Posted by Jan Willem on 05-08-2006 10:05
#5
Hi Nikita,
Louis is right:
Brunel in "Manual of Palaearctic Diptera, Volume 3":
The eggs are deposited at the base of stems near the soil, generally one egg per plant. Larvae penetrate the leaves and reach the heart of the plant. The developtment of the larvae causes damage referred to as "dead heart". External leaves remain green, central leaves turn yellow and die. At the end of development, which takes 28 to 40 days, the larvae leave the plant and pupate on the surface of the soil. Pupal development takes 20 to 30 days. SOme flies are also able to develop in winter.
According to Brunel, the adults can live for a period of three to six month.
And Nikita, on how to distinguish the sexes, I can only say, look at the tip of the abdomen! In females the cerci should be clearly visible, making the abdominal tip look rather pointed. Just have a closer look at a few specimens and you will see that the sexes are quite easy to distinguish in Opomyzidae.
Jan Willem