XA9951678

FAO/IAEA Int. Conf. on Area-Wide Fifth International Symposium on Fruit II-19 Control of Pests, of Economic Importance Penang, May 28 to June 2, 1998 1-5 June, 1998. Penang, Malaysia.

LEVELS OF INFESTATION OF THE FRUIT CURVICAUDA GERST. IN CANOABO AND BEJUMA, VENEZUELA Nancy Boscan and Freddy Godoy CENIAP/FONAIAP, Maracay, VENEZUELA

In order to determine the levels of infestation of papaya fruit in two plantations under different management conditions, one in Canoabo and the in Bejuma, both located in Carabobo state, Venezuela, weekly ramdom samples of fruits were collected during 10 months. Number of fruits sampled varied according to their availability in plants at the moment of sampling. Fruits were taken to the laboratory, measured and dissected individually; diameter of fruits, number of damaged fruits and number of larvae and eggs in each of the damaged fruits were determied . The percentages of monthly infestation in both plantations were also determined.

In Canoabo, 637 fruits were analyzed and 285 (44.74%) were found to be infested with larvae; the average number of larvae per sampled fruit was 1.46 and the mean number of larvae per infested fruit was 3.27. Only 57 out of the total fruits sampled had eggs (8.79%). The mean number of eggs per sampled fruit was 0.35 and the average number of eggs in infested fruits was 4.07. A total of 932 larvae were found in the 285 infested fruits and 228 eggs were counted in the 57 egg-infested fruits.

In Bejuma, out of 1225 fruits sampled, 73 (5.95%) showed larvae of papaya fruit fly, with an average number of 0.46 larvae per sampled fruit, while the average number per infested fruit was 0.78. Out of the total sampled, only 7 fruits contained eggs (3.34%), showing an average of 0.033 eggs per sampled fruit, and 5.85 eggs per infested fruit. A total of 57 larvae were found in the 73 infested fruit, and 41 eggs in the infested fruits.

The percentage of monthly infestation in papaya fruits in Canoabo varied between 93.75% in July 1995 to 14.60 in May 1996. In Bejuma, it varied between 22.80% in January 1996 and 1.26% in April Of the same year, becoming zero in September-October 1996. In Canoabo, the highest number of eggs per fruit was 12, while in Bejuma it was 8. In both localities, eggs were found between and inside the inmature seeds. The highest number of larvae per fruit was 17 in Canoabo and 29 in Bejuma. The size of infested fruits varied from 2.5 to 26 cm in Canoabo, and 3.2 to 9.4 cm in Bejuma. In Canoabo, all parameters measured (number of larvae and eggs in infested fruits, percent of larvae and eggs in infested fruits) were higher than in Bejuma.

The results indicated that the higher population levels occurred in Canoabo, where there was inadequate agronomic management in the plantation, inadequate planting density, no fertilization, and no pest control.

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