New Zealand Journal of Zoology abstracts

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The phenology and pollen feeding of three hover fly (Diptera: Syrphidae) species in Canterbury, New Zealand

N. A. IRVIN
S. D. WRATTEN

Ecology and Entomology Group
P.O. Box 84
Lincoln University
Canterbury, New Zealand

C. M. FRAMPTON

Applied Computing, Mathematics and
 Statistics Group
P.O. Box 84
Lincoln University
Canterbury, New Zealand

M. H. BOWIE
A. M. EVANS

Ecology and Entomology Group
P.O. Box 84
Lincoln University
Canterbury, New Zealand

N. T. MOAR

Landcare Research New Zealand Ltd
P.O. Box 40
Lincoln
Canterbury, New Zealand

Abstract  The phenology and sex ratios of three hover fly species on Canterbury farmland, New Zealand were recorded weekly from five yellow water-traps from October 15, 1993 to January 31, 1997. Gut fullness, egg number and pollen content were recorded weekly from September 8, 1994 to July 25, 1996. Catches of Melanostoma fasciatum (Macquart) and Melangyna novaezelandiae (Macquart) were higher during the summer months, with maximum male M. fasciatum catches at 0.7 per trap/day in January, 1997. Catches of female Eristalis tenax L. peaked at 0.24 in August, 1994. Gut fullness and egg number in M. novaezelandiae and M. fasciatum were low from June to September, 1995, a pattern opposite to that of E. tenax. For all species combined, gut fullness was significantly higher in gravid females compared with non-gravid females, and males. Thirty-nine different pollen types were recorded from all hover fly classes. Male E. tenax (the largest of the three species) consumed the widest range of pollen in summer and autumn whereas females consumed the widest range in winter and spring, a pattern opposite to that of M. novaezelandiae. The value of the work in possible population enhancement programmes for hover flies in crops is discussed.

Keywords  hover flies; Syrphidae; phenology; pollen; gut fullness; New Zealand

Z97035
Received 15 October 1997, accepted 8 September 1998

PDF file of entire paper: medium quality (717K); (scanned from paper original: notes about this process)

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