Fábio Souto Almeida

Caracterização da Cobertura Florestal de Unidades de Conservação da Mata Atlântica

This work aimed to characterize the forest cover of protected areas in the municipality of Tres Rios, Rio de Janeiro state, Brazil. Five Environmental Protection Areas (EPA) were studied: Bemposta, Lago do Caca e Pesca, Santa-Fe and Vale do Morro da Torre EPAs; Encontro dos Tres Rios Natural Monument; and Tres Rios Municipal Natural Park. The database of Landsat 5-TM satellite, processed with software Erdas Imagine 9.2 and ArcGIS 10.0, were used for the location of forest fragments. We found 527 forest fragments, covering a total area of 7075.77 ha (26.88% of the protected areas). Bemposta Environmental Protection Area presents the highest percentage of forested area (31.21%). Tres Rios Municipal Natural Park presents no forest fragments with at least 0.5 ha. The protected areas show a large number of relatively small forest fragments with irregular shapes and greatly isolated, which contributes to loss of biodiversity.

Efeito da estrutura de habitat sobre a abundância de parasitóides Pseudacteon Coquillett (Diptera, Phoridae) em ninhos de Solenopsis invicta Buren (Hymenoptera, Formicidae)

The influence of habitat characteristics on the abundance of the parasitoids Pseudacteon Coquillett (Diptera, Phoridae) of Solenopsis invicta Buren (Hymenoptera, Formicidae) was studied in organic polyculture agroecosystem in southeastern of Brazil. Parasitoids were collected during 30 minutes after fire ant colonies perturbation in plots with annual or perennial crops. A total of 228 parasitoids belonging to four species were obtained in 61.90% of the 84 fire ant colonies disturbed. Pseudacteon obtusus Borgmeier was the most abundant species (70 females), followed by Pseudacteon litoralis Borgmeier (37 females), Pseudacteon tricuspis Borgmeier (23 females) and Pseudacteon solenopsidis Schmitz (1 female). Pseudacteon litoralis was more frequent on fire ant mounds in plots with perennial crops than annual crops whereas P. obtusus and P. tricuspis had an opposed pattern. Negative significant correlation was found between air temperature and P. litoralis and P. obtusus abundances. Fire ant mound size and parasitoid abundance were positively correlated. Considering that phorids are important natural enemies of S. invicta, this study provides information for the management of fire ants in tropical polyculture agroecosystem.

Efeitos da temperatura e do alimento no desenvolvimento de Dysdercus maurus Distant (Hemiptera, Pyrrhocoridae)

Dysdercus maurus Distant, 1901 (Hemiptera, Pyrrhocoridae) is an important pest on Gossypium spp. (cotton tree), Citrus sinensis Osbeck (Rutaceae) and Citrus reticulata Blanco (Rutaceae) crops. This insect also feeds on seeds of Chorisia speciosa St. Hil. (Bombacaceae). This work aimed to evaluate the effects of temperature and food on the development of D. maurus. Eight treatments were carried out, in six of them bugs were fed with seeds of C. speciosa and kept at 15, 18, 20, 25 and 30 ± 1oC, 80 ± 3% RH and 12h photophase or in laboratory conditions (23.5 ± 2.6oC, 73.3 ± 9.9 % RH), and in the other two treatments bugs were fed with seeds of cotton variety IAC-22 and kept at 25 or 30oC. In all treatments five immature stages were observed. The increase of temperature caused reduction in the developmental time. The temperature of 15oC disabled nymphal eclosion and was also lethal to those nymphs ecloded at other temperatures. The lower mortality of nymphs occurred in the temperature of 25oC with cotton as food (24.07%). The lower threshold temperature (Tb) occurred for the 1st instar (11.54oC) and the higher for the 2nd instar (15.33oC). The females of D. maurus required more degree-days (329.93 degree-days) than males (300.49 degree-days) until adult emergence.

Caracterização da Cobertura Florestal de Unidades de Conservação da Mata Atlântica / Characterization of Forest Cover of Protected Areas of the Atlantic Forest

This work aimed to characterize the forest cover of protected areas in the municipality of Tres Rios, Rio de Janeiro state, Brazil. Five Environmental Protection Areas (EPA) were studied: Bemposta, Lago do Caca e Pesca, Santa-Fe and Vale do Morro da Torre EPAs; Encontro dos Tres Rios Natural Monument; and Tres Rios Municipal Natural Park. The database of Landsat 5-TM satellite, processed with software Erdas Imagine 9.2 and ArcGIS 10.0, were used for the location of forest fragments. We found 527 forest fragments, covering a total area of 7075.77 ha (26.88% of the protected areas). Bemposta Environmental Protection Area presents the highest percentage of forested area (31.21%). Tres Rios Municipal Natural Park presents no forest fragments with at least 0.5 ha. The protected areas show a large number of relatively small forest fragments with irregular shapes and greatly isolated, which contributes to loss of biodiversity.

Resposta da assembleia de formigas na interface solo-serapilheira a um gradiente de alteração ambiental

O estudo objetivou avaliar a resposta da assembleia de formigas que nidificam na interface solo-serapilheira a um gradiente de alteracao ambiental. O estudo foi realizado em tres ambientes com diferentes usos do solo: fragmento florestal, sistema agroflorestal (SAF) e pastagem situados em regiao de dominio da mata atlântica no sudeste do Brasil. Em cada ambiente foram demarcadas 10 parcelas de 1 m2 e todos os ninhos de formigas encontrados foram registrados. Foram encontrados 215 ninhos (103 no fragmento florestal, 64 no sistema agroflorestal e 48 na pastagem), de 31 especies. O numero acumulado de especies foi maior no fragmento florestal que na pastagem, mas nao diferiu do SAF. A composicao de especies foi diferente entre o fragmento florestal e os outros dois ambientes. A riqueza media de especies de formigas por parcela foi maior no fragmento florestal e menor na pastagem. A quantidade de serapilheira nao foi um fator importante para as diferencas na riqueza de especies. Atividades humanas que reduzam a heterogeneidade da vegetacao alteram a composicao e diminuem a riqueza de especies das assembleias de formigas.