In this presentation there is discussed about microbial insecticides, semiochemicals and botanicals.

1. MASTER’S SEMINAR
TOPIC: BIORATIONAL PESTICIDES IN PEST
MANAGEMENT
SPEAKER:
SHIVANI SHARMA

2. CONTENTS
 Introduction
 Classification of biorational pesticides
 Microbial pesticides
 Semiochemicals
 Botanicals
 Case studies
 Conclusion

3. BIORATIONAL PESTICIDES
 Biorational pesticides are composed of natural products, including animals, plants, microbes, and minerals, or are
their derivates.
 “Biorational pesticides” term derived from two words, “biological” and “rational” referring to pesticides that are
natural compounds or their derivatives which affect insect behaviour, growth or reproduction for suppression of
target pest and are less detrimental to non-target organisms. (Hara and Shi, 2000).
 Biorational pesticides were initially defined as naturally occurring substances (e.g. insect pheromones and hormones)
or microbial agents that are somewhat species specific.
 Biorational or 'reduced risk’ pesticides are natural compounds, that effectively control insect pests, but have low
toxicity to non target organisms (such as humans, animals and natural enemies) and the environment.

4. CLASSIFICATION OF BIORATIONAL PESTICIDES
Biorational
pesticides
Microbial
Biochemical
(Semiochemicals)
Botanicals
Rosell et al., 2008

5. MICROBIAL PESTICIDES
Bacteria
Fungi
Virus
Nematodes
Protozoan

6. Entomopathogenic bacteria
Spore producers
Obligate spore producers
e.g. Bacillus popillae
Facultative spore producers
Crystalliferous
e.g. Bacillus thuringiensis
Non-Crystalliferous
e.g. Bacillus cereus
Non-spore producers
e.g. Pseudomonas spp.
Reddy,2018

7. ENTOMOPATHOGENIC BACTERIA
 Spore forming:
 Obligate: Example :Bacillus popillae
 It attacks only members of family Scarabaeidae. It produces endospores which upon ingestion
by the susceptible host, germinate in the gut and the vegetative cells invade into the
haemocoel where they multiply and sporulate. At this point the blood becomes milky white,
hence the term "milky disease“ is used. After the death, host disintegrates and spores are
released into the soil.
 Use: The commercial product Doom is used against white grubs Holotrichia spp. in
groundnut.
 Facultative:
 Crystalliferous: Example : Bacillus thuringiensis
 In addition to endospores, produces a proteinaceous parasporal crystal in the sporangium at
the time of sporulation. The crystals contain an endotoxin capable of paralyzing the gut of
most lepidopteran larvae. The toxin is known as delta-endotoxin. It is the most widely
exploited microbial control agent. Lepidopteran larvae with a gut pH ranging from 9.0 to 10.5

8.  Non-crystalliferous: Bacillus cereus a common spore former and soil
inhabitant, effective against Coleoptera, Hymenoptera and Lepidoptera.
 Non-spore forming bacteria: The digestive tracts of most insect contain many
non-spore bacteria, many of which are potential pathogens when introduced
to insect blood.
 E.g. Serratia entomophila on grass grub in New Zealand.
 Disease symptoms: Reduced feeding, fluid discharge from anus and mouth,
finally septicemia. Excretory system is affected, body cells get disintegrated,
resulting in nervous system non-coordination.

9. MODE OF ACTION OF Bacillus thuringiensis
 Sporulation occurs when environmental conditions change, resulting in low nutrient levels or desiccation. It is during
the process of sporulation that the delta-endotoxin is produced.
 The crystal comprises a protoxin protein of 130 kilodaltons, which is solublized in the alkaline pH of the larval midgut
and subsequently cleaved enzymatically to active toxin of 60-70 kDa.
 The toxin diffuses through the peritrophic membrane lining the gut and binds to receptors present in midgut
epithelium. The gut is paralyzed and the insect stops feeding.
 The toxin is inserted into the membrane with the resultant formation of the pore. The pore interferes with the inward
potassium gradient and results in swelling of microvilli. These cells eventually lyse. The leakage of ions from the gut to
haemolymph results in ionic imbalance in haemolymph.
 Poisoned insects may die quickly from the activity of the toxin or they may stop feeding and die within 2 or 3 days
from the effects of septicemia. The disruption to the gut may also permit invasion of the haemolymph by the
bacteria, finally resulting in death.
Reddy, 2018

