Insects pests in tropical pastures Blissus spp.

In the previous publication it became clear that this insect adapts to dry climates and in its adult stage they usually climb to the top of the foliage and feed on the plant near the knots, insects have been found in the ligule of the leaf. As for the damage caused, the Blissus in its nymph and adult stage feeds on the sap of the roots and foliar area and inject toxins generating drastic damage to the entire vegetative zone, a yellowing of the leaves and stems is generated as a burnt effect, at first glance it could be confused with the attack of the candelilla since the symptoms are similar, the difference lies in the rainy or few rainy periods.

To corroborate if the pastures are being affected by the Blissus, it is necessary to carry out inspections in the paddocks, since small spaces are usually observed in the paddocks with the leaves of the grasses burned or dried, on the other hand it is recommended to carry out inspections in well-sunny hours from 10:00 am to 04:00 pm at the bases of the stems or in the nearby area of the ligula to verify if there are nymphs.

As for the control, first of all it is recommended to implement preventive management with the application of fertilizers and thus keep the plants vigorous, in addition to performing an adequate zootechnical management avoiding overgrazing of the crop, among other alternatives that allow to have a plant capable of tolerating the first attacks of the insect, likewise another preventive method would be biological control with the application of entomopathogenic fungi at the end of the rainy period, since it has been evidenced from some research that the eggs of some species are susceptible to Metarhizium anisiopliae.

On the other hand, if compacted soils and stoloniferous grasses are found, the harrow can be passed through the land to aerate it and decompact it a little, if there is an irrigation system on the farm they can be watered periodically to maintain low levels of the pest and finally in case there is a high threshold of infestation it is advisable to apply insecticides such as Lorsban, on certain occasions the rains facilitate the control of the same, because the intense rains cause the insects to go up to the parts areas, being exposed for the application of insecticides. On the other hand, it is necessary to remember that the indiscriminate use of agrotoxins can cause imbalances in the ecosystem.

Agrolectrores, it has been evidenced with the latest publications that establishing a forage crop is something complex, since the pasture is a crop and needs agronomic management such as pest control, controlling a pest on forage surfaces deserves to be taken into account when the animal can enter the paddock again, especially if agrotoxins are used, this way we avoid that the animal has contact with certain substances that can create imbalances in its organism and that products such as meat and milk present residues of the substance used.

Bracho, M. and Prieto, J. (2005).Integrated pest control in pastures. Report of the IX Seminar on pastures and forages. (p.192-194). San Cristóbal: Universidad Nacional Experimental del Táchira.

Espinoza, F. (1994). Pests of the grassland ecosystem in Venezuela. Maracay: FONAIP- Instituto de investigaciones zootechnicas.

González, B. (2010). Pests in tropical pastures. Rev. Of extension of the Faculty of agronomy of the University of Zulia Agrotecnico, (26), 50-53.

León, L. (2014). Biological pest control in tropical pastures and forages. In GIRARZ, Achievements and challenges of dual-purpose livestock farming (p.294-301). Maracaibo: University of Zulia.