NovitatesAMERICAN MUSEUM PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET NEW YORK, N.Y. 10024 U.S.A. NUMBER 2702 SEPIEMBER 22, 1980 JEROME G. ROZEN, JR. AND NED ROBERT JACOBSON Biology and Immature Stages of Macropis nuda, Including Comparisons to Related Bees (Apoidea, Melittidae) NovtautesAMERICAN MUSEUM PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK, N.Y. 10024 Number 2702, pp. 1-1 1, figs. 1-12 September 22, 1980 Biology and Immature Stages of Macropis nuda, Including Comparisons to Related Bees (Apoidea, Melittidae) JEROME G. ROZEN, JR.1 AND NED ROBERT JACOBSON2 ABSTRACT The present study treats the following topics tures are made with several Palearctic species. pertaining to the life history of the solitary bee The life history of this species agrees with ac- Macropis nuda (Provancher), the first North counts of European species in the literature. Sev- American species of the genus to be found nest- eral newly discovered characteristics of the co- ing: Nest site localities, nest description, nest coon of M. nuda correspond well with similar construction, flower relationships, provisioning, features in other Macropis and Melitta, but not development (including description of egg), larval with Meganomia and Ctenoplectra of South Af- feeding habits, cocoon construction, defecating rica. pattern, sleeping habits of adults, mating behav- The last larval instar and the pupa are described ior, daily and seasonal activity patterns, and par- taxonomically and agree closely with similar asitism and predation. Comparisons of these fea- stages of other members of the genus. INTRODUCTION The present paper reports on the life his- Canada and eastern and northern United tory of Macropis nuda (Provancher) and States and six or seven species in Europe, compares it with that of several Palearctic Russia, China, and Japan. Paramacropis is species of the same genus. The mature larva known only by M. ussuriana (Popov) from and pupa are described and compared with the Maritime Province of eastern Russia. those of other Melittidae (Rozen and Mc- The distribution of the species has been Ginley, 1974; Rozen, 1977a; Rozen, 1978). treated by Popov (1958) and Mitchell (1960). Macropis, consisting of the subgenera Because of the distinctive anatomical fea- Macropis and Paramacropis, is restricted to tures of adults, the genus has been placed by the Holarctic Region. Macropis, sensu stric- itself in the Macropidinae. Numerous larval to, contains approximately five species in features of Macropis are shared by members 1 Deputy Director for Research and Curator of Hymenoptera, American Museum of Natural History. 2 Department of Entomology and Economic Zoology, Rutgers University, New Brunswick, N.J. Copyright © American Museum of Natural History 1980 ISSN 0003-0082 / Price $1.00 2 AMERICAN MUSEUM NOVITATES NO. 2702 of other subfamilies, but little taxonomic sig- tion of mixed herbs and low-growing woody nificance can be attached to these similari- plants provided approximately 60 percent ties, as most are plesiomorphic (Rozen and cover. The nests were 0.5 to 1.0 m. from the McGinley, 1974; Rozen, 1977a; Rozen, ditch at the edge of the roadway. A thick 1978). stand of young hardwood trees east of the The nesting biologies of only Old World embankment shaded the nest entrances until Macropis have been described before about noon, after which the bank was fully (Bouwman, 1921; Lieftinck, 1957; Malyshev, exposed to the sun. Because road plows pile 1929; Phipps, 1948). Nests of a North Amer- snow on the embankment, it is snow-covered ican species were finally discovered on until April, according to Dr. Dalgleish (per- July 13, 1978, when the second author locat- sonal commun.). ed an extensive nesting site of Macropis The ground surface was strewn with shale nuda on the Edmund Niles Huyck Preserve, fragments, and outcroppings of the same Rensselaerville, Albany County, New York. rock occurred sporadically. Each nest con- It was studied July 13 to 18, 1978, and again centration was in moderately fine, well- July 27 to 29, 1978. Most of this report is drained soil containing small roots. The soil based on field observations made at those at one concentration had few stones com- times, but some additional information was pared to adjoining parts of the embankment, included in the manuscript from field exca- whereas soil at another held many stones. vations made on the same site by the first Dominant plants in flower along the embank- author on July 19 and 20, 1979. ment included: Apocynum androsaemifo- We thank Dr. Robert C. Dalgleish, Direc- lium L., Erigeron annuus (L.), Chrysanthe- tor of the Preserve, for his hospitality and mum Leucanthemum L., and Hypericum assistance during the course of