3rd of October:
I noticed some small eggs on my Silene cf. vulgaris seedlings, so I took a picture to see them up close.

6th of October:
It appears the eggs have hatched into the leaves. So they were leaf miners.

16th of October:
I have found one of the miners trying to change leaves. I have no idea what species they might be, but this website gives some potential suspects:
https://bladmineerders.nl/host-plants/plantae/spermatopsida/angiosperma/eudicots/superasterids/caryophyllales/caryophyllaceae/caryophylloideae/sileneae/silene/silene-vulgaris/

18th of October:
The population is not sustainable and the leaves are almost all eaten up. There are around 7 leaf miners in total, maybe a bit more. I have collected one of them for some close ups and to limit a bit their population. It later died as it got dehydrated. I gathered one more, but I had closed the cup with some paper towels, and the 2nd one died by touching them, losing all it's moisture.

19th of October:
All leaves are eaten, and the leaf miners hang out on the stems. Some seem to head for the soil.
This was the last time I saw them up to now. They must have burrowed into the soil.
Before that, I had gathered one more, which I managed to keep hydrated and feed with some Cerastium sp. leaves I found in the area. I will try to raise it to adulthood so it might be identified and the photos might become useful to some people.

25th of October:
The larva has eaten two and a half a leaves and disappeared inside the rubble of soil and debris (which I left to soak up the excessive moisture) inside its cup. I hope it hasn't died and just turned into a pupa without me noticing it.

4th of November:
Today I decided to check whether the experiment had failed, so like an archaeologist, I tried to dig up slowly and carefully the soil I had put in the cup.
To my relief... the larva had turned into a pupa! I will upload the photos tomorrow.
Now we wait...

13th of November
Today I woke up and noticed the fly had emerged from the pupa.
I took some pictures while it was inside the cup, but those unfortunately are not enough.
Even if morally I disagree, I have to refrigerate a bit the fly, so that I can take some close-up shots without killing it.
I managed to take a lot of close-up shots, though no focus stacks, and I am happy with the result, as the fly survived and flied away afterwards when I released it. I believe it is a Pegomya.

Day 1 (03.02.2021): 1st Observation
I have taken this caterpillar and will try to feed it until it becomes a moth while recording its progress and different stages.
The leaves on the area I found it were mainly Oxalis pes-caprae, but I will also add different kinds of leaves in its enclosure, as well as some soil.
Up until now it has eaten from the Oxalis leaves.

Day 2 (04.02.2021):
Today, and yesterday night, I noticed some bite marks on the Oxalis leaves. I was away most of the day, but the caterpillar was inactive the time I arrived. Not wanting to risk it having a narrow diet, I added a Lantana leaf, some fresh Oxalis leaves with some flowers, and a Prasium majus leaf. These are present in the area.
Tomorrow I will check which have been bitten.

Day 3 (05.02.2021):
As far as I could see, it didn't eat any of the leaves. What I noticed though, is that it started nibbling on the stalk of an Oxalis flower.
I brought it a Malva leaf, a fresh Oxalis leaf and an Oxalis flower. It got straight to work eating the pollen and then it stayed inside the flower resting (I guess).
It stayed in there for the rest of the day.

Day 4 (06.02.2021):
Today I noticed it is still inside the Oxalis flower, having eaten all the anthers of the stamens.
I brought 2 fresh Oxalis flowers and a leaf. It didn't want to grab onto the leaf, but it grabbed the flower. Again, it spent the whole day inside it, eating when needed, while acting completely disinterested to its surrounding foliage.
Before going to sleep I noticed some silk threads over the flower. Not many though.
I don't think I can leave it inside the flower tomorrow though, as the petals wither away.

Day 5 (07.02.2021): 2nd Observation
Not much changed today, it is still inside the flower and the silk threads are still there.
I made an observation of this, where you can see it residing in the flower and the silk threads in the entrance of the flower.
Let's see if anything happens tomorrow.

Day 6 (08.02.2021):
Today the caterpillar moved from one flower, which had withered away, to the fresher one.
In the evening, I noticed it had ripped the stamens and the caterpillar was hiding between the flowers.
It was doing something with its mouth, I guess producing silk or something like that, and then retreating back to the space between the flowers.

Day 7 (09.02.2021): 3rd Observation
Today I offered 2 more Oxalis flowers, plus a leaf, and took some pictures of the caterpillar's body. The markings have became more distinct, and my suspicion is that it might be a Gymnoscelis rufifasciata larva. I guess we will see in the next days.

Day 10 (12.02.2021):
Today the caterpillar was acting a little bit weird. I found it on the ceiling of its enclosure (which is a mask). I added the daily flowers and leaf, but it didn't seem interested this time.
Normally it goes straight to the pollen, this time it went around, like not knowing where to go.
Eventually it entered the flower again.

Day 11 (13.02.2021): 4th Observation
The caterpillar didn't move much this morning.
When I changed the flowers, it was barely moving. Its mouth had some silk stuck to it and the flower, but other than that, not much else.
Later today it, unfortunately, died...