. Unfortunately, the bees these producers raise are then marketed nationwide, resulting in the frequent shipment of locally non-native bees to the eastern United States. The potential ecological consequences of the western blue orchard bee hybridizing with its eastern subspecies are unknown. Similarly, these shipments have the potential to introduce locally non-native parasites and diseases. For the consumer, there is another significant drawback. The western bees may not develop in sync with local conditions, resulting in poor establishment and poor performance as pollinators. The net result is that people purchasing blue orchard bees over the Internet or through garden catalogs may be doing more to harm their local pollinator populations than to help them – and not be getting the pollination they paid for.
This is a family of bees that are often referred to collectively as plasterer bees, due to the method of smoothing the walls of their nest cells with secretions applied with their mouthparts; these secretions dry into a cellophane-like lining. This allows the bees to nest in periodically flooded areas such as stream banks. There are over 2000species, all of them evidently solitary, though many nest in aggregations. Bees in this are highly varied in appearance and have few common features. One feature consistent to all colletid bees is that their tongue has a branched tip (Figure 59) . The two genera most frequently seen are Colletes and Hylaeus.
Two of the subfamilies, Euryglossinae and Hylaeinae, lack the external pollen-carrying apparatus (the scopa) that otherwise characterizes most bees, and instead carry the pollen in their crop (enlarged portion of the foregut). These groups, and in fact most genera in this family have liquid or semi-liquid pollen masses on which the larvae develop.
Colletid Bee. Image Courtesy of Michael Becker.
They can be found all over the world, but the most species live in South America and Australia. Over 50% of all bee species living in Australia belong to this family. Only the 