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Project Title: Pesticide Management of

Brontispa longissima in Coconut

Project Leader: Leonila M. Varca

Study Leader: Lorenzo E. Fabro

Implementing Agency: National Crop Protection

Center, Crop Protection Cluster,

College of Agriculture, University

of the Philippines Los Baños

Cooperating Agency: Philippine Coconut Authority

Funding Agency: PCARRD, DOST

Project Duration: January 21, 2008 – October 20, 2008

Budget: PhP 559,537.00

Brontispa longissima

• One of the most

damaging pests of

coconut and other

palms

• Adults and larvae

feed on soft tissue of

the youngest leaf in

the throat of the palm.

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• Affected leaves turn

brown, resulting to

stunting of palm,

reduced nut

production and

eventually death of

the trees

Chemical control is practiced as part of CLB

control program of the government.

Trunk injection and spraying of insecticides are

implemented by PCA to fastrack the mitigation of

infestation and spread of the pest and allow recovery

of damaged trees.

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Concerns with chemical control

- Spray application to tall trees pose risk to applicator.

- Health concerns to workers, animals and to the

environment.

- Trunk injection may affect quality of the coconut

products.

- Insecticides recommended by PCA for trunk injection

are not registered for use in coconut with the FPA.

- No local residue data available.

Objectives of the project

- To evaluate selected systemic insecticides against

Brontispa longissima.

- To determine effective rates of application of

selected systemic insecticides to Brontispa.

- To assess the effects of stem injection of the

insecticides to beneficial insects.

- To determine the residues of these insecticides to

coconut fruits.

- To come up with good agricultural practices (GAP)

recommendations as control measures against

Brontispa.

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Insecticides evaluated for trunk injectionCommon

Name

Brand

Name

Recommend

ed Rate

Twice the

Recommend

ed Rate

Thiametoxan Actara

25 WG

1 gram

product/tree

2 gram/tree

Thiametoxn

+ L-

cyhalothrin

Alika

247 Zc

1.5 mL

product/tree

3 mL/tree

Clothianidin Danto

p 16

WSC

1 gram

product/tree

2 gram/tree

Imidachlopri

d + B-

cyfluthrin

Solom

on

1.65 mL

product/tree

3 mL/tree

Study 1. Evaluation of the effectiveness of

selected systemic insecticides for the control

of Brontispa longissima.

• Insecticides evaluated were effective against Brontispa longissima adult and larvae at the dosage applied. A second application is suggested after 30 days to sustain control of the pest.

• These insecticides did not affect the population of the common earwig, Chelisoches morio, a natural enemy of the coconut leaf beetle.

• Chemical control can be complemented with other pest management strategies for effective management of the pest.

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Study 2. Assessment of pesticide residues in

coconut from trunk injection of systemic

insecticides

• Coconut water was analyzed for residues of the

trunk injected insecticides at 1,3,7,15 and 60

days after trunk injection.

• Thiametoxam was not detected below 0.06

ug/ml;Imidachloprid below 0.065 ug/ml;

Clothianidin below 0.06 ug/ml; Lambda-

cyhalotrin below 0.009 ug/ml ; B-cyfluthrin below

0.07 ug/ml at 1day to 60 days after treatment

• Coconut milk was analyzed for residues of the

trunk injected insecticides at 1,3,7,15 and 60

days after trunk injection.

• Thiametoxam was not detected below 0.02

ug/g;Imidachloprid below 0.55 ug/g; Clothianidin

below 0.35 ug/g; Lambda-cyhalotrin below 0.39

ug/g ; B-cyfluthrin below 0.11 ug/g at 1day to 60

days after treatment

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Processing of treated nuts to virgin coconut oil

and coconut oil reduced the concentration of

thiametoxam by 98% and 100%,

Concentration of imidachloprid by 96.5% and

91% respectively.

Dietary Risk Assessment of Residues of

Trunk- injected Insecticides

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Theoretical Maximum Daily

Intake• First estimate of pesticide residue intake

applying CODEX MRLs or proposed MRL

• Calculated by multiplying the established

or proposed MRL by the estimated daily

regional consumption of the food

commodity

• Compared to the ADI of the pesticide

calculated for a 60 kg person and

expressed as % of the ADI

Acceptable Daily Intake (ADI)

Daily intake of the chemical which

during the entire lifetime appears to be

without appreciable risk to the health of

the consumer on the basis of all known

facts at time of evaluation.

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Average daily consumption of Filipinos for

coconut and derived products = 10 g/day

Reference: Phil Nutrition Facts and Figures (2001)

FNRI, DOST

Pesticides Concentratio

n mg/kg

TMDI mg/kg ADi mg/kg

bw

Remarks

Thiametoxam 0.06 0.00001 0.02 0.05% of ADI

Imidachloprid 0.55 0.000092 0.06 0.18 % of ADI

Chlothianidin 0.35 0.000058 0.097 0.06 % of ADI

L- cyhalothrin 0.39 0.000065 0.002 3.25 % of ADI

B- cyfluthrin 0.11 0.000018 0.02 0.09 % of ADI

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• Trunk injection of systemic insecticides will not

affect the quality of the coconut with respect to

pesticide residues.

• Treated nuts can be harvested within the week

after treatment of the trees. TMDI did not exceed

the ADI

• Processing of the nuts to virgin coconut oil and

coconut oil will reduce concentration of

thiametoxam and imidachloprid.