Locust presentation

Locust and their management

1. Speaker Dr. S. S. Shaw Professor Department of Entomology College of Agriculture Indira Gandhi Krishi Vishwavidyalaya   Raipur, (C.G.) - 492012 LOCUSTS AND THEIR MANAGEMENT

2. INTRODUCTION Locust belongs to a large group of insects commonly called grasshoppers, which are recognisable by the big hind legs used for jumping. They belongs to the order Orthoptera and the most important locusts are found in the family Acrididae

3. SWARM AND HOPPER Locusts are special grasshoppers, usually large ones, which have a capacity for changing their habits and behaviour when they occur in large numbers. When their numbers rise they become gregarious in habit and stay together in dense groups. These groups are called swarms and wingless young stages are commonly called ' hoppers '

4. Swarming of locust

5. Urban swarming Please double click on slide for video

6. Swarming Please double click on slide for video

7. BEHAVIOUR The swarms of several species of locust can migrate over great distances, and this gregarious behaviour are the outstanding characteristics that distinguish typical locusts from other grasshoppers. When locusts are in small numbers they lives individually like ordinary grasshoppers. There are several different kinds of typical locusts capable of forming large migrating swarms.

8. Conti.. These sudden population rise may start by unusual weather conditions or changes in land-use; they may not actually result in large migrating swarms but the groups formed will stay together in a typical locust way. Such species may be regarded as being intermediate between grasshoppers and typical locusts.

9. CHARACTER Locusts are the short-horned grasshoppers with highly migratory habit, marked polymorphism and voracious feeding behaviour. They are capable of forming swarms (adult’s congregation) and hopper bands ( nymphal congregation). They cause great devastation to natural and cultivated vegetation.

10. SPECIES Insects are very much associated with man’s life. Some are useful and some are highly harmful to mankind, one of which is Desert locust, the most harmful insect in the world. They are scourge of mankind since time immemorial. There are ten species mainly known from the worldwide (Table 1).

11. Table 1: IMPORTANT SPECIES OF LOCUSTS IN THE WORLD S. NO. COMMON NAME SCIENTIFIC NAME 1 Bombay Locust Nomadacris succincta 2 Migratory Locust Locusts migratoria manilensis ; Locusta migratoria migratoria oides 3 Italian Locust Calliptamus italicus 4 Moroccan Locust Dociostaurus morocannus 5 Red Locust Nomadacris septemfaciata 6 Brown Locust Locustana pardalina 7 South American Locust Schistocerca paranensis 8 Australian Locust Chortoicetes termenifera 9 Tree Locust Anacridium Spp. 10 Desert Locust Schistocerca gregaria

12. SPECIES FOUND IN INDIA Only four species of locust are mainly found in India (fig. 1). Desert locust ( Schistocerca gregaria ), Migratory locust ( Locusta migratoria ), Bombay Locust ( Nomadacris succincta ) Tree locust ( Anacridium sp. ) The desert locust is most important pest species in India as well as in intercontinental context.

13. Fig. 1: LOCUST REPORTED IN INDIA Species Nymph Adult Desert locust ( Schistocerca gregaria ) Migratory locust ( Locusta migratoria ) Bombay Locust ( Nomadacris succincta ) Tree locust ( Anacridium sp.)

14. LIFE CYCLE /BIOLOGY The life cycle of locust from egg to adult stage requires several weeks as indicated below: Table 5: Life cycle parameters Stage Egg, Hopper, Adult Duration Egg 10-65 days Hopper 24-95 days (36 days average) Adult 2.5-5 months Laying-fledging 40-50 days Adult maturation 3 Weeks-9 months (2-4 months average) Total 2-6 months Larval moults 5-6 (solitarious), 5 (gregarious) Phases Solitarious , transient and gregarious

15. Fig 5 (a) Sexual dimorphism male and female Male - tip of abdomen smooth and rounded Female - tip of abdomen jagged

16. Fig 5 (b) Mating

17. Fig 5 (c) Egg laying

18. Fig 5 (d) Egg pods

19. Fig. 5 (e). Locust egg pods

20. Fig. 6: Life cycle of Desert locust

21. BREEDING SEASON In all, there are three breeding seasons for locusts as follows: Winter breeding [November to December], Spring breeding [January to June] and Summer breeding [July to October] India has only one locust breeding season and that is Summer breeding. The neighbouring country Pakistan has both spring and summer breeding.

