INTRODUCTION

Scope

This standard describes tests for determining the host status of a fruit or vegetable variety at a defined stage of maturity to a particular tephritid fruit fly species. A fruit or vegetable may be classified as a non-host, conditional non-host or potential host on the basis of these tests.

References

Drew, R.A.I.; Lloyd, A.C. 1989. Bacteria associated with Fruit Flies and their Host Plants, pp. 131-140. In: Robinson, A.S.; Hooper, G. Fruit Flies - Their Biology, Natural Enemies and Control. Volume 3A, World Crop Pests. Elsevier Science Publishers, Netherlands.

Fay, H.A.C. 1989. Multi-host Species of Fruit Fly, pp. 129-140. In: Robinson, A.S.; Hooper, G. Fruit Flies - Their Biology, Natural Enemies and Control. Volume 3B, World Crop Pests. Elsevier Science Publishers, Netherlands.

Glossary of phytosanitary terms, 2002. ISPM No. 5, FAO, Rome.

NZ Ministry of Agriculture and Forestry (MAF) Standard.

Definitions and abbreviations

commodity	A type of plant, plant product, or other article being moved for trade or other purpose [FAO, 1990; revised ICPM, 2001]
conditional non-host (of a fruit fly species)*	Fruit and vegetables at a specified maturity and specified physical condition that cannot support the development of viable adults of a fruit fly species
eclosion*	The process of larva hatching from an egg or emergence of an adult insect from a pupa
fecundity*	The average number of eggs laid per insect over a specific time period
fruit and vegetables	A commodity class for fresh parts of plants intended for consumption or processing and not for planting [FAO, 1990; revised ICPM, 2001]
fruit fly*	Insect of the order: Diptera: family Tephritidae.
fruit fly host^[1]*	Any fruit or vegetable in which under field conditions fruit flies oviposit, the eggs hatch into larvae, and the larvae acquire sufficient sustenance to form pupae from which viable adults emerge.
gravid female*	Female fruit flies with fertilised eggs
incursion	An isolated population of a pest recently detected in an area, not known to be established, but expected to survive for the immediate future. [ICPM, 2003]
non host (of a fruit fly species)*	Fruit or vegetables that will not support the complete development of a fruit fly species regardless of the stage of maturity and physical characteristics
National Plant Protection Organization	Official service established by a government to discharge the functions specified by the IPPC [FAO, 1990; formerly Plant Protection Organization (National)]
NPPO	National Plant Protection Organization [FAO, 1990; ICPM, 2001]
Outbreak	A recently detected pest population, including an incursion, or a sudden significant increase of an established pest population in an area. [FAO, 1995, revised ICPM, 2003]
oviposition*	The act of laying or depositing eggs within a fruit
teneral adults*	Condition of the adult shortly after eclosion when its cuticle is not fully sclerotized or fully mature in colour

* Indicates terms which are not include in ISPM No. 5 Glossary of Phytosanitary terms.

Outline of requirements

Non-host or conditional non-host status at a particular stage of harvest maturity can be used as a phytosanitary measure to ensure freedom from fruit fly infestation. To facilitate the determination of this status, this standard describes the general and specific requirements for testing the response of a fruit or vegetable variety at a defined stage of maturity to a particular tephritid fruit fly species.

A series of laboratory and field trials, using a specific fruit damaging technique, are used to determine host status, the results of which are interpreted in the following way:

if punctured fruit (used in the botanical sense) show no sign of fruit fly infestation then the host is described as a non-host
if unpunctured fruit, from either laboratory or field trials, are not infested by a fruit fly species but damaged fruit is, the host is described as a conditional non-host
if both punctured and unpunctured fruit become infested, the commodity is described as a potential host.

Specific requirements should be followed for each stage of the testing - using punctured fruit in laboratory tests, unpunctured fruit in laboratory tests and unpunctured fruit in field or glasshouse tests. These requirements concern the testing of the fecundity of the fruit flies, the development of fruit fly populations, the selection of fruit used for the tests, the holding of the fruit after exposure to fruit flies and the assessment of the tests.

^[1] Based on Armstrong, J.W. 1986. Pest organism response to potential quarantine treatments. Proceedings 1985 ASEAN PLANTI Regional Conference on Quarantine Support for Agricultural Development 1:25-30. ASEAN Plant Quarantine and Training Institute, Serdang, Selangor, Malaysia.