Characters used in Identifying Bees

Bee Health September 07, 2010|Print
What kind of bee am I?

This page provides examples of morphological characters used to identify bees. To observe these characters, a dissecting microscope with a light source is used. Details on choosing a microscope, and many other aspects of Collecting and Identifying Bees can be found in the downloadable .pdf The Very Handy Manual: How to Catch and Identify Bees and Manage a Collection. manual edited by Sam Droege, USGS Patuxent Wildlife Research Center, Beltsville, MD.




A caliper can useful to measure tongue length and the length of the bee. These measurements can sometimes be useful in identifying bees.


In using the taxonomic keys, it is often helpful to first identify the sex of the bee. This can be done in numerous ways, but one consistent and easy way is to count the number of antennal segments. The apical, or last, 10 - 11 segments of the antenna form the section of the antenna called the flagellum. Female bees have 10 segments in the flagellum while male bees have 11 segments. Counting the segments of the flagellum in the bee above, this bee has 10 flagellomeres and is therefore a female. The other two segments in the antenna are called the scape and the pedicel. The scape is the segment closest to the head.


The location of the ocelli in relation to the compound eyes and the presence or absence of facial foveae can be important characters in identification. Ocelli are the three simple eyes on the top of the head. Facial foveae are depressions in the cuticle, the function of which is unknown.


The wing veins and "cells" that are produced between intersecting veins are very useful in bee identification. For example, pictured above is a front and hind wing. The front wing has three submarginal cells with a basal vein that is nearly straight. The second recurrent vein is also nearly straight and the first recurrent vein is entering the second submarginal cell. From these characters, we have now ruled out several possible groups of bees this specimen could belong to including; Halictidae (except Nomia spp.), Megachilidae, some Andrenidae, Neolarra spp., and Colletidae. From here we would examine other characters on the bee to further narrow down the possibilities.




Pollen packed in the corbicula on the hind leg of a bumble bee


Contents

Form and function

The form of the bee's structure is often extremely important in its function. The following three photos are examples of different structures bees use to carry pollen back to their nests for larval development or food stores. These different structures define very different behavioral strategies that separate families and genera of bees.

The social honey bee and bumble bee carry their pollen in a corbicula, sometimes called a pollen basket, on their hind tibia. It is mixed with nectar to form a pellet. In honey bees, this conveniently packed pollen load is sometimes collected in beehive traps and sold for human consumption.




Andrenidae

Most bees that do not carry pollen in corbiculae on their hind tibia instead carry most of their pollen in scopae, which are specialized hairs located on different areas of the bee. These bees can also have corbicular structures on other body parts such as the propodeum and hind femur. A few bees carry pollen internally. The location and characteristics of scopae can be very important in identification.

Female bees in the Megachilidae family carry pollen on scopa under their abdomen.

Bees in the family Megachilidae are unique in that they carry their pollen in scopae found under their abdomen. However, male Megachilidae bees can not be identified by this feature since they do not collect pollen or have these hairs.



For more information, see

References

Michener, C. D. (2000). The Bees of the World. The Johns Hopkins University Press.

Mitchell, T.B. (1960) Bees of the eastern United States. I. Technical bulletin (North Carolina Agricultural Experiment Station), 141, 1-538. insectmuseum.org/easternBees.php

Thorp, R. W. (2000). The collection of pollen by bees. Plant Systematics and Evolution 222: 211-223. springerlink.com

Thorp, R. W. (1979). Structural, behavioral, and physiological adaptations of bees (Apoidea) for collecting pollen. Annals of the Missouri Botanical Garden 66(4): 788-812. jstor.org

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