Entomologia Croatica, Vol. 13 No. 2, 2009.
Original scientific paper
Napomyza gymnostoma Loew (Agromyzidae: Diptera) biology in central Croatia
Aleksandar MEŠIĆ
orcid.org/0000-0003-3102-5078
; Faculty of Agriculture, University of Zagreb, Zagreb, Croatia
Marija DUPOR
; Faculty of Agriculture, University of Zagreb, Zagreb, Croatia
Jasminka IGRC BARČIĆ
; Chromos Agro d.d., Zagreb, Croatia
Abstract
The leek leaf miner, Phytomyza (Napomza) gymnostoma Loew is an insect of unknown origin. Since the first outbreak of diseased in 1999, this insect has been the dominant pest on onions, and is spread all over Croatia. In some years, it causes considerable economic damage. This paper presents the first description of the biology of Phytomyza gymnostoma in Croatia and the infestation rate on onions, leeks and chives. The research was conducted in the Sisak region and in Zagreb during the period of 1999 – 2001. It was found that Ph. gymnostoma develops two generations annually – the spring and autumn generations. The flight of adult flies starts in the second decade of March, and is continuous till the end of April. Females lay eggs a few days after copulation. Larvae that hatch from those eggs are present from the second decade of March till the end of May. After finishing their development, larvae transform into the stage of pupae. This stage lasts till September. The auutumn (second) generation flight starts at the beginning of September and lasts till the end of October. A couple days after copulation, the females lay eggs mostly on leek plants. the auutumn generation eggs are present from mid-September till the end of October. Larvae hatched from those eggs feed inside leek plants during October till mid-November. After finishing their development, the larvae transform into pupae. Pupae overwinter till the next spring and the emergence of new imagos. During the research, the highest infestation was recorded in 1999, when we found 40 larvae and pupae of Ph. gymnostoma per onion plant, 25 larvae and pupae per leek plant and 14 per chive plant. A higher infestation was recorded with untreated onions in smaller gardens than with onion plants grown in larger plantations (12.5 – 28.5% of all plants were infected with 1.3 – 1.9 larvae per plant, in average).
Keywords
Phytomyza (Napomyza) gymnostoma; appearing period; infestation; leek; leek leaf miner; onion; chives
Hrčak ID:
48345
URI
Publication date:
18.11.2009.
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