Thread subject: Diptera.info :: Agromyzidae on Helianthus annus

Posted by Sundew on 02-07-2020 02:13
#1

Hi,
The leaves of my sunflowers have been a meeting place for small Agromyzids for weeks. According to https://bladminee...us-annuus/, three species infest Helianthus annuus: Chromatomyia horticola, Ch. syngenesiae, and Liriomyza strigata. Can we get closer?

Posted by Sundew on 02-07-2020 02:13
#2

More pics; the lower one seems to be a male.

Posted by Sundew on 02-07-2020 02:17
#3

This is the result of their restless activity. As the mines of Liriomyza strigata are said to be associated with the leaf midrib, I think one of the Chromatomyias is to be blamed.

Posted by Sundew on 02-07-2020 02:22
#4

As also other ornamental plants in the neighbour pots are heavily mined (Raphanus sativus var. sativus, Tropaeolum majus - see below, Antirrhinum majus), the polyphagous Chromatomyia horticola is under suspicion.
Help is appreciated - thanks! Sundew

P.S. Location is southwestern Germany, 20 km west of Stuttgart.

Edited by Sundew on 02-07-2020 02:31

Posted by Jan Maca on 02-07-2020 12:56
#5

On Raphanus and Tropaeolum you should take into consideration also Scaptomyza flava, although the photographed mines on Tropaeolum are more probably those of some agromyzid.

Posted by John Carr on 02-07-2020 13:05
#6

The adults look more like Chromatomyia than Liriomyza.

Posted by Sundew on 02-07-2020 13:29
#7

Jan: You are absolutely right, Scaptomyza flava is an option. I cannot prove, of course, that all my different flowers are mined by the same fly species, and adults are only seen on the sunflowers. However, the mine shape of Scaptomyza is a bit different (https://bladminee...yza-flava/): though the mines in my Tropaeolum are not fresh, none of them has reached the blotch stage yet that is typical for Scaptomyza.

John: I totally agree. I shall label the pictures "Chromatomyia cf. horticola", which cannot be too wrong. It is a pity that Milos isn't around at the moment, he'd probably have supplied us with more detailed information.

Many thanks to both of you!

Edited by Sundew on 02-07-2020 13:32