On September 17th, 2020 we placed a "quart" of leaf cutter cocoons and a tapered tunnel habitat under the lemon tree at the residential lot in Gilbert, Site1a2i. This follows our original, wildly successful leaf cutter cocoon placement at Site1a2h.
On 19 October 2020, we checked the site and observed no activity. We had split the 'quart' of leaf cutter cocoons into two equal piles. One we placed in an open bowel on top of the habitat. A few days later the wind knocked it to the ground. We left it and hoped for the best.
The second set we placed in a 2 inch PVC tube with a hole drilled in the end cap. This is the standard method of placing blue orchard bee cocoons for release. Here's an example from Site2a last year in Cornville, Arizona.
Since we had not seen any bee activity at the new Site1a2i, from either the tube or the open container of cocoons, we opened the tube. We immediately saw a dead bee at the top of the cocoons. And many "opened" cocoons. We emptied out the entire PVC tube onto the top of the habitat.
And we immediately noticed live bees flying out of the pile. Some even went to the tubes in the habitat. We only saw a dozen or so bees flying.
There were a number of dead bees in the pile also.
Our conclusion is that the PVC method of placing leaf cutter cocoons is not effective. In fact, previously when we mentioned this to Wayne Mennie of JWM Leafcutters, he was unaware of that method. Perhaps the leaf cutter bees are not capable of climbing out of the tube? Or we placed the tube such that all the cocoons went to one end instead of being horizontally positioned? In any case, we will not use PVC tubes for leaf cutter bee cocoons in the future.
We did monitor the temperature and humidity at the site. There were no surprises with moderate temperature (for Phoenix) and humidity throughout the placement period, 17 September to 20 October 2020. Certainly the average temperature for the first two weeks appears to be 85-90 deg F. As you remember, leaf cutter bee cocoons require a precondition period of about 21 days at average temperature above 86 deg F. From the discussion with Wayne "The leaf cutter cocoons need to be 'preconditioned' by placing them in a 85 deg F or hotter environment for 17-21 days before they are placed in the field. Even better, wait until the males start emerging first."
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