entomopathogenic microbes in the management of insect

Entomopahtogenic microbes

1. WELCOME

2. Role of Entomopathogenic Microbes in the Management of Insects Doctoral Seminar Speaker Krishna Gupta Ph.D. Scholar on Seminar In -charge Dr. S. S. Shaw

3. Introduction: Entomopathogen

4. Different Types of Entomopathogens Virus Bacteria Fungi Nematodes Protozoa

5. History of bacteria First record on Bacillus thuringiensis in 1901 Ishiwata discovered a bacterium from diseased silkworm larvae Dr. Berliner received diseased Mediterranean flour moth larvae from mill in Thüringen (Germany) in 1909 Bt . was first used as an insecticide against European corn borer in South East Europe (1930) First commercial product, Sporeine was available in France for control of flour moth (1938)

6. Entomopathogenic bacteria   Spore formers Non-spore formers E.g. Pseudomonas spp.     Obligate spore formers Facultative spore formers E.g. Bacillus popillae Crystelliferous Non- Crystelliferous E.g. Bacillus thuringiensis E.g. Bacillus cereus (Dr. D. S. Reddy 2010)

7. Bacillus thuringiensis Bt is a Gram-positive, rod-shaped, spore-forming entomopathogenic bacterium. Bt protein toxins are highly selective to their target insect, are innocuous to humans, vertebrates, plants and are completely biodegradable. Bt is a viable alternative for the control of insect in agriculture and disease spreading vectors in public health. ( Ramanujam et. al., 2014)

8. Mode of action

9. Symptoms Larvae becomes inactive, stops feeding The head capsule becomes large compared to body size The larvae becomes flaccid and dies, usually within days or a week The body contents turn brownish-black as they decompose.

10. Different Bacillus thuringiensis spp . used in insect management Bacillus thuringiensis var. kurstaki : - Lepidopteran larvae (butterfly and moth) Bt var. israelensis : - Mosquito larvae Bt var . sandiego : - Coleopteran larvae (Beetles) Bacillus popillae : - Japanese beetle larvae (Dr. D. S. Reddy 2010)

11. History of virus Symptoms of Baculovirus infection in insect were first recognized in silkworms in 16 century Paillot (1926) described the first granulosis disease from the larvae of Pieris brassicae Bergold (1947) provided definitive evidence of the viral nature of disease ELCAR the first commercial viral pesticide produce by Sandoz Company in 1970

12. Entomopathogenic virus Baculoviridae Eubaculovirinae Nudibaculovirinae (Occluded virus particles) (Non-occluded virus particles)   NPV GV (Nuclear polyhedrosis viruses) ( Granulosis viruses)   ____ ____ ____ ____ ____ ____ (Dr. D. S. Reddy 2010)

13. Viruses Baculoviruses are the most common and most widely studied group of viruses pathogenic for insects. Baculoviruses are rod-shaped particles which contain circular double stranded DNA genomes. Viruses are obligate parasites hence need for multiplication.

14. The genus NPV is characterized by the presence of polyhedral shaped viral occlusions ( polyhedra ) containing randomly occluded viral particles. The genus granulose virus (GV) has one nucleocapsid per envelope and has granule shaped viral occlusions (capsules) containing one or rarely 2 or more virions . (Dr. T. V. Prasad) Conti….

15. Mode of action of virus

16. Symptoms They have a characteristic shiny- oily appearance and stop feeding. They climb to the top of the crop canopy, becomes limp, and hang from the upper leaves or stems, hence the common name “caterpillar wilt” or “tree top” disease. NPV – infected larvae may initially turn white and very dark

17. Different viruses used in insect management NPVs of Amsacta albistriga and A. moorei are used on groundnut for the control of red hairy caterpillers . Ha – NPV is used for the control of Helicoverpa armigera on chickpea and groundnut. Sl – NPV is used for the control Spodoptera litura on tobacco, groundnut, black gram and cotton. GV of Chilo infuscatellus is used for the management of shoot borer on sugarcane ( Canan usta 2013)

18. Entomopathogenic fungi reproduce sexually in soils and asexually in insect hosts. In its asexual form it produces spores known as conidia which are wind dispersed. It is usually need moisture to enable infection, and natural epizootics are most common during wet or humid conditions. ( Maina , et. al ., 2018) Entomopathogenic Fungi

19. History of fungi Louis Pasteur was the first to use fungus on grape vines in the vine yards to control the tiny inhabiting insect Beauveria spp. was discovered in 1835 as cause of the Muscardine disease of domesticated silkworms Verticillium lecanii was first observed in Ceylon (Sri lanka ) in 1861 on diseased Lecanium coffeae In 1879 and 1888 produced the fungus, Metarhizium anisopliae to control the wheat cockchafer and sugarbeet weevil

20. Mode of action of fungus Mode of action

21. Symptoms Infected insects stop feeding and becomes lethargic. They may die relatively rapidly, sometimes in an upright position still attached to a leaf or stem. The dead insect’s body may be firm and “cheese like”. (Dr. T. V. Prasad)

22. Different fungus used in insect management Beauveria bassiana : -They are used particularly to control sucking pests and caterpillars infesting crop plants. Spodoptera litura

23. Conti…. Metarrhizium anisopliae – This pathogenic fungus is used to control mainly coconut rhinoceros beetle, groundnut cut worm, rice brown plant hopper, diamond back moth and early shoot borer, top shoot borer and internode borer of sugarcane etc. Grass hopper Rhinoceros beetle grub Effected by Metarhizium anisopliae

24. Conti…. Nomuraea rileyi – It is used to control pod borers, cut worms, cabbage borers etc.

25. Conti…. Verticillium lecanii – This beneficial fungus is mainly used to control whiteflies, aphids, thrips , brown plant hopper, scale insects, mealy bugs and other sucking insect pests of crop plants. Green scale

26. Hirsutella thompsonii – These fungi are used to control different hoppers and bug pests, whiteflies, mites etc Coconut mite Citrus rust mite Conti…..

