1. Wheat: Insect pests and their
management
M. Macharia
Kenya Agricultural and Livestock Research
Organization, Food Crops Research Centre,
P.O. Private Bag- 20107, Njoro, Kenya.

2. I. Introduction
• Wheat is attacked by a number of insects,
some of which inflict severe damage,
while damage by others is not easily
noticeable.
• Others may not cause appreciable
damage on plant through direct feeding
but maybe vectors of diseases, which may
become a bigger problem.

3. Introduction …
• Insect pests damage the wheat crop either
mechanically or physiologically.
• Some pests are also vectors of infectious
pathogens such as barley yellow dwarf.
• For effective control, it is important that
wheat growers are able to recognize the
pest, damage and take appropriate control
strategies.

4. 1. Cereal aphids
• Greenbug,Schizaphis graminum
• Rose grain aphid, Metopolophium dirhodum
• Bird cherry aphid, Rhopalosiphum maidis
• Cereal leaf aphid, Rhopalosiphum padi
• English grain aphid, Sitobion avenae
• Russian wheat aphid, Diuraphis noxia

5. 1.Cereal aphids…
• Cereal aphids are a major constraint to wheat
production in Kenya.
• The aphids cause damage by directly feeding on
the wheat crop.
• Also transmit Barley yellow dwarf virus (BYDV).
• 47% yield losses have been recorded on wheat.
• Outbreaks of cereal aphids and BYDV makes
wheat production uneconomical, hence the need
to control cereal aphids.

6. 1.Cereal aphids…Status of Russian
wheat aphid
• RWA is a recent introduction in Kenya (1995).
• Currently, the most important cereal pest.
• Losses vary from 10-100% depending on
stage of infestation.
• Injects toxins causing leaf rolling.
• Feeding produces white streaks on leaves
of young plants.
• Also causes fish hooked sterile heads.

7. Symptoms of cereal aphids damage

8. Symptoms of Barley yellow Dwarf
Wheat Barley Oats

9. • Cultural control:
• Early planting.
• Early destruction of volunteer wheat and barley and grasses.
• Proper good fertilization to avoid stressed crops.
• Use recommended high seed rates.
Chemical control:
(i)Seed dressing insecticides
• Imidacloprid (Gaucho 350FS) @t 200ml/100kg seed.
• Thiamethoxam (Cruiser 350FS) @ 150ml/ 90kg seed.
• Clothianidin + prothioconazole (Redigo Deter 300FS) @200 ml/100 kg seed.
• Thiamethoxam + fludioxonil + difenoconozole (Celest Top 312FS) @150
ml/100 kg seed.
Management strategies of cereal
aphids

10. Management strategies of cereal
aphids…..
(ii) Foliar applied aphicides
• Pirimicarb (Pirimor 50WG) @ 0.75kg /ha.
• Betacyfluthrin + Chlorpyrifos (Bulldock star 262.5EC.) @
0.5l/ha.
• Imidacloprid + Betacyfluthrin (Thunder OD 145) @ 0. 3l/ha
• Oxydemeton- s- methyl (Metasystox 250EC) @ 0.51/ha.
• Cypermethrin + Chlorpyrifos (Nurelle* D 50/500EC) @
0.51/ha.
• Alpha-cypermethrin + Dimethoate (Alphadime) @ 0.75l/ha.

11. 2.The Red billed quelea birds
• Damage the crop after the
dough stage by eating the
grain directly from the spikes
and causing ears to shatter.
• Damage is recognized by
presence of wheat plants
showing 'whiteheads' where
the grain has been eaten.
•Early and late wheat crop is
more liable to damage by
birds.
Male in breeding
plumage
Female in breeding
plumage
Non-breeding
plumage

12. Management strategies: Red billed
quelea birds:
(i) Cultural control
• Manual bird scaring, scarecrows and noise making devises.
• Cutting trees harboring roosts and colonies.
• Good weed management – (weeds attract birds).
• Using reflective ribbons that scare birds from the field.
• Blowing up nest colonies & roosts using fire bombs &
dynamite.
(ii) Chemical control
Spraying avicides-
•Fenthion 60%EC to kill the birds wherever they have
roosted.
Due to its economic significance, management and control
is centrally co-ordinated by Crop Protection Directorate,
Ministry of Agriculture, Livestock and Fisheries.

13. 3.Rodents
2
Multi-mammate shamba rat
(Mastomys spp.)
African grass rat (Arvicanthis
spp.)
• Attack at germination where rats
retrieve sown seeds.
• Damage starts at early booting &
continues through the mature
grains.
•Damage recognized by visual
observation of patches of
whiteheads' in a wheat field.
•Presence of completely severed
stems and cut short lengths of stems
on the ground between the rows.
•Presence of runways, burrows and
nest sites.

14. Management strategies: Rodents
(i) Cultural control
• Disturb and destroy habitat (burrows) of the rodents.
• Trapping using kill and live-traps.
• Early harvesting and efficient harvesting of wheat.
• Environmental manipulation, by ploughing and grazing after harvest.
• Improving storage structures by rat proofing.
• Minimize the alternate food sources (weeds and crop residues).
Chemical control :
Use recommended rodenticides preferably as ready-made baits :-
• Bromadiolone 0.005% (Miratex, Lanrat).
• Difethialone 0.025% [Baraki]
• Flocoumafen 0.005% [Storm)
• Zinc phosphide 2.0% .

15. Poor post harvest management can lead
to:-
• Rapid deterioration in grain quality
• Decreasing germinability
• Decreasing nutritional value
• Development of grain storage pests and
mould development ( mycotoxins).
4.Major Insect Pests Of Stored
Wheat

16. Major Pests Of Stored Wheat
i
Weevil Larger grain borer
Lesser grain borer
Indian meal mothAngoumois grain moth Rats

17. Management strategies: Stored
insect pests
 To reduce the potential of infestation
• (i) Grain must have grain moisture content not higher than
9-12%.
• (ii) Store should be cleaned and treated with (Pirimiphos –
methyl spray –(Actellic 25EC).
• (iii) Regular monitoring of the store and grains.
 Chemical control. Always use approved insecticides.
• Malathion + permethrin (Skana Super).
• Pirimiphos-methyl + permethrin (Actellic super) .
• Pirimiphos –methyl +Thiamethoxam (Actellic Gold).
These are applied at 50g / 90 kg of wheat grains.

18. Conclusion
• Frequent scouting and monitoring of the crop under
field and grain storage conditions to identify possible
pest problems is important.
• Wheat must be harvested in a timely manner before
shattering, pre-harvest sprouting damage, bird damage
and weathering.
• Educating and training farmers on pre & post harvest
operations would greatly help in reducing yield losses
in wheat.

19. Thanks