11. Bacteria Target pest Trade name
1. B. thuringiensis var. israelensis Mosquitoes and black flies Thurimos, Vectobac.
2. B. thuringiensis var. kurstaki Caterpillar, looper and semilooper
Cabbage DBM
Cotton American boll worm, pink
boll worm, spiny and spotted boll
worms
Lepidopteran caterpillars
Delfin, Dipel, Thuricide.
Halt
Biolep, Bioasp
Biobit
3. B. thuringiensis var. thuringiensis Flies Muscabac
4. B. thuringiensis var. galleriae
5. B. thuringiensis var. aizawai
lepidopterans Spicturin
Mattch, Xentari
7. B. thuringiensis var. exotoxin Mites DiBeta
Srinivasan, 2016

12. ENTOMOPATHOGENIC FUNGI
 Fungal formulations are usually made up of growing hyphae and spores.
 Active ingredients are mixed with bentonite, kaolin clay or a carrier base. Formulations are
supplied as wettable powder or as a dust for spraying.
 MODE OF ACTION:
 Entomopathogenic fungi are able to penetrate directly the outer integument. Once it attaches
to the host, fungus penetrates the insect body wall with the help of hyphae produced from
the spores.
 The invasion of the hyphae in the cuticle is through wounds, joints between segments or
through sense organs. The fungal enzymes that mention the cuticle accelerate the physical
process of penetration.
 Once the hypha enters the body's circulatory system. The cause of the insect's death is
extensive fungal growth in the haemolymph and poisoning by fungal toxin.

14. ENTOMOPATHOGENIC FUNGI (EPF)
Fungi Target pest Trade name
1. Beauvaria bassiana Cotton bollworm, DBM, Coffee
berry borer
Ankush, Bio-powder, Daman,
2. Metarrhizium anisopliae Sugarcane pyrilla, Rhinoceros
beetle
Biomax, Bio-magic, Dispel
3. Verticillium lecanii White flies, Aphids, Scales,
Mealy bugs
Vertilec, Bio-catch
4. Hirsutella thompsoni
Hirsutella citriformer
Phytophagous mites
Brown plant hopper
Mycar
5. Metarrhizium (Nomuraea)
riley
Helicoverpa armigera,
Spodoptera litura
6. Entomophthora Aphids
Reddy, 2018

15. ENTOMOPATHOGENIC VIRUS (EPV)
EPV
DNA virus
Nuclear Polyhedrosis
Virus
(NPV)
Granulosis virus
(GV)
RNA virus
Cytoplasmic Polyhedrosis
virus
(CPV)

16.  Nuclear Polyhedrosis Virus (NPV): Important feature of NPV are:
 Occluded (rod shaped) singly or in groups in polyhedral bodies.
 Site of multiplication is cell nucleus of epidermis, fat body, blood cells and trachea.
 Symptom: Wipfel Krankheit or tree top disease - e.g. NPV of Spodoptera, Helicoverpa, RHC.
 Granulosis virus (GV): Virions (oval or egg shaped) are occluded singly in small inclusion
bodies called capsules.
 Site of multiplication is either cytoplasm or nucleus of epidermis, trachea and fat body.
 (eg.) GV of early shoot borer of sugarcane. It is virulent and pathogenic to all larval stages of
the host insect. The virus is also transmitted to off springs through diseased adults.
ENTOMOPATHOGENIC VIRUS

