Picture of female Drosophila hydei by
Hilary Burn
D. hydei Sturtevant 1921
Last update: 21 September, 2002
Picture of female Drosophila hydei by
Hilary Burn
Closely associated with man in all parts of the world. Dyson-Hudson (1954) found it particularly common in gardens and orchards, where 85% of all the D. hydei specimens were taken; only about 11% were taken from woodland habitats. Shaw (1968) records adults, larvae, and pupae on the open face of a covered pit of pea-silage. Farmyards and decaying plants also attract this species. Sobels et al. (1954) suggest a preference for open habitats. For example, on the open slope of a hill with scattered groups of trees and bushes, D. hydei was the dominant species. It is most abundant from June until August. In Dyson-Hudson's survey (1954) 80% of all the specimens collected were taken during this period.
Prof. B. Shorrocks
I know that many people have found the large, black species of Drosophila fickle to culture, and I think I may have discovered how to prevent this. Like most people, I have had failures of these flies for no apparent reason. Their life cycle is considerably longer than that of D. melanogaster, and the failed cultures usually moulded up. I have found that the problems can be alleviated by starting new cultures with masses of flies and by initially keeping them at about 30ºC. This way larvae appear after two or three days and the flies can then be used to start a new culture, or fed to the frogs. The medium is the standard mashed fruit mixed with some thickening agent (e.g. instant porridge oats) and then seeding with living yeast.
Mick Bajcar
Editor’s note: the life cycle of this particular Drosophilid is interesting. Those members who still have the booklet on Drosophila I produced for the BDG some years ago (about 1988) will appreciate this. The first flies to hatch from the cultures of this species are predominantly female, with very few males if any. Most people would use these flies as food and then use any subsequent flies as the next generation for their cultures. However, what they are doing, in fact, is to remove the majority of females from culture, leaving only males which, for reasons best known to themselves, hatch at a later time, usually several days after most of the females, and it is for this reason that cultures fail.
Try using the first flies produced from each culture to seed your next. I think you will find a big difference in your success rate.
John Skillcorn
Drosophila hydei
This, the large black species, can be fickle to produce with cultures often
failing. Dr Shin Sugiyama, has suggested that one of the problems seems to be
that: male adult hydei take at least a week after emerging to become
sexually mature This would probably effectively prevent mating between siblings
in the wild. Because the females are quicker the solution appears to be the
mixing of old males (+10 days) with new females to get good egg production that
can be done by simply mixing old and new flies. Shin no longer maintains this
species but would appreciate the results of any experiments carried out.
Dr. Shin Sugiyama
Bibliography
Dyson-Hudson,
V.R.D. 1954 The taxonomy and ecology of the British
species of Drosophila. D.Phil. thesis (deposited in
the Bodleian Library, Oxford, and in the library of the Department of Zoology
and Comparative Anatomy, Oxford University). Back
Shaw, M.W. 1968 Drosophila species (Dipt. Drosophilidae) associated with pea silage. Entomologists' Monthly Magazine. Back
Sobels, F.H., Vlijm, L and Lever, J. 1954 The distribution of the genus Drosophila in the Netherlands. Archives Neerlandaises de Zoologie 10, 357—374. Back