Anatomy and histology of the metapleural gland in the giant tropical ant Paraponera clavata (Fabricius, 1775) (Formicidae: Paraponerinae).

Ants are social insects with about 85 exocrine glands with different morphologies. The metapleural gland is exclusive to ants and its compounds have antimicrobial action, indicating a function in the defense against pathogens. Within ants, Paraponera clavata is the only living species representative of Paraponerinae. This study describes the anatomy and histology of the metapleural gland in workers of P. clavata. The metapleural gland is formed by secretory units that release secretion in a reservoir through collecting canaliculi. Secretory units are bicellular with a well-developed globular secretory cell, with 145 µm in diameter, and a duct cell forming the collecting canaliculi characterizing a class III gland. The metapleural gland is pointed out as a synapomorphy of ants. Paraponerinae constitutes one of the six subfamilies of the basal and paraphyletic Poneroide clade and knowledge of the metapleural gland morphology contribute to the understanding of evolutionary history of the basal ants' groups.

Morphology of male reproductive system of two solitary bee species (Hymenoptera: Apidae).

Bees can form all levels of social organization, from solitary to advanced eusocial societies. Although 80% of the species exist as solitary species, most researches emphasize social species. This study focuses on the description of the male reproductive system of the solitary beesThygater analis (Lepeletier) and Melitoma segmentaria (Fabricius) and searches for traits that support behavioral and phylogenetic studies. The reproductive system of males were dissected, fixed in 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer pH 7.2 and post-fixed with 1% osmium tetroxide. The tissue was dissected and included for light microscopy. The species presented similar anatomical traits, including paired testicles, seminal vesicles, deferent ducts, accessory glands and an ejaculatory duct. Each testicle was composed of four follicles. In both species, a testicle and a seminal vesicle were surrounded by a joint capsule, forming a seminal vesicle-testicle complex. The two species presented accessory glands with very distinct morphological traits. The anatomic pattern and the histological traits of the reproductive system of the species studied were similar to those described for other bees. In addition, these traits can be used to differentiate species and allow inferences concerning their reproductive biology.

Morphology of male reproductive system of two solitary bee species (Hymenoptera: Apidae)

Bees can form all levels of social organization, from solitary to advanced eusocial societies. Although 80 percent of the species exist as solitary species, most researches emphasize social species. This study focuses on the description of the male reproductive system of the solitary beesThygater analis (Lepeletier) and Melitoma segmentaria (Fabricius) and searches for traits that support behavioral and phylogenetic studies. The reproductive system of males were dissected, fixed in 2.5 percent glutaraldehyde in 0.1 M sodium cacodylate buffer pH 7.2 and post-fixed with 1 percent osmium tetroxide. The tissue was dissected and included for light microscopy. The species presented similar anatomical traits, including paired testicles, seminal vesicles, deferent ducts, accessory glands and an ejaculatory duct. Each testicle was composed of four follicles. In both species, a testicle and a seminal vesicle were surrounded by a joint capsule, forming a seminal vesicle-testicle complex. The two species presented accessory glands with very distinct morphological traits. The anatomic pattern and the histological traits of the reproductive system of the species studied were similar to those described for other bees. In addition, these traits can be used to differentiate species and allow inferences concerning their reproductive biology.

Morphology of male reproductive system in three species of Trypoxylon (Trypargilum) Richards (Hymenoptera: Crabronidae).

Variations in the adult male reproductive system among different groups of Hymenoptera offer characteristics that help studies on behavior and phylogenetics. The objective of this study was to describe the adult male reproductive system of three Trypoxylon (Trypargilum) species. For that, tissues were disseced, fixed in 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.2 and postfixed in 1% osmium tetroxide. The material was dehydratated and embedded for light and electron transmission microscopes. The species have similar reproductive systems, which are formed by a pair of testes, each one with three fusiforme follicles, from which emerges an efferent duct that later joins forming a deferent duct. The deferent duct opens into an ejaculatory duct. The first half of the deferent duct is enlarged and differentiated in a region specialized in sperm storage, the seminal vesicle. The accessory gland flows in the post-vesicular region of the deferent duct. The testes and vesicles are both covered with a conjunctive capsule. Sexually mature individuals have all spermatogenesis stages in their follicles. Sperms are released from testes in bundles which are disorganized inside seminal vesicles.