27. Entomopathogenic nematodes are soil-inhabiting, lethal insect parasitoids, live inside the body of their host. The most commonly studied genera are those that are useful in the biological control of insect pest, the Steinernematidae and Heterorhabditidae . Entomopathogenic nematodes (EPN)

28. History of EPN The first entomopathogenic nematode was described by Steiner as Aplectana kraussei (now Steinernema kraussei ) in 1923 The genus Heterorhabditis was described in 1976. In 1981, BR company supply S.carpocapsae on crickets and packaged a product called Neocide for use against the carpenter worm. In 1982, “The California Nematode Laboratories” was to produced the first commercial products, BioSafe , BioVector , etc from Steinernema spp .

29. Mode of action

30. Different nematodes used in insect management Steinernema carpocapsea – Against for lepidopterous larvae. S. faltiae – It is used for dipterous insects. Heterorhabditis bacteriophora – Soil-dwelling insects Nematodes in beet armyworm pupa (left) and termite worker (right)

31. Entomopathogenic protozoan Entomopathogenic protozoans are extremely diverse group of organisms comprising around 1000 species. They are generally host specific and slow acting. Producing chronic infections with general debilitation of the host. ( Ramanujam et al. 2014)

32. The first protozoa were seen by Antony van Leeuwenhock in 1674 Linnaeus included 2 species of free-living Protozoa in the 1758 edition of his Systema Naturae History of Protozoa

33. Mode of action Microsporidia must be eaten to infect an insect The pathogen enters the insect body via the gut wall, spreads to various tissues and organs These are relatively slow acting organisms, taking days or weeks to debilitate their host

34. Symptoms Infected insects may be sluggish and smaller than normal. Reduced feeding and reproduction, and difficulty in molting. Death may fallow if the level of infection is high.

35. Nosema locustae is used for the control of grasshoppers and crickets. Vairimorpha necatrix is used for the control of corn earworm, European corn borer, various armyworms and cabbage looper . Farinocystis triboli is used against red flour beetle. Different Protozoa used in insect management ( Dr. T. V. Prasad )

36. Advantages of Entomopathogenic microbes These are species- specific and hence safe to beneficial insects. Environmentally safe and safe to non target organisms. Compatible with other chemical insecticides. These are easy to apply. It is self sustaining and so economical.

37. Efficacy depend on environment conditions. Some pathogen (protozoan) are difficult to mass produce. Necessity of correct timing of application Results are not as quick as insecticides. Awareness among farmers is needed to adopt. Disadvantages of Entomopathogenic microbes

38. Example of entomopathogenic microbes A. Bacteria Targets insects Crop Product name Doses / ha. 1. Bacillus thuringiensis var . Kurstaki Lepidopteran larvae (butterfly and moth) Gram, chickpea Novodor , caterpillar killer, javelin, etc 1.5-3 kg 0.75-1.0 lit. 2. Bt var. Israelensis Mosquito larvae Skeletal, teknar , mosquito attack 3. Bt var . Sandiego Coleopteran larvae (Beetles) Storage crop Novardo, trident. 4. Bacillus popilliae Japanese beetle larvae Roses, grapes Doom, japidemic , grub attack 0.5-1 kg B. Virus 1. NPV Helicoverpa armigera and Spodoptera litura Tobacco , Soybean Gypchek virus 1.5-3.0 x 10 12 POB (250-500 LE) 2. GV Chilo infuscatellus , Achaea janata , Phthorimaea opercullela Sugarcane, potato Agrovir , madex 250 LE or 750 virosed larvae C. Fungi 1. Beauveria bassiana Whiteflies, aphids, thrips Glasshouse tomata/ ornamentals Mycotrol / botanigard 42.5x10 10 spore / m 3 or 2-3 kg dust 2. B. bassiana Sucking insects Cotton Naturalis 3. Verticillium lacanii Whiteflies, Aphids, Scales Glasshouse crop Vertalec 10x10 6 spores /ml 4. Metarrhizium anisopliae Termites House Bioblast 42.5x10 10 spore / m 3 5. M. anisopliae BPH, GLH Rice Bio magic 6. Nomouraea rileyi H. armigera . Achaea janata , S. litura Cotton Numoraea 10x10 10 spores /ml 7. Hirsutella thompsonii Mites Citrus Mycohit 1-5 g/ l of water D. Nematodes 1. Steinernema carpocapsea Larvae of soil-dwelling and boring insects Biosafe , ecomask , scanmask 1 lit. / 400-500 lit. water 2. Heterorhabditis heliothidis Soil-dwelling insects E. Protozoans 1. Farinocystis triboli Red rust flour beetle 2. Nosema locustae Grasshopper, European cornborer Nolo balt , grasshopper attack 3. Vairimorpha necatrix Corn earworm, armyworms, cabbage looper Cabbage , sorghum (Source: Ramanujam et al 2014, Canan Usta 2013, J. Alice et al., 2014, Maina UM, et al 2018 and Dr. T.V. Prasad)

39. Conclusions The application of entomopathogenic microbes for insect control is increasing largely because of Greater environment awareness. Food safety concerns. The failure of conventional chemicals due to an increasing number of insecticide resistant species. They provides us significant and selective insect control.