Lesson 1: Sorghum Midge

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Module 4 Earhead Pests
Virtual Academy for the Semi Arid Tropics
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Lesson 1 Sorghum Midge
The adult is a tiny fly with a yellow head, brown
antennae and legs, an orange-red thorax and
abdomen, and grayish hyaline wings (Fig.). The
fly can be seen hovering around the earhead
during early hours of the day. Each female lays
about 75 eggs in flowering spikelets during its
short span of 1-day life.
Adult Midge (enlarged)
Course on Insect Pests of Sorghum
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Lesson 1 Sorghum Midge
An orange colored maggot hatches from the eggs
in 1 to 3 days, and start feeding on the
contents of the fertilized ovary. The insect's
rapid developmental cycle permits 9-12
generations to occur during one season. High
infestations build-up when sorghum flowering
times are extended by a wide range of planting
dates or maturities.
Sorghum Midge
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Lesson 1 Sorghum Midge
The presence of midge flies can be identified by
visiting the sorghum field early in the morning
or late in the evening when the flies are active
hovering the flowering panicles. Midge
infestation can be identified from the red ooze
that comes out when the developing seed in the
spikelets are pressed with fingers.
Midge fly on sorghum earhead
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Lesson 1 Sorghum Midge
Crop damage Despite the fact that adult sorghum
midge live less than 1 day, midge is capable of
causing significant grain loss, as it is the
larvae that feed on newly fertilized ovaries
preventing seed development.
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Lesson 1 Sorghum Midge
Crop damage A sorghum panicle infested with
sorghum midge will have, depending on the degree
of damage, varying proportions of normal seed and
non-seed bearing spikelets (Fig.).
sorghum heads damaged due to midge
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Lesson 1 Sorghum Midge
Crop damage Under severe infestation the entire
earhead looks blasted with chaffy head appearance
(Fig.)
Healthy (right) and midge affected (left) sorghum
heads
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Lesson 1 Sorghum Midge
Management The first choice of management
should be early and uniform sowing of similar
maturity sorghum cultivars over large
areas. Destruction of wild host plants
including Johnson grass and sorghum volunteers
early during the season may slow midge population
development.
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Lesson 1 Sorghum Midge
Management Growing grain sorghum varieties and
hybrids, like SPH 837, possessing some level of
resistance to sorghum midge.
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Lesson 1 Sorghum Midge
Management Insecticide application is needed
when the infestation is very severe. This can be
identified by observing the number of midge flies
on sorghum earheads. When 2 to 3 midge flies
are found, then spray the insecticide on the
earheads when 90 of the heads have emerged in
the field.
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Lesson 1 Sorghum Midge
Management Insecticides such as Carbaryl 50SP
(3 kg in 500 L water/ha), or Endosulfan 4D or
Carbaryl 3D (20 kg/ha), and can effectively check
the midge infestation.