Diptera.info :: Identification queries :: Diptera (adults)
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Pollenia rudis (Fabricius, 1794) male
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MichelAngel |
Posted on 25-09-2018 12:10
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Member Location: Posts: 135 Joined: 31.12.12 |
Good evening, I would like to know if this specimen is a male of Pollenia rudis. It has been collected in Majorca, 03-05-18. Thanks in advance. Miguel Ángel Edited by MichelAngel on 28-09-2018 16:28 |
johnes81 |
Posted on 26-09-2018 12:16
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Member Location: Berlin, Germany Posts: 1978 Joined: 15.10.16 |
Hello Miguel, male genitalia are as difficult to match to drawings as female ovipositors. you must dissect the genitalia to create a better view. As a rule, you must always look at the wing to eliminate P. pediculata (pseudorudis). You could spend hours documenting a Pollenia that turns out to be pediculata. A simple look at the wing will save alot of time and misery. I've all ready added a photo of this wing to the gallery: https://diptera.i...o_id=10761 Then, you need to look at the palpi to eliminate the few species with orange/yellow palpi. If the palpi are black/dark with a pale tip, then you can proceed with other features. As for genitalia, you need perfect dorsal and perfect lateral views of the cerci and surstyli. You also need perfect dorsal and perfect lateral views of the aedeagus. I've attached a photo to illustrate this process. You need to view the genitalia in a manner which matches the drawings of Dr. Rognes. Also read the text associated with the genitalia in his pdf documents. Tips: the aedegus is attached to the surstyli by a thin strap-like appendage. you can break off surstyli if you try to pull the aedeagus to separate it. the thin strp must be clipped with scissors or a scalpel. it is extremely difficult to view the aedeagus in perfect dorsal once it is removed from the cerci/surstyli. it is better to view it in perfect dorsal while it is still attached. you've already shown it in your photos so you can skip this view. Best wishes, John johnes81 attached the following image: [71.01Kb] Edited by johnes81 on 26-09-2018 12:17 John and Nini. Naturalists not experts. |
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MichelAngel |
Posted on 27-09-2018 14:21
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Member Location: Posts: 135 Joined: 31.12.12 |
Dear John, It doesn't have a tuft of hairs below the wing. Then I see black/dark palpi. I have extracted the genitalia of another identical specimen and I found this, I think that is Pollenia rudis: Thank you very much for all information. I have another specimen that seems to be the Pollenia leclercqiana, I will post a thread later. Best wishes. Miguel Ángel johnes81 wrote: Hello Miguel, male genitalia are as difficult to match to drawings as female ovipositors. you must dissect the genitalia to create a better view. As a rule, you must always look at the wing to eliminate P. pediculata (pseudorudis). You could spend hours documenting a Pollenia that turns out to be pediculata. A simple look at the wing will save alot of time and misery. I've all ready added a photo of this wing to the gallery: https://diptera.i...o_id=10761 Then, you need to look at the palpi to eliminate the few species with orange/yellow palpi. If the palpi are black/dark with a pale tip, then you can proceed with other features. As for genitalia, you need perfect dorsal and perfect lateral views of the cerci and surstyli. You also need perfect dorsal and perfect lateral views of the aedeagus. I've attached a photo to illustrate this process. You need to view the genitalia in a manner which matches the drawings of Dr. Rognes. Also read the text associated with the genitalia in his pdf documents. Tips: the aedegus is attached to the surstyli by a thin strap-like appendage. you can break off surstyli if you try to pull the aedeagus to separate it. the thin strp must be clipped with scissors or a scalpel. it is extremely difficult to view the aedeagus in perfect dorsal once it is removed from the cerci/surstyli. it is better to view it in perfect dorsal while it is still attached. you've already shown it in your photos so you can skip this view. Best wishes, John |
johnes81 |
Posted on 27-09-2018 18:44
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Member Location: Berlin, Germany Posts: 1978 Joined: 15.10.16 |
Hello Miguel, the surstyli are curved more like pediculata but the cerci/surstyli are angled in the photo. Sometimes surstyli can appear to be curved at certain angles or if the surstyli are slightly twisted. I've seen this before with a rudis male but i always straighten them and dissect them for a perfect dorsal view. Normally i will agree with rudis but the curve is a bit stronger than i expected. Are you certain that there are no hairs at the node near the sc? the hairs are not very easy to detect at times. If you are certain that there are no hairs, then try to further dissect the genitalia for a better view. See if the surstyli are twisted a bit. If you can achieve a perfect dorsal view and the curve is significantly reduced, then i can agree with rudis. Please post your photos of Pollenia leclercqiana. Remember to show the wing because Pollenia leclercqiana has a petiolate r4+5. Also, Pollenia leclercqiana is a member of the amentaria group, so the abdomen will be black. Best wishes, John John and Nini. Naturalists not experts. |
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MichelAngel |
Posted on 28-09-2018 10:47
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Member Location: Posts: 135 Joined: 31.12.12 |
Dear John, Yes, I noted that. I have done another pic of the dorsal view: I also have checked the tuft of hairs below the wing in different angles and I didn't see anything: Thank you very much. Miguel Ángel johnes81 wrote: Hello Miguel, the surstyli are curved more like pediculata but the cerci/surstyli are angled in the photo. Sometimes surstyli can appear to be curved at certain angles or if the surstyli are slightly twisted. I've seen this before with a rudis male but i always straighten them and dissect them for a perfect dorsal view. Normally i will agree with rudis but the curve is a bit stronger than i expected. Are you certain that there are no hairs at the node near the sc? the hairs are not very easy to detect at times. If you are certain that there are no hairs, then try to further dissect the genitalia for a better view. See if the surstyli are twisted a bit. If you can achieve a perfect dorsal view and the curve is significantly reduced, then i can agree with rudis. Please post your photos of Pollenia leclercqiana. Remember to show the wing because Pollenia leclercqiana has a petiolate r4+5. Also, Pollenia leclercqiana is a member of the amentaria group, so the abdomen will be black. Best wishes, John |
johnes81 |
Posted on 28-09-2018 12:02
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Member Location: Berlin, Germany Posts: 1978 Joined: 15.10.16 |
Hello Miguel, Thank you for confirming the wing and straightening the cerci/surstyli. I am cautious with the rudis group because they look very similar. I agree with Pollenia rudis male. Best wishes, John John and Nini. Naturalists not experts. |
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MichelAngel |
Posted on 28-09-2018 12:08
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Member Location: Posts: 135 Joined: 31.12.12 |
Thank you very much John! Best regards. Miguel Ángel. |
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