To study the important pests of fruits and plantation crops

Horticulture Guruji

Exercise 7

To study the important pests of fruits and plantation crops

HORT 221
  1. Mango hoppers: Idioscopus niveoparsus, I. clypealis, Amirtodus atkinsoni

Symptoms of damage

  • Nymphs and adults suck the sap of inflorescence
  • Withering
  • Shedding of flower buds and flowers
  • Presence of honeydew secretion on lower leaves and development of sooty mould.

Management

  • Avoid close planting, as the incidence is very severe in overcrowded orchards.
  • Orchards must be kept clean by ploughing and removal of weeds.
  • Spray two rounds of acephate 75 SP@ 1g/lit or phosalone 35 EC@ 1.5 ml/li First spray at the time of panicle emergence, second spray two weeks after the first spray.
  • Wettable sulphur @ 2 g/lit may be sprayed after spraying carbaryl to avoid mite resurgence.
  • The mixture of toxaphene with sulphur (1:1) has been reported to be effective against pests.
  • Neem oil 5 ml/lit of water can be mixed with any insecticides
  • Spray 3 percent neem oil or neem seed kernel powder extract 5 percent

 

  1. Mango Fruit fly: Bactrocera (Dacus) dorsalis

Symptoms of damage

  • Maggot bore into semi-ripen fruits with decayed spots and dropping of fruits.
  • Oozing of fluid
  • Brownish rotten patches on fruits.

Management

  • Collect fallen infested fruits and dispose of them by dumping them in a pit
  • Provide summer ploughing to expose the pupa
  • Monitor the activity of flies with methyl eugenol sex lure traps.
  • Bait spray – combing any one of the insecticides and molasses or jaggery 10 g/l,
  • malathion 50EC 2 ml/l,
  • dimethoate 30 EC 1 ml/l,
  • carbaryl 50 WP 4 g/l. two rounds at 2 weeks interval before the ripening of fruits.

Biological control

  • Field release of natural enemies Opius compensates and Spalangia Philippines

 

  1. Cut worm of Banana: Spodoptera litura

Symptoms of damage

  • Young larvae feed by scraping the leaves from the ventral surface
  • Later on, feed voraciously at night on the foliage.

Management

  • Handpick and destroy the caterpillar
  • Collect and destroy the damaged plant parts
  • Summer ploughing to expose to the pupae
  • Use light trap
  • Spray azinphos-methyl or chlorphyriphos
  • In severe infestation apply Bacillus thuringenesis
  • Foliar spray with avanthe 1 ml in 100 ml of water
  • Field release of egg parasitoid such as Telenomus spodopterae and Telenomus remus
  • Field release of entomopathogenic fungus Nomuraea rileyi

 

  1. Rhizome weevil of Banana: Cosmopolites sordidus

Symptoms of damage

  • Grubs bore into the rhizome and cause the death of the plant
  • Presence of dark-coloured tunnels in the rhizomes.
  • Death of unopened pipe, withering of outer leaves.
  • Select healthy sucker and plant.

Management

  • Do not take regular crops in the same field to avoid initial infestation
  • Ensure clean cultivation
  • Removal of pseudostems below ground level
  • Trimming the rhizome
  • Avoid growing Robusta, Karpooruvally, Malbhog, Champa and Adukkar
  • Grow less susceptible varieties like Poovan, Kadali, Kunnan, Poomkalli
  • Use cosmolure trap at 5/ha

Banana corm split trap

  • Trap adult weevils with pseudostem chopped into small pieces
  • kept near infested clump at 65/ha.
  • Soil incorporation at the time of planting: carbofuran 3 G 10g, phorate 10 G 5 g/plant.
  • Before planting, the suckers should be dipped in 0.1 per cent quinalphos emulsion.
  • Apply castor cake 250g or carbaryl 50g dust or phorate 10g per pit before planting also prevents infestation
  • Severe attack dimethoate, methyl demeton may be sprayed around the collar region.

 

  1. Bark eating caterpillars of guava: Indarbella sp.

Symptoms of damage

  • Young trees may succumb to the attack.
  • Caterpillars bore into the trunk or junction of branches.
  • Presence of gallery made out of silk and frass.
  • Caterpillars remain hidden in the tunnel during daytime come out at night and feed on the bark.

Management

  • Remove and destroy dead and severely affected branches of the tree
  • Remove alternate host, silk cotton, and other hosts
  • Swab Coal tar + Kerosene @ 1:2 or Carbaryl 50 WP 20 g / lit of water on the basal portion of the trunk up to 3 feet height
  • Scraping the loose bark to prevent oviposition by adult beetles.
  • Padding with monocrotophos 36 WSC 10 ml in 2.5 cm /tree soaked in absorbent cotton.
  • If infestations are severe then apply the copper oxychloride paste on the trunk of the tree.
  • Hook out the grub from the borehole
  • After applying monocrotophos 36 WSC 10 to 20 ml/ hole
  • Apply carbofuran 3G 5 g per hole and plug with mud.

