ENTO 243 Most Probable Q&A



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1) Enlist any four important insect pests of citrus along with scientific name and describe nature of damage and management of any two insect pests. (Citrus Black Fly, Fruit Sucking Moth)

Lemonbutterfly                      Papilio demoleus

Citrus-psylla                           Diaphorina citri

Leaf miner                              Phyllocnistis citrella

Whitefly                                  Dialeurodes citri   

Blackfly                                   Aleurocanthus woghlumi 

Fruit sucking moth                Budocima fullonica, 

                                                 Eudocimamaternal, 

                                                 Achoeajanata

Aphid                                      Toxoptera aurantil

Citrus red scale                      Aonidiella aurantii

Mealy bugs                             Ferrisicoccus cameronensis


Leaf miner: Phyllocnistis citrella. S. (Phyllocnistidae: Lepidoptera.) 

Economic Importance: Most destructive pests, active in monsoon season, infestation noticed in seedling stage. The pest in suspected to be responsible for the spread of bacterial infection causing ‘citrus canker’

Marks of Identification: Moths: Small, silver white colour, forewings with brown strip & prominent black spot near the tip. Caterpillar: Yellow in colour with brown mandibles, apodous, passes through four instars 

Host Plants: All citrus species. 

Life History :

Eggs : singly on underside of leaves I.P. : 3 – 6 days. 

Larva : 1 – 2 weeks. 

Pupa : Pupation inside the larval mines of leaves P.P. 3 – 4 weeks. 


No. of generations : 9 – 13 / year.(Pest is active in monsoon season.) 
Population of the pests decreases during hot summer months. 


Nature of Damage: On hatching, the larva feed on leaf tissues between upper and lower surfaces 
of leaves making glistering zigzag tunnels. The leaves turn pale, curl & finally dry. Besides, mined 
leaves may get bacterial infection, which leads to ‘citrus canker’. 

Management Practices : 

Mechanical control: Use pheromone trap @ 5/acre. 
Pruning of affected parts during winter and burning
Removal of infested leaves and their proper disposal in the initial stage. 

Chemical control: Carbofuran3%CG @ 20000g/acre 
Foliar spray with Imidacloprid 17.8% SL@ 50ml and use spray volume depending on size of tree &Protection equipment used 
Foliar spray Permethrin25% EC @160-240 ml in 400 l of water/acre 
Granular application with Phorate 10% CG @ 6000 gm/acre 


Biological Control: 
Natural Enemies: The larvae are parasitised by Cirrospiloideus phyllocnistodes, the euliphod 
parasitoid’s Cirripilus quadristriatus and tretrachus phyllocnistoides.

Citrus psylla: Diaphorina citri K. (Psyllidae : Hemiptera) 

Economic Importance: Most destructive of all pests of citrus, also transmit “Greening Melody”, a micoplasma disease in citrus. 

Marks of identification: Adults: Small, dark brown in colour and measures 2.4 mm long. Wings are folded like roof over body. They remain mostly on the under surface of leaves with their heads almost touching the surface and rest of the body raised up 

Host plants: Citrus & other plants belonging to family Rutaceae. i.e Curry leaves 

Life History: 
Eggs: In the folds of half opened leaves and leaf axis, 800, orange colour elongate thicker at the basal end anteriorly it is slightly curved & tapering I.P. : 4-6 days summer & 22 days in winter. 

Nymph: They are light yellow with an orange tinge in the region of abdomen, five nymphal instars N.P. 2 weeks in summer & 3-4 weeks in winter.

Adult: Longevity may extend over 6 months. The insect is active from February and increase during March-April. It disappears by about the middle of October. In a year there are about 9 generations.
C.O.: Pests over wintering in adult stage. 

Nature of Damage: Both nymph & adult suck the cell sap from tender leaves, shoot & buds, which as a result curl, dry up & ultimately drop down. Complete crop failures are reported in case of servere infestation. Honeydew exertion of the nymphs favours multiplication of black sooty mould (Capnodium sp.) on the leaves. 

