ABSTRACT
Abstract: Two sites located in Tocantins State, Brazil, were selected for the bee's community survey. One of them was mostly covered by Cerrado vegetation and the other one is located in the Cerrado-Amazon Rainforest ecotone. Five expeditions were performed in each site throughout a 12-month period, between 2019 and 2020. The total of 771 bee specimens were collected and distributed into four families. Apidae presented the greatest species abundance and richness, it was followed by Halictidae, Megachilidae and Andrenidae, respectively. Trigona pallens (Fabricius) (Apidae) was the species presenting the greatest abundance in both sites, it totaled 118 specimens, which corresponded to 26.9% of the total abundance of individuals belonging to tribe Meliponini. In general, the community presented several species with few individuals and few species with many individuals. Bee collections were performed by using three different methodologies, among them one finds sampling based on the entomological net method, which allowed collecting the largest number of both individuals and species in comparison to the other used methods. Based on the frequency and abundance classes, only few species were classified as very frequent (VF) and very abundant (VA) in both sites based on the frequency and abundance classes. Most species were constant (W) in both regions, and there was a small number of dominant species (D); moreover, more than 70% of the sampled species were considered accidental (Z). According to the present study, either Cerrado or Cerrado-Amazon Rainforest studied sites presented higher species richness than other sites in these biomes sampled in Brazil.
Resumo: Duas áreas localizadas no Estado do Tocantins, Brasil foram selecionadas para o levantamento da comunidade de abelhas, uma área com vegetação predominante de Cerrado e outra em ecótono Cerrado-Amazônia. Durante cinco expedições em cada área em um período de 12 meses, entre os anos de 2019 e 2020 foram coletados 771 espécimes de abelhas, distribuídas em quatro famílias: Apidae, com a maior abundância e riqueza de espécies, seguida de Halictidae, Megachilidae e Andrenidae. Trigona pallens (Fabricius) (Apidae) foi a espécie com maior abundância em ambas as áreas, totalizando 118 espécimes, o que correspondeu a 26,9% da abundância total de indivíduos da tribo Meliponini. De um modo geral, a comunidade apresentou muitas espécies com poucos indivíduos e poucas espécies com muitos indivíduos. A metodologia de coleta com uso de rede entomológica permitiu a coleta do maior número de indivíduos e de espécies em relação a outros três métodos utilizados. Em ambas as áreas, poucas espécies foram classificadas como muito frequentes (MF) e muito abundantes (MA), de acordo com as classes de frequência e de abundância. Também para ambas as áreas, grande parte das espécies foram constantes (W) e um baixo número de espécies dominantes (D), com mais de 70% delas consideradas acidentais (Z). O presente estudo revelou que tanto o Cerrado como a área de transição Cerrado-Floresta Amazônica apresentou alta riqueza de espécies em comparação com outras áreas destes biomas amostradas no Brasil.
ABSTRACT
Abstract: The first case of parasitoidism of a Myrmicinae ant by a sarcophagid fly has been observed in the Brazilian Cerrado. The larva of a Helicobia Coquillet (Sarcophagidae) specimen fed on head tissues of an Atta laevigata Smith, 1858 soldier and an adult male fly emerged from a puparium formed outside the host.
Resumo: O registro do parasitoidismo de uma formiga Myrmecinae por uma mosca Sarcophaginae foi relatado no Cerrado brasileiro. A larva de um exemplar de Helicobia Coquillet (Sarcophagidae) se alimentou dos tecidos da cabeça de um soldado de Atta laevigata Smith, 1858 e um adulto macho emergiu de um pupário que se formou fora do hospedeiro.
ABSTRACT
Phlebotomine sandflies are the vectors for the protozoan parasites that cause leishmaniasis. The present study investigated the species composition of sandfly fauna in the rural district of Taquaruçú, municipality of Palmas, state of Tocantins, Brazil and compared the diversity of species among intradomicile, peridomicile and forest environments during the dry and rainy seasons. Sandflies were collected using CDC light traps over the course of three months during the dry and rainy seasons. A total of 767 specimens were captured, belonging to different 32 species. The most abundant species were Micropygomyia goiana (Martins, Falcão & Silva), Sciopemyia sordellii (Shannon & Del Ponte), Evandromyia carmelinoi (Ryan Fraiha, Lainson & Shaw), Evandromyia termitophila (Martins, Falcão & Silva), Nyssomyia whitmani (Antunes & Coutinho) and Lutzomyia longipalpis (Lutz & Neiva). The highest species diversity (30) and the greatest percentage of specimens (78.3%) were obtained during the rainy season. During the dry season, the species richness and abundance were greater in domestic environments. However, during the rainy season, the forest displayed the highest species richness and the domestic environment exhibited the greatest species abundance. Several important vector species are reported in this study.