17. ENTOMOPATHOGENIC VIRUS
 Cytoplasmic Polyhedrosis virus (CPV): Spherical virions occluded singly in polyhedral
inclusion bodies.
 Site of multiplication is cytoplasm of midgut epithelium.
 E.g. CPV of Cabbage looper (Trichoplusia ni) .
 Mode of action:
Occlusion bodies
(Polyhedra for NPVs,
CPV’s and Granules for
GVs) are ingested by
insect larvae and is
further degraded by
host alkaline proteases
due to high alkaline pH
of the midgut
Virus particles are
released from polyhedra
and attach to the
peritrophic membrane
lining the midgut. The
lipoprotein membrane
surrounding the virus
fuses with plasma
membrane of gut wall
cells and liberates
nucleocapsids into the
cytoplasm.
The nucleotide transport
virus DNA into the
nucleus of the cell and
virus gene expression
begins. The virus
multiplies rapidly and
eventually fills the body
of the host with the virus
particles.

18. Source: https://www.frontiersin.org/articles/10.3389/fmicb.2017.01337/full
Infection of insect by baculovirus

19. ENTOMOPATHOGENIC VIRUS
Name of virus Insect pest targeted Trade name
Nuclear polyhedrosis virus
(NPV)
Helicoverpa armigera,
Spodoptera litura
Gypsy moth
Helicide, Heliocel, Biovirus
H.
Spodocide, Litucide,
Biovirus S.
Gypcheck
Granulosis virus (GV) Agrotis segetum (cutworm)
Plutella zylostella (DBM)
Agrovir
Cytoplasmic Polyhedrosis
virus (CPV)
Cabbage looper
(Trichoplusia ni)
Ragumoorthi, 2016
The NPV dose commonly recommended in field conditions = 250 – 500 LE/ha

20. ENTOMOPATHOGENIC NEMATODES
 Most nematodes infect the insect as juveniles, entering through cuticle or
midgut. The non-feeding juvenile 3rd is the infective one. Important
entomopathogenic nematodes belong to four families of the Phylum
Nematoda are:
 1. Mermithidae
 2. Steinernematidae
 3. Heterorhabditidae
 4. Tylenchidae
Source:
https://www.ipmimages.org/browse/detail.cfm?imgnum=1316
020
Larva of Greater Wax Moth

21. ENTOMOPATHOGENIC NEMATODES
 Associated bacteria: Xenorhabdus and Photorhabdus
 Mode of action:
Non-feeding third stage infective juvenile (IJ) or dauer juvenile
carries cells of bacterial symbiont in its intestinal tract.
After locating a suitable host, the IJ invades it through natural
openings (mouth, spiracles, anus) and penetrate into the host’s
hemocoel.
It releases bacteria in the host which propagates and produce
substances that kill the host and protect the cadaver from
colonization by other microorganisms.
Nematode initiates its development, feeding on the bacterial
cells and host tissues, as the food resources in the host cadaver
are depleted, a new generation of IJs is produced that emerges
from the host cadaver in search of a new host

22. Source: https://www.researchgate.net/figure/General-life-cycle-of-entomopathogenic-nematodes-The-numbers-on-the-
figure-show-the_fig1_323416572

23. ENTOMOPATHOGENIC NEMATODES
Nematode Target pest
1. Steinernema feltiae Helicoverpa armigera,
Soil pests and termites
2. Heterorhabditis sp. White grub (Holotrichia serrata)
3. Tetradonema pelicans Sciarid flies and pests of cultivable
mushrooms
4. Romanomermis culicivorax Larvae of mosquito
5. Agamermis decaudate Grasshopper
Chen et al.,
2003

24. PROTOZOAN
 The microsporidia and their spores of protozoa enter into the insect body host by ingestion.
Once they invade the gut, they multiply vegetatively in the cytoplasm of cell, gradually
spreading throughout the body and causing a chronic disease and the insect infected with
the protozoan can be easily identified as it shows symptoms of soft body and the body is
easily breakable.
 Nosema locustae infecting grasshoppers is being exploited and product available under the
trade name of "Noloc".
Protozoa Pest
Malamoeba locustae Grasshopper, locusts
Nosema fumiferarae Spruce bud worm
Farinocystis tribolii Tribolium castenum (Red flour
beetle)
Vairimorpha nectarix Lepidopterans

