Abstract:
Bittergourd is very popular among the vegetable growers in Kerala. Fruit flies take a heavy toll of this crop and intense use of pesticides is a common practice of cultivators often leading to serious residue hazards in the marketed fruits. In the present investigation an attempt was made to standardise non-insecticidal methods of control for tackling this pest problem.
Laboratory evaluation of potential attractants of fruit flies viz. eugenol, eucalyptus oil, citronella oil, borar, ammonium phosphate, vanilla essence, jaggery, sugar, vinegar, honey, toddy and bittergourd fruits were screened for baiting the adults of D. cucurbitae. Eugenol, eucalyptus oil, citronella oil, borax, ammonium phosphate and vanilla essence did not show any attractiveness to the flies. Three graded concentrationsof honey, sugar, jaggery, toddy and vinegar were tested for their attractiveness to the files in the laboratory. The result showed that (1) honey at the highest concentration of 1% attracted the maximum number of flies (2) toddy was not effective for attracting D. cucurbitae. (3) immature stages of bittergourd fruits showed poor aatraction and (4) ripe bittergourd fruits showed poor attraction and (4) ripe bittergourd fruits showed maximum attraction to the files up to 12 h of exposure.