Subject(s)
Animals , Biodiversity , Insect Vectors/classification , Psychodidae/classification , Brazil , Leishmaniasis/transmission , Population Density , Rural Population , SeasonsABSTRACT
Parasitóides do gênero Neodohrniphora Malloch, 1914 geralmente atacam operárias de Atta sexdens rubropilosa Forel, 1908 em baixa freqüência, mas os ataques alteram o ritmo de forrageamento das colônias, reduzindo o número e tamanho das operárias e aumentando o abandono de fragmentos vegetais ao longo das trilhas. O forrageamento de A. sexdens rubropilosa pode ser diurno ou noturno, mas existem dúvidas se Neodohrniphora spp. atacam as operárias dessa formiga também durante a noite. Os objetivos deste estudo foram verificar a ocorrência de ataques e avaliar o grau de parasitismo de forídeos do gênero Neodohrniphora em operárias de A. sexdens rubropilosa sob três níveis de luminosidade em laboratório, incluindo a ausência de luz. Os níveis de luminosidade foram: alta (0,65 µmol/m³/s); baixa (0,05 µmol/m³/s) e ausência de luz (0,0 µmol/m³/s). Fêmeas de Neodohrniphora tonhascai Brown, 2001 e Neodohrniphora elongata Brown, 2001 coletadas no campo e liberadas em laboratório somente efetuaram ataques e foram obtidas operárias parasitadas sob alta luminosidade, sugerindo que essas espécies não são ativas no campo durante o período noturno (ausência de luz). Os resultados sugerem também que o estímulo visual em Neodohrniphora spp. pode ser um componente essencial para a localização e reconhecimento do hospedeiro.
Parasitoids of the genus Neodohrniphora Malloch, 1914 generally attack workers of Atta sexdens rubropilosa Forel, 1908 in low ratios. However these attacks alter the foraging rhythm and reduces the number and size of workers as well as increases the number of abandoned plant fragments along the trails. A. sexdens rubropilosa can have a diurnal or nocturnal foraging activity, but it is uncertain if Neodohrniphora spp. attacks workers of this host during the night. The objective of this work was to verify the occurrence of Neodohrniphora phorids attacks and the level of parasitism on workers of A. sexdens rubropilosa under three light levels in laboratory, including the darkness. The levels of illumination were: high-light (0.65 µmol/m³/s); low-light (0.05 µmol/m³/s) and darkness (0.0 µmol/m³/s). Field collected parasitoid females (Neodohrniphora tonhascai Brown, 2001 and Neodohrniphora elongate Brown, 2001) released in laboratory have attacked and parasitized A. sexdens rubropilosa workers only under high-light level. This suggests that these two Neodohrniphora species are not active in the field during the night (darkness) and that visual stimulus could be an essential component to the location and recognition of the host.
Subject(s)
Animals , Diptera/physiology , Ants/parasitology , Host-Parasite InteractionsABSTRACT
We determined the size characteristics of foragers of the leaf-cutting ant Atta sexdens in a mature eucalyptus forest in Campos dos Goytacazes, Rio de Janeiro State, Brazil, at daytime (7:30 to 10:00 hr) and nighttime (19:00 to 23:00 hr). There were no significant differences between daytime and nighttime ant mass (Ma), but leaf fragment mass (Ml) and burden (B = [Ma + Ml]/Ma), which indicates relative load capacity, were significantly greater at daytime. There was a positive linear relationship between Ma and Ml for the combined daytime and nighttime data, and increases in Ma resulted in lower B. We compared A. sexdens characteristics with published results for Atta cephalotes, a closely related species. A. sexdens is larger and therefore able to carry heavier loads, but its burden is about 72 of the average value for A. cephalotes. We suggest that the lower load capacity of A. sexdens in comparison to A. cephalotes is related to its relatively larger size.