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Most of the insects that attack the ini-
tial development phase of the plants are
pests that also infest other economical-
ly important crops. In the words of re-
searcher Paulo Afonso Viana, from Embra-
pa Corn and Sorghum, they damage the
seeds in the ground and attack the root
system, the lower portion of the stalk and
young corn plants. “The lesions result into
failures at field level, and the majority of
the plants that survive become unproduc-
tive, adversely affecting the performance
of the crop”, he explains. “These insects
constitute a dynamic and diversified group
of strains, associated to the ecosystem and
agricultural practices in use”.
In the past, according to the specialist,
the control of these pests, which include
several species with underground habitats,
used to be carried out with long-term resid-
ual insecticides and a wide spectrum of ac-
tion. Nowadays, only short-term residual
insecticides are used, and they are also in-
fluenced by their formulation, method of
application, incorporation and soil condi-
tions, like moisture level, temperature and
the presence of microorganisms.
Recently, integrated pest management
Shared pests
Succession cropping and full-time presence of plants enable the
pests tomigrate fromone region to another almost naturally
concepts take into consideration several
factors before any control decision is tak-
en. The IPM recommends the rational use
of several methods, like insecticides, biolog-
ical control, crop management and the use
of more resistant cultivars, with the aim to
keep all major pests at a level that causes no
economic damage to the corn fields.
Among the various strains of insect pests,
some are of note for their economic im-
portance. This group includes the Less-
er Cornstalk Borer (Elasmospalpus ligno-
sellus), with a big destruction capacity in
a short period of time. The maggots (Di-
loboderus abderus, Eutheola humilis, Dys-
cinetus dubius, Stenocrates sp., Liogenys
sp.) are relevant especially for the winter
crops, and they infest the seeds sown af-
ter soybean harvest. The stink bugs, south-
ern green stink bug (Dichelops furcatus ,
D. melacanthus) and green stink bug (Ne-
zara viridula) are pests that attack soybean
crops, but with corn planted after soy-
bean harvest, or even in rotation, they also
cause total or partial losses to corn fields.
Although outbreaks of the armyworm
(Spodoptera frugiperda) typically damage
the cornstalks, more developed worms
could reach the internal stem structure
and kill the plant. There are other strains,
like the wireworm (Conoderus spp., Mel-
anotus spp.), the brown burrowing bug
(Scaptocoris castanea and Atarsocoris bra-
chiariae), the termites (Procorniterms sp.,
Cornitermes sp., Syntermes sp. and Het-
erotermes sp.), the corn leafhopper (Dal-
bulus maidis), the tyhrips (Frankliniela
williamsi) and the brown burrowing bugs
(Scaptocoris castanea Atarsocoris brachi-
ariae), whihc, depending on the region
and biotic conditions, could assume the
status as relevant pests for any corn field.
