Thread subject: Diptera.info :: Eristalis pertinax laying eggs or defecating

Posted by Ocellar view on 13-04-2017 14:08
#1
This female syrphid was seen on 12 April 2017. Does it lay (or "throw"?) eggs? Do you have an idea about the genus / species?

Location: Kerzers, Switzerland 438 m above sea
Habitat: Found in a hedge, but there is also farmland a small forest and meadow nearby
Size: approx. 16-17 mm

If you have any idea what you see here please share your thoughts.

Regards,
Ov
Edited by Ocellar view on 18-04-2017 12:33

Posted by Ocellar view on 13-04-2017 14:15
#2
Do we see an egg here?

Posted by Juergen Peters on 14-04-2017 19:47
#3
Hello,

Ocellar view wrote:
This female syrphid was seen on 12 April 2017. Does it lay (or "throw"?) eggs? Do you have an idea about the genus / species?


this is Eristalis pertinax. I am not sure, whether it is laying eggs this early in the year or is simply getting rid of excrements.
Edited by Juergen Peters on 14-04-2017 19:47

Posted by Ocellar view on 18-04-2017 12:39
#4
Tank you very much for your reply!

Regards,
Ov

Posted by Paul Beuk on 18-04-2017 14:43
#5
Extensive ovipositor movements, AFAIK, can be see after emergence, after mating and after oviposition. The first can be excluded as the specimen is rather tattered. Considering the date, perhaps an overwintering specimen that just woke up and is doing some muscle stretching or a specimen that just did some ovipositing but certainly not where you photographed it. Eggs will be deposited near water or very wet locations as the larvae are aquatic.