22. Fig. 4: Breeding season behavior pattern of locust CONGREGANS DISSOCIANS SCATTERED LOCUST CONCENTRATION MULTIPLICATION GREGARIZATION HOPPER BANDS AND SWARMS

23. DISTRIBUTION The invasion area of desert locust covers about 30 million sq km which includes whole or parts of nearly 64 countries. This includes countries like North West and East African countries, Arabian Peninsula, the Southern Republic of USSR, Iran, Afghanistan, the Indian sub-continent. During recession periods when locust occurs in low densities, it inhabits a broad belt of arid and semi-arid land which stretches from the Atlantic Ocean to North West India. Thus, it covers over 16 millions sq kms in 30 countries (Fig. 2 & 3).

24. Fig. 2: World distribution of locust

25. Fig 3. LOCUST SITUATION: Period 01-15 June, 2020

26. LOCUST PLAGUES AND UPSURGES The attack of the desert locust used to occur earlier in a phases of plague cycles (a period of more than two consecutive years of wide-spread breeding, swarm production and thereby damaging of crops is called a plague period ) followed by a period of 1-8 years of very little locust activity called as the recession period again to be followed by another spell of plague. India witnessed several locust plague and locust upsurges and incursions during last two centuries (Table 2a, 2b)

27. Small scale localized locust breeding have also been reported and controlled during the period 1998, 2002, 2005 , 2007 and 2010. Since 2010 till 2012-13, situation remained calm and no large scale breeding and swarms have been reported. However, solitary phase of Desert locust has been reported from time to time at some locations in the State of Rajasthan and Gujarat.

28. During 2020 the swarms started from north west and east African countries and entered in India from Pakistan to Rajasthan and from Rajasthan to Gujrat , MP and from MP to Chhattisgarh. While writing this the migration of locust is towards UP and indication of reaching to adjoining state of UP i.e. Haryana & Delhi and NCR.

29. Table 2 (a): Locust plagues observed during different years Locust plagues observed during following years 1812-1821 1900-1907 1843-1844 1912-1920 1863-1867 1926-1930 1869-1873 1940-1946 1876-1881 1949-1955 1889-1891 1959-1962 Sources: Directorate of Plant Protection Quarantine & Storage

30. Table 2 (b): Locust upsurges observed during different years Year No. of swarms incursion 1964 004 1968 167 1970 002 1973 006 1974 006 1975 019 1976 002 1978 020 1983 026 1986 003 1989 015 1993 172 1997 004 Sources: Directorate of Plant Protection Quarantine & Storage

31. Table 3: Losses caused by locusts in India in different outbreak year S. No. Outbreak Estimated loss (in rupees) 1 1926-31 10 crores 2 1940-46 2 3 1949-55 2 4 1959-62 50 lakh 5 1978 2 lakh 6 1979 7.18 lakh 7 2020 Yet to calculate Sources: As per the data available with the Union Agriculture Ministry,

32. Table 4. Morphmetric characters of different phases of locusts Characteristics Solitary phase Gregarious phase Behavior -Do not form groups or swarms -Roost, bask, feed and move as individuals -Hoppers move short distance, adults fly as individuals at night -Form persistent and cohesive groups, bands and swarm -Roost, bask, feed and move together -Very mobile, fly as swarms by day. Hoppers move in band. Colour -Hoppers uniformly green in early instars but may be brown in last two instars. -Adult pale greyish brown, buffer peach coloured. Males change to pale yellow on sexual maturation . -Hoppers have black pattern on yellow or orange background -Adults rosy pink on fledging, darkens with age to grayish or brownish red then to yellow on sexual maturation. Males are brighter.

