Habitat management plays an important role in integrated pest management by manipulating the agricultural landscape to promote natural enemies of pest species. The objectives of habitat management are to create suitable habitat to enhance natural enemy populations and maintain pest populations at subeconomic levels. Key approaches include intercropping, strip cropping, trap cropping, and providing additional food and overwintering resources to support natural enemies. Case studies demonstrate how these techniques can increase levels of pest egg parasitism and reduce pest populations in various crop systems.

1. Habitat management and its role in
Integrated Pest Management
Dr. Mandeep Rathee

2. Contents
• Habitat Management : Terminologies and History
• Concept
• Importance in IPM
• Objectives
• Approaches
• Case Studies
• Future Prospects
• Conclusions

3. Habitat
“A habitat is an area with specific environmental conditions
in which an organism lives and reproduces”
Management-- set of decision rules based on ecological principles, economic
and social considerations ---- The backbone is EIL
Raft spider (Dolomedes fimbriatus) is only found acidic bog habitat
Management
“Foster and Harris (1997) defined manipulation as, “use of stimuli that either
stimulate or inhibit a behaviour and thereby change its expression”

4. Habitat Management
• “The practical exploitation of plant diversity” (van Emden and Peakall,
1996)
• Habitat management often involves increasing the species diversity and
structural complexity of agro ecosystems
• “Habitat management is manipulation of agricultural area and
surrounding environment with the aim of conserving or augmenting
population of natural enemies and reducing pest incidence”
Chocolate- Box Ecological
Management

5. IPM: Integrated Pest Management
• IPM refers to an ecological approach in PM in which all the
available necessary techniques are consolidated in a unified
program, so that pest populations can be managed in such a way
that economic damage is avoided and adverse side effects are
minimized
(NAS, 1969)
• IPM is a decision support system for the selection and use of
pest control tactics, harmoniously coordinated into a
management strategy, based on cost/benefit analysis that take
into account the interest of and impacts on producers, society
and environment
(Kogan, 1998)
www.ipmnet.org/ipmdefinitions

6. Where does Habitat management stands in IPM ?
Habitat management

7. Concept
1. Natural enemies’ hypothesis
Predators and parasitoids will be more abundant and diverse in mixed plant
assemblages than in pure stands
2. Resource concentration hypothesis
Specialist herbivores are more likely to find, remain on and successfully
reproduce in pure stands than in mixed plant assemblages (Root, 1973)

8. Advent of Habitat Management
• Promotion of generalist predators in agricultural systems for centuries (Sweetman,
1958).
• 2000 years ago Chinese farmers used straw shelters to provide temporary spider
refugia and overwintering sites (Dong and Xu, 1984).
• In Burma (1770s) farmers used connecting bamboo canes between citrus trees to
enable predatory ants to move between the trees (van Emden, 1989).
Total papers published from 1973 to 2002
Gurr et al. (2004)

9. Need of Habitat Management
• Ubiquity of pesticide use
• Decreased diversity of natural enemies and
increased likelihood of pest outbreaks
(Koss et al., 2005)
• Monocultures favour herbivore population
buildup
• Agricultural landscapes often do not
provide resources for natural enemies at
the optimal time or place

10. Objectives
• To create suitable ecological infrastructure
For enhancing habitat suitability for natural enemies
For maintaining non-economic levels of pest or alternate
hosts at long periods

11. Key considerations in Habitat management
Ecology of pests and beneficial organisms
 Economically most important pests
 Most important predators and parasitoids
 Primary food sources, habitat and other ecological requirements
 Basis of attraction
Timing of operations
 When do pest populations generally first appear and when do these
populations become economically damaging?
 When do the most important predators and parasitoids of the pest appear?
 When do food sources (nectar, pollen, alternate hosts, and prey) for
beneficials first appear? How long do they last?
 What native annuals and perennials can be provided in the habitat?

