Large Carpenter Bees Research Articles

Comparative morphology of the mesosomal ‘gland’ in male large carpenter bees (Apidae: Xylocopini)

The gross morphology of the reservoir of the mesosomal gland of male large carpenter bees (tribe Xylocopini) was examined in 46 taxa (species and subspecies) in the three genera of the tribe. Males of all but six species of Xylocopa examined possess a cuticle-lined invagination that originates along the suture between the metanotum and propodeum. Size of the reservoir and arrangement of the tubules are consistent within subgenera (with a single exception) but variable among most subgenera. The morphological extremes range from a simple, short invagination that opens medially to a complex set of convoluted tubules that open from paired, laterally-positioned openings and extend forward to the metanotum or scutellum and posteriorly to the propodeal pit. Comparisons of mesosomal shapes between the sexes or between males in taxa with and without this reservoir reveal that structural changes of the posterior elements of the mesosoma are associated with the presence of the large reservoirs. In turn, reservoir size is predictive of male reproductive behaviour. The probable mode of gland function, the potential use and limitations of this structure as a phylogenetic character and the relationship of gland reservoir size to the diversity of mate-locating behaviours found in the Xylocopini are discussed.

Cooperative Nesting in the Multivoltine Large Carpenter Bee Xylocopa sulcatipes Maa (Apoidea: Anthophoridae): Do Helpers Gain or Lose to Solitary Females?

AbstractWhether an individual strives to breed or restrains from reproducing directly but increases the fitness of another individual through its help, may be viewed as a result of a trade‐off between fitness costs and benefits arising from this decision. A population of the large carpenter bee Xylocopa sulcatipes Maa was studied in southeast Israel over a two year period. Female reproductive success, in terms of genetic representation in the gene pool (genetic gain), was calculated using coefficients of relatedness and the number of offspring produced by solitary, reproductively dominant and helper bees of social nests. In one year helper females, that shared a nest with a related female accrued a higher genetic gain than did solitary females. In the subsequent year solitary females did better than the helper bees. In nests founded by unrelated females a helper bee accrued only little genetic gain. However, evidence is presented to show that subordinate behaviour can have an adaptive value and can ultimately be beneficial through nest inheritance by the subordinate bee.

Pollination biology of two species ofKielmeyera (Guttiferae) from Brazilian cerrado vegetation

The pollination biology and breeding systems ofKielmeyera coriacea andK. speciosa, two sympatric woody species common in the cerrado vegetation of C. Brazil, were studied. Both species have similar nectarless, polystemonous “Papaver-type” flowers which are visited by a similar spectrum of insects, though they bloom in different seasons and are thus phenologically isolated. Large carpenter bees seem to be the most important pollinators and these and other bees effect “buzz pollen” retrieval despite the fact that anthers are not poricidal. Both species ofKielmeyera possess strong xenogamous breeding systems. The presence of staminate flowers and andromonoecy inK. coriacea, as well as the longevity ofK. speciosa flowers are discussed as alternative strategies to improve pollination success and reproductive efficacy.

Reproductive competition involving oophagy in the socially nesting beeXylocopa sulcatipes

Several types of nesting associations, termed quasisocial (females more or less identical, no division of labor), semisocial (females of the same generation, with division of labor) and matrifilial (overlap of generations, with division of labor) are described in many primitively social hymenopteran species. In the latter two types, at least one potentially reproductive female forgoes her own reproduction in favor of that of a dominant female. Quasisociality is generally of a temporary nature, because dominance relations develop. It turns then into semisociality [11. The large carpenter bee Xylocopa sulcatipes in southern Israel has been described as forming both solitary and social nests [2, 3]. This paper shows that in certain associative nests founded by two females an extreme example of reproductive competition, oophagy, occurs. A X. sulcatipes egg measures approximately 11 mm in length and 2.2 mm in diameter; for an adult female of 22 mm body length, egg cannibalism therefore represents a significant loss of investment. X. su/catipes typically nests in twigs o f dead branches where the female excavates a straight tunnel. Females also use pre-existing cavities in stems of Arundo, Ferula and other plants existing naturally in the habitat. The female builds a linear array of cells [4]. Each is provisioned with pollen and nectar, and an egg is deposited upon the loaf-like food mass. Finally the cell is sealed with masticated wood. As part of a study on Xylocopa at Hazeva Field Centre, Arava Valley,

Bionomics of the Large Carpenter Bees of the Genus Xylocopa

The large carpenter bees of the genus Xylocopa include more than 730 species, which are grouped into 48 subgenera (52). As their name implies, they include some of the largest bees, often exceeding 3 cm in length. Females of most species are conspicuous in their black or blue coloration, which may be variegated with lighter-colored pubescence. Males either resemble females or may be completely covered with a light brown, light green, or yellowish green pubescence. Most species occur in the tropics or sUbtropics. Less than 10% extend into the temperate zones, reaching as far north as the steppes of Russia (72). Nests are usually constructed in dead plant material; an almost infinite variety of wood, cane, and flowering stalks is used (49, 72). Recorded studies of carpenter bees date back almost 300 years (52) and now include observations on about 60 different species. However , apart from

Bionomics Of The Large Carpenter Bees Of The Genus Xylocopa

Bionomics Of The Large Carpenter Bees Of The Genus Xylocopa

Nests of a Tube-dwelling Bee in Quaternary Sediments of the Jeffara Plain, S. P. L. A. J.

