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Appendix IV. Prior Scientific Papers.
Appendix IV.A. “Single -Killing-Point” Laboratory Assessments of Bait Controls of Fruit
Flies
(Diptera: Tephritidae) in Pakistan
John Stonehouse a* , Qamar Zia b , Riaz Mahmood c , Ashraf Poswal c and John Mumford d
a
Department of Environmental Science and Technology, Imperial College of Science, Technology and Medicine, University of
London, Royal School of Mines, London SW7 2BP
b
University of Arid Agriculture, Rawalpindi, Pakistan
c
CABI Regional Bioscience Centre, Rawalpindi, Pakistan
d
Imperial College of Science, Technology and Medicine, Silwood Park, Ascot SL5 7PY
*Corresponding author. Tel 020 7594 9311 fax 020 7589 5319 E-mail j.stonehouse@ic.ac.uk
Crop Protection 21 (2002): 647-50
Abstract
In the evaluation of insect controls by baits and lures considerable advantages are offered by the assessment of the
efficacy of a single “killing point”. Modifications of Bait Application Technique (BAT) were evaluated in the laboratory in
Pakistan using choice chamber cages for pairwise comparisons of individual spot deposits of bait recipes. In attracting and
killing Bactrocera cucurbitae, a home-made beef meat broth had 68.7% of the effectiveness per unit volume of commercial
protein hydrolysate. The addition of urea and cucumber extract source did not enhance the effectiveness of broth bait. There
may be a substantial health risk from the mixing of insecticide with meat broth which is prepared in a way similar to a food
product. The methodology developed offers the rapid and reliable assessment of alternative bait mixtures and formulations.
Key words: Pakistan, fruit fly, bait control
Introduction
Tephritid fruit flies cause annual farm-level losses in Pakistan estimated at US$200 million (Stonehouse et
al., 1998). Bait Application Technique (BAT) offers a control which is reliable, economic and uses a minimum of
chemical insecticide. In BAT a mixture of hydrolysed protein and insecticide is applied in spot deposits
(Roessler, 1989). Adult fruit flies on eclosion need a protein meal for full maturation, particularly for reproduction,
and so before attacking fruit are attracted to these spots, feed on them and die from ingesting the insecticide.
Relative to cover sprays, BAT uses lower doses of insecticide, can be applied on foliage, avoiding the fruits
themselves, and generally offers superior control. BAT with protein hydrolysate bait has been successfully
evaluated in Pakistan (Latif et al., 1987).
This research sought ways to make BAT practical, cheap and reliable for farmers in Pakistan, evaluating
the potential for substitution of costly, imported protein hydrolysate bait with cheaper, home-made alternatives.
Many such studies have evaluated baits made from waste brewer’s yeast (Lloyd and Drew, 1997). Pakistan
having no substantial brewing industry, this study evaluated boiled meat broth. In Afghanistan the United
Nations Food and Agriculture Organisation successfully developed baits for melon farmers consisting of broth
made from cheap beef meat, with malathion, fermented cucumber extract as a cucurbit smell source and human or
animal urine or urea as an ammonia source (Stride, 1996).
Methods
The assessment of fruit fly controls is generally by conventional field trials, comparing whole plots
treated in different ways. Alternatively, BAT may be assessed by counting flies which are attracted to, and killed
by, a single “killing point” of a BAT spot. This produces direct information about the effectiveness of individual
killing points, allowing more detailed comparisons and information for the optimisation of spot size, spacing and
application. It also reduces demands for space, as only one point is assessed instead of an entire plot, and time,
as the number of killed flies itself comprises the data, instead of the assessment of fruit damage and yield. A
major objective of this research was the development and verification of such assessment techniques, to see
whether it is possible to obtain reliable information from such “single-killing-point” assessments, and thus to use
these techniques to “industrialise” the comparison of controls, allowing large numbers of options to be reliably
assessed with low demands for time, space and labour.
Lloyd and Drew (1997) used a laboratory technique for the assessment of baits against Bactrocera
tryoni Frogatt, assessing the attraction of flies to baits by counting flies on sponges soaked in candidate baits.
Baits were assessed individually, without an insecticide component, and the same flies re-used for successive
assessments. The method developed here included insecticide in the full field bait formulation, and aimed to
minimize uncontrolled effects by assessing baits not individually but as simultaneous comparisons of pairs in
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