Management Practices : 

Mechanical control: 
Collect and destroy the infested plant parts 

Biological control: 

Conserve parasitoids such as Tamarixia radiata, Diaphorencyrtus aligarhensis 
Conserve predators such as Chrysoperla carnea, Coccinellids, Syrphids. 

Chemical control:
Systemic insecticides like imidacloprid 17.8%SL@ 50ml depending on size of tree & 
Protection equipment used are very effective at controlling both the nymphs and the adults. 
Foliar spray Thiamethoxam 25%WG@40g in 400 l of water/acre. 
Foliar spray with Oxydemeton-methyl25% EC @ 600-800ml in 600-800 l of water/acre


White fly: Dialeurodes citri A.

 Black fly: Aleurocanthus woglumi A (Aleurdidae: Hemiptera)

Economic Importance: White fly, D. citri is common occurrence & destructive pest of citrus. It causes ‘Kolshi’ in citrus & reduce plant vigour. 

Marks of Identification: 

White fly: 

Adult: Minute insect with yellowish body & red eyes. Wings white or greyish, covered with mealy secretions. The longetivity of adults is about 2 to 8 days. 

Black fly: dark orange with smoky wings and fore wings having four whitish areas of irregular 
shape. 

Nymphs : Oval shaped, scale like & blackish with marginal bristle like fringes. 

Black fly: 
Smaller in size & black, in colour. 

Host Plant: Citrus, cotton, Castor Banana, Coffee & some ornamental plants. 

Life History: 

Eggs: Underside of leaves, I.P. 10 days. 

Nymph: N.P. 3 – 10 weeks. 

Pupa: Pseudo pupa (Quiescent stage) on underside of leaves, P.P.: 16 – 22 weeks. 

Nature of Damage: Nymphs & adults of flies suck the cell sap from leaves, as a result leaves wither & turn brownish. Nymphs excrete honeydew on which black sooty mould develops. The blackish coating commonly called “Kolshi”. Fruit setting is adversely affected in case of severe infestation. 

Management Practices : 

White Fly

Cultural control: 
A regularly maintained program of hedging and topping can help avoid whitefly problems. 

Biological control: Parasites and predators attack the citrus whitefly 

Chemical control: Oxydemeton–methyl 25% EC @600-800 ml in 600-800 l of water/acre

Black Fly

Mechanical control: 
Collect and destroy the damaged plant parts along with nymphs, pupa and adults. 
Use light trap (wavelength of 550 nm) 
Yellow sticky traps or cards reduce the density of black flies 

Biological control: 
Pupal parasitoids: Encarsia formosa, Eretmocerus spp 

Predators: Chrysoperla carnea, Coccinellids, Spiders. 

Chemical control:
Spray 0.05% Monocrotophos or0.03% dimethodate orphosphomidon 30 EC for second & third instar nymphs. 
Spray 0.05% monocrotophos or 0.1% dimethoate or phosphomidon for the control of pupae. 

Natural enemies: 

White fly : Prospaltella lahorensis is parasitic on the insect. 

Black fly: The hymenopterous insects parasitic on the insect are Prospaltella divergens, Encarsia bennetti E. longifasciata, E merceti, E opulenta, E smithi, E tinctoriae, E transvena, Eretmocerus Serius, and Ablerus inquiremda, Ablerus macrocheta, Ablerus cinnectens.

2) Write scientific name, host plants and management practices of turmeric rhizome fly and Onion thrips.

Turmeric rhizome fly 

Scientific name: Mimegralla coeruleifrons

Hostplants: Turmeric and ginger

Management: Destruction of stray plants in offseason, selection of healthy rhizomes for planting. Removal and destruction of rotten rhizomes. Spraying with recommended insecticides.

Onion thrips

 - Scientific Name: Thrips tabaci

 - Oviposition Site: Female thrips insert eggs into the leaves of onion plants.

 - Pupation Site: The larvae drop to the ground to pupate in the soil.

 - Damaging Stage: Nymph & Adult

 - Nature of Damage: Onion thrips damage onion plants by sucking sap from leaves, causing silvery streaks or blotches, stunted growth, and deformed bulbs.

 - Management: Use of  Blue Sticky traps, fipronil 5% SC

 - Host plants: Polyphagous

3) Explain nature of damage and management practices for mango stone weevil, mango stone borer and hoppers.

