BUG HOTEL – Cocoon harvest

The bug hotel opened in the spring of 2017, offering superior accommodation and personalized services in eight spacious yet cozy 9mm by 90mm holes drilled in healthy, un-treated, pinewood that’s easy to chew through should guests wish to make modifications to the otherwise comfortable cylinders.

The particularity of this property is that one of the outer walls has been replaced by crystal-clear 6mm glass that offers spectacular views. Privacy is ensured by a hinged flap that swiftly closes when so desired.

The official designation of the property is CB-890, because you can see the bee in all 8 rooms that measure 90mm in length.

It lies just outside my window, by some flower pots next to the wall (SE) It was populated every year, starting in early spring, with the holes sealed by May. The highest number of holes occupied must have been 5 or 6. Last year (2021) was the lowest so far with only 3 taken.

The tenants are solitary bees of various species, and there are, of course, various parasites that treacherously prey on their larvae.

This pretty cigar-looking structure is made by the leaf-cutter bee:

These are made by what I believe to be mason bees:

A whole row of cocoons has been killed by the larvae of the Carpet Beetle. They manage to break the cocoon, get inside and feed on the larva.

The life cycle is as follows: there is frenetic activity in early spring, when females find (or make) a hole in a vertical structure, usually wood, and fill it up with several mounds of pollen. The bee then lays an egg on each mound, separates them with little walls of mud and seals the entrance. The egg becomes a larva that feeds on the pollen and builds a cocoon in which the bee eventually develops. The following spring it chews through the cocoon, breaks the mud wall and flies out.

Females are about half the size of males and the smaller cocoons are always closest to the entrance, as females hatch first. The larger cocoons are the males that hatch last. A dead female near the front can mean the dearth of all cocoons, as sometimes the newly hatched bee does not have the strength to chew through several separations.


Sunspots AR2936, AR2937 and friends, the first being amongst the largest of young solar cycle 25 and which hurled a coronal mass ejection towards Earth in the early hours of January 30th, bound to reach us February 1st or 2nd.

AR2936 has multiple dark cores larger than Earth, and the entire group stretches more than 100,000 km across the surface of the sun. That’s about 8 Earths one next to each other, or a little less than a quarter of the way to the Moon (which is 30 earths away, roughly).

Beautiful footage from SOHO showing the CME that is expected spark auroras at mid-Northern latitudes:

MICROSCOPY- The Swamp III / one year

One year on, and there is an abundance of life in the jar, both macro and microscopic. Vegetation is now mostly on the bottom, and it largely consists of algae. More algae at and above the water line, on the walls of the jar. The lights have been on for the most part of the last 6 months, with maybe 48h of darkness in total. Temperature has been a steady and warm 22-24°C.

A superficial visual inspection with the unaided eye shows much activity, with a plaetoria of ostracods happily swimming around looking like they own the Swamp (they totally do). Intelligently estimating their number is an interesting exercise for which I am too lazy right now, but a quick guess would be several hundred of the larger specimens (0.5mm+) and thousands of the smaller ones.

This was filmed with a phone through the wall of the jar and I may have cropped:

Much activity visible with the naked eye – ostracods everywhere

This is a 1.5cm piece of wood at the bottom of the jar. Footage is from above, through the hole for collecting samples:

Ostracods on a 1.5cm piece of wood

The algae colonised the walls of the jar to the point of becoming quite opaque at one point, but then died and peeled off after about 9 months. The walls are now very clean (below the water line).

The most abundant micro-organism is a species of ostracod. This is a fresh water crustacean that lives inside a clam-like structure composed of two valves articulated on the dorsal side that swims around by agitating its antennae and claw-like appendages. Judging by their numbers, the Swamp contains no predators for this creature.

They move about quite rapidly and seem to rely entirely on touch. I saw no interaction between individuals apart from the occasional bump.

They are small enough to become transparent when backlit so internal structure becomes apparent quite easily:

The outside of the shell seems to be covered in what looks like fine hairs:

A different perspective at lower magnification:

And a close-up of its lovely face:

Now this is the interesting bit. I found this pair of paramecia that was twirling around in the same place, not moving about like their friends, and that seemed to be tied together in some way:

Paramecia have largely come to dominate the micro-organisms in the jar, their numbers now far exceeding rotifers, of which I only saw one:

Nematode worms continue to live in the substrate and range from very large ones (cm) to smaller, more agitated specimens. I cannot say whether there is one species of more.

The only rotifer I found. It was not feeding and I only saw it moving about. They used to be the dominant kind of micro-organism for the first 6 months or so.

This is a bug that I see for the first time. It’s large, about the size of the bigger ostracods (1mm) and there seem to be quite a few of them.


As the lightbulb regularly needs replacing I decided to stick it in a wine cork and allow for replacement without unsealing the main cover of the jar.

This came after my first attempt to change the lightbulb without unsealing resulted in catastrophic failure, as can be seen in the photo showing the lightbulb on the bottom of the jar.

The Swamp III is not a closed system, strictly speaking. I am not 100% sure the cork top is perfectly sealed to the glass of the jar and I have completely removed the top three or four times. I also made a hole for collecting samples that I open every time I do so. I have also added several mm3 of starch sometime in early winter. I give it non-stop light and temperature is steady at 22-24°C in winter and 24-30°C in summer.

This being said, it does its own thing in there and provides for excellent observation material. A great little toy.

This is an example of a sample that I collected, with some water, stuff from the side of the walls, from the surface of the water, from the bottom and from the substrate.

The camera records afocally through the microscope