The use of polliniferous resources by Melipona capixaba, an endangered stingless bee species.

Abstract Pollen types present in samples from corbiculae of Melipona capixaba (Moure and Camargo) (Hymenoptera: Apidae: Meliponina) worker bees were analyzed, as well as pollen samples from food pots inside the hives in three sites located at the bees' original habitat. The aim was to find out the sources used as a trophic resource by this species. The dominant pollen grains in the spectrum of the samples belonged to the families Myrtaceae and Melastomataceae. Eucalyptus was the most frequent pollen type in the corbiculae in Conceição do Castelo municipality; Eucalyptus, Myrcia, and Melastomatacea/Combretaceae in the Fazenda do Estado district; and Eucalyptus and Myrcia in the São Paulo de Aracê district, both in the Domingos Martins municipality. Eucalyptus and Melastomataceae/Combretaceae were the predominant pollen types in the food pots. Eucalyptus was the most prevalent type all year round or most of the year. The most common pollen types in the months that Eucalyptus was not present or dominant in the samples were of remaining native forest species, "ruderal" (field) plants, fruit-bearing plants, and introduced ornamental plants.

Interannual fluctuations in connectivity among crab populations (Liocarcinus depurator) along the Atlantic-Mediterranean transition.

An interesting evolutionary question that still remains open is the connectivity between marine populations. Marine currents can favour the dispersal of larvae or adults, but they can also produce eddies and gyres generating oceanographic fronts, thus limiting gene flow. To address this subject, we selected the Atlantic-Mediterranean transition, where several fronts are located: Gibraltar Strait (GS), Almeria-Oran Front (AOF) and Ibiza Channel (IC). Seven populations of the marine crab Liocarcinus depurator (Cadiz, West and East Alboran, Alacant, Valencia, Ebro Delta and North Catalonia) located along this transition were analysed in six consecutive years (2014-2019) using a fragment of the COI (Cytochrome Oxidase subunit I) gene. All sequences (966) belonged to two well defined haplogroups: ATL (most abundant in Atlantic waters) and MED (predominant in Mediterranean waters). Following a geographic variation, the frequency of ATL decreased significantly from Cadiz to North Catalonia. However, this variation presented steps due to the effect of oceanographic restrictions/fronts. Significant effects were recorded for GS (2015, 2017, 2018 and 2019), AOF (all years except 2018) and IC (2016). The intensity and precise location of these fronts changed over time. Multivariate analyses distinguished three main population groups: Cadiz, Alboran Sea and the remaining Mediterranean populations. These findings could be relevant to properly define Marine Protected Areas and for conservation and fisheries policies.

[Entomophilic pollination of squash, Cucurbita moschata (Cucurbitaceae)]. / Polinização entomófila de abobrinha, Cucurbita moschata (Cucurbitaceae).

The objectives of this work were to determine the squash entomofauna in the region of Viçosa, Minas Gerais state, to study their behavior on flowers and their importance for pollination, verifying the role of each pollinator. The most common species were Trigona spinipes (Fabricius), Trigona hyalinata (Lepeletier), Apis mellifera (L.) and Melipona quadrifasciata (Lepeletier). The visitation behavior of A. mellifera, M. quadrifasciata, and Bombus morio (Swederus) were similar. They visited flowers for nectar collection, positioning themselves vertically between the corolla and the sexual structures of the flowers, with the back directed toward the floral axis, which permitted the removal of pollen from the anthers of flowers with stamens and its deposition on the stigma of flowers with pistils, being considered therefore effective pollinators. Trigona spinipes and T. hyalinata foraged in groups, preventing other species from landing on the flowers which they occupied. Due to their small body size and only infrequent contact with the sexual structures of the flowers, these species are considered occasional pollinators. The number of fruits produced differed between freely visited flowers, those prevented from receiving visits and those visited only a single time by M. quadrifasciata, B. morio, A. mellifera, T. hyalinata or T. spinipes. Flowers prevented from receiving visits or visited only once by T. spinipes did not produce fruits. The remaining pollination systems led to fruitification, with open pollination or a single visit from either M. quadrifasciata or B. morio leading to most fruit production.

Polinização entomófila de abobrinha, Cucurbita moschata (Cucurbitaceae) / Entomophilic pollination of squash, Cucurbita moschata (Cucurbitaceae)

The objectives of this work were to determine the squash entomofauna in the region of Viçosa, Minas Gerais state, to study their behavior on flowers and their importance for pollination, verifying the role of each pollinator. The most common species were Trigona spinipes (Fabricius), Trigona hyalinata (Lepeletier), Apis mellifera (L.) and Melipona quadrifasciata (Lepeletier). The visitation behavior of A. mellifera, M. quadrifasciata, and Bombus morio (Swederus) were similar. They visited flowers for nectar collection, positioning themselves vertically between the corolla and the sexual structures of the flowers, with the back directed toward the floral axis, which permitted the removal of pollen from the anthers of flowers with stamens and its deposition on the stigma of flowers with pistils, being considered therefore effective pollinators. Trigona spinipes and T. hyalinata foraged in groups, preventing other species from landing on the flowers which they occupied. Due to their small body size and only infrequent contact with the sexual structures of the flowers, these species are considered occasional pollinators. The number of fruits produced differed between freely visited flowers, those prevented from receiving visits and those visited only a single time by M. quadrifasciata, B. morio, A. mellifera, T. hyalinata or T. spinipes. Flowers prevented from receiving visits or visited only once by T. spinipes did not produce fruits. The remaining pollination systems led to fruitification, with open pollination or a single visit from either M. quadrifasciata or B. morio leading to most fruit production.