this study. perforatum L. Although abundant in many The participation of the second author was moist, partly shaded areas in the Preserve, sponsored by the Reader's Digest Founda- the pollen plant, Lysimachia ciliata L., did tion through the Undergraduate Research not occur at the site. A dense stand, visited Program of the American Museum of Natu- by Macropis nuda, grew 25 m. away, on the ral History. west side of the roadway. Collections of immature stages, cocoons, DESCRIPTION OF NEST: We excavated and nest components are in the American approximately 12 nests with care to deter- Museum of Natural History. mine nest structure. At least 10 more were quickly examined and their contents re- moved for study and rearing in the labora- BIOLOGY tory. The presence of old cocoons indicated DESCRIPTION OF AREA: The Edmund that the nesting site had been used for a num- Niles Huyck Preserve is situated in hilly ber of years, and the site was again fully ac- country consisting of old fields and reforest- tive in 1979. The smallest aggregation con- ed woodlands of mixed hardwoods and soft- sisted of seven irregularly scattered, active woods. The nesting site occurred on an em- nests in an area 14 x 20 cm. Other aggre- bankment along the eastern side of a dirt gations were similar in density, although roadway, approximately 50 m. south of Ord- some contained more nests. All nests (figs. way House, one of the residences at the Pre- 1-3) were compact and very shallow, the serve. Although the embankment extended deepest cells being only 6.5 mm. below the nearly 20 m. and may have been used in its surface. entire length for nesting, four major nest con- Although some nest entrances were totally centrations accounting for most of the active exposed, most were partly or wholly con- nests occupied only a 4 m. stretch in 1978. cealed next to or under dried leaves, twigs, The same stretch had the most nests in 1979. rocks, projections of soil, and low-growing Nests were on surfaces that sloped approx- plants. Tumuli of dry, loose earth occurred imately 30 to 45 degrees, where the vegeta- on the downhill side of most entrances. Each 1980 ROZEN AND JACOBSON: MACROPIS NUDA 3 nest was inhabited by a single female and no tinge. A drop of water placed on it did not males. Main burrows, approximately 3.0 to penetrate to the substrate. The uneveness 3.5 mm. in diameter and circular in cross sec- and greenish hue contrasted markedly with tion, descended in a meandering fashion and the very smooth, shiny, reddish brown cell always were unplugged, open, and without lining of an halictine that nested in the same a waterproof lining. substrate. The darkish transparent coating of With the exception of one nest in early the Macropis cell melted at a temperature stages of construction (fig. 1), all nests con- below the boiling point of water. It visibly tained numerous cells (figs. 2, 3). Most cells penetrated the soil surrounding the cell and seemed to be arranged in linear series of two, may have accounted for the cell wall tending although a few series of three and four cells to be harder than the soil. The hard cell wall were also encountered. Where only single was about 1 mm. thick and occasionally per- cells were found, the second cell of the series mitted us to excavate cells intact. probably had yet to be constructed or the We could not determine the sequence of area behind the single cell was occupied by construction of cell series in relation to the a rock, root, or cell from another nest. In an main burrow. In some cases, cells with larger area 6 cm. square, 25 "active" cells and a larvae seemed to have been connected to the number of cells from previous generations main burrow both above and below cells were uncovered, all from 2.5 to 6.5 cm. in with younger larvae or eggs. However, all depth. This surprisingly high concentration four cells still open and being provisioned was the result of close grouping of nest en- when we excavated were the lowest ones in trances, short main burrows, cells being near the nests. Clearly a cell was constructed, to the main burrows, and cells arranged in provisioned, oviposited in, and closed before linear series. The cell of a series closest to another cell was started. It is logical that, in the burrow was approximately 5 mm. from a series, the cell farthest from the main tun- it in all cases, and the short passage leading nel was constructed, provisioned, and closed to the burrow was filled with fine, moderate- before the tunnel in front was widened into ly compact soil. Distances between cells in the next cell. Although most observations a series invariably were short, so that the corroborated this assumption, larvae in ter- center of the spiral closure was 1 to 2 mm.