Bee Families Research Articles

Rates of cross-pollination inLycopersicon pimpinellifolium: Impact of genetic variation in floral characters

Cross-pollination was tested between different genotypes ofLycopersicon pimpinellifolium in an experimental plot situated in the southerly range of the species. Rates of cross-pollination were found to be highly correlated with flower size and were related to a lesser extent with degree of stigma exsertion. Comparisons of fertility suggest that exsertion of 1.5 mm or more from the anther tube orifice interferes with automatic self-pollination, thereby increasing rates of cross-pollination. A single species ofExomalopsis (Anthophoridae), observed to visit all tested genotypes ofL. pimpinellifolium, was responsible for most of the pollination. Other species of solitary bees and other bee families participated in cross-pollination.

A new electrophoretic approach to biochemical systematics of bees

SDS electrophoresis of soluble proteins from 49 species of bees from 8 families produce a conservative character set. Differences between species appear to be actual differences in polypeptides and their concentrations rather than spurious differences. The data set based on the absorption values of bands proves to be more useful than does a data set based on the molecular weights of bands present or one based on the presence and absence of bands. Numerical analysis of a matrix of distance coefficients based on absorption values of bands shows much overlap between families of bees. Also, some taxa of questionable affinities when compared morphologically can be shown to be biochemically quite similar to other members of their traditional morphological families. Other taxa, which appear very similar morphologically, are highly differentiated biochemically. Examples are presented to compare and contrast the data from the SDS-separated character set to predictions based on the theories of regulatory and constant rate protein evolution. The results of the study largely agreed with predictions based on constant rate protein evolution. Exceptions may be understood in the framework of regulatory evolution. Consequences of discordance between morphological and biochemical phenetics are discussed as they affect systematic classifications.

Mating Behavior in Halictine Bees (Hymenoptera: Halictidae)

AbstractStudied two types of mate‐orientation behavior in ♂♂ of the sweat bee,Lasioglossum rohweri: microterritoriality and patrolling. Observations were made in both the laboratory and the field. These ♂♂ behave uniquely for Hymenoptera in that 2–5 of them establish microterritories immediately around the same nest entrance. Some ♂♂ are exclusively patrollers, flying about flowers and nest sites. Rendezvous places (locations where animals are likely to find mates) in bees are: flowers, nesting sites, vegetative parts of plants, nest entrances, air, and nests. Territoriality in male bees may have arisen independently in 7 of the 9 families of bees.

The bee family Oxaeidae with a revision of the North American species (Hymenoptera, Apoidea)

The bee family Oxaeidae with a revision of the North American species (Hymenoptera, Apoidea)

GREGARIOUS NESTING OF THE MASON BEE HOPLITIS ANTHOCOPOIDES AND THE EVOLUTION OF PARASITISM AND SOCIALITY AMONG MEGACHILID BEES.

As E. 0. Wilson (1971) has shown in his modern classic Insect Societies, social insects are among the great achievements of organic evolution. Recent attempts to provide a theoretical basis for the evolution of insect sociality (e.g., Hamilton, 1964, 1972; Lin and Michener, 1972; Wilson, 1971) have relied heavily upon the bees (Apoidea), among which sociality has arisen repeatedly and all intermediate stages of social behavior occur (Michener, 1969). A second interesting evolutionary development has repeatedly arisen among the bees, that of cleptoparasitism or cuckoo behavior, in which species of bees lay their eggs in the nests of other species. Field studies of incipient sociality and cleptoparasitism, based upon populations of individually marked bees, are necessary for an accurate understanding of the evolution of these phenomena. Hoplitis (Ho plitis) anthocopoides (Schenck), a European mason bee (Hymenoptera: Megachilidae) that has recently emigrated to New York State (Eickwort, 1971), is normally a solitary nester-each female makes her own nest cells, provisions them, lays her eggs in them, and does not again contact her offspring. This behavior is typical of most species of bees. However, when nests are closely aggregated, the females exhibit two tendencies: to form communal associations in which several females share a single nest, and to usurp the cells made by other females. This species thus provides insights into the evolution of both sociality and cleptoparasitism. Most species in the family Megachilidae conceal their nests in cavities such as hollow twigs. The mason bees, however, build freestanding, mortar nests on the exposed surfaces of rocks and are thus excellent subjects for behavioral study. Fabre (1914) has made famous two species of the mason bee genus Chalicodoma, C. parietina (called C. muraria by Fabre) and C. pyrenaica, with his experimental studies of their nesting behavior. Fabre observed communal and parasitic behavior in C. pyrenaica and his observations will be compared with mine on Hoplitis anthocopoides in the following account. Although the nests of Hoplitis s.s. are superficially similar to those of Chalicodoma s.s., the genera are not closely related within the Megachilinae. Hoplitis is related to the predominantly cavitydwelling Osmia while Chalicodoma is related to the leafcutter-bee genus Megachile. I have previously given a general account of the biology of H. anthocopoides in New York (Eickwort, 1973) and described its nest-building behavior (Eickwort, 1974). A manuscript is in preparation on male territorial behavior. In connection with these studies, I individually marked all the mason bees that were nesting gregariously on a bridge foundation and I observed their behavior almost daily for their entire flight period in 1970. The following account describes communal and parasitic interactions and their importance on the population level. These interactions provide the basis for a discussion of how cleptoparasitism might have evolved in the Megachilidae and why true societies have not evolved in this family as they have in three other families of bees.