  

  1. White fly of Papaya: Bemisia tabaci

Symptoms of damage

  • Nymphs and adults suck the sap from the undersurface of the leaves
  • Yellowing of leaves.

Management

  • Field sanitation
  • Removal of host plants
  • Installation of yellow sticky traps
  • Spray application of imidacloprid 200SL at 0.01% or triazophos 40EC at 0.06% during the heavy infestation.
  • Spray neem oil 3% or NSKE 5%
  • Release of predators viz., Coccinellid predator, Cryptolaemus montrouzieri
  • Release of parasitoids viz., Encarsia haitierrsis and guadeloupae

 

  1. Bud worm of Sapota: Anarsia epotias

Symptoms of damage

  • Webbed flowers and buds
  • Shedding of buds and flowers.
  • Boreholes and excreta were seen on attacked flowers.

Management

  • Spray phosalone 35 EC 2 ml/lit or phosphamidon 40 SL 2 ml/lit.
  • Application of neem oil 2% of neem seed kernel extracts 5 %.

 

  1. Citrus psyllid: Diaphorina citri

Symptoms of damage

  • Both nymphs and adults suck sap from the plants and injection of toxic saliva
  • Nymphs – are more destructive, the crowd on the terminal shoots, buds, and tender leaves
  • Excrete honeydew- growth of sooty moulds
  • Affected plant parts dry and die away
  • It transmits the “Greening” virus

Management

  • Collect and destroy the damaged plant parts
  • Spraying with systemic insecticides at flush growth periods
  • Spray malathion 0.05% or carbaryl 0.1%
  • Encourage the activities of natural enemies such as Syrphids and Chrysopids

 

  1. Citrus butterfly: Papilio demolious, P. Polytes, P.helenus

 Symptoms of damage        

  • Caterpillars prefer on light-green tender leaves feeding voraciously and leaving only the mid-ribs
  • Severe infestation the entire tree gets defoliated

Management

  • Handpick the larvae and destroy
  • First instar – Spraying of 1ml DDVP (Nuvan)
  • Field release of parasitoids Trichogramme evanescens and Telenomus sp on eggs of Brachymeria sp larvae and Pterolus sp pupae

 

  1. Apple Woolly aphid: Eriosoma lanigerum

Symptoms of damage:

  • Nymphs and adults suck the juice from the bark of the trunk or fruits
  • Weakening and death of the smaller plants
  • Infested twigs shrivel and die
  • Galls on the roots
  • White, woolly patches on the trunk.

Management

  • Use resistant root stocks M 778, M 779, MM 14, MM 110, MM 112
  • Spray dimethoate 30 EC 0.06% or methyl demeton 25 EC 0.025%
  • Release the parasitoid: Aphelinus mali
  • Predators: Chilomenus bijugus and Coccinella septumpunctata

 

  1. San Jose scale of Apple: Quadraspidiotus perniciosus

Symptoms of damage:

  • The infested region in bark becomes reddish-pink
  • Purple discolouration on fruits
  • Infested shoots – loss of vigour and death of young trees or branches.

Management:

  • Select nursery stock free scale infestation
  • Summer spray with phosalone 50 EC 0.05%
  • Winter spray with diesel oil emulsion at 8-12 l/ tree (diesel oil 4.5 l, soap 1 kg, water 54 -72 l)
  • Encourage the activity of parasitoids: Prospaltella perniciosi and Aspidiotophagus sp
  • Field release of coccinellid, Chilocorus circumdatus predator

 

  1. Rhinoceros beetle of coconut: Oryctes rhinoceros

Symptoms of Damage

  • The adult beetle bores into the unopened fronds and spathes. Damage by the pest leads to 10 to 15% loss in yield.
  • The attacked frond when fully opened shows characteristic triangular cuts.
  • The central spindle appears cut or toppled
  • Fully opened fronds showing characteristic diamond-shaped cuttings
  • Holes with chewed fiber sticking out at the base of central spindle.

 

Management:

(i) Cultural Method:

  • Remove and burn all dead coconut trees in the garden (which are likely to serve as breeding ground) to maintain good sanitation.
  • Collect and destroy the various bio-stages of the beetle from the manure pits (breeding ground of the pest) whenever manure is lifted from the pits.

(ii) Mechanical Method:

  • During the peak period of population build-up, the adult beetle may be extracted from the palm crown using GI hooks.
  • Set up light traps following the first rains in summer and monsoon period to attract and kill the adult beetles.

