Category: Insects

Observations on Pollinators , September 2024

In  cleaning out my mason bee nest houses this fall I took the following photos showing some of the variety of pollinators and the parasites I encountered as well .

The first observation was that this was a very poor year for mason bee cocoon production. In many  of the 10 houses like this that I set out on farms in the Metchosin area, there were barely enough cocoons to even break even with the amount of cocoons I had stocked the house with when I set it out in the spring. I believe that spring weather patterns played a big part in the problem 

It may be that early warm spring weather followed by cooler and rainy weather where temperatures did not reach the necessary 13 degrees for several hours a day for hatching and pollination might have influenced the lack of success.

This image of the different types of sealed phragmites tubes shows the presence of different pollinators. note the smooth mud layer sealing versus the fibrous covering .  The smooth ones can indicate the normal blue mason bee or very smooth ones, pollinator wasps ( see below) . The fibrous ones are typical of the smaller species of mason bee, also below.

 

 

 

This is what the normal sized blue mason bee cocoons look like in successful tubes. There can be up to 12 cocoons like this in a phragmites tube.

 

 

 

 

The black cigar-shaped pellets are frass , or bee manure. They often totally cover a cocoon as is shown here in this photo.

 

 

 

 

I noticed his year for the first time that long curly frass like this often was an indicator of the cocoon being parasitized by the mono wasp so I would separate these out and candle them later .

 

This was another parasite finding. the Houdini Fly for which I have provided a separate post for here. 

 

Another different looking cocoon is from a smaller species of mason bee. These are found in the tubes with a fibrous sealant as mentioned above.
The cocoons of the smaller version of mason bees appear with a silvery coating over them . Identification of some of the mason bee species is difficult. I have included many on my iNaturalist site  at https://www.inaturalist.org/observations?subview=table&taxon_id=630955&user_id=garryfletcher

 

 

 

I also found several tubes where several species of mason bee had shared the same tube, although this is not very common.  Here you can see the three larger blue mason bee cocoons near the bottom

 

 

 

Below are some of the different small sized mason bees that hatched this year

So my last message is that you need to be prepared for several alternatives when you open your Phragmites tubes in September and don’t throw away those other good pollinator species.

See also this post on Some more new pollinators from last year

Also see this post on other pollinator species and on the mason bee mites

This link is to an iNaturalist curator , Dr. John Ascher who is an expert on pollinator bees

Beware the Houdini Fly!

Last year (2023), I first heard about the Houdini fly and I posted a message here about them occurring in the Duncan Area. Recently while i have been cleaning out my tubes I have found them in two of the locations where I provide bee boxes for my neighbours . One was in the Tower Point area  where most of the tubes in one bee house were affected. The other was in the William Head area of Metchosin.

So it is essential that any old boxes with tubes should be eliminated or cleaned regularly if they are going to be reused. The Houdini flay maggots will consume all the cocoons in a tube . They are much larger than the Mono wasp larvae which are always inside a cocoon case.  Also note the twisted purple mass of what I assume are feces

From Wikkipedia:

Cacoxenus indagator is a species of fruit fly.[1] It is a kleptoparasite, laying its eggs in the pollen-filled nest cells of mason bees.[2] On account of its ability to break out of those cells once hatched, it is commonly known as the Houdini fly.[3][4]

Scientific classification
Kingdom:
Animalia
Phylum:
Arthropoda
Class:
Insecta
Order:
Diptera
Family:
Drosophilidae
Genus:
Cacoxenus
Species:
C. indagator
Binomial name
Cacoxenus indagator

Loew, 1858[1]

Pollinator problems caused by Glyphosate–Round-up pesticides

Glyphosate, the active ingredient in Roundup, is one of the most commonly used herbicides in the world by commercial gardeners. However, many pesticides – including insecticides, fungicides, and herbicides – harm pollinators and other beneficial insects. 

To help educate those in the farming and gardening industries about this toxic chemical, drugwatch.com  has created a comprehensive guide with organic, and homemade; and a second guide with agricultural alternatives. please take a look:

drugwatch.com/roundup/glyphosate/
Glyphosate
Glyphosate is an herbicide used to kill weeds. It’s the active ingredient in Roundup and other weed killers, and can cause a variety of side effects. Recent lawsuits have claimed exposure to glyphosate in Roundup has led to certain cancers, including non-Hodgkin lymphoma.Alternatives to Roundup

See the article at this link:
https://www.drugwatch.com/roundup/alternatives/

Roundup products contain glyphosate, a chemical linked to cancer and other illnesses. Chemical alternatives to Roundup can also contain toxic ingredients, but safe alternatives to Roundup include soap, vinegar, salt or iron-based sprays, mulching and integrated weed management.

