To verify the presence of adults of the insect in the field, technical teams from both INIA La Platina and INIA La Cruz, travel every week to carry out sampling of this pest, mainly concentrated in the Metropolitan Region and the Valparaíso Region.

These tasks are fundamental for the follow-up studies of the phenology of the insect, which is part of the project that is financed by the FIA ​​Foundation for Agrarian Innovation "Development of an Integrated Management System with low environmental impact aimed at mitigating populations of the painted bed bug, Bagrada hilaris, for a sustainable and competitive horticulture ”.

The technical team is made up of Nancy Vitta, project manager; Eduardo Tapia, José Lagos, Natalia Olivares, Ernesto Cisternas, Aart Osman with the field support of Miguel Cuello, Julio Bravo and Víctor Canales.

This is a plague of recent irruption in our country (2016); and, although there are registered chemical products for their control, since entering Chile, INIA together with SAG and other entities have been developing different projects with the idea of ​​generating information on a pest that was unknown in our country.

The importance of this species lies in that it attacks the crops of the Brasicaceae family mainly in the emergence of seedlings and in adult plants in leaves, stems and soil, which causes economic losses in the crop.

INIA La Platina entomologist, Nancy Vitta, affirms that knowing the phenology of the plague well is very important. "Phenology is the study of the life stages of plants and animals in relation to weather and climate. From phenology, important consequences associated with the climate and especially the microclimate can be obtained, observing the start date of the different phenomena, such as the appearance of the first insects throughout the year. This indicates the behavior of the insect during one or two seasons depending on where it is monitored, which gives a start on when a control can be carried out ”.

Sampling

Sampling and monitoring of the pest is carried out in the fields that were selected and that the pest is known to be present. How is the sample obtained? The sample is taken directly from the plant (if there is a crop), from weeds and from the soil. Nancy Vitta explains that "it is mainly sampled where brassicas are found since this host is their preference."

The collected individuals are conditioned and transferred to the laboratory in transparent plastic flasks, with a lid sealed with anti-aphids mesh.

Once the material enters the laboratory, the different stages of development of the pest (stages of its life cycle) are processed and separated, in order to know the proportion of them in the different periods. "If it is required for aging (carrying out tests) it is necessary to take them to bioclimatic chambers with a determined temperature to maintain and feed them. If it is only for counting, they are left without food until their death and they are counted for adults and immature states ”.

We asked him if at this time it is possible to find the plague. "In winter the populations drop considerably, and this is due to the temperature, since it is below the lower limit that the pest can withstand. This does not mean that the insect disappears, since it is possible to find it hidden as an adult in crevices on the ground or under clods and in weeds of the Brassicaceae family ”. Damage itself, adds the specialist, "it is difficult to cause as it does in summer, since between January and April is when the highest populations occur, then decrease in winter, until November when the first adults appear visually and nymphs ”.

Of course, stresses the specialist, "the geographical area where the sampling and monitoring is carried out is very important, due to the temperatures. It is important to point out that the pest meets high temperatures, being active during the day when temperatures are highest. "

In organic crops have they also detected the presence of Bagrada? Nancy Vitta says yes. "In organic crops as well as in conventional crops it is present with the difference that the control is different, since conventional crops apply pesticide products repeatedly, while in organic crops many times, depending on the pressure, they are controlled with biopesticides or mechanical form ”.

Chemical management has not been enough to stop the invasion of this pest. For this reason, INIA has been evaluating other complementary alternatives to chemical control such as the use of entomopathogenic fungi (by Eduardo Tapia), biological control (Dr. Ernesto Cisternas) and the use of attractive cultures (Dr. Aart Osman). All of them, for the most part, sustainable and innocuous strategies.