Lecture No.31 Mulberry – pests and diseases management PESTS OF MULBERRY Sl. Common Name Scientific Name Family Order No. 1 Pink mealybug Maconellicoccus hirsutus Pseudococcidae Hemiptera 2 Jassid/leaf hopper Empoasca flavescens Cicadellidae Hemiptera 3 Black Scale Saissetia nigra Coccidae Hemiptera 4 Red Scale Aonidiella auranti Coccidae Hemiptera 5 Spiralling whitefly Aleurodicus dispersus Aleyrodidae Hemiptera 6 Thrips Pseudodendrothrips mori Thripidae Thysanoptera 7 Tobacco leaf caterpillar Spodoptera litura Noctuidae Lepidoptera 8 Moringa hairy Eupterote mollifera Eupterotidae Lepidoptera caterpillar 9 Tussock caterpillar Euproctis fraterna Lymantriidae Lepidoptera 10 Brown hairy caterpillar Porthesia scintillans Lymantriidae Lepidoptera 11 Mulberry leaf -webber Diaphania pulverulentalis Pyralidae Lepidoptera 12 Ash weevil Myllocerus spp Curculionidae Coleoptera M. subfasciatus M. viridanus M. discolor 13 Grasshopper Cyrtacanthacris tatarica Acrididae Orthoptera Neorthacris acuticeps nilgriensis 14 Stem girdler beetle Sthenias grisator Cerambycidae Coleoptera 15 Mango stemborer Batocera rufomaculata Cerambycidae Coleoptera 16 Bark eating caterpillar Indarbela quadrinotata Metarbelidae Lepidoptera 17 Termite Odontotermes sp. Termitidae Isoptera 18 White grub Holotrichia spp. Melolonthidae Coleoptera 19 Mite Tetranychus sp. Tetranychidae Acarina I. Suc in! "e#t# 1. Pink mealy bug: Maconellicoccus hirsutus F:Pseudococcidae O: Hemiptera Diagnostic symptoms Malformation of apical shoots, retarded growth. Wrinkling and curling of affected leaves become dark green in colour. Symptoms are collectively called as Tukra (Bushy top). Nature of damage: Nymphs and adults suck the sap from tender leaves and buds by piercing the plant tissue. The infestation occurs in the nodal joints and succulent apical region. Nutritive value of leaves, leaf yield and plant height are drastically reduced. The affected leaves when fed to silkworm cause a significant reduction in larval weight, cocoon weight, shell weight and shell ratio. Biology The mealy bug lays eggs (=250 no) in a loose cottony terminal ovisac. Freshly laid eggs are orange in colour, smooth a smooth and oval with slightly tapering ends. Eggs turn pink before they hatch. Mealy bug completes its life cycle in 23 – 29 days. Egg: 5 – 6 days; Nymph: 2 –3 months. Management Destroy the affected parts Release Australian lady bird beetle Cryptolaemus montrouzieri @ 150 No./ ha. Release Scymnus coccivora @ 1000 beetles / ha Follow sequential release of predators. Spray DDVP (1l/ha) or FORS 25 mg/l. safe period : 17 days. 2. Leaf hopper / jassids : Empoasca flavescens (F) F: Cicadellidae O: Hemiptera Diagnostic symptoms Triangular dark brown spot at the tips and margin of leaves. Drying starts from periphery to midrib of leaves. Finally leaves become cup shaped and leathery. Hopper burn symptoms on the leaves. Nature of damage Nymphs and adults suck the sap from lower side of the leaves and deplete nutritive value of leaves. Also, suck the sap from tender shoots and twigs causing characteristic hopper burn symptoms. Biology: Female lays pale yellow coloured elongated eggs in the epidermis on the under surface of leaf blade. Nymphs are pale green colour, elongated. Egg : 4 – 9 days; Nymphs : 4 instars. Management . Setting up of light traps for attacking and trapping adults. Spraying of DDPV (Dichlorovos) 76% - 0.05% or dithioate 0.1%. Safe period – 11 days. 3. Black scale : Saissetia nigra F:Coccidae O: Hemiptera Diagnostic symptoms . It occurs on the stem, branches and also as small scales on the bark, . Generally observed in hilly regions on medium sized trees. Nature of damage . Nymphs and adults suck the sap and kill the plants . The surface of the stem is covered all over with scales. Biology Adult female of S. nigra lays about 300 –600 eggs – minute white elongated. It secretes a fibrous waxy material which hardens to form the scale. ♀ moults three twice ♂ moults twice. They lose appendages in reproduction. Parthenogenetic reproduction. b. Red scale : Aonidiella auranti F:Coccidae O: Hemiptera Nymphs and adults attack twigs branches and stems causing a loss of vitality. It does not attack the older plants. In case of heavy infestation, leaves turn yellow and finally the plant while plant dries up. Plants shoots are covered with reddish brown scales with dark patches of sooty mould growing on honey decoration. Management of scale insects . Prune and destroy the affected branches. Mechanical removal of insects in the initial stages of infestation. Apply Fish Oil Resin Soap (FPRS) @ 40 g / l in branches; add wetting agents for better adherence on the scales, spraying of 0.05% malathion . In endemic areas smear with insecticidal solutions, just after