  • Mango nut weevil

- Scientific Name: Sternochetus mangiferae

- Oviposition Site: mango fruits

- Pupation Site: inside stone

- Damaging Stage: Grub and adult

- Nature of Damage: Grub enter into fruit discolour the pulp  OR

Grubs bore through the pulp, enter into the stone and pass entire life inside the stone.

- Management: Spray the kerosene oil, Digging of Soil, Destruction of infected fruit   OR

Ploughing of orchard after harvest. Collection and destruction of infested and fallen fruits. Destroy all left over seeds in the orchard and also in the processing industries

The mango stone borer (Hypochrysopsarafa) is an insect pest that primarily affects mango trees. The adults of this pest are small beetles that lay their eggs on the fruit or near the base of the fruit stalk. The larvae then bore into the fruit, feeding on the flesh and causing damage.

  •  Mango stone borer

Nature of damage:

1. Fruit damage: The larvae bore into the mango fruit, creating tunnels and feeding on the pulp. This feeding activity can lead to rotting, discoloration, and spoilage of the affected fruit. The damaged fruit becomes unfit for consumption and loses its market value.

Management practices:

1. Cultural practices: Proper cultural practices are essential to manage mango stone borers. Some measures include:

   - Sanitation: Regularly remove fallen fruits and destroy them to minimize the population of the pest.

   - Pruning: Prune and remove infected branches and twigs to prevent the spread of the pest to healthy parts of the tree.

   - Irrigation and fertilization: Ensure that the mango tree is receiving optimal irrigation and nutrient levels to maintain its health and vigor, making it less susceptible to pests.

2. Biological control: Implement biological control methods to manage mango stone borers. These include:

   - Natural enemies: Encourage the presence of natural enemies such as parasitic wasps, predatory beetles, and ants that feed on mango stone borers.

   - Biological control agents: Release beneficial organisms like Trichogramma wasps, which parasitize the eggs of the pest, or entomopathogenic nematodes, which infect and kill the larvae.

3. Chemical control: If the infestation levels are severe, chemical control may be warranted. However, it is important to follow proper pesticide application practices and adhere to local regulations. Some considerations include:

   - Insecticide selection: Choose an insecticide that is specifically labeled for mango stone borers and follow the recommended dosage.

   - Timing: Apply insecticides at the appropriate time, considering the life cycle of the pest, to target the most vulnerable stage.

   - Rotational use: Rotate different classes of insecticides to prevent the development of resistance in the pest population.

4. Trap crops: Planting trap crops, such as guava or other suitable host plants, nearby can attract the mango stone borers. Regularly monitor and destroy the infested fruits on the trap crop, reducing the pest population in the main mango orchard.

5. Monitoring: Regularly monitor mango trees and fruits for signs of infestation. This allows for early detection and timely intervention, preventing the spread of the pest and minimizing damage.

Integrated pest management (IPM) practices that combine various strategies, such as cultural practices, biological control, and targeted chemical control, should be employed for effective and sustainable management of mango stone borers.

  • Mango hoppers

Nature of damage: The nymphs and adults suck the sap from the tender leaves, inflorescence causing withering and shedding of flowers. The hoppers also secrete honeydew which encourages the development of fungi. 

Management practices: Avoid dense planting. Keep orchards clean by regular ploughing and removal of weeds. Avoid excess use of nitrogenous fertilizers. Smoking of orchards by burning of crop residues/cow dung cake during evening hours. Application of bio-agents, Metarhizium anisopliae or Beauveria bassiana. Spraying of recommended insecticides.

4) Describe shoot and fruit borers on okra and brinjal.

  • Okra Shoot and Fruit Borer

Scientific name: Earias vitella, E. insulana (Noctuidae: Lepidoptera)

Site of oviposition: On shoot tips, buds, flowers and fruits

Nature of damage: Caterpillar bores into tender terminal shoots in the vegetative stage and buds, flowers and flower young fruits in the fruit stage. The shoots dry droop, wither and up. The fruits are deformed and become unfit for holes are consumption. Bored plugged with excreta.

