"echinosum" wrote in message
...

VX Wrote:
Just today and yesterday I have seen numerous flies, maybe a little
larger
than a hoverfly but otherwise similar, but with bright yellow bodies
and
black wings (seen at rest). These have all been apparently laying eggs,
or
doing sometthig very similar with their rear end, in or on the stems
of
roses- all but one of these were on young succulent rose stems. They
spend
several minutes doing whatever they are doing, then fly away.

If they are that still, perhaps you could take a photo? Colour doesn't
help very much in identifying insects, it's shape that matters, and
that is rather hard to describe in words unless you already know enough
insect anatomy to know (roughly) what it is.

You say they look like hoverflies. Do they also behave like hoverflies
(ie. hover)? If so, I'd guess hoverflies. There are many different
kinds and they come in different sizes and colours and shapes.
Hoverflies is good - they eat aphids even better than ladybirds.

I suggest buying a book on insects, one that describes the different
groups and their basic anatomies. It doesn't take long to be able to
identify the anatomical differences between the different groups of
insects, and it's very interesting. A whole new world of wildlife
opens up.




--
echinosum
In pedantic mode, hoverfly larvae eat aphids-the flies feed on nectar.
regards
David T