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Your search keyword '"TORRETTA, Juan P."' showing total 159 results
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159 results on '"TORRETTA, Juan P."'

34. Positive relationship between crop centrality and pollination service

Author

Rufford Foundation, Agencia Nacional de Promoción Científica y Tecnológica (Argentina), Instituto Nacional de Tecnología Agropecuaria (Argentina), Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina), Ministerio de Economía y Competitividad (España), European Commission, Consejo Superior de Investigaciones Científicas (España), Govern de les Illes Balears, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Allasino, Mariana L., Haedo, Joana P., Lázaro, Amparo, Torretta, Juan P., Marrero, Hugo J., Rufford Foundation, Agencia Nacional de Promoción Científica y Tecnológica (Argentina), Instituto Nacional de Tecnología Agropecuaria (Argentina), Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina), Ministerio de Economía y Competitividad (España), European Commission, Consejo Superior de Investigaciones Científicas (España), Govern de les Illes Balears, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Allasino, Mariana L., Haedo, Joana P., Lázaro, Amparo, Torretta, Juan P., and Marrero, Hugo J.

Abstract

The topological structure of interaction networks determines community dynamics and stability. Closeness centrality is a species-level attribute that measures the relative position and proximity of species in the interaction network. We assessed the link between closeness centrality of crops in plant-pollinator interaction networks and crop seed production. We worked with five crop species used for seed production distributed in 14 farms. At each farm we recorded pollinators’ interactions with the crop and with the co-flowering plants at crop edges and built quantitative plant-pollinator interaction networks. For each network, we calculated weighted closeness centrality of crops and related it to crop seed set by using generalized linear mixed models. Our results show that crop centrality is positively associated with crop seed production, and suggest that the use of ecological interaction network metrics in agricultural systems could be useful to design agronomic management plans and enhance crop yields.

Published
2023

35. The Neotropical Cleptoparasitic Bee Mesocheira bicolor (Hymenoptera: Apidae: Ericrocidini) in Argentina.

Author

Torretta, Juan P., Graffigna, Sofía, Allasino, Mariana L., Avalos, Adan A., Marrero, Hugo J., and Álvarez, Leopoldo J.

Subjects
*BEES, *BIOGEOGRAPHY, *APIDAE, *HYMENOPTERA
Abstract

Mesocheira bicolor (Fabricius) is a cleptoparasite bee, widely distributed in the New World from Mexico to northern Argentina. In Argentina, this species is only documented from Formosa. In this contribution, we report new records of males and females reared from trap nests obtained from different studies about nesting biology of solitary bees in pre-existing cavities in several Argentinian provinces. Also, we studied material from Argentinean research collections, and we searched for occurrence data in the Global Biodiversity Information Facility. Adults of M. bicolor were reared from nests of Centris (Hemisiella) tarsata and C. (Hemisiella) nigriventris Burmeister. Here, we reported eight new provincial records that widely increase the geographical distribution of this species in Argentina, expanding its austral-most distribution record by more than 1,000 km. [ABSTRACT FROM AUTHOR]

Published
2024
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36. The rare robber fly genus Pronomopsis Hermann (Diptera: Asilidae: Dasypogoninae) in Argentina.

Author

Álvarez, Leopoldo J., Camargo, Alexssandro, Lucia, Mariano, Lamas, Carlos J. E., and Torretta, Juan P.

Subjects
DIPTERA, TERMINALIA, SPECIES, MALES
Abstract

Pronomopsis rubripes Hermann, and Pronomopsis talabrensis Artigas are reported for the first time from Argentina (Salta and Jujuy) and the male terminalia of P. chalybea Hermann and P. talabrensis are described and illustrated for the first time. An updated distribution map and a key of the species of Pronomopsis Hermann are also provided. [ABSTRACT FROM AUTHOR]

Published
2023
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38. Nesting Biology of Megachile(Chrysosarus) jenseni(Hymenoptera: Megachilidae) in Two Contrasting Pampean Agroecosystems: A Potential Pollinator for Alfalfa?

Author

Torretta, Juan Pablo, Basilio, Alicia M., Haedo, Joana P., and Marrero, Hugo J.

Abstract

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. Based on observations from two populations occurring in contrasting agroecosystems, this bivoltine species showed common behavioral features shared with other species of subgenus Chrysosarus, such as the use of petal pieces and mud as nesting materials and the utilization of pre-existing cavities. Both studied populations showed a bivoltine life cycle with a rapid early-summer generation and a second generation, with most individuals overwintering. Main causes of mortality were unknown diseases (or other factors), causing the death of preimaginal stages. Moreover, this species was attacked by a cleptoparasite megachilid (Coelioxys remissa), a parasitic eulophid wasp (Melittobiasp.), and a bee fly (Anthrax oedipus). Finally, we discussed the potential use of this leaf-cutter bee species for alfalfa pollination.

Published
2024
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45. Nesting biology of two sympatric species of Megachile(Chrysosarus) (Megachilidae) in Argentina

Author

Torretta, Juan Pablo, Basilio, Alicia Mabel, and Marrero, Hugo Javier

Abstract

Leaf cutter bees (genus Megachile) are a diverse group of pollinators of wild and cultivated plants. Many species nest in pre-existing cavities and use diverse building materials to construct their brood cells. For instance, species of subgenus Chrysosarusadd a mud layer between two layers of leaves or petals. We studied similarities and differences in their nesting biology from 13 nests of Megachile(Chrysosarus) concavaand 72 nests of Megachile(C.) diversa(Megachilidae) obtained in trap nests in northern Argentina. Females of M. concavaused trap nests with higher diameters, shorter length, and built a lower number of brood cells per nest compared to females of M. diversa. In the latter species, the sex ratio was female-biased, but we observed male-biased progeny in shorter trap nests, thus the sex ratio of M. diversacould be context-dependent. Reproductive success was different between species: 40.5% for M. concavaand 75.8% for M. diversa,desiccation and/or mold being the principal factor of mortality of immature stages. The attack from parasitic species represented 10.8% for M. concavaand only 1.2% for M. diversa. Megachile concava, based on observations of a few nests collected during autumn, could be a bivoltine species and oligolectic of Faboideae, while M. diversais a partially bivoltine or multivoltine, and polylectic species, with a marked turnover of pollen resource throughout its extensive reproductive season. Differences in the trophic niche and, to a lesser extent, in the inner diameter of trap nests used could allow their coexistence in the studied forests.

Published
2023
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