Control of Mango Mealy Bug

INTRODUCTION

Mealy bugs are sucking insects, soft bodied, oval shape and cottony in appearance. Mealy bugs are found on leaves, stems, roots and fruits which are covered like whitish powder. This condition is very difficult to eradicate the mealy bugs. The mango mealy bugs suck a large amount of sap from all parts of the tree. Recently in Pakistan the mango fruit in Punjab districts like Multan, Bahawalpur, Muzzaffargarh, Rahim yar khan is being seriously infested with mango mealy bugs. Mealy bugs are found in moist warm climate and also act as a vector for several plant diseases. They attach themselves to the plant and secrete a powdery wax layer used for protection while they suck the plant juices. Some species of mealy bug lay their eggs in the same waxy layer used for protection in the quantities of 50-100; other species are born directly from the female.

MODE OF TRANSFER    

Juvenile mealy bugs can crawl from an infected plant to non-infected plant. The other mode of transfer is the small ‘crawlers’ are transferred by wind, rains, birds, ants, clothing and vehicles and settled on new plants. The wax which sticks to each egg also facilitates passive transport by equipments, animals or people. The female mealy bug is unable to fly and not active. In fact, humans are great friends helping in transport of mealy bug. As the infested plant back the colonies of mealy bugs migrate from shoot tips to twigs, branches and finally down the trunk. Ants attracted by the honeydew, have been seen carrying mealy bugs from plant to plant.

NATURE OF DAMAGE   

• Heavy clustering of mealy bugs can be seen under leaf surface giving the appearance of thick mat with waxy secretion.
• They excrete copious amount of honeydew that attracts ants and help in development of black sooty mould which inhibits the plants ability to manufacture food.
• Nymphs and adults suck the plant sap and reduce the vigour of the plant which also causes the withering and yellowing of the leaves.
• Fruit may drop prematurely on crop plants. Heavy infestation can cause defoliation and even death of the plant.
• They infest the plant during flowering season and if the control measures are not taken timely, the crop may be destroyed completely.
• Excessive and continuous draining of plant sap causes wilting and finally drying of infested tissue.

CONTROL    

1. Cultural and mechanical control

2. Biological control

3. Chemical control

4. Integrated pest management (IPM)
5. Cultural and mechanical control

Polythene (400 gauges) bands of 25 cm width fastened around the tree trunk have been found affective barrier to stop the ascent of nymphs to the tree. The band should be fastened well in advance before hatching of eggs, i.e. around November-December. All crop residues in previously infested fields should be removed and burnt. Fields borders should be free from weeds and debris that may support mealy bugs between planting. Apply sticky bands like ‘Track-trap’ on main stem to prevent crawlers of mealy bugs reaching the bunch.

2. Biological control

Monochillus sexmaculatus, Rodolia fumida and Suminius renardi are important predators in controlling the nymphs. The entomogenous fungus Beauveria bassiana is found to be an effective bioagent in controlling the nymphs of the mealy bug. Foliar spray of Verticillium lecanii or Beauveria bassiana 5g/ml per liter of water is effective during high humid months in reducing the population of mealy bugs.

3. Chemical control

Application of 250 g per tree of Methyl Parathion dust 2 percent or Aldrin dust 10 percent in the soil around the trunk kills the newly hatched nymphs which come in contact with the chemical. Spraying of 0.05 percent Monocrotophos or 0.2 percent Carbaryl or 0.05 percent Methyl Parathion have been found useful in controlling early instar nymphs of the mealy bug.

These sprays can also use to control the mango mealy bug.

• Deligate spray

It is mostly used for vegetables and fruit trees.

Quantity = 7.5ml/10L water

Active ingredients = Spintoram 250g/kg,25 % w/w

• Transform spray

Quantity = 7.5ml/10L water

Active ingredients = Sulfoxaflor 500g/kg, 50 % w/w

• Chloropyrifos spray

Quantity = 50ml10L water

Active ingredients = chloropyrifos 40% w/v

4. INTEGRATED PEST MANAGEMENT (IPM)

The IPM schedule of mealy bug is very important and useful if timely operations are done. Flooding of orchards with water in the month of October kills the eggs. Ploughing the orchards in the month of November exposes the eggs to sun’s heat. In the middle of December, 400 gauges alkathene sheet of 25 cm width may be fastened to the tree trunk besides raking the soil around the tree trunk and mixing of 2 percent Methyl Parathion dust. The dust may also be sprinkled below the alkathene band on the tree. The congregated nymphs below the band may be killed by any of the suggested insecticides. The above IPM schedule holds promise to control the mealy bug but spraying of Neem product and the spores of the fungus Beauveria bassiana will further ensure the reduction of the pest population.

Waseem Siddique (2012-ag-3480)

B.Sc. (Hons) Agricultural Sciences

Institute of Horticultural Sciences,

University of Agriculture Faisalabad, Pakistan

Email: [email protected]

Cell#: 0344-5292457

Author

WASEEM SIDDIQUE

Author * institute of Horticultural Sciences

University of Agriculture Faisalabad, Pakistan