33. Characteristics Solitary phase Gregarious phase Colour - Female show no colour change on maturation at low density. Morphometrics F/C Male 3.75 and above Female 3.85 and above E/F Male 2.025 or below Female 2.075 or below F/C Male 3.15 or below Female same as above E/F Male 2.225 and above Female 2.272 and above Note: C = Width of head, E = Length of forewing, F = Length of hind femur, measuring Unit in milimetre

34. MANAGEMENT OF LOCUST

35. Locust monitoring organization In India, the scheme Locust Control and Research (LC&R) is responsible for control of Desert Locust and is being implemented through Organisation known as “Locust Warning Organisation (LWO)” established in 1939. Later amalgamation of LWO with the Directorate of Plant Protection Quarantine and Storage in 1946. Locust Warning organization (LWO) is responsible to monitor and control the locust situation in Scheduled Desert Area (SDA) mainly in the States of Rajasthan and Gujarat while partly in the States of Punjab and Haryana by way of intensive survey, surveillance, monitoring and control operations where required.

36. Management of locust There are following ways by which locust can be managed: Mechanical methods – digging trenches, beating and burning Biological control- natural enemies of the desert locust. Baiting – scattering locust food impregnated with insecticide Dusting – applying a fine dust impregnated with insecticide Spraying liquid insecticides (chemical or biological)

37. Digging trenches is effective measure to manage hopper and prevent crop damage. Locust eggs can be destroyed by digging or ploughing the field. Proper information of the previous swarming sites is necessary to locate the locust egg beds in order to increase the effectiveness. Crop damage can be prevented if the locust infestation is less but in case of high infestation other measures control can be used Mechanical management

38. BIOLOGICAL CONTROL (NATURAL ENEMIES OF THE DESERT LOCUST) Most of the natural enemies of the Desert Locust are now known, but knowledge about the proportion of locusts killed by them is very scanty. Much more information is required so that we can have a better idea of how much assistance can be expected from these natural enemies at various times and places.

39. Insect enemies There are several parasitic wasps of the genus Scelio (Fig. 7 ) which can destroy the eggs of locusts. When a female locust lays its eggs, the female Scelio digs through the froth plug of the egg pod and lays its own minute eggs inside the locust eggs. (I)Egg parasites and Predators (A) Scelio antorides :

40. One Scelio egg is laid in each of several of the locust eggs. The parasite hatches and, feeding on the contents of the locust egg and complete larval stage inside the locust eggs. The adult Scelio emerges by biting round the end of the locust egg. Infested locust eggs are easily recognised since they become more opaque and darker than normal eggs. Scelio occurs more frequently in egg pods of scattered solitarious locusts.

41. Fig. 7: Scelio antorides , adult male.

42. (B) Locust Blowfly, Stomorhina lunate Stomorhina lunate resembles the housefly (Fig. 8). This fly is probably the most important natural enemy of the Desert Locust. It often destroys up to 20% of locust eggs locally. It is very often seen where swarms of desert Locusts, red locust, brown locust, and migratory locust are laying their eggs.

43. The adult Stomorhina lay its eggs in the top of the locust egg pod. The fly's eggs hatch in a few hours and the larvae feed on the locust eggs. There may be one or several Stomorhina in a single egg pod. They usually prevent all the eggs in the pod from hatching.

44. Fig. 8. Stomorhina lunate

45. (C) Bee Fly, Systoechus somali Systoechus somali belonging to family Bombyliidae , which are sometimes called 'bee flies' because of their hairiness which makes them resemble bees (Fig.9). The adult flies are active only on warm sunny days and fly rapidly, rarely settling. The females fly close to the ground and lay eggs in cracks and hollows in the soil. When the larvae hatch they move through the soil until they find locust egg pods.

46. The second and third instars of the larvae feed in the egg pod. The third- instar larva is a creamy colour, markedly curved and legless. (The difference between these and beetle larvae is that the latter have three pairs of legs at the front end of the body.)

