Interação mutualística entre Aethalion reticulatum (Hemiptera: Aethalionidae), abelhas-sem-ferrão e formiga, em açaizeiro no estado do Acre.

Foi verificada a associação entre a cigarrinha-das-frutíferas, Aetalion reticulatum (Hemiptera: Aethalionidade) e duas espécies de abelhas-sem-ferrão do gênero Trigona, além de uma espécie de formiga do gênero Camponotus, em plantas de açaí-de-touceira, Euterpe oleracea (Arecaceae), em Rio Branco, AC. Foram realizadas vistorias em plantio de açaizeiro, localizado no Campo Experimental da Embrapa Acre (10°01'26''S; 67°41'39''W), onde foi constatada uma alta infestação de A. reticulatum em ráquilas açaizeiro, provenientes de uma população melhorada geneticamente da cultivar BRS-Pará. Em algumas plantas vistoriadas foi verificada a associação entre A. reticulatum e duas espécies de meliponíneos (Trigona spp.), as quais estimulavam as cigarrinhas a liberarem o exsudado (honeydew), por meio do caminhar sobre o corpo e batimento das antenas no abdômen dos hemípteros. O mesmo comportamento foi verificado para uma espécie de formiga-doceira (Camponotus sp.), a qual também recolhia o alimento açucarado, no momento em que era liberado pelas cigarrinhas. A suposição da existência do mutualismo se baseou na constatação do fornecimento de honeydew, produzido pelas cigarrinhas, às abelhas e/ou formiga, que, por sua vez, protegiam as cigarrinhas da aproximação de outros insetos e apresentavam comportamento agressivo pela aproximação de pessoas. No entanto, não foi verificada a presença de abelhas e formigas associadas às cigarrinhas simultaneamente, bem como não foi verificado a presença das duas espécies de Trigona, associadas à mesma colônia de cigarrinhas, nas plantas amostradas. Este registro configura no primeiro relato da associação de A. reticulatum com formiga e meliponíneos no estado do Acre, e em açaizeiro

Brachyuran crustaceans from the bycatch of prawn fisheries at the mouth of the Amazon river.

The present paper is a pioneering study on the Brachyura bycatch associated with the artisan prawn fisheries at the mouth of the Amazon River. The study was conducted at four collection sites distributed along the mouth of the Amazon River between the months of January/2009 and January/2010. The animals were caught using handcrafted traps called ?matapi?, which are used by prawn fisherman in the region. Twenty matapis were used at each collection site. A total of 145 specimens were captured and six species were identified, all belonging to the Trichodactylidae family - Sylviocarcinus maldonadoensis, S. pictus, S. devillei, Valdivia serrata, Dilocarcinus septemdentatus and D. pagei. The most representative species, S. maldonadoensis, S. pictus and S. devillei were classified as regular. Regarding the composition of the capture, there were three specimens of D. pagei , only one male specimen of D. septemdentatus, forty-eight specimens of S. maldonadoensis, sixty-eight specimens of S. pictus, twenty-two specimens of S. devillei and three specimens of V. serrata. In all months, the brachyuran fauna showed a considerably lower biomass when compared to the prawns, representing only 5% of the catch, in a ratio of 1:0.06. For most species, the number of males was always higher than the number of females in almost all collection months

Natural diet and feeding habits of a freshwater prawn (Macrobrachium carcinus: Crustacea, Decapoda) in the estuary of the Amazon River.

Macrobrachium carcinus is a Brazilian native prawn with recognized potential for use in aquaculture activities. However, there is little information about the natural diet and feeding habits of this species. The aim of this study was the identification of the diet items of M. carcinus based on the analysis of the stomach contents. Specimens were collected in the Amazon River estuary between January 2009 and January 2010. The stomach analysis was carried out by using the frequency of occurrence (FO), methods of points (MP) and feeding index (FI). It was observed that prawns fed on detritus, animals and plant fragments as the most important food items. Sediment accounted for the main stomach content, accounting for 43.2% by the MP, 44.9% by FI and 100% by the FO. Sexual differences in feeding preferences were not found in this study, and seasonal differences in the frequency of items ingested by M. carcinus were not observed. The results indicated that M. carcinus can be considered omnivorous species, but with an important carnivorous component, similar to that found in other Macrobrachium species

Relação peso-comprimento do camarão pitú, Macrobrachium carcinus (Crustacea, Decapoda, Palaemonidae) na foz do rio Amazonas.

Resumo simples

Reproductive aspects of Macrobrachium amazonicum (Decapoda: Palaemonidae) in the State of Amapá, Amazon River mouth.

Macrobrachium amazonicum is an indigenous prawn vastly distributed in basins of South America, widely exploited by artisanal fisheries in northern and northeastern Brazil and, with great potential for aquaculture. This study aimed to investigate general aspects of population structure and reproductive characteristics (size at first maturity, fecundity and reproductive output) of M. amazonicum from two important areas to artisanal prawn fishing located at the mouth of the Amazon River, State of Amapá. The specimens were captured using 20 handcrafted traps called ?matapi?. A number of 5,179 prawns were captured, 2,975 females and 2,195 males resulting in 1.35:1 female to male ratio. Santana Island and Mazagão Velho showed females predominated in the population. A reproductive peak period was observed from January to April/2009 and in December/2010, coinciding with the period of higher rainfall. The recruitment peak occurred in June and July/2009. Egg-bearing females ranged in size (carapace length) from 11.10 to 29.6 mm. Fecundity increased with female size and reached up to 7,417 eggs. This amount of eggs is considered low if compared with other Macrobrachium estuarine species. Mean egg volume increased gradually from 0.121 to 0.24 mm3 during embryogenesis, representing 68.5% of overall increase from Stage I to Stage III. Eggs of M. amazonicum are small; this is typical for Macrobrachium species, which depends on brackish water to complete the larval development. Irrespective of female size, reproductive output of M. amazonicum varied between 4.8 and 21.85% of their body weight into eggs production

Primeiro registro de tripes (Thysanoptera: Thripidae) em hortelã (Mentha sp.) no Acre.

O objetivo deste trabalho foi relatar o primeiro registro de duas espécies de tripes, causando danos em plantas de hortelã, em Rio Branco, AC.Publicado no formato de pôster dinâmico