THE WEEVIL
Weevils measure around 30 -60 mm, and are brown or black beetles. Adults can live for 6-8 months and will not necessarily be very close to infested items, it is possible to discover them with a distance between insects and their food. In the larval stage, the immature weevil is a legless larva that develops within the grains and seeds of corn and wheat, or in other cereals. The development from egg to adult lasts as little as one month.
ROUGH FOOTS DAMAGE
the "soil weevils". They were usually one of the main plagues of the cultivation of alfalfa, but in these last campaigns they have also been found causing damage to the soybean crop. The importance of the plague is that it has been
observed with a high frequency in almost all the fields of the region, where in the In most cases, the number of individuals found is low and the damage caused has been significant .. However, in those sectors with higher densities,
observed a reduction of the stand of plants causing considerable damage. The ground weevils are located within the family of the Curculionidae (Order: Coleoptera), forming a complex of around 22 species, which mostly belong to the genera Naupactus and Pantomorus. The main species that known as harmful in the cultivation of soybean are P.
viridisquamosus, P. leucoloma, P. ruizi and N. cinireidorsum.
Damage:
The adult of the weevil, attacks the aerial part of the plant feeding on leaves, buds and pods, while the larva, being of underground habit, feeds on roots. This last, it is the one that produces the most damage, since it attacks the radical system of cultivation and it produces the death of the plants. In the cultivation of soybean, the damage is observed throughout the cycle of it. During implantation, it affects the seedling by cutting the hypocotyl or damaging the cotyledons. In more advanced states, it damages the main root by consuming the bark and rootlets, manifesting the damage as an early withering. In others In some cases, the lesions caused by the root cause the entry of pathogens, which are the they end up causing the death of the plants.
Because the larva lacks appendages to move, take advantage of the furrow of sow to move more easily. This generates that the damages manifest themselves to along the sowing furrow, causing loss of plants in line. The reduction of
plant stand causes a decline in yields and increased competition from weeds, because the furrows are exposed. In general, the most affected lots are the of sandy texture. The most serious damages are observed in the soybean crops of second, question that could be related to the higher temperature that exists at the beginning of the culture and with it, an increase in the activity of insects.