Flat-tailed Leafcutter Bee - Megachile mendica (very likely)
If you thought that this blog ran out of novel and interesting Bees to cover, here's one more species to add to the catalogue. Looking at these images in retrospect, I really wish that at the time I was skilled enough to take photos which better highlight the front of this insect. While the rear and dorsal side of this side are well represented, a more comprehensive view of the head, face, mandibles, and antennae would have gone a long way in aiding with this inconspicuous Leafcutter Bee's identification. In particular for this species, as well as many other Bees in the genus Megachile, it has an array of hairs adorning its face, and although you can make out a lot of them across the images of this individual, a frontal view would've better showcased the hair's color, density and fineness. That also goes for the whitish rings of hair around this Bee's thorax. Such as it is when you're looking back at older images and you realize that this Bee may have continued to turn away in order to have a solid escape plan if the camera and its operator were to get too close. All kidding aside, that's a useful mindset for an insect to have if it lacks any immediately visible defenses to counter an approaching threat. For this particular individual, it will have to rely on strong flight and predators having a prior association of stings from the females, or other similar-looking Bees, as defensive measures, as it is actually a male Bee.
The best characteristics, or lack thereof, that inform us that this Bee is a male, rather than a female, are the shape and proportions of its abdomen. From the images that I've seen, female Flat-tailed Bees have an abdomen which bulges out a bit on the sides while also tapering to a defined tip towards the end, like a small Wasp. The aforementioned tip will have copious sensory hairs which are positioned upright. The male Bees by comparison, as can be gleamed from these images, have a broad and squared-off abdomen with a flattened rear end which lacks the upright hairs. Finally, there is one more key observation which also helps make the distinction between females and males of many other species of Leafcutter Bees too. The underside of a female Flat-tail Bee's abdomen always houses row upon row of golden scopae (hairs, plural of scopa) on the underside of their abdomen which transport and hold (with assistance from the legs) collected pollen and fibers during flights back to the nest. Although faint, an example of these hairs can be seen in this post featuring an Oblong Woolcarder Bee. Despite this insect's small size, the array of golden hairs would be easily visible. Especially given that all pictures here are of this Bee's backside. I suppose it was useful in the long run to photograph this behavior, though I would've still liked to share a frontal view here. In any case, since the male Bee's primary objectives are to stay healthy, and secure a mate, it doesn't need scopae. Meanwhile females make great use of them to carry materials back to their nest for egg provisioning and retaining warmth. Therefore, we find this male locking for pollen and nectar from these black-eyed susans (a popular choice for our yard's myriad pollinators).
Pictures were taken on August 26, 2017 with a Samsung Galaxy S4.