12. Habitat Manipulation Approaches
Top down Control
Bottom up Control
Ecological Engineering
Kumar et al. (2013)

13. Rodriguez-Saona (2013)
Strategies for manipulating natural enemies in
agroecosystems

14. Plant characteristics deterring natural enemies
Natural
enemy
Pest Crop Mechanism
Trichogramma
chilonis Ishii
Helicoverpa
armigera
Hubner
Chickpea Malic and oxalic acid deter females
Trichogramma
spp.
H. armigera Pigeon pea Trichomes inhibit parasitoid
searching
Hyposoter
exiguae
Viereck
Helicoverpa
zea Boddie
Tomato Increased tomatine reduces longevity
and survival of parasitoid
Bellows and Fisher (1999)

15. Plant characteristics attracting natural enemies
Natural enemy Pest Crop Mechanism
Diaretiella rapae Cabbage
aphid
Crucifers Allyl isothiocyanate
Chrysoperla
carnea
Aphids Cotton Caryophyllene in foliage
Trichogramma
spp.
Heliothis zea Soybeans Volatiles of Amaranthus
retroflexus attract females
Bellows and Fisher (1999)

16. Conservation techniques commonly used for
natural enemies in greenhouse crops
Messelink et al. (2014)

17. Habitat manipulation techniques
• Intercropping
• Strip cropping
• Relay cropping
• Trap crops
• Adult food sources
• Modified tillage
• Overwintering sites
• Host plant resistance
• Limited use of pesticides
• Behaviour modification
• Push Pull Strategy

18. Natural enemies augmented in row intercropping system
Main crop Intercrop(s) Pest(s) Natural enemy(ies)
Cabbage Tomato Plutella xylostella L. Cotesia plutellae
(Kurjumov)
Clover Aphids, flea beetles Syrphids
Chickpea Coriander H. armigera Campoletis chlorideae
Uchida
Cotton Sesame H. armigera T. chilonis
Maize H. zea Spiders, Coccinellids,
Chrysopids

19. Influence of intercropping on defoliators in Groundnut
Treatments Reduction over control (%)
Amsacta albistriga
Walker
Spodoptera litura
Fab.
Groundnut + Bajra 43.8 45.7
Groundnut + Sorghum 35.8 34.5
Groundnut + Maize 32.3 39.9
Groundnut + Sesame 28.3 28.7
Groundnut + Onion 24.4 11.2
Groundnut + Marigold 23.4 20.5
Groundnut + Red gram 23.9 24.6
Groundnut (Pure crop) - -
Partibhan et al. (2016)

20. Influence of intercropping on insect pests
in Cabbage
Brandford et al. (2011)

21. Parasitisation of Helicoverpa armigera eggs by Trichogramma
chilonis Ishii on cotton in two cropping systems
Cropping
system
No. of eggs
collected
No. of eggs
parasitized
Per cent
parasitization
Pure cotton 100 Nil Nil
Cotton-sesame 130 41 31.5
Ram et al. (2002)

22. Impact of intercropping on egg-parasitism of Earias vittella Fab.
due to T. chilonis in cotton crop
Yadav and Anand Jha (2003)
Catopsilia pyranthe (L.) Cassia occidentalis L. T . chilonis

23. Natural enemies augmented in strip-cropping system
Main
crop
Strip
crop(s)
Pest(s) Natural enemy(ies) Reference
Cotton Lucerne H. armigera Beetles, Bugs,
Lacewings, Spiders
Mensah (1999)
Maize
Sorghum
Cowpea
Bollworms and
sucking pests
Spiders, Coccinellids,
Chrysopids, Rove beetle
Kavitha et al.
(2003)
Soybean Maize H. armigera Tachinids Abate (1991)

24. Lucerne strips (centre) interplanted in commercial cotton:
Impact on NEs
Mensah (1999)
Cotton
Lucerne

25. Natural enemies conserved by relay cropping system
Main crop Relay
crops
Natural
enemies
Reference
Cotton Wheat All natural
enemies
Xia. et al. (1994)
Cotton Maize All natural
enemies
Sharma (1996)
Cotton Barley All natural
enemies
Zhang et al. (1991)
Cotton Rapeseed All natural
enemies
Slosser et al. (2000)