25. SOME OTHER MICROBIAL INSECTICIDES:
Avermectins: derived from the culture of soil bacterium Streptomyces
avermitilis. E.g. Avamectin [Vertimec], Emamectin benzoate [Proclaim].
Milbemycins: derived from Streptomyces hygroscopius sub
sp. aurelacrimosus. E.g. Milbemectin [Milbenock]
Spinosyns: derived from actinomycetes, Saccharopolyspora
spinosa. E.g. Spinosad [Tracer and Success]

26. SEMIOCHEMICALS
Semiochemicals
Pheromones
Primers Releaser
Sex
Aggregatio
n
Alarm Trail Marking
Allelochemicals
Apneumones Allomones kairomone
s
Synomone
s
Reddy,
2018

27. SEMIOCHEMICALS
 The term semio-chemical is derived from a Greek word ‘semeon’ meaning a mark or a signal.
 Chemicals which modify behaviour in perceiving organisms at sub micro/nano gram
levels are known as Semio-chemicals.
 These are employed both for intra and interspecific communication systems.
 Pheromones: The compounds which convey information between member of same species
(Intraspecific Semiochemicals). Pheromones are ectohormones produced by Exocrine
Glands and are secreted outside the body.
 Allelochemicals: The compounds which convey information between member of different
species (Interspecific Semiochemicals)

28. TYPES OF PHEROMONES (BASED ON RESPONSES ELICITED)
1. Primer Pheromones: They trigger off chain of physiological changes in the
recipient without any immediate change in the behaviour. They act through
Gustatory (taste) sensilla. E.g.: They regulate caste determination and
reproduction in social insects.
2. Releaser Pheromone: These pheromones produce an immediate change in
the behaviour of recipient. They act through Olfactory (smell) sensilla.
They directly act on the Central Nervous System (CNS) of the recipient and
modify their behaviour.
Ragumoorthi et al.,
2016

29. TYPES OF RELEASER PHEROMONES
 1. Sex pheromones: Sex pheromones are released by one sex only and trigger behavioural
patterns in the other sex that facilitates in mating (To attract a mate).
 These are mostly produced by Females but may be produced by some males and are highly
species specific.
Pheromone Name of insect
1. Bombykol Bombyx mori (mulberry silkworm)
2. Gyplure, Displure Lymantaria dispar dispar (Gypsy moth)
3. Gossyplure, Pectinlure Pectinophora gossypiella (Pink
bollworm)
4. Looplure Trichoplucia ni (Cabbage looper)
5. Spodolure, Litlure Spodoptera litura (Tobacco caterpillar)
6. Helilure Helicovepa armigera (American
bollworm) Ragumoorthi et al.,

30.  2. Aggregation Pheromone: Pheromones which induce aggregation or congregation of
insects for protection, reproduction and feeding or combination of these are called as
Aggregation Pheromones.
 Insect orders producing aggregation pheromones : Coleoptera, Blattodea, Mantodea.
Aggregation pheromone Producing insect
1. Frontalin Female of Dendroctonus frontalis
(Southern Pine/ Bark beetle)
2. Cosmolure Cosmopolites sordidus
3. Ipsenol Male of Ips confusus (Pinyon Pine/ Phloem
Beetle)
4. Grandlure Anthonomous grandis
5. Dimethyl decanol Tribolium confusum
6. Ferrugineol Rhynchophorus ferrugineus
Kumar and Biji, 2017

31. 3. Alarm Pheromone: These are chemical substances released by insects to warn members of the
same species about the presence of or attack by an enemy.
 Example:
 Aggression in ants and soldier termites.
 Dispersion or escape in aphids and bugs.
 Attraction and aggression in wasps and worker bees.
Insect Chemical name of alar pheromone
1. Aphids Terpenes
2. Soldier Termites Mono terpenes hydrocarbons
3. Ants Formic Acid

