Again, before disclosing my favourite candidate I'll try to scrutinize the entries a bit

#1. claustn - (N9, camera+)
Lovely colour and hue, the larva seems to absolutely glow by itself. The background is a bit of a distraction, however it is nice that it is dark. (first glimpse does not even reveal the shot has been taken inside a room)
Also the flash casts a shadow under the animal which is a small problem.
There's my pet peeve again; the picture size is way too small! When enlarging it a bit it is also evident that the focus plane does not lie tack sharp on the main object.
Also I'd like to have seen this as a closeup; macro photographs generally get additional punch when the frame is filled with as much of the object as possible.

#2. meemorph - (N9, camera+)
Humoristic shot, the main object fills the frame nicely. Background would be nicer without the shadow on the bottom half of the frame.
Focus is on the text, and face of the figure lies behind the focus plane which is a bit of a distraction.
And as in the previous image, again way too small a picture!

#3. Dave999 - (iPhone 6s Plus)
Really ugly bugger, which is a good thing!
This is a borderline case whether it can be called macro shot unless the fish is of rather smallish breed.
The highlights are really distracting, either from overhead lighting or flash. When photographing shiny objects like a reflective/slimy fishies it is essaential to control the stray reflections, black reflectors come handy here.
Size of the image is good enough but it seems to me the camera autofocus has had a bit of a trouble coping with the subject.

#4. saponga - (N900)
Exposure and sharpness is tack on, really good capture of the flaky texture of the inkcap. Good control of DOF, nice macroish mushroom capture.
Nice round shapes with perfect mass-handling and directionality produce a perfect still life.

#5. tommo - (BlackBerry Passport)
Again, bit stretching the definition of a macro here. Sharpness in the main object is good, but too wide DOF to my liking; background is distracting.

#6. ste-phan - (Samsung Galaxy S7 Edge)
Good separation of main object and background, however there is too much background. These kinds of pictures *really* benefit from going as close as possible! However the mirror/glass is an excellent device here as it shows the mosquito in a nice posture, from both sides at the same time
Excellent sharpness but again the image is way too small!

#7. robthebold - (N9)
Lovely control of DOF, beautiful and well-exposed capture. Nice autumn colours and good mass-handling of the background burrs.

#8. shanttu - (Panasonic Lumix CM1)
Lovely colours, lovely fragile shapes. DOF a bit uncontrolled, it seems to me that the bront blossoms are slightly out-of-focus (probably camera has focused to the pattern on the leaves in bottom left quadrant)

#9. pasko - (Jolla Phone)
The burnt highlight on the whole right half distracts too much. Again a way too small image and the main subject seems to be somewhat out-of-focus.
The background idea (map/book?) is a good one and worth developing, however technical execution lacks in the finalized image.

#10. tvicol - (Jolla Phone)
Nice reeds, good colour and very good powerful leading lines. Focus is good, however again the image size is way too small.

#11. hedayat - (N9)
Main object fills the frame nicely, backgroung/foreground color balance is nice. The image is a fair bit underexposed (which is usualtypical of the sbj-1 device btw.) and would really be enhanced by better lighting.

#12. minimec - (Nexus5 SFOS)
Main object fills the frame nicely, interesting technical view of the subject. However stray reflections of room around the object add too much distraction.

#13. rm250j - (Sony Xperia Ultra)
Good sharpness on the main subject, well exposed and balanced. Presents the subjects well and edible

#14. briest - (N9)
Nice dreamy capture, good autumn feeling. Droplets are notoriously difficult to capture well.

#15. mosen - (Nexus5 SFOS)
Good rythm and strong lead-lines in the picture. However the same applies what I've said about captureing reflective surfaces. Background (coffee machine) is bit of a distraction.

#16. mihsun - (Sony Xperia Z3 Compact)
Nice lead-in with the main subject and the background tube and remote. I'd like to have seen the texts right-side up. The image is slightly grainy even though it looks to be exposed correctly.

#17. catbus - (N9)
Absolutely spot-on capture, very nice texture and colours. the whole frame is filled with interesting detail, culminating into the fold-up leave tips and the freen detail in top right quadrant.

#18. Macros - (Nokia 808 Pureview)
Sharpness is maybe just-nigh-off the mark, cannot really see where the DOF middle point is. Whiter part of the background in the lower half is a bit distracting. Droplets are nice idea but I'd like to have seen some highlight there.

#19. juiceme - (Jolla Phone)
N/A

#20. klinglerware - (Nexus5 on SFOS)
Excellent sharpness and good exposure. Stretching the theme a bit however.

#21. nieldk - (Oneplus X on SFOS)
Excellent sharpness, pretty good exposute but again way too small an image!
Interesting take on a tomato plant? Different-than-usual colour gives additional interest.

#22. danpio - (N9)
Absolutely beautiful posture, the fly in it's element really. The image is way too small, cannot really make out whether the focus is spot on!! Just a tad overexposed but in this case it dose not matter, it adds ethericity to the image. I kind of like the way background burns evenly in the top right quadrant.

The competition was really tough this time, with a lot of excellent candidates. Many images would have been great, if too small image size had not pushed them out of the race.
In the end, all things considered I will vote for #17, catbus.