The Bee That Works in Stone; Perdita Opuntize Cockerell

Abstract

Some seven miles east of Boulder, nestled at the foot of the Colorado Rockies, there rise some sandstone cliffs of peculiar interest to the biologist and the geologist. These are termed the White Rocks in reference to their appearance when seen at a distance. Around them there stretch for miles and miles the fertile farming lands of Boulder County. Thus the White Rocks are isolated from other similar rock formations; and here there lives a bee that has been officially reported from nowhere else in the world. It is Perdita opuntio Ckll. One may find this remarkable bee in the early summer, in the months of May ad June, as it hovers and darts from flower to flower in its tireless search for pollen. And in this one notices a peculiar adaptation. Apparently it visits but one plant species, the bright yellow flowers of the cactus, Opuntia mesacantha Raf., from which it derives its name. How specially adapted this insect is! Not content with limitation to White Rocks, it must also depend on the flowers of but one kind of plant for its existence. 1The writer is indebted to Mr. S. A. Rohwer and Miss Grace Sandhouse. for the determination of specimens; to Dr. Edna Johnson for the identification of some plants; to Miss Helen Mowry and Miss Celia Light for assistance in the photography and for helpful suggestions; to Professor R. D. George for some geological material as well as interesting information concerning tunnelways in the rock formations of different localities; and to Mrs. B. O. Custer, Miss Arline Elftman and Mr. Russel Mann for assistance in the field work. 2Determined by Miss Grace Sandhouse. 3Determined by Dr. Edna Johnson. Synonyms are O. humifusus

First records, phenology, habitat, and host-plant associations of <i>Macrotera opuntiae</i> (Cockerell) (Hymenoptera: Andrenidae) in Montana

“…They also provide a new species record for the state of Nebraska. Custer (1928) discussed factors that seemingly restricted the distribution of M. opuntiae to White Rocks Nature Preserve and concluded it was not a dependence on host plants (cacti are distributed throughout the West), but the sandstone outcrops in which the bees make their nests. Though we did not observe nesting activity by M. opuntiae in Montana, all sites contained both exposed sandstone and cacti (see details below); such outcrops were also present for the Mesa County, Colorado records.…”

“…3,4). After its discovery, Custer (1928Custer ( , 1929 conducted detailed studies on the nesting habits and biology of this species. Bennett & Breed (1985) later conducted further study of its nesting biology, mating behavior, and foraging ecology.…”

“…Bennett & Breed (1985) later conducted further study of its nesting biology, mating behavior, and foraging ecology. Though a solitary species, M. opuntiae nests communally with one to multiple entrances connected by tunnels that branch repeatedly into individual nests with brood cells provisioned by individual bees (Custer, 1928(Custer, , 1929.…”

“…; Cactaceae) specialist. This species is one of a small group of stone-nesting bee species and makes its nests in sandstone (Custer, 1928;Michener, 2007;Danforth et al, 2019). There is, however, some debate as to whether the bees use existing cracks or actually tunnel into solid sandstone (Custer, 1928(Custer, , 1929Bennett & Breed, 1985).…”

“…This species is one of a small group of stone-nesting bee species and makes its nests in sandstone (Custer, 1928;Michener, 2007;Danforth et al, 2019). There is, however, some debate as to whether the bees use existing cracks or actually tunnel into solid sandstone (Custer, 1928(Custer, , 1929Bennett & Breed, 1985). Macrotera opuntiae was described by Cockerell (1922) after its discovery at White Rocks Nature Preserve (a Laramie sandstone formation; Cockerell, 1928) near Boulder, Colorado.…”