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SSNAIK TNAU

TERM PAPER PRESENTATIONON

STEPS IN HOST SELECTION STEPS IN HOST SELECTION PROCESS OF PARASITOIDS PROCESS OF PARASITOIDS

COURSE TEACHER: Dr. S. SRIDHARAN, ProfessorENT 822 - ENTOMOPATHOGENS

CPPS, DEPT. OF AGRL. ENTO., TNAU,COIMBATORE-641 003

NAME :SABHAVAT SRINIVASNAIKID. NO: 2015800506YEAR : I Ph. D, 2015-2016DEPT.: AGRICULTURAL ENTOMOLOGY

Introduction

Conclusion

PART I

PART II

PART III

INDEX

Steps involved in host selection process

INTRODUCTION

PART I

PARASITOID

Parasitoid “An insect parasite of arthropod is parasitic only in immature stages, destroys its host in the process of development and free living as an adult (or) Parasitoid is an insect that feeds on the body of another insect or arthropod during the larval stage of the their life cycle and adult is a free-living insect, no longer dependent on the host” -Ramesh , 2010

TYPES OF HOST SELECTION PROCESS

1.Host selection process by herbivore/phytophagous insects

2.Host selection process by parasitoids

HOST SELECTION PROCESS-TERMS

1. Host 2. Herbivore/ phytophagy

1. Host/prey 2. Parasitoid/predator3. Phytophagy

HOST SELECTION PROCESS- A CONCEPT

“Host selection process is the manner by which the hosts are actually found and further development of the host parasitic relationship by crossing many physical and biological barriers in a habitat ”

Parasitoid and host are two components Two components must meet each other Seasonally, Geographically and Ecologically coincident Must cross Physical, Psychological and Physiological/Nutritional

barriers

HOST SELECTION PROCESS- A LIMIT

Potential parasitoids and hosts separated by the time and space Laboratory readily develop host-parasitoid relationship on the

factitious host species/unnatural Limits its parasitism- fraction of the host species in nature

(Salt,1937) A distinct and consecutive steps and its operation restricted to few Basis for the study of the host searching behaviour

STEPS IN HOST SELECTION PROCESS

PART II

Salt’s (1934) steps in HOST SELECTION PROCESS

1. Ecological selection 2. Psychological selection 3. Physiological selection

1. Host habitat finding 2. Host finding 3. Host acceptance 4. Host suitability

Host habitat finding and host finding comes under ecological selection Host acceptance come under psychological selection Host suitability comes under physiological selection

1. HOST HABITAT FINDING Most of the species habitat not coincided First activity seeking the habitat or the environment irrespective of the host Aysia manducator attracted towards the meat with/without the maggots

(Laing, 1937) Nasonia viripennis attracted to the infested meat only (Jacobi 1939) Preoviposition period no attraction to the host, Eg.,Opius flecheri (Nishida,

1956)

Opius flecheriNasonia viripennis

1. HOST HABITAT FINDING… Parasite of the Pine moth (Rhycionella buolina) is Pimpla ruficollis Ovarian development due to the oil of the pine tree (Thorpe and

Caudle, 1938) Eurytoma curta under natural conditions attracted to the flower

heads of the knap weed after that opens its bracts for gall fly. Closely related species different host selection process Eg. Aphytis chrysomphali and Aphytis lingnanensis on Aoniedella

aurantii

Pine tree knap weed

1. HOST HABITAT FINDING… EncarsiaEncarsia formosaformosa prefers to lay eggs on white flies feeding on prefers to lay eggs on white flies feeding on glabrous leaves.glabrous leaves.

1. HOST HABITAT FINDING…

Visual Tactile Acoustic Allelochemcals Pheromones Associative learning (conditioning).

Cues:

Attract stimuli

2. HOST FINDING It is difficult to separate two process /salt ecological selection Location of the host in the habitat Arrestant stimuli Random and non random searching movement Host finding most by tactile and olfactory cues Many sharp turnings on the patch of the host eg. Nasonia sp. Finally contacts the host

2. HOST FINDING……

2. HOST FINDING……

2. HOST ACCEPTANCE May not attack the host if there is no proper stimuli Determines the host specificity Truly host selection process and is clearly innate behaviour of the

parasitoid It is the salt’s psychological selection of the host Nasonia sp. with puparium of the Musca domestica no

marked attraction until it became 2-3 mm and climbed on the puparium

Move forward and downward projecting its antennae vertically and tapping the surface known as drumming.

The parasite stops drumming and flexes its body and tapping the body with its ovipositor.

In a such a way to drill the abdomen with its ovipositor.

2. HOST ACCEPTANCE…….

If the host is suitable the eggs are laid and feeding tube was formed.