Management practices: Resistant cultivars like AE 57, PMS 8, Karnual Special, Collect and destroy infested shoots, buds, flowers and fruits. Remove the alternate hosts, Egg parasitoid T. chilonisand larval parasitoid Chelonusblackburnii. First instar larvae of Chrysoperlacarnea@ 1 lakh/ha. Set up light traps, pheromone traps @5/ha. Spray Bit formulation @ 2 g/lit. Spray NSKE 5% or Azadirachtin 5% 400 ml or Fenpropathrin 30 EC 250-340 ml with 500 L water/ha.

  • Brinjal Shoot and Fruit Borer

 - Scientific Name: Leucinodes orbonalis

 - Oviposition Site: ventral side of the leaves

 - Pupation Site: Inside the fruit or on nearby vegetation

 - Damaging Stage: caterpillar

 - Nature of Damage: Tunneling and feeding inside shoots and fruits, resulting in wilting, fruit damage, and yield reduction

 - Management: Crop rotation, planting resistant varieties, timely insecticide applications, removing affected plant parts, and using pheromone traps


5) Enlist any four important pests of Pomegranate & Describe Anar Butterfly. 

Four important pests of Pomegranate are:

1) Anar Butterfly (Virachola isocrates)

2) Pomegranate Fruit Borer (Deudorix isocrates)

3) Aphids (Aphis punicae)

4) Whiteflies (Bemisia tabaci)

Anar Butterfly, also known as the Pomegranate Butterfly or the Common Pierrot, is a significant pest of pomegranate trees. It belongs to the family Lycaenidae and is commonly found in India and other parts of Asia.

Description:
- Adult Anar Butterflies have a wingspan of about 3-4 cm. The upper side of their wings is white with black spots, while the underside is pale yellow with black markings.
- The males have a distinctive black mark on their forewings, which resembles an exclamation mark.
- The females have a more rounded shape and lack the black mark on their forewings.
- The body of the butterfly is black with white stripes.
- The caterpillars of Anar Butterfly are green in color with a yellow stripe running along their sides. They have a spiky appearance due to numerous small spines on their body.

Life Cycle:
- Anar Butterflies undergo a complete metamorphosis, consisting of four stages: egg, larva (caterpillar), pupa, and adult butterfly.
- The female butterfly lays eggs on the underside of pomegranate leaves, usually in clusters.
- The eggs are small, round, and pale yellow in color.
- After about 4-5 days, the eggs hatch into caterpillars.
- The caterpillars feed on pomegranate leaves and grow rapidly, going through several molting stages.
- The mature caterpillar measures about 2 cm in length.
- Once fully grown, the caterpillar pupates by attaching itself to a leaf or stem using silk threads.
- The pupa is green initially but turns brown as it matures.
- After about 10-12 days, the adult butterfly emerges from the pupa.

Damage:
- Anar Butterfly caterpillars are voracious feeders and can cause significant damage to pomegranate plants by defoliating the leaves.
- The caterpillars chew irregular holes in the leaves, leaving behind only the veins.
- Severe infestations can lead to stunted growth, reduced fruit production, and even death of the tree.
- The presence of Anar Butterflies can also lead to the spread of fungal diseases as they excrete honeydew, attracting ants and promoting the growth of sooty mold.

Control Measures:
- Regular monitoring of pomegranate trees for the presence of eggs, caterpillars, or butterflies.
- Manual removal of eggs and caterpillars whenever possible.
- Application of appropriate insecticides or biological control agents, following recommended dosage and safety guidelines.
- Maintaining good orchard hygiene by removing fallen leaves and fruits to reduce the chances of overwintering pests.
- Implementing integrated pest management strategies, including cultural practices like pruning and proper irrigation, to minimize pest infestations..

Site of oviposition: On calyx of flowers and on tender fruits. 

Site of pupation: Inside the fruits; occasionally on stalk of fruits

Damaging stage: Caterpillar 

Nature of damage: Larvae bore inside the developing fruits and feed on pulp and seeds. Rind exhibit round bore holes. Infested fruits are attacked by bacteria and and give fungi, an offensive smell, fall off.

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