This week I took out a few more mason bee which had already emerged from their cocoons while still in the containers in the refrigerator. They sit very dormant when cold but take only minutes to get active as they warm up. Their normal time of emergence from dormancy would be much earlier in the year but releasing them now ensures pollination of the late blooming fruits.
It was time to add a few more bees to the population outside since the strawberries continue to bloom and the kiwi fruit have started to bloom with this very warm weather we are having.
Kiwi fruit flower buds
Female kiwi fruit flower. Note brush of stigmas in the centre of the flower.The yellow capsules serve to attact the bees.
Male Kiwi fruit flower
Stamens in the male Kiwi fruit with pollen on the terminal anthers.
Strawberry flowers
I also went around to all my mason bee boxes and removed the few cocoons that had not already hatched.
Bee cocoon with one of the many parasitic wasps which had developed in it.
Parasitic wasp
Try not to let these hatch
They either contained a dead bee or the larvae of the Monodontomerus, or “mono” which is a parasitic wasp that lays its eggs on the larva, usually within the cocoon of the mason bee. The tiny adult wasps emerged from one such cocoon. You can see the long penetrating ovipositer on the tail end. These have to be destroyed before they get to the bee larvae in the new cocoons.
NOTE: I have updated this 2015 post in order to make it appear closer to the other mason bee information
ARCHIVAL: This post has been re-dated from 2016 in order to position it closer in the blog to Mason Bee Information
The mason bees have almost stopped their work of pollination by now. However several bumblebee species and honey bees were very active around certain plants in the yard this week.
Honey Bee Apis melliferaon Deutchia
Bombus calignosus??Bee on Deutzia gracilis
Bombus sp.
Today the bees preferred the shrub Deutzia gracilis
Two different bee species
Note differing location of colour bands on these bumblebees.
An unidentified bee on Deutzia
A hover fly on Escallonia possibly Lapposyrphus lapponicus
A few weeks after your mason bee cocoons have hatched, remove the empty cocoons and any that have not opened and destroy them. In some of the unopened ones you might find the tiny larva of the parasitic mono wasp, referenced here on an earlier post.
In the centre of this ring of hatched mason bee cocoons are some paprasitic wasp larvae
When cleaning out the mason bee tubes and recovering cocoons in the winter, I came across several tubes which had been completely colonized by another species of bee/wasp. Images and comments on this can be found in this post:
Unidentified wasp/bee :Currently under inquiry with the experts.
Showing the compartment it has just come from.
Note the small yellow shoulder patches
Wings held partly erect.
abdomen banding pattern is very distinct.
At first I thought these were the paper wasps as they held their wings outspread but the image below of those wasps from the Polistinae family shows a completely different body pattern. Dr. Matthias Buck of the Royal Edmonton Museum is working on samples of these to do DNA sequencing.
Polistes dominula, the European wasp which have become abundant in recent years.
NOTE: I have updated this 2016 post in order to make it appear closer to the other mason bee information
Today I came across two unopened reed tubes which I had forgotten in the refrigerator so the cocoons had not hatched out. The image below shows why it is important to clean your tubes out in the winter and not leave them until late spring.
One cocoon remains on the left at the inside base of the tube. It had a live female which when she hatched would have had to crawl out of the tube through several compartments filled with mites, represented by the orange deposits they leave after consuming parasitised larval bees. The mites are in the compartments on the right side, toward the open end of the tube.
If people leave mason bee homes out unattended from year to year, the parasite population expands . They wouldn’t be so successful in the wild where mason bee nests are more dispersed in holes in wood or under tree bark. . When we provide homes for them however, along with increasing the bee population, we are also multiplying the success of the parasites. So if we are going to encourage bee populations, it is our responsibility to attend to the cocoons in the fall or winter to be sure they are not contaminated with a new generation of mites.
I have experimented for a few years with a kind of plasticized paper tube someone gave to me which were promoted as mason bee home tubes. This year when removing the cocoons from the tubes I noticed small black dots (holes) in two of the tubes which had been mixed in with the phragmites tubes in the nest box . they were suspiciously drilled at very regular intervals, in fact the distance that cocoons are apart.
Sure enough, when I opened these tubes, the cocoon which had occupied the spaces beneath the holes did not contain live bees, but instead they were cocoon hulls containing 6-10 live white mono wasp larvae , or hulls with holes and outside of them dead mature mono wasps. Here are a few pictures taken when I was opening the tubes: I had never before seen an example where all cocoons in the same tube had been parasitised like this .
note the hole in the tube
note the hole in the cocoon
mono wasp larvae in one cocoon
dead mono wasp adults
larvae and cocoons with holes where adults have emerged.
Phragmites reed grass tubes are resistant to the penetration by wasps, so thats one reason they are considered to be superior .
(See https://masonbeesforsale.com/choosing-nesting-materials/) . QUOTE: ” pros: Phragmite Reeds are by far our top choice in nesting materials! They are the best option for several reasons,
1- Size/Shape-Reed tubes naturally vary in size, bees also vary in size and preferences so most bees will find a size they like to nest in. Each tube is cut between nodes so there is a natural back wall. Solitary bees prefer a fully enclosed space to nest in.
2-Protection-They are pest resistant. Mites and parasites aren’t able to burrow through the sides/backs of the tubes.
3-Waterproof– Water will not soften or ruin the tubes. phragmite reeds will naturally wick away moisture. This also decreases the risk of mold, fungus and mildew affecting the bees.
4-Sustainable-Each reed is hand cut to the ideal length (approx. 6inches) from natural sources. Cutting reeds is more environmentally friendly than the burning that usually takes place to get rid of the reeds.
5-Easy Sorting– At the end of the season the reed tubes can easily be split in half. Bees can easily be sorted without damaging the cacoons.
cons:
1- Disposable-Reeds need to be replaced after each season, this requires purchasing new tubes. Luckily they are affordable.
2- Predators– Squirrels and Raccoons are sometimes able to get the tubes out of the bee house if not packed tightly enough. Placing some chicken wire over the front of the bee house and packing the reed tubes tightly in the house will prevent predators from getting your bees. “
https://www.gfletcher.ca/?p=2103
here are some links for various species of parasitic wasp
ARCHIVAL: This post has been re-dated from 2015 in order to position it closer in the blog to Mason Bee Information
I find that if I remove a set of Mason Bees from the refrigerator and put them out by the colonies to emerge from their cocoons as the weather warms up, if they are not hatched within a week, and yet look like viable cocoons, you can suspect that they may have Monodontomeruswasp parasites,
The white larva of Monodontomerus parasitic wasps. In the cocoon on the left, nothing remains of the bee. On the right the bee is still intact but slowly being digested.
In a few the larva are still small and havent completely eaten the now dead bee.
I opened several cocoons today and the results are shown below. In many of the cocoons the bee was still alive, but must be weakened so that they can’t chew their way out. If I got them soon enough before they were being thoroughly eaten, often with small white eggs attached to the outside which the bee brushes off easily, they can fly away after a few minutes. In the handful of about 100 cocoons that I looked through today, less than 5 % seem to be affected like this.
So that’s what we call them when people drill holes into blocks of wood and then never clean them out. The result is an eventual loss of the colony from an ever increasing infestation of mites.
If you aren’t willing to look after and properly clean your colony every year in the fall, then you are not doing a service to help in pollination, you are harming it.
I have been posting my photos of different species I have encountered on the iNaturalist website. Many are species I have found here in the Metchosin Community.