47. Systoechus larvae feed on locust eggs by puncturing them and sucking the contents. A single locust egg pod may contain several larvae, and as many as 50% of the pods in an egg field have occasionally been found to be attacked and partially destroyed. Damage up to 10% of the eggs is only recorded. Other species of genus Systoechus have been also recorded feeding on the eggs of the Brown Locust and Senegalese Grasshopper.

48. Fig. 9. Systoechus somali , adult female.

49. (D)  Hide beetles, Trox procerus Trox procerus is o ne of the commonest beetle found digging up locust eggs (Fig. 10). It is an important egg predator in the summer breeding areas of West Africa south of the Sahara, Sudan, the Red Sea coasts and the Indo-Pakistan desert.

50. Fig. 10. Trox procerus (Adult)

51. Tiny mounds of earth all over the egg field often indicate that Trox larvae are present. The full-grown larva is about 40 mm long with three pairs of legs and a black head. Sometimes the larvae eat locust eggs for a while and then wander away in the soil before they are full-grown, presumably to complete their feeding on other eggs or larvae. It is therefore difficult to decide exactly how much damage they do to locust egg fields.

52. Blaesoxipha filipjevi is one of the sarcophagid flies, commonly called flesh flies (Fig. 11). The adult flies are generally seen sitting on plants or on the ground. Blaesoxipha eggs hatchs indside the female’s body. (II ) Parasites of hoppers and adults (A) flesh flies, Blaesoxipha filipjevi

53. When the female contains larvae it become very active, and if a locust flies, the flesh fly strikes it as darts. The larvae burrow through the membranes at the base of the wings and then feed and grow inside the locust. When the larvae are fully grown they leave the locust and pupate in the ground. Blaesoxipha filipjavi is an effective control agent against small stationary populations of Desert Locust.

54. Blaesoxipha filipjavi are non-migratory and takes three weeks to complete their life cycles. Blaesoxipha filipjavi has also been recorded parasitising Tree Locusts, Diabolocatantops axillaris , Kraussaria angulifera and Variegated Grasshoppers. Other Blaesoxipha spp. Parasitise African Migratory Locusts, Red Locusts, Sudan Plague Locusts, Diabolocatantops axillaris , Cataloipus cymbiferus and Bombay Locusts.

55. Fig. 11. Blaesoxipha filipjevi

56. (B) Nemestrinid flies, Symmictus costatus Symmictus costatus belongs to family Nemestrinidae (Fig. 12). Symmictus costatus had been reported parasitizing Brown Locusts and Sudan Plague Locusts. It lays a large number of minute eggs in cracks of the soil or the bark of trees. After hatching, the young larvae are blown by the wind.

57. If they find hoppers they enter inside them through the soft membrane and pass through four instars inside the hoppers. This takes 9-14 days, after which they leave the hoppers and enters the ground for rest of the life cycle. Pupation is induced by rain and may not occur for several months or even years if the soil is dry. The adult emerges about 14 days after pupation. In East Africa, in a band of fourth- and fifth- instar hoppers, 34% of the hoppers contained Symmictus larvae.

58. The larvae were mainly in the fourth- instar hoppers. It seems that moulting was delayed owing to the presence of the parasites and few of the affected hoppers survived. The hoppers containing parasites appeared swollen and had chalky pinkish-white markings instead of the usual yellow ones.

59. Fig. 12. Symmictus costatus , adult male.

60. It occurs in Locust which eat each other (Fig. 13). This happens particularly in the hopper stage and especially at hatching time. The first hoppers after hatching often eat other hoppers that hatches later. It sometimes occurs on a large scale, especially in very dry conditions under unavailability food. (III ) Predators of hoppers and adults (a) Cannibalism

61. Fig. 13. Cannibalism in locust

62. (b) Ants In some places ants are very numerous and they probably eat large numbers of young hoppers. They have been seen carrying away numerous hatchlings which is seen at the surface of the soil (fig. 14). Research is needed to know much about their effect on locust populations.

