Download Pests in Grain Storage, English

Insect Pests of storage
Dr Baoua Ibrahim
INRAN-NIGER PICS COORDINATOR
Kaboul, AAEP project training
May 26-27
Hands-on Exercice
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Four group
Each group will have one bag
Open the bag
Each members of the group take a sample of the
product using Petri dishes
• Collecte the following data
– Number of living insect per species
– Take a sample of 100 grains:
• Record number of grain with insect eggs
• Record number of grain with hole
– Take a sample of 10 wet grain, open and record any insect
larvae or adult
Insect Pests of Stored Products
Primary storage pests:
Insects that infest undamaged grains
Common name
Pest
Host
Rice weevil
Sitophilus oryzae, S.
zeamais, S. granarius
Rice, wheat, sorghum, barley, maize
Khapra beetle,
Lesser grain borer
Trogoderma granarium Cereals, groundnut and pulses
Angoumois grain moth
Sitotroga cerealella
Pulse beetle
Callosobruchus
Pulses, bean and gram
chinensis, C. maculatus
Tamarind/Groundnut
Bruchid
Caryedon serratus
Ground nut, tamarind and other
legumes
Lasioderma sericorne
Wheat flour, cereal bran, peanuts,
cocoa beans, spices, turmeric, chillies,
ginger, stored tobacco, cigarette
Cigarette beetle
Rhyzopertha dominica Paddy, maize and wheat
Rice, wheat and maize
Secondary storage pest:
Insects that damage broken or already damaged grains
Common name
Red flour beetle
Pest
Tribolium castaneum,
Tribolium confusum
Host
Broken grains, damaged
grains, milled products,
machinery
Long headed flour beetle
Latheticus oryzae
Saw toothed grain beetle
Cryptolestus minutas,
Laemophloeus pusillus
Dry fruits , maize, cereals
and oil seeds
Rice moth
Corcyra cephalonica
Cereals, oilseeds nuts, dry
fruits, rice and pulse
Fig moth or almond moth
Ephestia cautella
Indian meal moth
Plodia interpunctella
Maize, cereals, dry fruits,
groundnut, and cereals
products
Cowpea weevil
Callosobruchus chinensis (Linneaus)
The cowpea weevil attacks field beans and
peas. It then becomes a storage pest in
granaries where it breeds continuously on
dried pulses. It attacks chickpeas (Cicer sp.),
lentils (Lens sp.), garden peas (Pisum sp.)
and mung beans (Vigna sp.).
The damage is distinctive. Larvae feed and
develop inside the seed and when adults
emerge they leave a neat circular exit hole.
Each adult consumes approximately 25% of
the seed from which it develops. Heavy
infestation causes the commodity to heat.
This results in loss of quality and mould
growth.
Rice Weevils (Sitophilus oryzae)
• The adult weevil can be readily identified by its
long slender snout
• Adults are less than 3/16 of an inch in length,
and color varies from medium brown to black
• The thorax is pitted with elongate depressions,
and there are no wings under the wing covers,
so the species is flightless
• The granary weevil female chews a small hole in
a kernel, into which she deposits an egg
• Each female can deposit between fifty and two
hundred and fifty eggs
Lesser Grain Borer (Rhizopertha dominica)
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The adults of this species are readily distinguished
by the squared-off appearance at the front of the
body
The adults are less than 1/8 of an inch in length and
range from reddish brown to dark brown
This species is a good flier, and adults are readily
trapped in pheromone-baited traps at harvest
The lesser grain borer is a long-lived species and a
female can lay up to 500 eggs
Heavy infestation with lesser grain borers can be
identified by a sweetish, musty odor in the storage.
This odor is a result of the male-produced
aggregation pheromone that has been
demonstrated to be an effective lure for use in traps
Khapra Beetle (Trogoderma granarium)
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The adults are oblong-oval beetles, approximately
1.6 to 3.0 mm long by 0.9 to 1.7 mm wide
Males are brown to black with indistinct reddish
brown markings on elytra. Females are slightly
larger than males and lighter in color
The head is small and deflexed with a short 11segmented antennae
The antennae have a club of three to five
segments
The adults are covered with hairs
Adult khapra beetles have wings, but apparently
do not fly and feed very little
This beetle has never been observed to fly;
therefore, its spread is probably dependent on
movement of infested goods or in containers
where it may be transported while in diapause
Flour Beetle (Tribolium castaneum)
• These elongate, shiny beetles have short,
clubbed antennae
• Flour beetle is seldom found in grain and is
more often associated with milled products
• The insects reproduce faster when some fine
material is present in the stored grain
especially if grain moisture is more than 12%
• Under optimal conditions females can lay up
to 450 eggs over a lifespan that may be as
long as eighteen months
• The adults are good fliers
• A pungent, bad odour in the grain is a sign of
a large infestation of flour beetles
Angoumois Moth (Sitotroga cerealella)
• Angoumois grain moth adults are
brownish gray, slightly less than 1/2
inch long, with a long fringe of hairs on
the wings
• The forewings are clay-yellow and
without markings; the hindwings are
gray
• Angoumois grain moths can be found
infesting a variety of grain and food
materials. They attack all cereal grains,
however are most often found in corn
and wheat
• It is the only storage pest that will
attack standing grains in the field
Rice Moth Corcyra cephalonica (Stainton, 1866)
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A pest of stored rice, millets and other cereals. Prefers
broken grains and flour.
