I have not seen any black swallowtail butterflies flying in our garden this year, but it is evident that they have been visiting. I noticed today that our fennel plants are getting chomped on by three enormous swallowtail caterpillars. It the wasps don't get them first, these caterpillars should go into their cocoons in another week or two.
Our two passion vines are really doing much better this year and are starting to get more mature. In fact, we are getting some nice blooms.
I was thinking to myself this morning that the passion vines are doing so well that we should expect some gulf fritillary caterpillars and butterflies in the near future. Within forty-five minutes of having that thought, this little gulf fritillary butterfly started flying all around the vegetable garden and visiting our culinary sage that is blooming like crazy.
Our asparagus plants are full sized already and are filled with tiny, dainty greenish-yellow flowers that are really attracting the bees. The flowers are so small that I would not think that a bee could get much pollen out of them; however, they are plentiful.
The bees working on these flowers this morning appeared unusual to me. In particular, they all had these bulbous orange sack-looking things on their back legs. The orange bulbs were different for each individual bee. Some were larger than others. Here are a few photographs of different bees in which you can see these sacks. As you can see, the sack is much more pronounced in the second photograph. It almost looks like a tiny little orange balloon attached to the leg.
In doing some looking on the internet, it appears that these bees are just normal bumble bees, genus Bombus, and the orange bulbous looking bags on their hind legs are "loads of pollen and nectar that they pack into their 'pollen baskets.'"
This pollen basket is also called a corbicula. It is a "polished concavity" surrounded by hairs, into which the pollen is placed. The pollen is "combed, pressed, compacted, and transferred to the corbicula . . . ." A single hair secures the pollen load. Wikipedia (citing Cedric Gillott, Entomology, Springer, 1995; 798 pages; pg. 79; Dorothy Hodges, The Pollen Loads of the Honeybee, published by Bee Research Association Limited, 1952).
I have been watching bees and insects pretty closely in the garden for at least the last fifteen years or so, and I have never noticed this before. I am very surprised that I hadn't. I wonder if it is the particularly light colored pollen that they are collecting from the asparagus that made the pollen basket appear so striking this morning. Or maybe some of these bees were being overly industrious in filling up their pollen baskets to the point of looking like they were going to explode, that made them more noticeable today as opposed to other days. I am definitely going to keep my eye out in the future to see if I notice these little pollen baskets on other bees in the garden from here on out.