32.  4. Trail pheromone: These are also called as Path Marking Pheromones which are released in
the form of intermittent or continuous lines on a soil substrate which the trail followers
perceive by their antennae to find mate or food sources more efficiently.
 Trail pheromones can be used to attract and kill ants. These are mixed with baits that can
attract ants which when transported to their nests, kill all young ones.
Insect Chemical nature of trail phermone
Termites (Zootermopsis sp.) Caproic acid
Ants (Formicidae) Hexanoic acid, Heptanoic acid and
Decenoic acid
Srinivasan et al., 2016

33.  5. Marking pheromone: (also known as spacing pheromone)
 These are produced by females of both herbivores and entomophagous insects to mark hosts
in which they have laid eggs.
 It deter further oviposition which serves to reduce intraspecific larval competition.
 It is produced by insect orders: Lepidoptera, Diptera, Coleoptera and Hymenoptera.
 Conspecific females encountering the marking pheromone spend less time foraging the
marked fruit and search for unmarked fruits. These pheromones are also called as Epideictic
pheromone.
 Examples: Apple maggot fly (Rhagoletis pomonella) Female drags her ovipositor over the fruit
surface leaving a chemical signal (synthesized by cells of midgut).
 The presence of feeding larvae of Pieris brassicae inhibits egg laying (larvae produce
pheromones).

34. ALLELOCHEMICALS
 Allelochemicals are inter-specific semiochemicals. They mediate the communication
between two different species of organisms or insects. Allelochemicals may be classified into:
 Allomones:- Allomone is a chemical or mixture of chemicals released by one organism that
induces a response in another organism which is advantageous to the releaser. For example
the defensive secretions of insects and plants that are poisonous or repugnant to attacking
predators. Allomones in other insects include:
 Sting glands in bees
 Reflex bleeding in aphids
 Secretion of osmeteria in Papilio demoleus (Citrus caterpillar)
 Formic acid in ants

35.  Kairomones: Kairomone is a chemical or mixture of chemicals released by one organism that
induces a response in another organism which is advantageous to the recipient.
 Example: 1. Heptanoic acid released by larva of potato tuber moth Phthorimoya operculella
increases searching by its parasitoid.
 2. Benzyl cyanide from Pieris brassicae attract Trichogramma.
 Synomones: Synomone is a chemical or mixture of chemicals released by one organism that
induces a response in another organism which is advantageous to both the releaser and the
recipient, It encourages mutualistic relation between organisms.
 E.g. Termites and protozoans, Woodroaches and protozoans.
 Apneumones: A chemical substance emitted by a non-living material that evoke a behavioral
or physiological reaction adaptively favorable to a receiving organism, but detrimental to
another species, which may be found in or on the non-living material.
 For example an Ichnuemonid parasite Venturia canescens is attracted by the smell of the
oatmeal, which is the food of its host. Here it is advantageous to the recipient which is the
parasitoid but detrimental to host insect living on the oat meal (non-living material).

36. SEMIOCHEMICALS IN PEST MANAGEMENT
 Monitoring:
 Development of effective monitoring systems provides valuable information
for coordination of the treatment schedule with pest phenology.
 Semiochemicals are used in traps to monitor changes in population levels
allowing a better knowledge about the onset of adult emergence and the
flight peak.
 The most widely used attractants in monitoring systems are sex pheromones
to monitor aggregation pheromones to monitor coleopteran species and host
plant odors for dipteran species.
Rosell et al., 2008

37.  Mass trapping (attract and kill):
 In mass trapping, a very high proportion of insects are caught in traps baited with chemical
lures before mating or oviposition to reduce the pest population.
 Techniques in attract and kill programs range from entanglement in sticky materials to
outright killing with pathogenic micro – organisms and insecticides.
 For Lepidoptera it is essential that males are trapped before mating and this is most likely to
occur with insects that mate only once.
 For Coleoptera it is highly recommended that both sexes are caught (if trapping is based on
aggregation pheromones) before eggs are laid or damage is inflicted by feeding adults.