63. Fig. 14. Ants eating hoppers

64. (c) Ant lions The large ant lion species are seen predating both hopper as well as adult stage of locust (fig. 15). Both hoppers and adults of the Desert Locust have been seen crossing the pits in which ant lion larvae lie in hiding, the larger species of ant lions often predate them. These predators are neither specific to locusts nor significant in numbers.

65. Fig 15. Ant lion

66. (d) Wasps Wasps, particularly species of Sphex (Fig. 16), have frequently been seen attacking Desert Locusts. They paralyse them, drag them away and bury them after they have laid eggs on them, one egg on each. The total numbers of locusts killed must be very small compared with the number in the swarm but the predation is reported.

67. Fig 16. Wasps

68. (e) Birds Many kinds of birds, both large and small, feed on locust hoppers and adults. In East Africa, a swarm was attacked by several birds, mainly Marabou Stork, White Stork and Eagle (fig. 17) . It was seen that 1093, 309 and 23 numbers of locusts found in their oesophagus , crop and stomach, respectively.

69. Fig. 17 (a) Marabou Stork

70. Fig. 17 (b) White Stork

71. Fig. 17 (c) Eagle ( Aguila calva )

72. (f) Reptiles and mammals Lizards and snakes feed on locusts. sometimes, foxes, dogs, hyenas, jackals, ant bears and smaller mammals like hedgehogs and rats also feed on locust. Nothing is known of their overall effect on locust populations.

73. Fig. 18. Reptiles and mammals eating locust

74. There are many entomopathogenic microbes which kill the locust. The details are as under (III ) Microbes (a) Nematodes Nematodes, which are thin worms, commonly occur inside locust hoppers and adults. The entomopathogenic nematodes Heterorhabditis megidis and Steinernema feltiae turned out to be successful antagonists of the orthopteran insects Locusta migratoria and Schistocerca gregaria .  

75. feltiae

76. (b) Protozoa Protozoa such as Nosema locustae can kill locusts and grasshohppers . The efficacy is still need to be work out.

77. Figs 1-6. Developmental stages and spores of Nosema locustae and Perezia dichroplusae as fresh preparations under phase contrast microscopy. 1 -mature spores of N. locustae , 2 - disporoblastic sporogony of N. locustae , 3 - diplokaryotic stages ( meronts ) of N. locustae ; 4 -mature spores of P. dichroplusae , 5, 6 - moniliform plasmodia and polysporoblastic sporogony of P. dichroplusae . Scale bar 10 µm.  

78. (c) Bacteria As per report two species, namely Serratia marcescens   Bizio and  Pseudomonas aeruginosa  ( Schroeter ) Migula consistently infect locusts when ingested with food.

79. Serratia marcescens   Bizio under microscope

80. (c) Fungi Fungi are also found infecting locusts which are as follows. Fungus such as Entomophaga grylli attacks Bombay Locusts, Variegated Grasshoppers, Brown Locusts, Red Locusts and Tree Locusts. Symptom: Infected Desert Locusts were found dead and dying, hanging from trees by their front legs.

81. Green Muscardine Disease is caused by the fungus Metarrhizium anisopliae . The spores stick to insects in warm humid conditions, they germinate and grow through the cuticle to infect the insect. Finally, within 2-4 days under favourable conditions. Symptom: Infected Desert Locusts were found dead and dying, hanging from trees by their front legs. In favourable conditions, Green Muscardine Disease can destroy complete swarms. It has also been recorded in Red Locusts, Tree Locusts and Javanese Grasshoppers.

82. Desert Locust nymph infected by Metarhizium anisopliae

83. (e) Virus Virus such as entomopox viruses infect locusts. They are comparatively expensive to produce since they are made in vivo, i.e. in live insects.

84. Entomopox viruses

85. Baiting This method was popular up to the 1950s but has been used very little in recent years. It involved mixing insecticide dust with a carrier such as maize meal or wheat bran, and scattering the mixture among or in the path of the locusts. A big disadvantage of this method is the amount of work involved in preparing, transporting and applying the large quantities of bait (5-15 kg/ha for marching bands and over 50 kg/ha for settled hoppers and adults).