pruning or with diesel oil and soap solution (1:3); lime sweeping of stems; scraping of the scale . Release of Cryptolaemus montrouzieri @ 750 No. / ha. Release Chilochorus kuwanae against the red scales II. Foliage feeders 1. Leaf webber, Diaphania pulverulentalis F:Pyraustidae O: Lepidoptera Symptoms . Webbing of leaves and tender shoots . Skeletonization: The larvae web the leaves together and feed from inside on soft tissues and skeletonize them. Grown up caterpillars feed voraciously on tender leaves. Apical leaves are preferred for feeding resulting in stunting. Apical shoots are destroyed due to egg laying. Quality of leaf and yield is severely affected. Biology Egg : ♀ moth lays 100-400 eggs. Eggs are laid one each along the leaf vein on the under side of mulberry leaf. Larvae: 5 instars. Life cycle : 18 – 25 days. Adult : Pale brown spots on yellow back ground of wings. Management . Collection and destruction of affected shoots along with the larvae. Setting up of light traps to attract the adult moths . Follow the TNAU – IPM package. i) Flooding of mulberry field to expose the leaf webber pupae. ii) Release of pupal parasitoid Tetrastichus howardi @ 50,000 / ha ( 1 day after pruning) iii) Release of egg parasitoid Trichogramma chilonis @ 5cc/ha (10 days after pruning iv) Spraying of dichlorvos @ 1ml/lit (500ml/ha) v) Mechanical clipping and burning of affected shoots (40 days after pruning) III. Internal feeders 1.Stem girdler – Sthenias grisator F:Cerambycidae O:Coleoptera Symptoms: The beetles cut around the main stem leaving a clear girdle. The portion above the girdle gradually wilts and dries. Season: Through out the year. Life cycle: Adult is a longihorn beetle. Female deposit eggs underneath the girdled branch at night. Incubation of egg 8 days. The grub tunnels into main stem and feeds. Life cycle : 7 – 8 months. Management: Cutting and burning of affected branches Swabbing the base of the main stem or branches with 0.1% malathion 50 EC emulsion. Care in insecticide usage in mulberry gardens: Silkworm is highly sensitive to insecticide residues. Avoid applying insecticide in mulberry garden. If insecticidal application is essential allow a waiting period of 15 days from spraying to picking of mulberry leaves. Always select safe chemicals with short persistence like dichlorvos, malathion and FORS and plant products. Control measures for mulberry pests in general: Adopt cultural practices like pest free cuttings, removal of weeds, regular pruning Physical methods like collection and destruction of eggs, larva or pupa stage Biological methods like introduction of pathogens and predators have to be carefully done because silkworms are susceptible to Bacillus thuringiensis Select a safer insecticide and avoid insecticide having a long residual life. Generally organophosphorus group of compounds are recommended $ISEASES OF MULBERRY 1. Cercospora leaf spot: Cercospora moricola (Cooke) 2. Powdery mildew: Phyllactinia corylea (Pers) 3. Leaf rust: Cerotelium fici / Aecidium mori (Cast) 4. Bacterial blight: Pseudomonas mori Boyar and Lambert 5. Mulberry leaf mosaic disease: (Viral) 6. Dwarf disease: (Viral) 7. Root rot : Fusarium solani, F. oxysporum Macrophomina phaseolina 8. White root rot: Rosellinia necatrix Berlese 9. Violet root rot: Helicobasidium mompa Tanaka Foliar di#ea#e#& 1. Powdery mildew: Phyllactinia corylea (Pers) Order: Erysiphales Class: Ascomycetes Symptoms Initially white powdery patches appear on the lower surface of leaves which cover the entire leaf surface At a later stage and term black to brown in colour Epidemiology P. corylea is an ecto-parasite It obtainer nutrients by sending haustoria into the epidermal cells through the stomata The diseases is more prevalent during rainy in hills seasons in plains during cooler months. Management Leaves with thick cuticle and epidermises, less number of stomata and more of leaf hairs are less susceptible to the disease Spraying of Dinocap 2% / Wettable sulfur are effective Leaves can be used 10 days after spray Dusting of fine sulphur or sulphur suspension or lime sulphur mixture on the back of the leaves may be effective Spray 0.2% karathane or bavistin or dithane. II. Soil Borne pathogen 1.White root rot: Rosellinia necatrix Berlese Order: Spheriales Class: Basidiomycetes Symptom: Diseased plant growth retards Withering of leaves Stump of the infected plant are covered with white grey mycelial mat Roots rot, finally plant dies 2.Violet root rot: Helicobasidium mompa Tanaka Order: Tremellales Class: Basidiomycetes Symptom: Plants become weak Withering of leaves Stump of the infected plant are covered with violet colored mycelial mat Fails in budding Finally plant dies Season: Throughout the year Management: Infected plants