Pest Management Series 2000/02 The Citrus Leaf Miner (C.L.M.) A Farmer’s Guide to Identification and Control Published and Printed by the Extension Unit Regional Administration South, Ministry of Agriculture, Land and Marine Resources, Kings Wharf, San Fernando, Republic of Trinidad and Togago January 2000 Revised February 2000

Introduction

The Citrus Leaf Miner (C.L.M.) originated in Asia.

It can now be found in Florida, Texas, Mexico, throughout the Caribbean and Central America.

It was first identified in Trinidad in 1997 and has now been located throughout Trinidad and Tobago.

How can I identify the C.L.M.?

The adult insect is a 2mm long moth with white, silver rainbow coloured forewings and brown stripes and black markings on each wing tip. It measures 4mm across the wings.

What is its life cycle?

The C.L.M. undergoes complete metamorphosis (change) from egg through larva and pupa then the adult emerges. (Figure 1)

What are the symptoms of C.L.M?

1. Silvery mines or tunnels form when the larvae burrow between the leaf surfaces of the young leaves to suck sap. (Figure 2). The surface of the leaves show a characteristic silvery or bronzed appearance.

2. The larva moves towards the edge of the leaf just before it pupates. The presence of the pupa causes the edge of the leaf to curl around it, thus protecting it. (Figure 2)

3. Patches of dead tissue (yellow or light brown) can be seen when the tunnels are extensive and join together. Leaves then dry.

4. Young leaves are very susceptible to C.L.M. attack.

5. Nursery plants or recently planted citrus are at risk.

6. Yields are reduced since food production in the leaves is lowered.

How can I control the C.L.M.?

Use an integrated approach, i.e. a combination of cultural practices, biological measures and application of chemicals. The combination depends on the age of the plants and severity of infestation.

1. Cultural Control

This is the primary approach once C.L.M. is identified.

1. Remove infested shoots.
2. Prune younger trees thoroughly since they are more susceptible to C.L.M.
3. Do not apply fertiliser until C.L.M. is controlled because fertilisers encourage new flushes that are susceptible to C.L.M.
4. Reduce stress on the plant by draining area and controlling weeds and other pests.

2. Biological Control

Locally occuring indigenous natural enemies have reduced the insect spread. Encourage these by minimising chemical use. Insecticides can kill beneficial insects along with the C.L.M. Ageniaspis citricola, an internal parasite of the C.L.M. is being used to control it in the U.S.A.  It is not available in Trinidad.

3. Chemical Control

C.L.M. is very difficult to control using insecticides. This is because the larvae hide between the leaf surfaces and the pupae are enclosed in the rolled leaf. Do not rely on chemical control alone. Use cultural control also.

Chemicals recommended

Malathion

Neem-X

Agri-Mek

Petroleum and Agricultural soap e.g. Mpede, citrole

Admire

Use the above chemicals at the manufacturer’s recommended rate.

The assistance of staff from the Research Division and the Extension, Training and Information Services Division is gratefully acknowledged.

For further information please contact

R.A.S. - (868) 657-5189, (868) 657-5455
St. Patrick (E) - (868) 647-8460
St. Patrick (W) - (868) 648-2384
Victoria - (868) 652-2622/2033, (868) 655-3428
Nariva/Mayaro - (868) 644-2326

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