Pf. Dowd et al., ADHERENT MALATHION FLOUR GRANULES AS AN ENVIRONMENTALLY SELECTIVE CONTROL FOR CHEWING INSECT PESTS OF DENT CORN EARS - INSECT CONTROL, Journal of economic entomology, 91(5), 1998, pp. 1058-1066
In a small-plot field study, malathion formulated in pregelatinized co
rn flour as granules at 0.1% was hand applied at a rate of 11.1 kg/ha
of granules (0.011 kg [AI]/ha) of granules in 1992 and 1993. Control o
f Carpophilus lugubris Murray and Helicoverpa zea (Boddie) with ii sin
gle treatment of the granules was generally equivalent to that seen wh
en a commercial formulation of malathion was applied in 5 sprays at a
rate of 1.1 kg (AI)/ha (1 lb [AI]/acre) DPT spray. In 1994 and 1995, 1
% malathion granules at 11.1 kg/ha of granules significantly reduced c
orn ear insect pests in 2 different corn varieties. No significant eff
ect on coccinellid or Orius spp, numbers was noted compared with untre
ated plots when the malathion granules were used. Over the top treatme
nts of 0.1-10% granular malathion at 11.1 kg/ha of granules were less
effective in controlling ear feeding insects at another site in 1994 c
ompared with the multiple sprays of malathion applied to the ear zone.
However, when granules were applied at ear level in 1995, equal or gr
eater control of ear-feeding insects compared with the conventional ma
lathion sprays was noted, depending on the level of active ingredients
in the granules. All active ingredients rates of granules had no sign
ificant effect on coccinellids compared with untreated plots in 1995,
but the conventional malathion sprays killed up to 95% of the coccinel
lids. When properly applied, these adherent granules should provide ac
ceptable control of many ear-feeding insects in field corn, be more se
lective toward predators. and use loa er levels of active ingredient c
ompared with conventional malathion sprays.