Caterpillars cause the damage by webbing together
grains and forming lump and feed from inside it.
Larvae before pupation wander about and leave a lot
of webbing in the grains, causing excessive lumping,
which reduces marketing quality of the grains.
Adults light greyish-brown in colour, 12 mm long and
with a wing span of about 15 mm, without any
markings on the wings but veins are slightly darkened.
Head bears a projected tuft of scales. Moths are short
lived but realise a fecundity of 150—200 eggs per
female within a few days after emergence. Larval
period is 25-35 days in summer and may be extended
in winter.
Indian Meal Moth (Plodia interpunctella)
• Adult moths are about 3/8-inch (8 to
10mm) long when at rest and have a
wing spread of about 1/2 to 3/4 inch
(18 to 20mm)
• The overall body color is generally
dirty gray but the tip half of the wing is
rusty brown or nearly bronze
• This wing marking pattern allows
Indian meal moth to be easily
distinguished from other household
moths
• Indian meal moths develop in many
kinds of stored foods. Coarsely ground
grains and cereal products are
commonly infested
Drugstore Beetle (Stegobium paniceum)
• The adults are about 1/10 of an inch
in length, cylindrical and uniform
brown with fine silky hairs
• The adult drugstore beetle has a
three-segmented, sawlike antennae
that is pressed to the body when at
rest
• This beetle lays eggs in almost any
dry organic substance
• The entire life cycle may be passed
in less than two months
Tobacco Beetle( Lasioderma serricorne)
• The tobacco beetle is a small stout,
oval, reddish-yellow or brownish-red
beetle, with the head bent down
nearly at a right angle to the body
• It varies in size, but is usually about
1/10 of an inch long
• The antennae of the tobacco beetle
are saw-like and the head is
somewhat retracted
• The adult tobacco beetle lives 2 to 4
weeks, during which time each
female may lay as many as 100 eggs
Rusty Grain Beetle (Cryptolestes spp.)
• These small insects (2 mm) are readily
identified by their very long antennae
• The antennae of both male and female
rusty grain beetles are about half the
length of the body
• The rusty grain beetles have been
recorded from wheat, flour, oilseeds,
cassava root, dried fruits, and chilies
• The adults are good fliers
• Females can lay up to 400 eggs over a
lifespan of up to nine months
Saw-Toothed Grain Beetle (Oryzaephilus
surinamensis)
• Saw-toothed grain beetle is a slender, flat,
brown beetle about 1/10 of an inch long
• It gains its name from the peculiar
structure of the thorax, which bears six
sawtooth-like projections on each side
• The female beetle lays 43 to 285 eggs
• Eggs are deposited on cracks in the
kernels and adults and larvae feed on
damaged kernels, fines, and occasionally
the germ of the intact grain
• This species is a good flier, but is most
commonly associated with areas of high
temperature and humidity
Large Grain Borer (Prostephanus truncatus)
Prostephanus truncatus is commonly referred to
as "larger grain borer" with reference to its close
cousin Rhyzopertha dominica which is relatively
smaller in length hence referred to as "lesser grain
borer". Prostephanus truncatus is approximately
35 millimetres (1.4 in) long as compared to 26 mm
(1.0 in) long in Rhyzopertha dominica. At optimum
conditions of 80% relative humidity and 32 °C
(90 °F), and available food, Prostephanus
truncatus completes its life cycle within 27 days. It
is a serious pest of dried grains especially maize
and dried cassava in West Africa.
Control
Control
Number of insects
Wheat
Mungbean
PICS
Control
PICS
Control
1
-
1
0
-
2
0
-
-
15
3
-
0
-
1
4
0
-
-
10
5
-
3
0
-
6
0
-
-
27
7
-
1
0
-
8
0
-
-
33
Rate of seed with hole and insect eggs
Wheat
Mungbean
PICS
Control
PICS
Control
1
-
3
0
-
2
0
-
-
15+3eggs
3
0
-
0
-
4
-
8
-
32
5
-
0
-
4
6
-
4
-
25+5eggs
7
-
1
0
-
8
-
8
-
5+28eggs