MANAGEMENT OF STORED GRAIN PESTS;NEW APPROACHES

1. Insect pest losses in stored grains
and their management
Nahida Ahad
Gk-0314
M.sc Entomology(2nd Yr)

2. ● 80% of human food comes from grains.
● Stored -product insect can cause serious post harvest losses,estimated to be
from 9% in developed countries and 20% or more in developing
countries. (Pimental,1991)
● Worldwide an annual loss of 8-10%(13mt of grains lost due to insect)and
100 mt due to failure to storage properly.
● It was estimated greater than 20,000 species of field and storage pests
destroy approximately 1/3rd of world food production.
INTRODUCTION

3. Post Harvest Losses in INDIA
● In India almost 8.5% of total
annual production is lost during
post harvest handling and storage. (Agrawal et al;1988)
● Estimates of losses of food
grains during post harvest
operations.

9. Detection of storage insect-pest
● Acoustic detection;relies on sound produced by insect during feeding and
movement on the grain bulk.
● Equipment s used; Microphones and Piezoelectric sensors.
● Small insects,young larvae:weak emmiters of sound.

10. ● Near infrared spectroscopy;fast, accurate and economical
technique.Provides information based on the reflectance properties of
different substances present in a product.Based on absorption of
electromagnetic wavelengths in the range 780-2500nm.
● Drawback; can't discriminate between dead and live insect and can't
detect low levels of infestation in bulk samples.

11. X-ray imaging
● Simple,fast and non destructive method.
● Karunakaran et al.(2004) used soft X-ray to detect internal and external
infestations of Rhyzopertha dominica in wheat kernels.
● Luci Fluoroscope: source ofsoft x-rays.
● X-ray images were acquired as grey scale images.

14. from Azadirhacta indica,Glycine max and● Sliver nanoparticles;synthesized
camellia sinensis.
NANOPARTICLES USED AGAINST STORED GRAIN PEST
 Silver nanoparticles like;AgNO3
 Silica like;diatomaceous earth,synthetic silica(SiO2),sands,silica Aerogel
 Aluminium oxide(Al2O3)
 Zinc oxide(ZnO)
 Copper oxide(Cu2O3)
 Titanium oxide(TiO2)

15. Silica nanoparticles
● Diatamaeceous earth and synthetic silica used in the form of inert dusts.
● Kills by physical rather than chemical means.
● 100% mortality of corcyra Cephalonica by amorphous silica nanoparticles (Vani and
Brindha 2013).
● 80-90% mortality of s.oryzae was observed(Debnath 2011)
Novel use of nano structured alumina as an
insecticide
● Goswami et al; 2010 observed 86% mortality of sitophilus oryzae.
● Sabbour,2012 and salem et al;2015: reported :higlhly effective against sitophilus
oryzae and highly oviposition deterrent.
Zinc oxide nanoparticles; effective against s.oryzae.
● Act as feeding deterrent to the insect and destruction of natural water barrier in the
waxy layer of the insect cuticle.
● 65% mortality of s.oryzae was observed(Goswami et al;2010).

16.  TNAU TRAP
 The insect trap has to be kept in the grain vertically with the white plastic cone
 downside.
 The top red cap must be with the level of grain.
 Insects will move towards air in the main tube and enter through the hole.
 Once the insects enters hole it falls down into the detachable white cone at the bottom.
 PITFALL TRAP
 .Used for capturing insects active on grain surface and in other layers of grain
 (Monitoring and mass trapping tool).
 It has a perforated lid,cone shaped bottom which tapers into a funnel shaped trapping tube.
 Cone is coated with sticky substance to hold trapped insects.
TNAU - TRAP
PITFALL -TRAP

17. UV LIGHT TRAP for grain storage godowns
● Consists of an ultraviolet source.
● The light is fitted at the centre of funnel.
● Trap is place in storage godowns at 1.5m
above ground level.
● 2 numbers of UV light traps per 60m×20m
(L×B) godown with 5m height is suggested.
● Egg removal device
● The gadget has:outer container,an inner
perforated container and a rotating rod fixed
with plastic brushes.Rod is rotated for 10
minutes 3 times a a day.
● Splashing action of brush crush the eggs.

18. ● BOTANICALS
● Plant extracts are commonly referred to as botanicals.
● Secondary plant metabolites.Extremely low toxic to mammals.
● Killing or reppelant property makes seeds unsuitable for insect pests.

19. Azadirhactin causes 100% mortality to sitophilus oryzae(Athanasiou et
al;2005).
Methanol extracted from chrysanthemum reduced the population of
Trogoderma granarium( Derbalah,2012)
The treatment of castor oil @1.0ml/100g seeds caused maximum
reduction in egg viability of stored pest.
The karanj extract was most effective and mehandi oil was least
effective in reducing the fecundity,egg viability and longevity of adults.