86. Dusting Dusting involves mixing pesticide dust with a material such as powdered chalk or talc and scattering it on the locusts. Like baiting, insecticide dusting has the advantage that it can be carried out without specialist application equipment – a hessian bag of dust beaten with a stick has commonly been used. Many countries do not go for dusting because it requires large quantities of product to be transported and applied (up to 10 kg/ha), with the fact that control is sometimes poor, especially with later instar hoppers and adults.

87. Spraying Spraying is the most commonly used method for locust control. It involves a sprayer to atomize a liquid pesticide, i.e. to break it into droplets, which are then distributed over the target area. Mainly spraying of insecticides are done to combat locust population effectively with in short period of time.

88. CHOOSING AN INSECTICIDE Most of the locust control carried out in the last 40 years has used conventional chemical insecticides ( organochlorines , organophosphates, carbamates and pyrethroids ). These insecticides has been worked using three methods: By direct contact action (droplets land on the locusts) or By secondary contact action (locusts touch the droplets on the vegetation). By stomach action (locusts eat the sprayed vegetation).

89. Conti.. The chemical insecticides are usually neurotoxic , i.e. they kill the locust by interfering with its nervous system. There are some newer chemical and biological products which offer advantages such as lower environmental impact, lower operator hazard and greater logistical efficiency, e.g. large areas can be treated in a short time.

90. Insecticides should have following characters: Efficacy – The more toxic is the active ingredient (the poisonous part of the insecticide) to the locusts, the smaller the amount of active ingredient needed. Safety – The product should ideally have a low toxicity to mammals (humans, livestock) and other animals such as birds and fish.

91. Conti.. Specificity – The product should be specific in toxicity to locusts as compare to other non targeted insects particularly natural enemies. Route of entry – Whether it is a contact or stomach in action, the product will determine its suitability for different target insect, e.g. Flying swarms need a product with contact action. Shelf life – The insecticide which are to be used should have longer self life.

92. Availability – Locust insecticides must be available as ulv formulations in large quantities at short notice. Cost – Insecticides are one of the most expensive elements in any control campaign so cheaper products will greatly reduce control costs.

93. Characteristics of the main types of insecticide Conventional insecticides ( organochlorines , organophosphates, carbamates , pyrethroids ): fast, reliable, but full cover spray usually required. Some are dangerous to operators and environment. Insect growth regulators (IGRs): slower acting, barrier spraying possible and relatively safe to operator and environment.

94. Conti.. Newer conventional products such as fipronil : slower acting, barrier spraying possible and relatively safe to operators because of low formulation concentrations. Botanicals (extracts from plants): slow action and incomplete kill. Semiochemicals : pheromones may produce useful behavioural or developmental changes, but no direct kill. They are still being researched.

95. New and alternative types of chemical insecticide Some other types of chemical product with useful new characteristics have recently been introduced. These products are as under: Insect growth regulators (IGRs) Botanicals insecticides Semiochemicals

96. Insect growth regulators (IGRs) IGRs such as diflubenzuron , teflubenzuron and triflumuron interfere with production of chitin, the hard material in insect cuticle. As a result the insect dies because it cannot make the new cuticle when it moults. IGRs are very safe for mammals (WHO classes them as unlikely to present acute hazard) and there is little effect on other organisms such as birds and fish.

97. Conti.. IGRs are also quite selective in nature. IGRs are persistent, remaining active on vegetation for several weeks and are effective barrier spray products. Some disadvantage is that they are slow-acting, they kill some species of arthropod in fresh water and they are not effective against adult locusts.

98. Botanicals insecticides Products such as the extract from the neem tree are used as insecticides and/or anti- feedants . Mortality is slower and usually lower as compare to conventional insecticides. The mixture of active ingredients in locally produced neem extract is very complex and varies from batch to batch, and it would be difficult to produce sufficient quantities to combat a large-scale locust infestation at short notice.

99. Semiochemicals Locusts produce pheromones that cause responses in locusts of the same species. Some of these pheromones influence insect interactions, so it may be possible to use them to reverse the process of gregarization or to disperse bands and swarms. Various other effects such as reduced feeding and marching, increased predation and cannibalism and increased susceptibility to insecticides and pathogens. However, their control efficacy has not been demonstrated and no products are available commercially.

