Luciana Iannuzzi

Attractivity of omnivore, carnivore and herbivore mammalian dung to Scarabaeinae (Coleoptera, Scarabaeidae) in a tropical Atlantic rainforest remnant

In this study, performed in a remnant of Brazilian Atlantic Forest, three types of dung from animals with distinct alimentary habits were utilized, in order to verify possible differences of attractivity of these dungs to the Scarabaeinae and the influence of seasonality in the attractivity. Three habitats were sampled: edge, clearing and forest core, each with 40 pitfall traps. A total of 2,137 beetles were collected from August 2005 to July 2006. Canthidium sp. 1 (43%) and Dichotomius sericeus (41%) were the most abundant species. From the total number of beetles collected, 80.5% were attracted to human dung, 11% to jaguar dung, 7.8% to waterbuck dung and 0.7% to the control. The species Canthidium sp.1, Canthidium sp. 2, Ateuchus sp., Canthon nigripenne, Canthonella sp. and D. sericeus came to all three bait types. Eight species were found in the baits with human dung, where Canthidium sp.1 (49%) and D. sericeus (39%) were the most common. A significant difference in attractiveness of the different baits was observed; the highest abundance found in traps baited with human dung (F = 36.59; g.l. = 3; p < 0.0001). A significant difference in richness was observed between rainy and dry seasons (F = 12.29; g.l. = 1; p < 0.001), the highest richness found in the dry season.

How Habitat Change and Rainfall Affect Dung Beetle Diversity in Caatinga, a Brazilian Semi-Arid Ecosystem

Abstract The aim of the present study was to evaluate how dung beetle communities respond to both environment and rainfall in the Caatinga, a semi-arid ecosystem in northeastern Brazil. The communities were sampled monthly from May 2006 to April 2007 using pitfall traps baited with human feces in two environments denominated “land use area” and “undisturbed area.” Abundance and species richness were compared between the two environments and two seasons (dry and wet season) using a generalized linear model with a Poisson error distribution. Diversity was compared between the two environments (land use area and undisturbed area) and seasons (dry and wet) using the Two-Way ANOVA test. Non-metric multidimensional scaling was performed on the resemblance matrix of Bray-Curtis distances (with 1000 random restarts) to determine whether disturbance affected the abundance and species composition of the dung beetle communities. Spearmans correlation coefficient was used to determine whether rainfall was correlated with abundance and species richness. A total of 1097 specimens belonging to 13 species were collected. The most abundant and frequent species was Dichotomius geminatus Arrow (Coleoptera: Scarabaeidae). The environment exerted an influence over abundance. Abundance and diversity were affected by season, with an increase in abundance at the beginning of the wet season. The correlation coefficient values were high and significant for abundance and species richness, which were both correlated to rainfall. In conclusion, the restriction of species to some environments demonstrates the need to preserve these areas in order to avoid possible local extinction. Therefore, in extremely seasonable environments, such as the Caatinga, seasonal variation strongly affects dung beetle communities.

Distribution pattern of herbivorous insects in a remnant of Brazilian Atlantic Forest

In this study we selected three habitats that correspond to a light gradient, and consequently a proportion of pioneer plant species gradient edges, trails and forest core and described their herbivorous insect assemblage. We tested five hypothesis about the herbivorous assemblage: (1) there is a different distribution of abundance and richness of order between habitats, (2) species similarity between habitats is smaller than within habitat, (3) in forest edge the herbivores are more abundant than in trails and interior of the forest, (4) in nuclear areas herbivore richness and diversity are higher than in the trails and edge, and (5) the abundance and richness of herbivores are different between seasons. Herbivorous were sampled during November 2000 - May 2001 by scanning the plants in ten 1,000-m 3 transects per habitat, five per season. We sampled 1,424 adult individuals from 367 species of six orders. Orthoptera and Coleoptera were the most abundant herbivores in the edge and interior, respectively. Coleoptera showed the highest species diversity in the forest edge, while Lepidoptera was in the interior. The similarity of the fauna between habitats was smaller than within habitats. The values of abundance, richness and diversity in the edge were higher than those of trails and interior for both seasons. We suggest that the low richness of herbivores in the interior of the forest is due to a reduction of specialist groups associated to plant species characteristic of mature forest, which are locally extinct in the study area.

