Nesting Biology of Megachile (Chrysosarus) jenseni (Hymenoptera: Megachilidae) in Two Contrasting Pampean Agroecosystems: A Potential Pollinator for Alfalfa?

Several crops depend on both managed and wild bees to produce fruits and/or seeds, and the efficiency of numerous wild bees is higher than that of some managed species. Therefore, knowing and understanding the required resources for wild bees could enabled the establishment of management practices to increase their populations. Here, we provide information about the nesting biology of Megachile (Chrysosarus) jenseni, a Faboideae-specialist bee species.

Comparative analysis of the processes involved in the loss of elaiophores in two species of the christianelloid clade (Malpighiaceae).

Alicia anisopetala and Callaeum psilophyllum are two closely related species that belong to the christianelloid clade of the family Malpighiaceae. Both species are pollinated by oil-collecting bees and exhibit variations at specimen and population level in the number of elaiophores per flower. These floral glands that secrete non-volatile oils constitute an ancestral trait for the family.

Colleters, osmophores, and nectaries in the species Ceropegia lenewtonii: a sapromyiophilous stapeliad (Asclepiadoideae, Apocynaceae).

Ceropegia lenewtonii (Plowes) Bruyns (=Huernia keniensis), currently belonging to the Huernia section of the genus Ceropegia, is a stapeliad species distributed in Africa and the Arabian Peninsula; but it is widely cultivated as ornamental in most parts of the world. This species of stapeliad presents "carrion flowers" associated with a sapromyophilous pollination syndrome since the flowers emit an unpleasant odor. In this work, we describe the floral morphology and anatomy of the calyx, corolla, and corona of this species based on bright-field and scanning electron microscope techniques.

Structural diversity of elaiophores in Argentine species of Malpighiaceae: morphology, anatomy, and interaction with pollinators.

Most Neotropical Malpighiaceae species are characterized by having zygomorphic flowers and oil glands in the sepals called elaiophores; these floral characteristics are associated with a particular pollination syndrome through oil-collecting bees. This work proposes a study about the structural characteristics of elaiophores in 18 species of Malpighiaceae present in Argentina. The main objectives are to describe the morphology and anatomy of the elaiophores, to detect variation in the number of glands, to compare similarities or differences in elaiophores of species belonging to different lineages, and to know about the potential pollinators and their association with the structural traits of the elaiophores.

New austral-most records of the genus Heterostylum Macquart (Diptera: Bombyiliidae) in Argentina.

Bee flies of the genus Heterostylum Macquart are medium-sized species (1015 mm) characterized primarily by a robust body covered with long pile and by an indented hind margin of the eye (Cunha et al. 2007). There are several studies on the immatures of some species of Heterostylum (Bohart et al.

Anatomy and ultrastructure floral osmophores of Catasetum fimbriatum (Orchidaceae).

Catasetum fimbriatum is a dioecious species whose flowers fully adapted to an euglossinophilic mode of pollination. Euglossini male bees collect the volatile fragrances which are produced in osmophores on the flowers. In order to understand the mechanism of scent secretion and floral interaction with the pollinator, we describe the location, histochemistry, anatomy, and ultrastructure of osmophores in pistillate and staminate flowers of this species.

Gynoecium with carpel dimorphism in Tricomaria usillo, comparison with other genera of the Carolus clade (Malpighiaceae).

We analyzed the gynoecium morphology and anatomy of Tricomaria usillo in young and mature flowers from diverse populations in order to analyze the differentiation of structure and function of the parts of the carpel. We also aimed to find the potential pollinators and associate the morphology of the gynoecium with its role. We compare the characteristics of the gynoecium of T.

Structure of the stigma and style of Callaeum psilophyllum (Malpighiaceae) and its relation with potential pollinators.

The family Malpighiaceae, particularly in the Neotropic, shows a similar floral morphology. Although floral attraction and rewards to pollinators are alike, stigmas and styles show more diversity. The stigmas were described covered with a thin and impermeable cuticle that needs to be ruptured by the mechanical action of the pollinators.

Descriptions of unknown sexes, new geographical records, and host associations for two South American species of Megachile (Hymenoptera: Megachilidae).

The cosmopolitan genus Megachile include many species described on the basis of only one sex. Sexual dimorphism is very pronounced in these taxa and therefore sexes are often difficult to associate, thus making species identification nearly impossible. The females of M.

Elaiophores in Gomesa bifolia (Sims) M.W. Chase & N.H. Williams (Oncidiinae: Cymbidieae: Orchidaceae): structure and oil secretion.

Background And Aims: Oils are an unusual floral reward in Orchidaceae, being produced by specialized glands called elaiophores. Such glands have been described in subtribe Oncidiinae for a few species. The aims of the present study were to identify the presence of elaiophores in Gomesa bifolia, to study their structure and to understand how the oil is secreted.

[Pollen dispersion and reproductive success of four tree species of a xerophytic forest from Argentina].

The "talares" in eastern Buenos Aires province, Argentina, are coastal xerophitic forests structured by few arboreal species surrounded by a lower and moister soil matrix. We studied the reproductive parameters of the most representative arboreal species (Celtis tala, Scutia buxifolia, Jodina rhombifolia, and Schinus longifolia). Pollen dispersion was studied through floral visitor traps (biotic dispersion) and using gravimetric pollen collectors (abiotic dispersion).

Flesh flies species (Diptera: Sarcophagidae) from a grassland and a woodland in a Nature Reserve of Buenos Aires, Argentina.

Temporal changes of flesh flies abundance were simultaneously recorded at monthly intervals during a year in a woodland and in a grassland at the "Reserva Ecológica Costanera Sur" (RECS), Buenos Aires city, Argentina. Samples were taken at monthly intervals (February 2004-January 2005). Hourly captures of adult flies (10:00 am - 04:00 pm) were taken each sampling date with a hand net.

Winter survival of immature instars of Mansonia indubitans Dyar & Shannon and Mansonia titillans Walker (Diptera: Culicidae), in Buenos Aires, Argentina.

We conducted a whole year research on the ecology of Mansonia indubitans and Ma. titillans in Macáes Pond, Costanera Sur Reserve, Buenos Aires, Argentina. The usage of different floating plants by immature instars and their overwintering was analyzed.

Host plant selection of two Mansonia blanchard species (Diptera: Culicidae) in a heterogeneous habitat of Buenos Aires City, Argentina.

Larvae and pupae of the genus Mansonia Blanchard attach to the roots of aquatic plants by means of modified structures to obtain oxygen. A study of the association of larval Ma. indubitans and Ma.