Division of Labor among Primitively Social Bees

Australian bees of the genera Allodapula and Exoneura which commonly live in colonies of two to several individuals exhibit a division of labor among the adult females. Most foraging individuals are unfertilized and have slender ovaries, yet gather pollen and carry it to the nest; in contrast, fertilized egg-laying bees are not commonly foragers. Such castes are functionally similar to workers and queens found in some members of two other families of bees and represent a noteworthy example of physiological and behavioral parallelism in which the activities of different individuals are coordinated to form a functional unit.

The Males of Dialictus laevissimus (Smith) and D. rohweri (Ellis) (Hymenoptera: Halictidae)

Proper association of males with females of the bee family Halictidae presents difficulties not found in most insect groups. In the north temperate zone males emerge in late summer, mate with the females and then die, only females surviving over winter. Collecting in spring and early summer therefore yields only females and only in the later collections do males appear.Correct association between males and females may be secured by excavating burrows after males have emerged from the pupae, by collecting mating pairs or by making such extensive collections in a limited area that statistical evidence may be secured to support conclusions based on morphological features. This technique was used by the junior author in his original studies of Andrenidae and Halictidae (Atwood, 1933) but is by no means a universal practice. Consequently, many species names in the Halictidae are based on descriptions of one sex only while in other instances the association between male and female rests upon a very shaky foundation. This paper is designed to clarify the status of two species which are now in the above categories.

Structure and Classification of Bees

THE Bulletin of the American Museum of Natural History, 82, 1944, contains a very comprehensive memoir on the above subject, written by C. D. Michener, an assistant curator of the Museum. The method which the author has adopted is to make a detailed study of the morphology of a single species of bee, for example, Anthophora edwardsii, and then to compare numerous other bees with this species. Finally, with these comparisons as a basis, the author gives an account of the interrelationships of the various groups of bees followed by a general scheme of classification. The latter deals with all groupings, from families to genera, represented in America north of Mexico. The memoir is one intended for the specialist on the order Hymenoptera. The anatomical section is concerned with external organs and parts only; the internal organs and musculature being outside the scope of the work. A certain number of new terms are used including the expressions mesosoma and metasoma for the regions commonly referred to as thorax and abdomen respectively. Six families of bees are recognized. The Colletidæ and Halictidæ are the two oldest groups. The next in order of antiquity are considered to be the Andrenidæ and Apidæ followed doubtfully by the Megachilidæ. The last family—the Melittidæ—is too imperfectly known to suggest its position in the series. The largest family is the Apidæ which is held to include a large number of bees usually considered to be outside its limits. The author mentions that certain of these have often been placed in separate families largely on the basis of the presence or absence of the pygidial plate. This character is regarded as being unreliable since it is often lost in very different bees.

XLV.—Observations on the synonymy of the genus Nomada of Fabricius, belonging to the family of cuckoo or parasitic bees

(1849). XLV.—Observations on the synonymy of the genus Nomada of Fabricius, belonging to the family of cuckoo or parasitic bees. Annals and Magazine of Natural History: Vol. 4, No. 24, pp. 436-441.

XVI. On some circumstances relating to the economy of bees

In a paper which I had the honour to address to the Royal Society about twenty years ago (in the year 1807) upon the Economy of Bees, I stated, that having adapted cavities in hollow trees for the reception of swarms of those insects, I had observed that several days previous to the arrival of a swarm, a considerable number of bees were constantly employed in examining the state of the tree, and particularly of every dead knot above the cavity which appeared likely to admit water into it. At that period it appeared to me rather extraordinary, that animals so industrious as bees, and so much disposed to make the best use of their time, should, at that important season of the year, waste so much of it in apparently useless repetitions of the same act: for I, at that time, supposed that on different days, and at different periods of the same day, I saw only the same individuals. But in a case which at a subsequent period came under my observation, where the cavity into which the bees apparently proposed to enter, was not more than a quarter of a mile distant from the hive whence a swarm were prepared to emigrate, I witnessed a very rapid change of the individuals who visited their future contemplated habitation; and the number which in the course of three days entered it, appeared to me to be fully equal to constitute a very large swarm: and upon the evidence of these and other facts, which I shall proceed to state, I am much disposed to infer, that not a single labouring bee ever emigrates in a swarm without having seen the future proposed habitation of that swarm. That the queen bee has also always seen her future habitation, I am also much inclined to believe, as she is well known to absent herself from the hive some time previously to the emigration of a swarm: though her object may be to meet a male of another hive; for I much doubt whether she ever receives the embraces of a brother. The results of some of Huber’s experiments are very favourable to this conclusion, as is the otherwise excessive number of male bees, and in both the animal and vegetable world nature has taken very ample means of facilitating what the breeders of improved varieties of domesticated animals call cross breeding. I have also been led by the following facts to believe, that not only the future permanent habitation of each swarm, but the place where they temporarily settle, apparently to collect their numbers, soon after they quit their hive, is known also to each individual. Different families of domesticated animals of every species present some peculiarities of disposition and habit; and the swarms of the family of bees, which were the subject of my experiments, showed, I think, more than an ordinary disposition to unite, by two apparently joining the same queen. My attention was consequently attracted to the circumstances which preceded such unions.