26. Increased parasitism due to presence of adult food sources
Parasitoid Pest Crop Food sources
Aphelinus mali
(Haldeman)
Aphids Apple Nectar from the honey
plants, Phacelia and
Eryngium sp.
Aphytis proclia
(Walker)
San Jose scale
(Quadraspidiotus
perniciosus Borchsenius)
Orchards Nectar from the honey plant,
Phacelia sp.
Various species Codling moth (Cydia
pomonella L.)
Apple Nectar from weeds
Lixophaga
sphenophori
(Villeneuve)
Sugarcane weevil,
Rhabdoscelus obscurus
(Boisduval)
Sugarcane Nectar from weeds
(Euphorbia species)
Powell (1986)

27. Increased parasitism due to presence of alternate hosts
Parasitoid Pest Crop Alternate host
Lydella grisescens
(Tachinidae)
Ostrinia nubilalis Hubner Maize Stalk borer, Papaipema
nebris on giant ragweed
Trichogramma chilonis Helicoverpa armigera Cotton Acherontia styx on sesame
Lysiphlebus testaceipes
Cresson (Aphidiidae)
Schizaphis graminum Sorghum Aphis helianthi on
sunflowers
Emersonella niveipes
(Eulophid egg
parasitoid)
Chelymorpha cassidea
(Tortoise beetle)
Sweet
potato
Stolas sp. beetles on
morning glory
Opius spp. (Braconid
larval-pupal parasitoid)
Rhagoletis pomonella
(Apple maggot)
Apple Other Tephritidae fruit flies
on weeds
Powell (1986)

28. Buckwheat strip in the
margin of an Australian potato crop
Strip cutting of a lucerne
hay stand in Australia
New Zealand vineyard with
buckwheat ground cover
Beetle bank in British arable field in
England
Nectar, shelter and overwintering sites

29. Trap crops are stands of plants grown that attract
insect pests away from the target crop
Parker et al. (2013)
Brassica
juncea L.
Brassica oleracea L.
var. italica

30. Perimeter trap cropping (Border trap cropping)
Row trap cropping
Strip trap cropping
Trap cropping arrangements
30

31. Perimeter trap cropping (border trap
cropping)
 The trap crop completely
surrounds the main cash crop
 Feasible on small to medium
scale
 Too resource intensive on
large scale (seed, time,
management)
31

32. Rows of sorghum and sunflower line the edge of a crop field to protect
tomato plants from the leaf-footed bugs, Leptoglossus phyllopus (L.)
Cullman (2012)

33. Control of soybean stink bugs, Nezera viridula (L.) using
the trap crop Sesbania rostrata
Nezara viridula population on soybean
with and without trap crop
Comparison of damage caused by stink bugs on soybeans
planted with and without trap crops

34. Row trap cropping- planting of the trap crop in
alternating rows within the main crop
Sustainable American
Cotton Project
Aalfalfa within the main
crop cotton for control
of Lygus bug
Stern et al. (1981)

35. Marigold and coriander used as a trap crop for management of
tomato fruit borer, H. armigera in tomato
Summer
Saugat
Pusa
Narangi
Local
Punjab
Sugandh
Sandhu and Arora (2014)

36. Dead end trap cropping
• Trap crop is highly attractive to insect pest, the trap crop does
not support its growth and development
• Yellow rocket, Barbarea vulgaris (L.) W.T. Aiton was evaluated
as a trap crop for diamondback moth, Plutella xylostella (L.)
(Lepidoptera: Plutellidae) in cabbage
36