38. Mating disruption:
• Mating disruption is the most widely and successfully used control method for a
variety of insects. It prevents mating and, hence, reduces the incidence of larvae in the
next generation.
• This is normally done by releasing a large amount of pheromone or pheromone
analogue in the treated area, and has been used against lepidopteran species and
other orders like Coleoptera, Hemiptera.
• It is species-specific, has low environmental impact and is more sustainable than other
broad spectrum techniques without evidence of resistance.
• Mating disruption by air permeation (confusion or decoy method): In this method
synthetic pheromone is permeated into the environment to mask the natural
pheromone and thus disrupt the normal pheromonal www.communication among
insects. Such disruption will cause failure of insects to locate their mates thereby
prevent mating. Formulations like flakes, hollow fibres and microcapsules containing

39. BOTANICALS
 These are the insecticides which are made from naturally occurring plant chemicals.
 For example, Pyrethrum from Chrysanthemum cinerariifolium Vis. (Compositae)
 Nicotine from Nicotiana tabacum (Solanaceae).
1. Azadirachtin:
 Main active ingredient that has potential insecticidal activity present in Neem is
azadirachtin, which is present in seeds and leaves and it varies from 2-4mg/g kernel.
 Neem has various effects on insects, viz., antifeedant action, Insect growth regulatory
activity inhibits juvenile hormone synthesis, oviposition deterrent, repellent action,
reduction of life span of adults and intermediates are formed giving rise to larval-
pupal, nymphal-adults, and pupal-adult intermediates.
Oguh et al., 2019

40. 2. Rotenone:
 It is a resin derived from roots of leguminous plants Lonchocarpus spp (South American plant)
plant) and Derris eliptica (Malaysia).
 It is a broad spectrum contact and stomach poison affects nerve and muscle cells in insects
and sometimes causes insects to stop feeding, inhibits respiratory metabolism.
 It is used as dust containing 0.75-1.5% rotenone and effective against beetles and caterpillars.
3. Sabadilla:
 It is a alkaloid found in seeds of tropical lily Schoenocaulon officinale (Liliaceae). It is a contact
poison.
 The alkaloids mainly, cevadine and veratridine act as nerve poisons.
4. Ryanodine:
 It is a alkaloid derived from woody stems of south American shrub, Ryania speciosa
(Flacourtaceae).

41.  It acts as slow acting stomach poison and causes insects to stop feeding after they eat it.
 It is reportedly effective against thrips and worms. It is used as dust (20-40%)
5. Nicotine:
 Nicotine is obtained from tobacco plants, Nicotiana tobaccum and N. rustica (Solonaceae) to
the extent of 2-8%
 Activity: mimics acetylcholine in the nerve synapse, causing tremors, loss of coordination
and eventually deathIt is extremely fast acting, causing sever disruption and failure of nervous
system.
 It is used as fumigant in greenhouses, It acts as contact poison.
 Effective against sucking insects( thrips, leaf hoppers mealy bugs) and leaf miners. Sold
commercially as a fumigant (Nicotine) or as a dust (Nicotine sulphate) It is commercially
available as nicotine sulphate 40% (Black leaf 40) and manufactured in India only for export
purpose.

42. 6. Pyrethrum:
 "Pyrethrum" refers to powdered dried flowers of Chrysantheum cinerarifolium.
 "Pyrethrins" are all the toxic constituents of the pyrethrum flowers. It breaks down quickly
from sunlight.
 Commonly used synergist used for pyrethrins is piperonyl butoxide (PBO).
7. Limonene and Linanol:
 These are citrus peel extracts which causes insect paralysis.
 They evaporate quickly in environment and are used to control aphids, mites and fleas.
8. Ryania:
 Ryania botanical insecticides are made from grounded stem of Ryana speciosa. Is highly toxic
to the fruit moths, and citrus thrips, obtained by grinding the wood of the Caribbean shrub
Ryania speciosa (Flacourtiaceae).
 It is used to a limited extent by organic apple growers for control of the codling moth, Cydia
pomonella.

