“Key Informant Survey” of Production, Value, Losses and ... - DfID

coast. In the Faisalabad area attack on bitter gourd, presumably by B. cucurbitae, was reduced from
66.33 to 21.33% by methyl eugenol traps at 8 per acre (Anon., 1988).
Benzyl acetate attracts Bactrocera cucurbitae and dorsalis (Kapoor, 1993). Adult Dacus
longistylus, apparently largely males, are attracted to the plant Calotropis gigantea (GAU,
pers.comm.). No lure is known against Dacus ciliatus (Patel and Patel, 1998b; Qureshi et al., 1987,
who found no response to seven known lures, three plant extracts, eight essential oils and two others),
which also has shown only poor attraction to protein hydrolysate on St Helena (J Mumford,
pers.comm.). There is concern at the occurrence in Pakistan of Myiopardelis pardalina, which
appears indifferent to methyl eugenol, although it is found in traps containing cue-lure and gouminal.
Some role in monitoring, if not control, may be played by coloured traps which mimic ripe fruit:
Jalaluddin et al. (1998) found that B. correcta is more readily attracted to yellow and orange targets
than to red, green, white, violet or blue.
MAT has been successfully used for Tephritid control in South Asia in mango (Moyhuddin and
Mahmood 1993; Mahmood et al., 2000) and in guava (Qureshi et al., 1981; Marwat et al., 1992;
Entomologist, 1997 - the latter showing a net increase in farmer income of 58% from MAT use,
although no improvement was demonstrated in persimmon or cucurbit fields).
There is some isolated evidence of cue-lure serving for MAT control of B. cucurbitae. Table
II.7 shows the results of a trial in Bangladesh.
Table II.7. Comparative effectiveness of BAT and MAT trapping against B. cucurbitae in
cucumber in Bangladesh (Nas ir Uddin et al., 2000c). Data are means of three replicates.
Control Nothing Mashed pumpkin BAT Cue-lure MAT
Percent infestation (%) 22 13 2
Yield (kg/plot of 4m 2 150 230 260
Apart from the nature of the attractant chemicals, the trap delivery system also affects the
usefulness of lure-based killing points. Methyl eugenol or tulsi may be used in a variety of formulations
such as plastic traps, with and without insecticide, and soaked-wood killer blocks; which of these are
most cost-effective for farmers with different resource availabilities in terms of chemicals, traps and
labour, would be a useful study. Indian researchers have developed effective research into, for
example, “lobster-pot” methyl eugenol traps which trap and kill males without insecticide (Patel and
Patel, 1995, 1996, 1998). There are also available commercially prepared blocks microformulated to
release lure at a steady rate (Agrisense, pers.comm.) - these may use lure more cost-effectively than
simpler preparations, but may be beyond the reach of all but the most sophisticated growers. To our
knowledge, soaked-block trap MAT, which offers considerable advantages over all traps in terms of
durability, efficiency and relative imperviousness to destruction by sunlight, wind, theft and mischief
(Stonehouse, et al., in prep. 20001 a&b) has not been successfully evaluated in India.
Mixtures Bait/bait mixtures are widely recommended, as in the prevalence of mixtures of more than
one ingredient in the list of different bait recommendations given above, though the specific comparison
of different quantities of different ingredient have not much been systematically researched in India or
anywhere. Lure/lure mixtures have recently been compared with melon fly in Bangladesh: Table II.8
shows an interesting hint that for the attraction of melon fly a combination of cuelure and methyl
eugenol may show a positive interaction and be greater than the sum of its parts.
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