Morphology of male reproductive system in three species of Trypoxylon (Trypargilum) Richards (Hymenoptera: Crabronidae) / Morfologia do sistema reprodutor masculino em três espécies de Trypoxylon (Trypargilum) Richards (Hymenoptera: Crabronidae)

Variations in the adult male reproductive system among different groups of Hymenoptera offer characteristics that help studies on behavior and phylogenetics. The objective of this study was to describe the adult male reproductive system of three Trypoxylon (Trypargilum) species. For that, tissues were disseced, fixed in 2.5 percent glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.2 and postfixed in 1 percent osmium tetroxide. The material was dehydratated and embedded for light and electron transmission microscopes. The species have similar reproductive systems, which are formed by a pair of testes, each one with three fusiforme follicles, from which emerges an efferent duct that later joins forming a deferent duct. The deferent duct opens into an ejaculatory duct. The first half of the deferent duct is enlarged and differentiated in a region specialized in sperm storage, the seminal vesicle. The accessory gland flows in the post-vesicular region of the deferent duct. The testes and vesicles are both covered with a conjunctive capsule. Sexually mature individuals have all spermatogenesis stages in their follicles. Sperms are released from testes in bundles which are disorganized inside seminal vesicles.

Variações no sistema reprodutor entre os diferentes grupos de Hymenoptera oferecem caracteres que auxiliam nos estudos de comportamento e filogenia. O objetivo deste trabalho foi descrever o sistema reprodutor masculino de três espécies de Trypoxylon (Trypargilum). Para isso, os tecidos foram dissecados, fixados em glutaraldeído 2,5 por cento em tampão cacodilato de sódio 0,1 M, pH 7,2 e pós-fixados em tetróxido de ósmio a 1 por cento. O material foi desidratado e incluído para microscopias de luz e eletrônica de transmissão. As espécies possuem os sistemas reprodutores muito semelhantes, formados por um par de testículos, cada um com três folículos fusiformes, a partir dos quais emerge um ducto eferente que depois se juntam formando o ducto deferente. O ducto deferente termina no ducto ejaculatório. A primeira metade dos ductos deferentes é dilatada e diferenciada em uma região especializada no armazenamento de espermatozóides, a vesícula seminal. A glândula acessória desemboca na região pós-vesicular do ducto deferente. Testículos e vesículas seminais são envoltos por uma única cápsula conjuntiva. Indivíduos maduros sexualmente apresentam todos os estágios da espermatogênese em seus folículos. Os espermatozóides são liberados dos testículos em feixes, os quais estão desorganizados na vesícula seminal.

Diversity of bees and their floral resources at altitudinal areas in the Southern Espinhaço Range, Minas Gerais, Brazil

A porção sul da Cadeia do Espinhaço apresenta amplas áreas cobertas por campos altitudinais tropicais, quartizíticos ou metalíferos. Esses ecossistemas estão extremamente ameaçados, devido ao alto impacto antrópico, como a mineração e a urbanização. Nesse estudo inventariou-se a fauna e flora apícola durante um ano em uma área de campo rupestre (Serra de Ouro Branco) e durante dois anos em uma área de canga (Ouro Preto). Foram realizadas coletadas quinzenais de 8:00h às 17:00h. Foram coletados 677 indivíduos pertencentes a 91 espécies de abelhas de cinco famílias. Apidae foi a família mais rica e abundante, seguida por Halictidae e Megachilidae. As abelhas visitaram 46 espécies de plantas e as famílias mais visitadas foram: Asteraceae (n = 220), Malpighiaceae (n = 95), Melastomataceae (n = 94), Fabaceae (n = 78), e Solanaceae (n = 63). A região de Ouro Branco apresentou maior diversidade (H = 1,47) que Ouro Preto (H = 1,17). A baixa riqueza e abundância de abelhas, quando comparada a outras regiões de cerrado, podem ser atribuídas aos fatores ambientais das áreas de estudo: alta altitude, temperatura e disponibilidade de recursos florais. Áreas de canga e campo rupestre abrigam espécies raras e ameaçadas de extinção da fauna e flora. Áreas no sul do Espinhaço podem, entretanto, serem consideradas possíveis áreas de conservação biológica permanente.

Diversity of bees and their floral resources at altitudinal areas in the Southern Espinhaço Range, Minas Gerais, Brazil.

The Southern Espinhaço Range consists of large areas covered by quartzitic or metaliferous tropical altitudinal fields. The Espinhaço Range ecosystems are endangered by anthropic high impacts, particularly due to mining and urbanization. We conducted a one-year inventory of the bee flora and fauna at the quartzitic Ouro Branco Mountains and a two-year survey of the metaliferous Ouro Preto fields. The samples were collected twice a month, from 8:00 am to 5:00 pm. The bees (677) belonged to 91 species, five families. The family Apidae was the richest and most abundant, followed by the Halictidae and Megachilidae. The bees visited 46 flowering plant species; the most visited plants were the Asteraceae (n = 220), the Malpighiaceae (n = 95), the Melastomataceae (n = 94), the Fabaceae (n = 78), and the Solanaceae (n = 63). Diversity was higher in Ouro Branco (H = 1.47) than in Ouro Preto (H = 1.17). The low richness and abundance of bees in our research site when compared to other Brazilian "Cerrado" areas can be due to the high altitude, low temperature, and low availability of flowers we found. "Canga" and rupestrian areas house fauna and flora species that are rare and threatened by extinction. The southern Espinhaço areas can, therefore, be given the status of permanent biodiversity preservation area.