(iii) Chemical Method:

  • The topmost three-leaf axils around the spindle may be filled with any of the following mixtures as a prophylactic measure:
  • Sevidol 8G 25 g + fine sand 200 g, which is to be done thrice in a year in April-May, September-October, and December-January.
  • For seedlings, apply Naphthalene balls 10.5 g (approx. three to four balls) covered with fine sand, once in 45 days.
  • Place phorate 10 G 5 g in perforated sachets in two innermost leaf axils for 2 times at 6 months intervals.
  • Treat manure pits and other possible breeding sites with 0.01% carbaryl (50 % WP) on a w/w basis. Treatment will have to be repeated every six months.

(iv) Trap Method:

  • Set up Rhino lure pheromone trap @ 5 traps/ha to trap and kill the beetles. The dispenser may be hanged in a plastic bucket having 2 liter of insecticide solution once a week. Trapped beetles can be disposed off.

(v) Biological Method:

  • Application of green muscardine fungus, Metarrhizium anisopliae @ 5 x 1011 spores / m3 – spray 250ml Metarrizhium culture + 750ml water in manure pits to check the perpetuation of the pest.
  • Field release of Baculovirus oryctes inoculated adult rhinoceros beetle @ 15 beetles/ha reduces the leaf and crown damage caused by this beetle.
  • Soak castor cake at 1 kg in 5 liter of water in small mud pots and keep them in the coconut gardens to attract and kill the adults.
  • Apply the mixture of either neem seed powder + sand (1:2) @150 g per palm or neem seed kernel powder + sand (1:2) @150 g per palm in the base of the 3 innermost leaves in the crown.

 

  1. Red Palm Weevil: Rhynchophorus ferrugineus

Symptoms of Damage:

  • The hole can be seen on the stem with chewed-up fibres protruding out.
  • Many times reddish-brown liquid can be seen oozing out from the hole.
  • The grubs cause damage inside the stem or crown by feeding on soft tissues and often cause severe damage especially when a large number of them bore into the soft, growing parts. In case of severe infestation, the inside portion of the trunk is completely eaten and becomes full of rotting fibres.
  • In the case of young palms the top withers while in older palms the top portion of the trunk bends and ultimately breaks at the bend (wilting).
  • Sometimes the gnawing sound produced by the feeding grubs inside will also be audible.
  • In the advanced stage of infestation yellowing of the inner whorl of leaves occur. The crowns fall down or dry up later when the palm is dead.

 

Management:

Cultural Method:

  • Remove and burn all wilting or damaged palms in coconut gardens to prevent the further perpetuation of the pest.
  • Avoid the cutting of green leaves. If needed, they should be cut about 120 cm away from the stem in order to prevent successful inward movement of the grubs through the cut end.

Chemical Method:

  • In attacked palms, observe for the bore-holes and seal them except the topmost one. Through the topmost hole, pour 1% carbaryl (20gm/lt) or 0.2% trichlorphon @ one litre per palm using a funnel. Then plug this hole also. If needed repeat after one week.
  • When the pest infestation is through the crown, clean the crown and slowly pour the insecticidal suspension. In case of entry of weevil through the trunk, the hole in the trunk may be plugged with cement/tar. A slanting hole is made with the aid of an auger and the insecticide solution is poured with a funnel.
  • Fill the crown and the axils of the topmost three leaves with a mixture of fine sand and neem seed powder or neem seed kernel powder (2:1) once in three months to prevent the attack of rhinoceros beetle damage in which the red palm weevil lays eggs.

Trap Method:

Coconut log traps:

  • Setting up of attractant traps (mud pots) containing sugarcane molasses 2½ kg or toddy 2½ litres (or pineapple or sugarcane activated with yeast or molasses) + acetic acid 5 ml + yeast 5 g + longitudinally split tender coconut stem/logs of the green petiole of leaves of 30 numbers in one acre to trap adult red palm weevils in large numbers. Incorporate any of the insecticides into each trap to kill the weevils trapped.

Pheromone trap

ü  Install pheromone trap @ one trap per ha

ü  Step 1: Specialized buckets with 3 of 4 holes are made, the bucket is wound with coconut fibre/ jute sack, so that the pests can enter.

ü  Step 2: The lure (Ferrolure +) is suspended inside the bucket and one lit of water is added along with 100g pineapple/ sugarcane, 2g yeast, and 2g Carbaryl in the bucket.

ü  Step 3: The bait buckets are placed at sites in the farm, where the infestation is seen most.

ü  Step 4: After a week the water is checked for the catch & re-filled to prevent mosquitoes from breeding.

 

References cited

  1. Commercial Fruits. By S. P. Singh
  2. A text book on Pomology, Vol,1. by T. K. Chattapadhya
  3. Tropical Horticulture, Vol.1, by T. K. Bose, S. K. Mitra, A. A. Farooqui and M. K. Sadhu

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