# Bee in ground



## Barry Digman (May 21, 2003)

These are over in Nazlini, near Canyon de Chelly in NE Arizona.


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## Church (May 31, 2007)

why the big abdomen and fuzzyness? Could they beeeee NOT honey bees? could they be cactus bees?

Cactus bees in the U.S. Southwest:
5 species of Diadasia (including rinconis; Apidae: Emphorini) -- large ground-nesting bees 
Melissodes paucipuncta (Apidae: Eucerini) -- large ground-nesting bees 
Idiomelissodes duplocincta (Apidae: Eucerini) -- large ground-nesting bees 
5 species of Lithurge (Megachilidae: Lithurgini) -- large, chew into wood like carpenter bees 
Ashmeadiella opuntiae (Megachilidae: Osmiini) -- small, cavity nesters 
9 species of Perdita (Andrenidae: Panurginae) -- tiny ground-nesting bees 
Dufourea echinocacti (Halictidae: Rophitinae) -- medium-sized bee


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## Barry Digman (May 21, 2003)

Church,

That's the one! The hairy legs and the shape of the adomen are identical to what I saw. The description on the saguaro site matches what I saw and what the people there described. Thanks.


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## Church (May 31, 2007)

Coyote,

Please let the woman know they seldom sting like regular bees and they are an important part of the Navajo..........they pollinate the landscape, most importantly the cactus blooms and are very important to the plants of her area. 

They will move on, but let her know she is blessed to share her home with such wonderful and resiliant creatures. 

There is a research biologist who tracks the locations of these huge solitary ground hives and is dedicated to protecting the bees since they are such value to an arid but beautiful land... please encourage her to protect them.


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## Church (May 31, 2007)

From:

desertdiscovery.arizona.edu/find.html


The Search for Elusive Cactus Bee Nest Sites
-- information for Lo Que Pasa article, by Stephen Buchmann
-- updated and revised by Margrit McIntosh, June 1998 and February 2007

NOTE: Many different kinds of ground-nesting bees! 

This page has information about finding the nests of ground-nesting cactus bees. But there are many other kinds of ground-nesting bees -- only a few of them are cactus bees! If cacti are not native to your area, your ground-nesting bees are some other kind! See the Links page for more info.

Introduction
Each spring in the Sonoran desert around Tucson, from mid April to early May, a special type of bee is waiting for the prickly pear and cholla cacti to bloom. These bees are ground-nesting solitary bees belonging to the species Diadasia rinconis (of the digger bee family Anthophoridae) and are brown with abdominal bands. They are slightly smaller than honey bees. This species is a specialist: its females forage for nectar and pollen only from cacti, usually from the abundant prickly pear and cholla cacti. The pollen and nectar are used as food for themselves, and more importantly, for their larvae in underground cells. They and other cactus- specialist bees are the primary pollinators of these cacti in the Sonoran desert. 
Although the cactus bee is solitary (each female constructs and provisions her own underground nest), they gather together into "aggregations", with many solitary females nesting right next to each other. They often nest very close to each other in a very small area, even though areas of apparently identical habitat exist in the same place. The reasons why they select one particular area to gather are unknown, but we do know that they seem to prefer recently disturbed soil (probably because it is easier to dig) in areas that have abundant cacti. The aggregation may grow as females are chemically attracted to places where other females are already nesting. There may be tens or several hundred thousand females actively nesting in an area roughly the size of a typical city residential lot. Although there is lots of activity, you can stand or sit in one of these sites and not be stung. The bees will not chase you in an attempt to sting. Only if they are held roughly or pinched will they sting. 

National Geographic has posted a video clip from their show "Sonoran Desert: A Violent Eden" that contains AWESOME footage of ground-nesting cactus bees! You have to watch a very short advert first, but then... check it out! 


The Nests
Each nest is prominently marked by a round, even pile of excavated soil (the "tumulus") similar to an ant mound but neater. 
Nest hole of a ground-nesting bee, with tumulus. 

This tumulus is the excavated materials from the underground cells and main burrow of the nest. The nest entrance may also have a mud "turret" or tube appressed against the soil surface. Each nests may contain up to a dozen cells, and are approximately 15-25 cm deep. Each cell is provisioned with a ball consisting of cactus pollen and some nectar, upon which the female lays one egg. The cell is then sealed and there is no further parental care. 

Female bees returning home with brilliant yellow pollen loads do not pause but fly directly into their open burrows. This frantic nesting and food collection phase will last for about 7-14 days, after which the site will appear dead. It is not. Underground, the eggs laid by these females are developing rapidly into larvae and pupae ready to metamorphose into a new adult generation of bees. In some nests, this may happen as soon as 2-3 weeks after the last females were observed nesting. In most nests, the developing larvae wait (in a kind of suspended animation called "diapause") until the following spring to complete their development and emerge. 
When ground-nesting bees aggregate, the ground looks like it has measles! 

The first bees of the new generation to emerge are male bees which swarm over the site flying in low erratic flights looking for potential mates among the virgin females about to emerge. Thus the nesting site of a few weeks ago may turn into an orgiastic frenzy of male and female bees during the early morning hours. This activity lasts for several weeks until all the males have died and the females have dispersed. This species *usually* nests only once in the same locality. It is not known whether the females that emerge from this second generation later in the spring start nesting right away, or wait until summer cacti (such as barrel cacti) come into bloom, or diapause as adults until the next spring. 
A nesting aggregation of Diadasis rinconis bees. 


Help Us Find Them...
If you live on the outskirts of Tucson in an area with lots of prickly pear and cholla cacti, please watch carefully for the telltale signs of the little dark mounds of soil and the frantic foraging activity of thousands of females. Because the bees do not usually nest twice in the same place, it can be difficult to locate new nesting aggregations until they are already well developed. As a result, we know little about how such aggregations form. If you or your neighbors think you have located a nesting site of this bee, please give Steve a call immediately!


Dr. Stephen L. Buchmann
The Bee Works, LLC
1870 W. Prince Road, Suite 16
Tucson, Arizona 85705 U.S.A.
Office: 520.888.7422
FAX: 520.888.7332
E-mail: [email protected]
Online: www.thebeeworks.com 




Please contact: 
Dr Margrit McIntosh
Department of Ecology and Evolutionary Biology
[email protected]


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## Barry Digman (May 21, 2003)

I sent a note to both of the people in the article with a link to the photos. I'll let the lady know to leave the bees alone, and that they'll move along.


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