Resposta da comunidade de formigas aos atributos dos fragmentos e da vegetação em uma paisagem da Floresta Atlântica nordestina

The objective of this study was to determine the effects of forest fragmentation on ant richness in a landscape of Atlantic Forest in Northeast Brazil. More specifically, the ant richness was related to the attributes of fragments (area and distance from the fragment central point to the edge), landscape (forest cover surrounding the fragments), and tree community (plant density, richness, and percentage of shade tolerant species). The surveys were carried out in 19 fragments located in Alagoas State from October 2007 to March 2008. Samples were collected through a 300 m transect established in the center of each fragment, where 30 1-m2 leaf litter samples were collected at 10 m intervals. A total of 146 ant species was collected, which belonged to 42 genera, 24 tribes and nine subfamilies. The attributes of fragments and landscape did not influence ant richness. On the other hand, tree density explained ca. 23% of ant richness. In relation to functional groups, both density and richness of trees explained the richness of general myrmicines (the whole model explained ca. 42% of the variation in this group) and percentage of shade tolerant trees explained the richness of specialist predator ants (30% for the whole model). These results indicate that ant fauna is more influenced by vegetation integrity than by fragment size, distance to edge or forest cover surrounding fragments.

Seasonality of Fruit-Feeding Butterflies (Lepidoptera, Nymphalidae) in a Brazilian Semiarid Area

A survey of 6,000 trap/hours using fruit-bait traps was conducted, in order to characterize the community of fruit-feeding butterflies and their seasonal variation in a semiarid area of NE Brazil, which exhibits a highly seasonal rainfall regime. The community was composed of 15 species, the four most abundant comprising more than 80% of the total individuals. In the first sampling month, 80% of the species had already been recorded. A strong positive correlation was found between butterfly abundance and precipitation of the sampled year. The highly seasonal pattern of the studied community may be related to the availability of both larvae and adult food resources. The endemic Fountainea halice moretta presented the highest positive correlations with other butterfly species and with total butterfly abundance and illustrates well the seasonal variation of the whole community. Hamadryas februa was the only species trapped in all sampling months, probably due to the ability of adults to aestivate during the dryer months. The open and more disturbed sample area showed higher abundance of butterflies in the rainy season and lower abundance in the dry season. Both abundance and richness were affected by season in a manner that the rainy period had significantly more individuals and species.

What is the importance of open habitat in a predominantly closed forest area to the dung beetle (Coleoptera, Scarabaeinae) assemblage?

What is the importance of open habitat in a predominantly closed forest to the dung beetle assemblage? The Atlantic Forest in Brazil is one of the most highly disturbed ecosystems and is mainly represented by fragmented areas. However, in places where human disturbances have ceased, certain areas are showing a natural regeneration pattern. The aim of the present study was to determine how the dung beetle assemblage responds to distinct habitat structures in a fragment of Atlantic Forest. For such, open and closed forest areas were sampled in a fragment of the Atlantic Forest in the northeastern region of Brazil. Pitfall traps baited with excrement and carrion were used to collect the beetles. A total of 7,267 individuals belonging to 35 species were captured. Canthon chalybaeus and C. mutabilis were restricted to open areas. Nearly 90% of the individuals of C. aff. simulans and Deltochilum aff. irroratum were identified in these areas. A higher percentage (> 50%) of Canthon staigi, Dichotomius aff. depressicolis and D. aff. sericeus occurred in closed areas. Abundance differed between areas, with higher values in closed areas. Richness was not influenced by the habitat structure. NMDS ordination exhibited the segregation of areas and ANOSIM confirmed that this variable explained the assemblage of dung beetle species. The findings of the present study validate that open areas are associated to more restrictive conditions, limiting a higher abundance of dung beetle. Although situated near preserved fragments, the studied open areas increase the heterogeneity of the general landscape.

