Bactrocera zonata (Saunders)

--Its recognition--
by Dr Ian M. White

	Presentation made by Dr Ian M. White, The Natural History Museum, London, at the EPPO Workshop on Bactrocera zonata (Paris, 2002-03-05/06)

	All close-up photographs are Copyright of the Natural History Museum, London, 2002 Drawings are reproduced with the permission of CABI International

Contents
Identification problems Collecting methods (specific methods aid identification) Fruit rearing and family identification Fruit rearing and genus identification Methyl eugenol trapping	Identification of the family Identification of genera, including Bactrocera Identification of the species Easily confused species Larval identification

There are a lot of fruit flies
- approximately 4000 species and 500 genera of Tephritidae
- almost all phytophagous
- approximately 40% attack fruit
- others in flowers, stems, leaves, roots
Most fruit pests belong to 5 genera
Bactrocera is the largest of these
- approximately 500 described species
- specialists aware of many more

Fruit rearing
- Tephritidae are the only flies that attack fresh fruit
Methyl eugenol trapping
- only collects males of a restricted set of Bactrocera spp.
Other methods (including use of protein and food baits)
- all potentially collect other families and genera
Conclusion: the rest of this presentation will concentrate on identification of reared and methyl eugenol trapped flies

Other flies in fruit usually do not
- Drosophila spp. (Drosophilidae) associated with fallen, over-ripe or damaged fruit
- Silba and Neosilba (Lonchaeidae) oviposit into holes made by Tephritidae
- Atherigona (Muscidae) usually in damaged fruit.

approximately 100 fruit pest Tephritidae
approximately 90% belong to just 5 genera
- the other 10% are in unusual hosts
Conclusion: if we rear from a mainstream commercial fruit it is almost certainly a member of one of these 5 genera

Attracts the males of some Bactrocera spp.
- 81 species recorded at methyl eugenol
- 211 species recorded at cue lure
- 33 apparently neither
- 188 unknown response

Conclusion
- positive response to methyl eugenol helps narrow down the species
- the 211 that go to cue lure can at least be eliminated

Methyl eugenol ...

... can catch an awful lot of flies !

Traps used with methyl eugenol

Steiner trap		Morocco trap

Most Tephritidae have patterned wings
- a few do not
- some other families also have patterned wings

The shape of one wing cell needs to be examined to verify identity
- only the family Psilidae (e.g. carrot fly) is similar but they are not in fruit

Wing veins and family identification

Not Tephritidae	Tephritidae vein Sc bent almost 90 degrees and then reduced to a fold


*Anastrepha*
		- vein M curved forward near end - pattern usually as above


*Ceratitis*
		- cell bcu extension swollen - dark flecks basally - pattern usually similar to above


*Rhagoletis*
		- cell bcu with a short extension - pattern usually similar to above


Bactrocera and Dacus
		- cell bm twice height of cell bcu - cell bcu extension very long - pattern usually as above (sometimes with additions or subtractions)


*Dacus*
		- all terga fused

Bactrocera

- all terga separate (except terga I and II
that are fused in all higher Diptera)