43. CASE STUDIES

44. Table 1: Concentration mortality response of Metarhizium rileyi to different larval
instars of Helicoverpa armigera after 7 days of treatment:
Conidial suspension/ml
Larval
instars
108 107 106 105 104 103 102 control
1st _ _ 83.33 76.67 53.33 36.67 20.00 0
2nd _ _ 80.00 60.00 43.33 30.00 16.67 0
3rd 83.33 66.67 56.67 43.33 33.33 20.00 _ 0
4th 76.67 66.67 56.67 40.00 26.67 16.67 _ 0
5th 53.33 46.66 36.66 23.22 20.00 13.33 _ 0

45. TABLE – 2: Concentration mortality response of 2nd and 3rd larval instars of Helicoverpa
armigera to Metarhizium rileyi incorporated with azadirachtin (1.02 and 1.53 ppm):
Azadirachtin conc
(ppm)
Larval instars Conidial suspension/ml control
(water)
108 107 106 105 104 103 102
Larval
mortality
(%)
1.02 2nd _ _ 86.21 68.97 44.33 27.59 10.34 0
1.53 3rd 89.66 72.41 51.72 37.93 27.59 13.79 _ 0

46. TABLE – 3: Concentration mortality response of 2nd and 3rd larval instars of Helicoverpa
armigera to Metarhizium rileyi incorporated with indoxacarb (0.72 ppm)
Larval instar Conidial suspension/ml control
(water)
108 107 106 105 104 103 102
Larval
mortality (%)
2nd _ _ 86.21 68.97 44.33 27.59 10.34 0
3rd 85.71 67.86 51.72 37.93 27.59 13.79 _ 0

48. Cabbage butterfly Pieris brassicae (l.) mortality (%) of different stages of larvae and
pupae against entomopathogenic nematodes
 Pieris brassicae mortality (%)
Treatments Stage Steinernema feltiae Heterorhabdus bacteriophora
48 hrs. 72 hrs. 48 hrs. 72 hrs.
Control 2nd instar
4th instar
Pupae
0.00 0.00
0.00 0.00
0.00 0.00
32.50 42.50
0.00 0.00
0.00 0.00
0.00 0.00
30.00 42.50
20 / IJ’s 2nd instar
4th instar
Pupae
(37.71) (44.98)
45.00 55.00
(42.09) (47.86)
37.50 52.50
(37.71) (46.42)
47.50 62.50
(39.15) (44.98)
67.50 77.50
(55.26) (61.74)
47.50 57.50
(43.54) (49.30)
47.50 57.50
40 / IJ’s 2nd instar
4th instar
Pupae
(43.54) (52.31)
57.50 67.50
(49.37) (55.41)
50.00 60.00
(44.98) (50.81)
55.00 70.00
(43.54) (49.30)
72.50 57.50
(58.42) (49.37)
57.50 85.00
(49.30) (67.47)
60.00 70.00

49. Pieris brassicae mortality (%)
Treatments Stage Steinernema feltiae Heterorhabdus bacteriophora
48 hrs. 72 hrs. 48 hrs. 72 hrs.
80 / IJ’s 2nd instar
4th instar
Pupae
(47.86) (56.92)
67.50 77.50
(55.26) (61.74)
62.50 72.50
(52.31) (58.58)
67.50 85.00
(50.81) (56.92)
80.00 90.00
(63.78) (74.12)
65.00 77.50
(53.75) (62.12)
72.50 87.50
160 / IJ’s 2nd instar
4th instar
Pupae
(55.26) (67.47)
80.00 87.50
(63.78) (69.50)
75.00 90.00
(60.08) (74.12)
(58.58) (72.08)
90.00 97.50
(74.12) (85.38)
77.50 90.00
(61.74) (74.12)
LSD
(p< 0.05)
2nd instar
4th instar
Pupae
4.17 6.44
6.03 6.05
5.69 8.78
7.24 10.03
8.46 9.80
4.39 8.54