AbstractVertical, tubular borings, either simple or subdivided into cells by horizontal, spirally ornamented partitions of cemented fine silt, are common in the uppermost part of Unit Q3 of the Quaternary floodplain deposits in the eastern part of the Jeffara Plain. The structures display many features similar to those found in nests constructed by tube-dwelling, solitary wasps and bees. The size of the cells, the spiral construction of the partitions and the general architecture of the cells is closely comparable to the nest structure of the large carpenter beeXylocopa virginica krombeiniHurd., and it is suggested that the Quarternary nests were constructed by a bee of Xylocopid type.

Mortality, Sex Ratio and Fecundity in Natural Populations of Large Carpenter Bees (Xylocopa Spp.)

SUMMARY (1) Data on the sex ratio, fecundity, mortality caused by predators, parasites and unknown factors (probably mostly excessive dampness or dryness in the larval cell) and the availability of nesting substrates obtained by an extensive sampling method for fifteen Xylocopa species are analysed and discussed. (2) The sex ratio averaged 36 males to 64 females and average fecundity was 7.35 eggs per female. (3) Mean total mortality of immature stages was 44%. Parasitism tended to be lower where only univoltine Xylocopa species were present partly because of the absence of two parasites, Coelopencyrtus and Paralipsa, occurring with multivoltine species. (4) Destruction by man and predation by woodpeckers, baboons, small mammals and invertebrates such as ants was low on average but occasionally severe (over 50%). (5) Calculated multiplication rates persistently above x 1.00 per generation on the one hand and the observed light exploitation of nesting substrates on the other are incompatible except for relatively short periods. This indicates incompleteness of the data caused possibly by the missing of substantial mortality of prereproductive adults and the underestimation of predation.

BOOK NOTICE

An index to the Collembola. By J. T. Salmon.University of California Publications in Entomology, Vol. 29. A classification of the large carpenter bees (Xylocopini) (Hymenoptera: Apoidea). By Paul D. Hurd, Jr., and J. S. Moure.University of California Publications in Entomology. Vol. 39. Skeleto‐muscular morphogenesis of the thorax and wings of the honey bee Apis mellfera (Hym.Apidae). By Howell V. Daly.

New Books

New Books

Erratum: Evolutionary Mechanisms in Pollination Biology

In the article "Evolutionary mechanisms in pollination biology" by H. G. Baker [ Science 139, 877 (8 March 1963)] the fifth line up in the next-to-last paragraph (column 3, page 880) should have read: (. . . visited by large carpenter bees of the Xylocopidae ). In the published version Xylocopidae read Megachilidae .

Evolutionary Mechanisms in Pollination Biology

In the article Evolutionary mechanisms in pollination biology by H. G. Baker [ Science 139, 877 (8 March 1963)] the fifth line up in the next-to-last paragraph (column 3, page 880) should have read: (. . . visited by large carpenter bees of the Xylocopidae ). In the published version Xylocopidae read Megachilidae.

The Nesting Habits of the Little Carpenterbee, Ceratina Calcarata

The large carpenter-bee, Xylocopa virginica, is rightfully entitled to this name; the small carpenter-bee, Ceratina calcarata Robt., (Fig. 1), can furnish only part of the qualifications necessary to entitle her to the name. The former actually carves out with her powerful jaws new tunnels in the solid wood, grinding out sawdust as yellow and as real as any that comes from a steel blade. She seeks no soft or decayed portions, but cuts on into the sound wood with joyous vigor. The small carpenter-bee, so-called, burrows only into the soft pith of elder or sumac, and even then is able to use only the stems which have been cut or broken off, so as to afford her direct access to the soft pith within. If the soft portion is unexposed, Ceratina is unable to break through the ligneous wall and is obliged to seek another stem. Thus it is in only a very limited sense that this species may be called a carpenterbee. The similarity of common name of the two insects might lead one to expect similarity in looks, but in their physical appearance there is all the difference of David and Goliath, the one large and powerful in build, the other small and delicate. That they find the stems which have been cut was proven by a little experiment. In the middle of June, 1918, a large clump of sumac at Meramec Highlands gave no evidence of harboring any of these bees within their stems. I cut off the tops of about one-fourth of them (sixty-five in number) to make a place which would be attractive to home-seekers. When I returned a month later, seventy-five per cent, of the cut twigs were occupied by Ceratina calcarata, and not one of those uncut contained an occupant.