conidia, that is, germination structures that penetrate the whitefly on contact, which is an important aspect as infection does not depend on the insect feeding from it.

According to the manufacturer Lallemand Plant Care, Lalguard Java has a good shelf life (about a year) if stored in suitable conditions and with temperature control.

Embrapa entomologist Eliane Quintela, who is one of the scientists responsible for the research that originated the Lalguard Java product, explains that the new bioinsecticide was tested in all crop seasons (summer, drought and winter) to control whiteflies in crops that are attacked by the pest. According to her, this is another option for the limited strategies to control the insect. "This bioinsecticide provides plants with protection, leaves no trace in the food, and is compatible with other insecticides, herbicides and adjuvants. The product also reduces the possibility of whitefly resistance and causes low impact on beneficial insects to crops, as it is an alternative to conventional chemical pesticides", Quintela adds.

She underscores the new input's potential as a tool to be incorporated into Integrated Pest Management (IPM) programs in crops that are socioeconomically important to Brazil, such as cotton, soybeans, beans, tomatoes, potatoes, melons, watermelons and ornamental plants, among others. "The prospective use of Lalguard Java should be in line with the set of IPM practices aimed at maintaining a balanced level of the whitefly population in the fields; aggregating crop and cultivar rotation; monitoring insects in crops; and observing the periods of sanitary breaks established for each location in the country, when whitefly host plants cannot be cultivated," Quintela concludes.

---

The 4th Biopesticides, Biostimulants and Novel Fertilizers International Summit (BioEx 2023) will take place on 9th & 10th March in Hangzhou, China.