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Hi, I think this is Musca autumnalis, but I'm really not sure if the hair distribution on gena match this species or M. larvipara. The suprasquamal ridge seems to be bare on most of its lenght, but I'm also not sure if I'm seeing it right. Could you give me your opinion?

location: Porto, Portugal
date: 28/06/2019

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Are the photos not good enough to confirm the ID? :|

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this is the time of year when alot of dipterists are in the field. I guess everyone is busy or missed your post.

the hairs on the suprasquamal ridge do not extend along the entire length and the distance between eyes is less than the width of the flagellomere. So it seems that male Musca autumnalis is your only option.

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Thank you! So, am I right to think that in M. larvipara the area to which the red arrows are pointed in the picture below should be hairy?

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The distribution of hairs is better answered by an expert. I do not have a larvipara specimen for comparison, however, i prefer genitalia. I cannot find genitalia either. I've asked for drawings but noone answers. I'm not sure if there is a Musca expert. My opinion is always the same: if i have a specimen, then why would i look at the ridge instead of genitalia? interesting.

so, since i am not an expert, i can only convey my personal thoughts. anterior is supposed to mean toward the head. yes? well i do not see hairs at the end where your red arrows point to. So, i consider anterior to mean the group of hairs to the right of your red arrows. my specimens also have these hairs. Thus, i think that the hairs would extend all the way to the end of this ridge to the scutellum or just to the bend. This is my interpretation of text because i do not see hairs anywhere else. Thus, anterior must mean the anterior part of this lower ridge.

I will attach a modified version of your photo with a yello arrow indication what i believe to be the anterior hairs. The yellow bar will then indicate the extent of the hairs for larvipara. I assume this to be correct but what the hell do i know :-D

you should probably ask a Doctor of biology/entomology. I'm just a naturalist perse.

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Thanks again! |t It would be great if someone could post a picture of the suprasquamal ridge of M. larvipara. B)

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well, if we focus on something less debateable, such as the distribution of hairs on the gena, then by all means this specimen is M. larvipara. Look at the distribution of hairs. The drawing of Hennig matches your photo. I will attach a photo of my Musca autumnalis gena for comparison. You will see that the hairs rise up to the dark line. Whereas, the hairs on the gena of your specimen do not reach the dark line. I think that the suprasquamal ridge is open to interpretation because noone shows a drawing or a photo. Thus, this feature is creating too much confusion.

I suggest writing a pm to Stephane. He should be able to confirm larvipara for you. I think that the hair distribution matches. However, the space between the eyes is not distinctly narrower than the first flagellomere. So i consider it to be Musca autumnalis. I don't have larvipara but i'm actively seeking it. I want this species so that i can separate the two more easily. I'd like to master this genus.

I'll write a pm to Stephane. No matter what, Stephane knows much more than i do. It will be what he says it is. I can only confirm that i have autumnalis male and female.

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Hi Rui !

You can see a drawing of the suprasquamal carina of Musca larvipara here https://books.goo...mp;f=false

Not sure if it will help you ...

BR

Leif K

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Thank you John and Nini for the photo of the head of M. autumnalis! I also thought that the hairs on gena match better the drawing of M. larvipara, but I'm always suspicious of old illustrations. In your photo the hairs indeed look like they are higher up on gena. It would be really nice to see photos of the gena of both species to compare. :)

Hi Leif! Thank you so much for the link to the drawing! That is really helpful because now I'm more confident this is M. autumnalis. In M. larvipara the hairs should be present in the area more to the left of the red arrows, but in my specimen that area is bare. Great!

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Thank you for the link, Leif :) very good resource.

Hello Rui, i am actively seeking larvipara but i've been slowed down by my injury. I will say that when i find it, i will add photos to this post and to the gallery. I may have to upgrade my microscope to make better photos.

Meantime, i do believe that this specimen is M. autumnalis. I've examined four males and two females, so i'm quite used to seeing them under the microscope now. It doesn't make me an expert but i'm quite familiar with them by now. I hope that you also find a larvipara for comparison.

:)

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I'll label the specimen as M. autumnalis, thanks! I hope you find M. larvipara! I'll search for this species and if I succeed I'll also add photos to this post. :)

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I hope that one of us can find a larvipara. I'm going to increase my energy toward finding it. Meantime, my Wife and i were discussing Portugal a few times. Alot of people visit Spain but we are interested in visiting Portugl sometime. I am wondering if you can suggest a nice place to accomplish two tasks with one visit:
1. relax and enjoy ourselves. 2. photograph birds, spiders and insects.
maybe you can reommend a place where we can accomplish both tasks?

answer anytime. in this thread or pm.

Thank you.