What are these larva in my Mason Bee block?

Mason bee newbie trying to figure out what these creatures are....

    I had my mason bee block in the garage over the winter then moved it to the garage refrigerator when the weather started to climb into the 40's.  I know I should have harvested my mason bee cocoons during the winter, but I just never got around to it.  This past summer was my first year with mason bees so when I harvested my cocoons tonight, (which I only got 10!!!, not very happy) I found these strange larva in some of the trays.  I numbered them for easier identification.  

#1 - What the hell are these disgusting things?  As you can see they are walled off with mud and do move around a little even though it was in a cold garage (about mid 30's).  I believe they may be some kind of wasp larva, but not sure what kind.

#2 - I believe these may be those grass carrying wasps.  Not sure if that is there official name.  I think they paralyze prey and wrap them up with an egg for their larva to feed on.  

#3 - I have no idea what these are.  They are about 1/8" long...maybe a little longer.

#4 - These little cocoons were grouped together and I also found them in another area of the block.  

    Any help in identifying these would be helpful.  I don't know which of these if any are pests or predators of the mason bee.  I can send a high res picture if that helps take a closer look at some of the stuff.  

I bought 20 or 30 cocoons last winter to start off my mason bee block, but disappointingly only got 10 cocoons to harvest.  6 female and 4 male.  I think I may have gotten one....yes...1... leaf cutter cocoon also!!!  Does anyone have any suggestions for getting more mason bees to occupy my block?  It looks like I'm getting more of other insects using it than mason bees.  I left out a good mud supply near the block, I have a small plum tree, a big apple tree, and a small peach tree in the yard.  All three are within 30 yards of the mason bee house.  I also have my garden about 25' away also.  I figured this would be the perfect place for them to shack up.  The mason bee house gets sun from morning up until mid/late afternoon.  

Thank you for any info you may have.....and if anyone happens to have a pile of extra cocoons and might be looking for a way to get rid of a few, I may be interested.  LOL.  I will gladly cover shipping costs as long as you are not buying them a first class plane ticket!!

 

Wax moth larvae maybe?

It is possible they are Soldier Fly Larvae.  It is hard to tell exactly from the picture.  The cases look slightly different so i can't be one hundred percent sure.

But if they are the Soldire Fly Larvae these are good bugs - just not in your hive.  They are usually attracted to rotting matter so perhaps there was something in there that was dead.

Take them out and put them in your compost pile.  Or put them in a container with holes and some food and see what they do.

If they munch through the waste they are probably the Soldier Fly.  

When they are ready to pupate they will get a hard black casing around them before they turn to a fly, fly away, mate, lay their larvae again and die.

Shame they got into your hive.  

Or they could be those big fat rhinocerous beetle larvae.  They get as big as half of your little finger. but they usually are found in soil or compost heaps.

Again  - put them in a conatiner with some food and see what they do.

Cheers,

Hi Korsz,

here are solutions for you:

#1- all bees start from eggs that consume pollen and turn into larva. some bees are larva through the summer and metamorphous into bees by the end of summer. They are typically spring mason bees. Other bees overwinter as the larva and do their development to bees in the early spring through early summer. This is what you have here. All good bees, just needing a bit of energy to become summer bees.

#2 - exactly what you said. parasitic solitary wasps that are optimal predators to your acreage.

#3 - carpet beetles. Scavengers that shred through everything living. kill them.

#4 - don't recognize the species... if they were found in a chamber for each, then solitary bee, on the tiny side. if multiple in one chamber, then potentially wasp, though could be a parasite that nuked the bee that should have been in there.

Hi Dave,

I know nothing of bees so wanted to ask - If they were solitary bees would they normally make a mud case to live in.

The case they are living in appears to be mud to me.  I thought bees casings were wax.

So therefore would that be an indication that they were in fact parasitic wasps and not solitary bees.

And what is a solitary bee?  Is that a bee that has no queen or hive?

Cheers,

Hi Dave,

I googled Solitary bees, so no need to answer that question.

Cheers,

Solitary bees that nest in holes protect their pollen/egg chamber with something. Some spring bees use mud, others use leaf bits, chewed up leafy material, resin, cotton from flowers, etc. What is in the area that the bees evolved with is what they'll use for protecting that chamber.
Only honey bees use wax like this. Bumbles will as well.
and nope... solitary bees.

Glad you're asking!

Thanks Dave, Better than google.  lol