100. THE TECHNIQUE OF SPRAYING On the basis of Volume of spray fluid per unit area, Spraying is classified as:-

101. The range of spray volume for field crop spraying High Volume Spraying 300 - 500 L/ha Low Volume Spraying 50 - 150 L/ha Ultra Low Volume Spraying < 5 L/ha

102. SPRAYING TECHNIQUE – I (HIGH VOLUME SPRAYING) This is very common and popular method of pesticide spraying. The spray solution is prepared by mixing water with pesticide formulation in appropriate quantities. This diluted mixture is sprayed through hydraulic nozzles. In this method large volume of spray liquid is applied. Usually the spraying volume is 300-500 L/ha.

103. All types of high volume sprayers have some kind of pump to supply pressurised spray liquid to the hydraulic nozzle which breaks the liquid into spray droplets and throws the spray away from it. The high volume sprayers are both manually operated or power operated type.

104. Types of High Volume Sprayers Slide pump or hand sprayers Stirrup pump sprayer Compression sprayer Foot operated sprayer Rocker sprayer Lever operated Knapsack sprayer High pressure power sprayer

105. SLIDE PUMP OR HAND SPRAYERS

106. STIRRUP PUMP SPRAYER

107. COMPRESSION SPRAYER

108. FOOT OPERATED SPRAYER

109. ROCKING SPRAYER

110. LEVER OPERATED KNAPSACK SPRAYER

111. HIGH PRESSURE POWER SPRAYER

112. SPRAYING TECHNIQUE – II (LOW VOLUME SPRAYING) The high volume spraying is labour intensive and time consuming. In water scarcity area it is difficult to practice high volume spraying. Also in situation where large area treatment in very short time is important, the high volume spraying has limitations. The low volume spraying methods essentially reduce quantity of spray solution.

113. Spraying as against 300 to 500 L/ha in high volume spraying technique is reduced to 50 to 150 L/ha in low volume spraying technique. Motorised knapsack sprayer, also called Mist blower is a low volume sprayer in which gaseous energy nozzle is used for fine breakup of spray liquid. This type of nozzle is also called Air blast nozzle. The force of escaping air at high velocity is utilised to shear down the spray liquid into fine spray droplets.

114. The size of spray droplets depends upon: 1. Air velocity and volume 2. Liquid flow rate 3. Properties of spray liquid

115. SPRAYING TECHNIQUE – II (LOW VOLUME SPRAYING)

116. S. No. Chemical Dose (gram active ingredient per ha.) Dose of the formulation/ha Hopper Adult 1 Bendiocarb 80% WP 100 100 125 gm 2 Chlorpyrophos 20% EC 240 240 1.2 liters 3 Chlorpyrophos 50%EC 240 240 480 ml 4 Deltamethrin 2.8%EC 12.5 12.5 450 ml 5 Deltamethrin 1.25%ulv 12.5 12.5 200 ml 6 Deltamethrin 25%WP 60 Na 240 ml Recommended insecticides for low volume sprayers

117. S. No. Chemical Dose (gram active ingredient per ha.) Dose of the formulation/ha 7 Fipronil 5%SC 6.25 6.25 125 ml 8 Fipronil 2.92%EC 6.25 6.25 216 ml 9 Lambda cyhalothrin 5%EC 20 20 400 ml 10 Lambda cyhalothrin 10%WP 20 20 200 gm 11 Malathion 50%EC 925 925 1.850 litres 12 Malathion 25% WP 925 925 3.7 kg

118. SPRAYING TECHNIQUE – III (ULTRA LOW VOLUME SPRAYING TECHNIQUE) Ultra low volume (ULV) spraying uses small amounts of concentrated insecticide. In locust control, about 0.5-1.0 litre /hectare is applied. The insecticide is not mixed with water or solvent. It is oil-based to prevent evaporation and is usually applied ready to spray. The ULV spraying is the method of pesticide application at minimum volume to achieve economic pest control.