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Also this article explains the problem with pollinators and Roundup:

Roundup Shown to Kill Bees—But Not How You Might Expect.   https://beyondpesticides.org/dailynewsblog/2021/04/roundup-shown-to-kills-bees-but-not-how-you-might-expect/

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Beware : THE HOUDINI FLY-(Cacoxenus indagator) Kleptoparasite of Mason Bees

Recently there is a concern in the Pacific Northwest about an invasive species, the Houdini Fly  (Cacoxenus indagator) .  which is a kleptoparasite which invades mason bee homes and destroys the developing larvae and source of food pollen.
Brian Guzda of Brian’s Mason Bees  (https://www.instagram.com/briansmasonbees/?hl=en ) provided this picture. Note that the white maggots are not contained within the cocoon as they are with the Mono wasp, another kleptoparasite which I profile in other posts here.  It is essential to clean out whatever kind of tubes your mason bees have capped any time from October to December in order to catch these flies before they mature and cause further damage. hou

The following video gives more information about this invasive species and emphasizes the importance of taking good care of  your bees.

 

https://agr.wa.gov/departments/insects-pests-and-weeds/insects/apiary-pollinators/pollinator-health/houdini-fly

Phragmites Reed Tubes vs Plastic tube-trays for Mason Bees.


Cindy, one of my regular mason bee customers has had to move East and she was so dedicated to her mason bees that she left them with me to look after.  She had run a small experiment in her bee box that I thought would be useful to comment on here.

Today I opened the tubes to remove the Cocoons for storage over winter in the refrigerator.

On first glance, the plastic containers appear to have a good number of successful plugged tubes. When the plastic containers were opened however, it was obvious that mites had taken a large toll on the cocoons:

Top and bottom halves of the plastic containers, The parasitic wasps were present in many of the plastic tubes.

 

I was interested in comparing the productivity of the phragmites tubes versus the plastic tubes so I kept track of the number tubes, the number of cocoons and the number of tubes with parasitic mites. Here are the results:

Number of plastic tubes: 24    —  Number of phragmites tubes: 18

Number cocoons in plastic=108 — Number cocoons in phrag= 91

Ave. number -plastic tube=4.5—-Average number-phrag.tube =5

Mite-infected-plastic tubes=14  —- Mite-infected-phrag. tubes=2


So it appears from this small sample that the Phragmites tubes produced more cocoons and had fewer mite infestations.

 

NOTE : I have created this post in order to place it closer to the recent mason Bee posts

 

Mason Bee (Blue Orchard Bee) tube cleaning and unidentified wasp larvae.

NOTE: I have updated this 2015 post in order to make it appear closer to the other mason bee information

masonbeefulltube
Successful mud-filled tubes of Mason bees.

masonbeewasptubeThe photo above is of one of the better colonized box of tubes from the summer of 2015. Each mud-sealed tube in this box will contain on average 5 mason bee cocoons.

In the lower section of the box shown below, several mud plugs are of lighter colour and a smoother texture. I have found that these ones are colonized completely by another bee, I thought they may probably be resin bees , but now I have found out they are from the Subfamily Eumeninae (Potter and Mason Wasps):

See  hatched bee/wasp images  in May 1/2016 post: https://www.gfletcher.ca/?p=1538

When the tubes from several boxes which had the light coloured mud plugs were split open they appear as in the photo below.

2015-12-22wasplarve2
In opening my tubes for cleaning in the winter, I saved several tubes which are probably resin bees which are also pollinators. I have saved these in a separate container to see what hatches from them. Resin bees hatch when the weather gets warmer in later summer. That’s why these are still in the larval stage.

Other postings on parasites

NOTE: I have updated this 2015 post in order to make it appear closer to the other mason bee information

Video of Parasitic Pollen Mites

I took this video with my iphone of pollen mites in November when I was cleaning out the mason bee phragmites tubes. This was the first time had seen so much movement of the mites. Removing of the cocoons from their tubes early in the fall can help to control infestations of these mites. If you don’t clean out the colony  and refridgerate the cocoons until release in the spring, eventually  the mites will lead do a large decline in productivity and therefore pollination.