The life of Cyclocephala celata Dechambre, 1980 (Coleoptera: Scarabaeidae: Dynastinae) in captivity with descriptions of the immature stages

We collected 76 specimens of the Cyclocephala celata Dechambre in Igarassu, Pernambuco, Brazil, in March 2008 for captive breeding and rearing to document its life cycle and to describe the immatures. A total of 98 eggs was obtained from captive-reared insects, each individually enclosed in an egg chamber assembled with the surrounding substrate. Viability was highest in the egg phase (92.8%). Pupae were enclosed in pupal cells. The duration of the life cycle was 164 days (n = 2), and only 2% of the eggs developed into adults. Third instar characters documented for the first time in the genus are: epitorma on the epipharynx, three dorsolongitudinal striae on the right mandible and one fringe of setae on the hypopharynx. Our data support the possibility of captive rearing and breeding of C. celata, contributing to the formulation of accurate management and conservation plans for native pollinators.

Tityus stigmurus (Thorell, 1876) (Scorpiones; Buthidae): response to chemical control and understanding of scorpionism among the population

In this study, the events following application of the insecticide Demand 2.5 concentrated solution (CS) in the field, to control Tityus stigmurus, were investigated. Data on attitudes and practices relating to scorpionism were collected using a questionnaire. During the months of May to July 2005, 69 premises were monitored on different days following insecticide treatment, focusing on scorpion frequency and mortality. According to the results, 42% of the premises showed scorpion incidence, with an average of three specimens per house. The highest incidence was recorded during the first week following the treatment. Only 7% of the specimens were found dead. Most (72%) of the population showed knowledge about prevention and control measures. Despite this, 100% of the premises presented breeding sites, mainly in debris (79.7%). These results indicate that the scorpion control method used by health agents during this investigation was not efficient, and the results suggest that the method may have had a dispersive effect on these animals.

New Biological and Immature Morphological Records of the Masked Chafer, Cyclocephala paraguayensis

Abstract In order to obtain information on the biology of the masked chafer, Cyclocephala paraguayensis Arrow (Scarabaeidae: Dynastinae: Cyclocephalini), and its immature morphology, the beetle life cycle was studied under laboratory conditions. After field collection, adults were placed inside containers filled with soil obtained in the original capture to provide an oviposition site after mating ocurred. Eggs were collected daily and isolated for manipulation experiments and life cycle observations. Detailed information about the eggs, instars and life cycle duration, and morphological features of immature stages were noted and examined. Egg viability was higher in the “nonmanipulated” batch. The complete ontogenic cycle of C. paraguayensis was 171 ± 11 days (n = 7). Despite the records of Cyclocephala being crop pests, reared larvae of C. paraguayensis thrived and developed into well-formed, fertile adults on an entirely saprophagous diet, indicating that they are not rhizophagous in the wild. The third instar can be distinguished from the other species mainly by the following unique characters: maximum width of the head capsule, distal antennal setae, and bifurcated setae on the raster.

Description of Cyclocephala distincta Burmeister (Coleoptera: Scarabaeidae: Dynastinae: Cyclocephalini) immatures and identification key for third instars of some Cyclocephala species

The larval instars and pupa of Cyclocephala distincta Burmeister (Coleoptera: Scarabaeidae: Dynastinae: Cyclocephalini) are described and compared to those of other known congenerics. Adult C. distincta, specialized flower visitors of Neotropical palms (Arecaceae), were collected in an area of native Atlantic Forest cover in the northeastern coast of Brazil and reared in captivity. The larvae of C. distincta diff---er from those of the other congenerics because of a distinctive pattern and arrangement of the setae on the raster.