At the end the host blood will be sucked and remove its ovipositor. Drumming not always leads to tapping Tapping definitely leads to the drilling Drumming will be changed to the different place of the puparium Again the tapping and drilling This process will be continued 2-3 times before complete insertion

of the ovipositor

2. HOST ACCEPTANCE…….

Insertion followed by oviposition and feeding tube formation Feeding tube formation occurs without the oviposition when there

is no ovaries

1. Finding host area, 2. Finding fly puparium, 3. Drumming and drilling response and 4. Oviposition and feeding response

Host habitat finding Host finding Host acceptance

ContactClimbing on the puparium Movement forward and down ward Start of drumming mechanism Tapping DrillingVenom injection Repetition Oviposition Feeding tube formation Suck the bloodHost marking Left the host

Nasonia sp. climbing on the puparium of blow fly

MANNER AND PLACE OF OVIPOSITION

Leads to the host specificity Oviposition habitat divides into the 3 categories

1. Oviposition apart from the host eg. Dipterans and few hymenopterans

2. Oviposition on the host eg. Hymenopterans 3. Oviposition in the host eg. Hymenopterans

UTILIZATION OF THE OVIPOSITOR

It is an power of parasite to utilize its ovipositor for effective parasitization (Flanders, 1947)

Power is measured by the Strength Length Flexibility Time The egg size is the major factor for changes in the ovipositor Small- easily flow Bigger- distortion of the ovipositor

PARALYSATION OF THE HOST First investigation on the Bracon hebetor by Beard in 1952 Injection of the venom Bracon hebetor first paralyse all the hosts then go for the oviposition He concluded that 1/200 parts of the host blood-permanent paralysis It is not compulsory Site of action is neuromuscular junction

4. HOST SUITABILITY It is an internal factor of the host Physiological in nature If the host found immune or unsuitable the host-parasitic

relationship may not established It is the final step in the host selection process Oviposition not a index of the host suitability According to the place of the host the suitability will vary Eg. Mesoleius tenthredinus x Larch sawfly, Pristiphora erichsonii (Canada) Mesoleius tenthredinus x Larch sawfly, Pristiphora erichsonii (Manitoba and Saskatchewan)

HOST DEFENCE MECHANISMHOST DEFENCE MECHANISM

Enemy-free space, Concealment or physical counter-attack Uptake of the antibacterial and antifungal substances

Internal

External

HOST DEFENSE MECHANISMHOST DEFENSE MECHANISM1.Cellular reactions

The formation of a cyst by host cells around foreign objects. Encapsulation has been reported to occur in epidermal,

tracheal, gut, muscle and nervous tissue. Haemolymphic capsules are formed by the haemocytes

congregating and differentiating into two layers; and the cells of the inner layer form connective tissue fibers

Encapsulation (Phagocytosis)

HOST DEFENCE MECHANISMHOST DEFENCE MECHANISM

Melanization involves the deposition of pigment around a parasitoid.

Many authors feel that Melanization is associated with encapsulation and is essentially a cellular phenomenon.

The melanin formed is derived from tyrosine by way of the phenolase reactions

Melanization

Pigmentation formation around the egg

HOST DEFENCE MECHANISMHOST DEFENCE MECHANISM

2.Humoral reactions2.Humoral reactions

Body fluids or the cellular secretions on or inside the parasitoid Coccophagus gurneyi female larvae gradually disintegrate in the

body fluids of Pseudococcus longispinus without visible reactions.

Leptomastix dactylopii larvae in Phenacoccus solani Monoctonus paladum in the aphid Aulacorthrum circumflexum.

CONCLUSION

PART III

CONCLUSION “Biological control is an ecofriendly and naturally

acceptable method of pest management included in the integrated pest management programmes. Biological control involved with parasitoids and predators. A parasitoid can select the host by a various steps like host habitat finding, host finding, host acceptance and host suitability. Understanding of the host selection process” host suitability in which the parasitoid will dominate the defence mechanism and establish a host parasitic relationship for continuous excavate the nutrients for developing progeny. Understanding these complex steps will enhances the sustainable biological control”

Please keep watch......

Host selection behaviour in parasitoid

TEXT BOOKSBiological control of insect pests and weeds by Paul DebachIntroduction to Insect behaviiour.123-127p Atkin. Introduction to general and applied entomology by Awasthi VB. Insect pest predators YA. Sathe and TV. Bhosale Insects as natural enemies a practical perspective by Mark A Jarvis WEB SITESwww.wikipedia.comwww.cirrus.comwww.nature magnified.comwww.tolweb.orgwww.tiptopbio.comwww.naturenorth.comwww.biobest.bewww.entnemdept.ufl.eduwww.britannica.comwww.nycaes cornell.com

REFERENCES

Thank You

Presented bySabhavat Srinivasnaik

ID.NO:2015800506I Ph. D (Agrl. Entomology)