51. TABLE 1: EFFECTS OF DIFFERENT INSECTICIDES ON OKRA JASSID AFTER THE
FIRST SPRAY.
Jassids count per plant
Treatments 3rd day of first spray 5th day of the first spray 7th day of first spray
Cannabis extract 10.06 (1.00) 9.36 (0.97) 12.35 (1.09)
Neem 4.70 (0.67) 8.32 (1.01) 10.81 (1.07)
Jholmol 8.15 (0.91) 10.33 (1.01) 14.44 (1.16)
Chemical 1.22 (0.08) 1.86 (0.27) 2.57 (0.41)
Control 19.23 (1.28) 21.12 (1.32) 25.19 (1.4)
CV
LSD0.05
27.38
0.33
16.89
0.24
17.21
0.27

52. TABLE – 2. EFFECTS OF DIFFERENT INSECTICIDES ON OKRA
JASSID AFTER THE SECOND SPRAY.
Jassids count per plant
Treatments 3rd day of 2nd spray 5th day of 2nd spray 7th day of 2nd spray
Cannabis 67.52 (1.83) 71.30(1.87) 74.26(1.87)
Jholmol 76.24(1.88) 88.40(1.95) 92.14(1.96)
Neem 58.13(1.76) 62.23(1.79) 64.83(1.81)
Chemical 11.00(1.04) 12.35(1.09) 13.29(1.12)
Control 104.13(2.02) 107.25(2.03) 112.96(2.05)
CV(%)
LSD
1.98
0.05
2.24
0.06
1.52
0.04

54. TABLE: BIORATIONAL PESTICIDES AGAINST APHIS GOSSYPII ON
WATERMELON
Treatment Cummulative mean no.
aphids/top three leaves
(PTC)
Cummulative mean
of aphids/top three
leaves (After
Per cent
reduction over
untreated check
Fruit yield
(t/ha)
Vitex negundo - leaf
decoction
5%
31.88 11.38 ±1.40 81.58 19.93
Azadirachta indica - oil 3% 30.30 4.39 ±0.63 92.89 25.5
Ricinus communis -oil 3% 33.16 15.93 ±1.34 74.21 23.03
Beauveria bassiana (1x108cfu
spores) -8g.L-1
30.53 6.01 ±0.80 90.27 24.43
Metarhizium anisopliae-
(1x108cfu spores) 8g.L-1
32.95 11.95 ±1.26 80.66 18.5

55. Treatment Cummulative mean
no. of aphids/top
three leaves (PTC)
Cummulative mean
no. of aphids/top
three leaves (After
treatment)
Per cent reduction
over
untreated check
Fruit yield (t/ha)
Emamectin
benzoate 5%
SG@0.4g.L-1
30.09 11.86 80.80 20.37
Spinosad 45% SC@
0.3m.L-
32.96 9.16 85.17 23.53
Untreated check 33.06 61.79 __ 16.3

56. CONCLUSION
 By the prolonged use of synthetic pesticides there is so much harm caused to
the environment resulting mainly in air and soil pollution because these
pesticides take so long to breakdown in nature. These pesticides are also
harmful to the animals, microorganisms, plants as well as human health. In
order to meet the continuing challenge agricultural scientists and
entomologists must increasingly focus their efforts on the study of those
elements of basic insect biology that will allow the development of safe and
selective products for plants and animals. Biorational pesticides give better
control than conventional insecticides, that satisfies the demands of pest
managers, farming communities and consumers to require pesticides with low
to moderate mammalian toxicity; have broader spectrum of activity, safer for
the environment and for beneficial insects.