37. Shelton and Nault (2004)
Mean P. xyllostella larvae in treatments with only cabbage and 5, 10 and 20%
yellow rocket

38. Recent examples of trap cropping systems
successfully applied in agriculture
Moshefi and Bahojb Almasi (2016)

39. Crop practices: Tillage
• Intensity of soil tillage, the method used, the number of
operations, the frequency, and the period of soil cultivation
have an impact on predatory arthropods
• Reduced tillage systems create a more stable environment,
encouraging the development of more diverse species (Altieri,
1999)
• Abundance and diversity of the soil fauna tend to increase with
decreasing tillage intensity (Holland, 2004)

40. Crop practices: Host plant resistance
• Since natural enemies, particularly parasitoids, select their
host depending on weight, size, or growth stage, plant
resistance may indirectly affect the biological control of pests
• Brewer et al. (1998) reported that parasitoid populations
were larger on susceptible barley cultivars than on cultivars
resistant to aphids, due to the larger aphid populations on
susceptible cultivars

41. Crop practices: Fertilization
• Aphid populations associated with Brassica crop plants are
particularly known to increase in response to higher soil
nitrogen levels (Altieri and Nicholls, 2003)
• Sarfraz et al. (2009) demonstrated that parasitoid, Diadegma
insulare (Cresson) of the oilseed rape pest, P. xylostella
performed better on plants grown with high levels of fertilizer

42. Crop practices: Harvesting
• Harvesting produces a brutal perturbation of the
agroecosystem involving microclimate changes that affect
natural enemy populations
• For winter crops (such as winter oilseed rape and most
cereals), harvesting dates generally coincide with the
period during which the abundance and activity of some
predators are maximum (Buchs, 2003)

43. Effect of strip-harvesting and normal harvesting on the average
number of natural enemies in alfalfa
Natural enemies Thousands per hectare
Normal harvesting Strip-harvesting
Coccinellid adults 114 507
Coccinellid larvae 27 573
Chrysopid larvae 483 509
Hymenopterous parasitoids 173 709
Heteropterans 492 991
Aphidophagous spiders 259 2703
Total 1547 5992
(Schlinger and Dietrick, 1960)

44. Use of behavioural chemicals
• Chemicals produced by host, host food, plants attract natural
enemies to the host habitat
• Kairomones (tricosane) from moth scales attract
Trichogramma species
• The onion fly, Delia antigua (Meigen) can be deterred from
laying eggs on seedling onions by cinnamaldehyde and
stimulated to lay eggs on worthless cull onion bulbs that are
planted in the same field (Cowles and Miller, 1992).

45. Mean per cent parasitisation of H. zea eggs by naturally occurring
Trichogramma in field plots treated with
H. zea sex pheromone
Observation Treated Control
Day 1 24.4 18.6
Day 2 45.5 20.2
Mean 35.6 22.6
Lewis et al. (1981)

46. Parasitisation of H. zea eggs by Trichogramma pretiosum
Treatment Parasitisation (%)
Corn treated with tomato extract
Treated 37.7a
Control 28.5b
Nordlund et al. (1985)

47. Z.R. Khan et al. at the International Centre for
Insect Physiology and Ecology, Nairobi, developed
the concept for the management of cereal stem
borers of food and forage crops
The technology has been especially successful for
the management of Chilo partellus Swinhoe and
‘witchweed’ Striga hermonthica (Delile) Benth. in
maize and sorghum
PUSH - PULL IPM
Khan et al. (1997, 2004, 2011)
47

48. Components and mode of action
of the ‘‘push–pull’’
PUSH - PULL IPM
(Zhang et al., 2011)
48

49. Push Crops Repel ovipositing borers
STEM BORER MANAGEMENT BY
PUSH - PULL IPM IN KENYA:
A classic example of habitat management
Molasses grass (Melinis minutiflora) & Silverleaf
(Desmodium uncinatum)
Pull Crops
Trap plants and reservoir for natural
enemies
Napier grass (Pennisetum purpureum) & Sudan grass
(Sorghum vulgare sudanense)
Molasses grass, when intercropped with maize, not only reduced stem borer
infestation, but also increased parasitism by Cotesia sesamiae (Cameron)