A quote from the website  of Crown Bees

Pollen Mites

  • What it is: Pollen mites, more specifically Krombein’s hairy-footed mites, are clear and you need a magnifier to see them. What you can see easily is an orange mass that is mite feces. Pollen mites are found throughout North America; more in moist environments than arid. If you don’t harvest your cocoons, the pollen mites are reintroduced into your yard which accelerates the decline of your nesting mason bees. The mites also stay within an opened hole waiting for more pollen delivered by an unsuspecting mason bee.
  • What it does: A pollen mite’s role in life is to eat pollen. They hitchhike on the backs of insects from flower to flower to find more pollen. Unfortunately, they also hitchhike into nesting holes and eat the mason bee’s pollen loaf. The pollen mite either eats the egg and then the pollen loaf, or just the pollen loaf and the larva then starves.
  • What to do: As you harvest your mason bee cocoons in the fall keep an eye out for signs of pollen mites. We recommend dry brushing reusable wooden trays with a stiff brush to remove debris and pollen mites. You might also bake your wood trays at 250 degrees for 20 minutes. Harvesting mason bee cocoons is the easiest and best way to reduce pollen mite infections.

Attracting pollinators

NOTE: I have updated this 2015 post in order to make it appear closer to the other mason bee information

We seem to have no problem with insect pollinators here. By providing  certain plants which flower at different times in the year, insect pollinators can be attracted.  I show a few plants here that have been  very effective in the last few weeks and have swarms of pollinators around.

 

Release of the Last Mason Bees and isolation of Parasitic Mono wasps June 2015

The natural time for mason bee adults to emerge from the cocoons is normally hatchedmasonquite early, in February or March in the lower part of Vancouver Island. This year I decided to hold some dormant in the refrigerator for a longer time to see if they would still hatch out successfully. By early June some of the bees were actually emerging and remaining very still in their jars in the refrigerator.

As soon as jar was removed from the fridge, once they heated up they would fly off.  (Note: as of June 25 they are still very active around the nest boxes.)

After a week of leaving the cocoons, I isolated the unhatched ones in a sealed jar, and sure enough in a few days the parasitic wasps were on the inside of the container.

Each time i had made a release of cocoons throughout the spring, I waited for at least a week and if they didn’t hatch, I opened them with a razor blaid and released any live bees. about one in 30 unhatched cocoons would have parasitic larvae, so maybe they are programmed to emerge more than a week after the regular bees emerge, in that way, they would have active cocoon building so they could immediately begin laying eggs in the cocoons. ??

 

NOTE: I have updated this 2015 post in order to make it appear closer to the other mason bee information

Identification of Wasp Larvae from Mason Bee tubes

ARCHIVAL: This post has been re-dated from 2016 in order to position it closer in the blog to Mason Bee Information

Wings held partly erect.
Wings held partly erect.

In the previous post I indicated I was trying to identify wasps that had taken up residence in mason bee tubes, without actually parasitizing the mason bees

 

 

largewasplarvaeI found the larvae in tubes while removing the mason bee cocoons in the winter, and transferred them to a separate jar where I  let them hatch. By May 1 they were hatching so after taking a few pictures, I sent the images off to BugGuide.

The result after several months was an identification by an expert in entomology : Our thanks to  Matthias Buck of  The Invertebrate Zoology Section, Royal Alberta Museum, Edmonton, Alberta, Canada
http://bugguide.net/node/view/1218699#2158789

So he thinks there are actually three species represented in these pictures.

Food
Eumenines prey mainly upon moth larvae, although some take larvae of leaf-feeding beetles.
Adults take nectar.
Classification

Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Hymenoptera (Ants, Bees, Wasps and Sawflies)
No Taxon (Aculeata – Ants, Bees and Stinging Wasps)
Superfamily Vespoidea (Yellowjackets and Hornets, Paper Wasps; Potter, Mason and Pollen Wasps and allies)
Family Vespidae (Yellowjackets and Hornets, Paper Wasps; Potter, Mason and Pollen Wasps)
Subfamily Eumeninae (Potter and Mason Wasps)
Genus Ancistrocerus

There were three species identified from my photographs( labelled above) although it is very difficult to confirm identity without being able to examine a specimen. Next year I will be sure to send him samples to confirm, and I will certainly not destroy these larvae when cleaning out mason bee tubes.