20. • Interfere with the insect mechanism of development and molting.
• No progeny capable of reproduction.
• IGR-NYGUARD
• IGR-(HYDROPRENE)-Gentrol
• IGR-(s)-METHOPRENE-Diacon
• Novaluron
• It is abiological insecticide.
• Derived from bacterium;
• Saccharopolyspora spinosa
• Mode of action ;contact and stomach
• Stage specific;Adult
•
USE OF PROTECTANTS
GROWTH REGULATORS
SPINOSAD

21. INSECT GROWTH REGULATORS
 Three possible ways of application of pheromones to control storage pest;
 Trapping with sex attractant
 Using aggregation pheromone with insect pathogen or chemosterilant
 Profusing the warehouses atmosphere with pheromone to disrupt normal
courtship behaviour of males
 4,8 DMD – Aggregation pheromone effective against Tribolium spp.
 Sitophinone against Sitophilus oryzae
 Tribolium castaneum also trapped by synthetic lures i.e; PT6 Allure and Trappit
under lab.conditions.
 JUVINILE HARMONE ANALOGUE
 Ambika and Abraham (1982);topical application of Methoprene at a dose of 1.0
and 0.5 micro/4th instar larvae gave 100% mortality.
 Larval duration,length,width,pupal weight,pupal period increased due to
Fenoxycarb treatment.

22. BIOLOGICAL CONTROL
 Biological control in storage is not very
 effective.
 Some Hymenopterous parasites ;
 Anisopteromalus calandrae effective against
 Sitophilus oryzae
 Lariophagus distinguendus against
 Rhizopertha and Sitophilus
 Bt is the first microrganism to be approved
 for us in stored pest.It is compatible with
 most protectant fumigant and seed fungicide.

23. HOST RESISTANCE
• With the advancement of science a lot of crop varieties are developed that show varying degree of
resistance against different insect pests.
• The most common example is pea havinf foreign gene (alpha-AI-Pv) resistant to pulse beetle and
tobacco having a-ai gene resistant to Tenebrio molitor.
• FUMIGATION
• Process of exposing pests or pest affected stocks to the fumes of chemical at a lethal strength in a
gas tight space. FUMIGANTS DESCRIPTION
Durofure Mixture of EDB and CH3Br (Resistant sp. of Tribolium ,Trogoderma)
ECO2FUME 2% phosphine by weight in 98% CO2
Phosphine 3g tablet of Almunium phosphide releases 1g of phosphine
PROFUME Sulfuryl flouride;doesnot deplete ozone layer,effective as methyl
bromide
Grain-o-cide CS2 and CO2 (4:1) @ 30-40 /1000 Quintals for 7 days exposure
CCl4 Less toxic to insects,slow acting
CS2 Highly phytotoxic

24. PHYSICAL CONTROL MEASURES
 TEMPERATURE
 25-30⁰C;optimum for growth and reroduction
 13-25⁰C and 33-35 ⁰C ;suboptimal range at which insects are able to complete development and produce
offspring.
 <13 ⁰C or >35⁰C ;insects eventually die.
 All immature stages of Sitophilus,Rhizopertha,Sitotroga cerealella are killed when exposed to temperature
of (80,70,60)⁰C respectively for about 4,6,11 minutes respectively.
 Although heating of grains to 50⁰C is lethal to many stored insect pest,it is not advisable as the grain lose
viability at such temperature.
 MOISTURE
 Grain stored at 10% moisture content escape from attack of insects.khapra beetle develop even below this
temperature.
 Over the moisture range of about 12-16%,the rate of seed deterioration increases as moisture content
increases.
 OXYGEN
 Khapra beetle is very susceptible to decrease in O2 content.Reduction of O2 can be achieved by addition of
CO2 and N2.

25. –GRAIN PROOFING
 Some inert dusts are abrasive and scar the cuticle,causing dessication and
starvation but actual efficiency depends upon particle size(max,10µm),particle
hardiness,particle shape.
 Some common dusts used for grain proofing are wood ash,lime,calcium
carbonate,gypsum,calcium chloride,talc.

28. Chemical control measures
 Among the present methods of control of stored grain pests chemical control is the
most popular and the most effective one.
 Surface spray of bags and when the insect pests are visible are done with
insecticides such as malathion,DDVP,fenitrothion etc.
 Malathion 50EC is sprayed over the bags in the ratio of 1:100@ 3L/100m2.
 Recently the deltamethrin 2.5WP@3mga.i/m2 has been found very effective.
 Dust formulations of the insecticides contain additives,which increased the
adhesion to the stored produce.
 Dust formulations are suitable for mixing with grain and for applying in layers in the
stored produce (sandwich method) as well as for surface treatment of individual
bag,bag stacks and stores.

29. CONCLUSION
 Stored grain infestation is a very serious problem as various life stages of insects cause
economic damage and deteriorates the quality of food grains and food products.There
are number of stored grain insect pests that infest food grains in farmer stores and
public ware houses and massively surge due to uncontrolled environmental conditions
and poor warehousing technology used.
 However ,for suppression of multiplying insect population highly specific and more
appropriate modern methods are to be used.few important methods such as ionizing
radiation,IGRs,use of entomopathogens are proved highly effective against stored grain
insects.
 However these methods,repellents and oviposition inhibitors isolated from various
plant species are considered as much safer in comparision to synthetic pesticides.
 However,non residual non persistant and less toxic bio-organic pesticides should be
used that may not affect the quality of food grains.