50. A diagrammatic presentation on how push-pull strategy works
for cereal stem borers (Pickett et al., 2014)

51. Parasitism of stem borer larvae by C. sesameae in maize-M. minutiflora
intercrops planted in various ratios

52. Helicoverpa in cotton
Colorado potato beetle in potato
Pea leaf weevil in beans
Pollen beetle in oilseed rape
PUSH-PULL IPM IN OTHER CROPS
Push-pull strategies has also been effectively demonstrated against
Onion maggot on onions
Thrips on chrysanthemum
Bark beetles on conifers
Veterinary and medical pests
(Cook et al., 2007)

53. Push-Pull Strategies in Insect Pest Management
Insect Pest Crop Components Reference
Push Pull
H. armigera Cotton Neem seed
extracts to the
main crop
Trap crop, either pigeon
pea, Cajanus cajan (L.)
Huth or maize, Zea mays
L.)
Pyke et al.
(1987)
C. partellus
Busseola fusca
Fuller
Maize and
Sorghum
Molasses grass
(M. minutiflora),
silverleaf
desmodium (D.
uncinatum)
Napier grass, Pennisetum
purpureum Shumach or
Sudan grass, Sorghum
vulgare sudanense (Piper)
Hitchc.
Khan and
Pickett
(2004)
Meligethes
aeneus (Fab.)
Oilseed
rape
Perimeter turnip
rape trap crop
Cultivars of oilseed rape
with low proportions of
alkenyl glucosinolates
Cook et al.
(2004)
Frankliniella
occidentalis
(Pergande)
Chrysanthemu
m
Volatiles of the
non-host plant
rosemary
Antifeedant polygodial
(extracted from Tasmannia
stipitata (Vickery) A.C.
Sm.
Bennison
et al.
(2001)

54. Contd..
Insect Pest Crop Components Reference
Push Pull
Ips
paraconfusus
Lanier
Torrey
pine
trees
Antiaggregation
pheromone
Traps baited with
aggregation
pheromones
Shea and Neustein (
1995)
Mosquitoes Botanical
repellents
Attractive
pheromones
Fradin et. al. (2004)
Cockroaches Insect repellent
n-methylne
odecanamide
Pheromones
contained in their
frass have volatile
attractants
Nalyana et. al. (2000)

55. Striga weed control
• Witchweed or Striga are obligate root parasites of cereal crops
• Striga infests 40% of Africa’s arable
• loss of $7-11 billion to agricultural economy
• Desmodium intercrops suppress S. hermonthica through an
allelopathic mechanism
• Desmodium root exudates contain novel flavonoid compounds,
which stimulate suicidal germination of S. hermonthica seeds
and dramatically inhibit its attachment to host roots (Khan et
al., 2010)

56. Comparison of means of maize stem borer damage, striga weed
rating and maize yield from a 'push-pull' trial
Parameter Maize + Sudan grass +
Desmodium sp.
Pure maize Difference
Stem borer
damage (%)
11.1 22.0 -10.9
Striga weed
rating
0.1 2.4 -2.3
Maize yield
(t/ha)
6.7 5.2 1.5
Khan (2001)

57. Economics of push–pull strategy in KENYA (2004)
Hassanali et al. (2008)
a, b and c represent data averages for 7, 4 and 3 years, respectively
*p<0.05

58. • Need to strengthen the research in improving the efficiency of the natural
enemies
• Periodical training is necessary to educate the extension workers and
farmers
• A concerted research effort between different disciplines
• Studies should be conducted in larger areas so as to generate good amount
of data to increase adoption
• Socially acceptable, economical and environmentally safe
Future Strategies

59. Conclusions
• Habitat management is a human activity that modifies the
environment according to ecological principles
• The effects of habitat management on trophic interactions
show that farming practices might play an important role in
regulating natural enemy and pest populations
• Pesticide risks can be avoided substantially side by side
promoting natural biological control
• Future of IPM lies in increasingly sophisticated ecological or
habitat manipulation techniques