119. Conti.. In this technique of pesticide application the volume applied per hectare is less than 5 litres which is extremely low as compared to the conventional High Volume and Low Volume spraying methods. The spray droplets in ULV spraying methods are very fine in size. Therefore, the nozzles used in these methods are different.

120. Various designs of rotary atomiser are used to generate droplets of 70 to 100 µ Volume Median Droplets (VMD). The vortex nozzles produce droplets in aerosol range i.e. 20 µ VMD. For large area ULV spraying as in the case of locust control exhaust nozzle sprayer which is mounted on a vehicle is used where thermal energy of the engine exhaust gases is used to atomise the pesticide liquid in droplets of 20–50 µ.

121. The rotary atomiser utilises centrifugal energy to break the pesticide liquid into droplets. The range of spray droplet diameter produced by centrifugal nozzle is generally narrow spectrum. Therefore, this method of ULV spraying with the help of centrifugal energy nozzle is also called as Controlled Droplet Application ( CDA ). The movement of extremely fine spray droplets depends upon natural air movement. These small particles usually take long time to settle and very much influenced due to prevailing wind. The spray therefore is not direct type but it is drift spraying.

122. Controlled Droplet Application ( CDA )

123. Important consideration during spray Do not spray during the hottest part of the day (1100-1600 hr) when convection may occur and carry the spray up into the sky instead of down onto the locusts Do not spray at low wind speeds less than 1 m/s Do not spray at high wind speeds more than 10 m/s. The best time for spraying is usually in the morning between 0800 and 1100 hours and in the afternoon after 1600 hours. Effective spraying may be possible before 0800 hours if the wind is strong enough. It may also be possible to spray effectively between 1100 and 1600 hours if it is either cloudy or relatively cool (less than about 30°C) or if there is a steady wind over 4 m/s that will tend to prevent convection.

124. Important consideration for ulv spray Better to spray field when steady wind of at least 2 miles/second at a height of 2 m prevalent and do not spray when the wind is more than 10 miles/second. Never spray when there is strong convection. Convection occurs when the sun rises high in the sky and heats up the ground. The hot ground warms up the air near to it, which then rises and may carry spray droplets out of the target area. Never spray if rain is falling or seems likely to fall soon, because the rain may wash off some of the insecticide from the vegetation.

125. SPRAYERS 1. Hand held battery operated ULV sprayer. 2. Knapsack motorized type 3. Tractor/ vehicle mounted ULV sprayer 4. Aircraft ULV sprayer

126. Hand held battery operated ULV sprayer

127. Knapsack motorized type

128. Electric Sprayer

129. Tractor/ vehicle mounted ULV sprayer

130. ULV Cold Fogging Machines / ULV Sprayers  Please double click on slide for video

131. Aircraft ULV sprayer

132. ULV spraying by drones

133. Watch: Drones used to spray insecticides on locusts  Please click for video Please click for video

134. Recommended insecticides for ultra low volume sprayers Insecticides Recommended dose (g a.i ./ha) ulv Formulation (g/l ulv ) ORGANOPHOSPHATE Chlorpyrifos 225-240 240 450* Diazionon 450-500 980 600* Fenitrothion 450-500 500 1000* 1250* Melathion 900 960 * means at higher doses

135. Conti.. Insecticides Recommended dose (g a.i ./ha) Formulation (g/l ulv ) CARBAMATE Bendiocarb 100 200 SYNTHETIC PYRETHROIDS Deltamethrin 12.5 12.5 25* Lambdacyhalothrin 20 8 40* * means at higher doses

136. Conti.. Insecticides Recommended dose (g a.i ./ha) Formulation (g/l ulv ) MIXTURE/COCKTAILS Organophosphate+carbamate Phoxim+propoxure 358+42 300 900 Organophosphate+synthetic pyrethroids Fenitrothion+esfenvalerate 245+5 250 500 * means at higher doses

137. Media coverage

138. USEFUL LINKS

139. THANK YOU