Marta Luciane Fischer

Microhabitats Occupied by Loxosceles intermedia and Loxosceles laeta (Araneae: Sicariidae) in Curitiba, Paraná, Brazil

Abstract A survey was done of the environments and substrata occupied by Loxosceles intermedia Mello-Leitão, 1934 and Loxosceles laeta (Nicolet, 1849) (Araneae: Sicariidae) in urban woods and anthropic constructions in Curitiba. In total, 2,099 trees, 364 decaying logs as well as stones and roots, built-up areas, and wasteland in six urban parks and 60 residences were inspected. In total, 1,775 m2 of vegetation was inspected, but spiders and their vestiges were collected only in and around buildings in urban parks and residences. L. intermedia was more common than L. laeta and occurred both indoors and outdoors, whereas L. laeta was more common indoors in wooden houses. The two species did not occur in the same microhabitats, although both preferred paper, wood, and construction materials. Spiders collected in urban parks were heavier than those collected in residences, although only males collected in urban parks were larger than those from residences. The lack of vestiges indicative of a previous occupation in the urban parks suggested that both species occupied primarily the anthropic environment where they found numerous substrata that offered thermal isolation and suitable conditions for web fixation, ecdysis, and reproduction.

THE PREY AND PREDATORS OF LOXOSCELES INTERMEDIA MELLO-LEITÃO 1934 (ARANEAE, SICARIIDAE)

Abstract We examined the prey caught in L. intermedia webs in one fragment of forest and in the garage of an urban house in Curitiba, Brazil. A total of 693 prey items was recorded in 131 webs. The prey richness was greater in the forest. The results show that L. intermedia is a dietary generalist. We found remains of L. intermedia in the feces of a frog and a bat in the forest.

Avaliação dos problemas enfrentados no manejo do caramujo gigante africano Achatina fulica (Gastropoda: Pulmonata) no Brasil

Evaluation of the problems faced in the management of the giant African snail Achatina fulica (Gas- tropoda: Pulmonata) in Brazil. The giant African snail Achatina fulica Bowdich, 1822 was introduced into Parana, Brazil, in the 1980s. Since then, it has spread across the country, despite its known invasive status on a global scale. The main objective of this study was to assess the problems faced in the management of the giant African snail. To accomplish that, we gathered and analyzed information available on the internet, scientific databases, field studies, as well as interviews and consultations with official agencies, NGOs, museums, the scientific community and people that coexist with the species. Despite the fact that extensive information has been generated regarding A. fulica (1,340 articles, 65 summaries in national annals, 40,700 pages on the internet), essential to promote control measures to hinder the propagation of this species, the majority of the available information remains inaccessible to the world at large. Moreover, the environmental, economic and health impacts of this species remain unclear, which may contribute to discouraging the initiation of management actions. Finally, control measures are still inefficient due to the generalist profile of this species and the lack of knowledge concerning its biology and ecology. Thus, in conclusion, even though A. fulica has been an invasive species for over a century in many other countries, it is difficult to find evidence supporting the need to subsidize its management. This may be an indication that many other, poorly known exotic species will have time and the proper conditions to become established and cause problems before they come to be recognized as invasive.

Distribuição das espécies do gênero Loxosceles Heinecken & Lowe, 1835 (Araneae; Sicariidae) no Estado do Paraná

The State of Paraná registers on average 2,577 loxoscelic accidents annually. For the elaboration of control and management programs one should first determine the distribution of the species of the genus Loxosceles. A mapping was performed of Loxosceles references in various scientific collections. A total of 1,561 spiders were found, identified as Loxosceles intermedia (67%), Loxosceles gaucho (19.5%), Loxosceles laeta (10.8%) and Loxosceles hirsuta (2.4%), originating from 20 regional and 69 municipal health districts. Loxosceles intermedia was present in all areas of the state (50 municipal districts), while Loxosceles gaucho occurred in the north and northwest, (17 municipal districts), Loxosceles laeta in the south (13 municipal districts) and Loxosceles hirsuta in the west and central areas (10 municipal districts). Paraná has four of the eight species of Loxosceles registered in Brazil. Given the medical importance of accidents caused by these spiders, it is necessary to perform studies on the location of such incidents and investigate areas that have not yet been sampled.

DEVELOPMENT AND LIFE TABLES OF LOXOSCELES INTERMEDIA MELLO-LEITAO 1934 (ARANEAE, SICARIIDAE)

Abstract Loxosceles intermedia is a medically important species that is abundant in Curitiba, Paraná State, Brazil. Knowledge of the postembryonic development of this species is fundamental for preventing bites by this species and for controlling its population size. In this report, postembryonic development (n = 212 spiderlings) was studied in the laboratory under ambient conditions of temperature and humidity with a standardized diet. The average duration of development (from emergence from the egg sac to maturity) was 356 ± 33 days (n = 189; range = 213–455). Spiders matured after 5th–8th molt, although most individuals matured after 7th molt. The sex ratio was 1:1. The mortality in the laboratory was low, most pronounced in the 4th and 5th instars and was associated mainly with molting. The longevity of females (1176 ± 478 days) was significantly longer than it was for males (557 ± 88.6 days). The abundance of L. intermedia in Curitiba, city in the southern part of Brazil, is related to aspects of its life cycle, since a slow growth, low mortality, and greater longevity enhance the reproductive potential of the species.

Espécie invasora em reservas naturais: caracterização da população de Achatina fulica Bowdich, 1822 (Mollusca - Achatinidae) na Ilha Rasa, Guaraqueçaba, Paraná, Brasil

The African snail Achatina fulica is one of the 100 most harmfull invasive alien species, causing serious damages mainly in islands. We had as objective to characterize the population of A. fulica in Ilha Rasa, Guaraquecaba, Parana, Brazil. Seasonal and diurnal collections of A. fulica and associated fauna were driven in the border and interior forest, sandbank, swamp and urban area of Almeida and Ilha Rasa communities. We collected 959 snails, with an average of 66.4 animals for inspected place, being considered that there is around 9,000 snails in the island. However the frequency of the animals was conditioned the time of the year, size of the animal and community. The small and recent population of A. fulica associated to the anthropic environment demands an urgent and effective plan of eradication avoiding its establishment and the dispersion for the wild areas.

O caramujo exótico invasor na vegetação nativa em Morretes, PR: diagnóstico da população de Achatina fulica Bowdich, 1822 em um fragmento de Floresta Ombrófila Densa aluvial

Fischer, M.L.; Simiao,M.; Colley, E.; Zenni, R.D.; Silva, D.A.T. and Latoski, N. Alien invasive snail on native forest in Morretes, PR: diagnostic of the Achatina fulica Bowdich, 1822 population in an remnant of alluvial Ombrophylous

PARAMETERS AFFECTING FECUNDITY OF LOXOSCELES INTERMEDIA MELLO-LEITAO 1934 (ARANEAE, SICARIIDAE)

Abstract In this study, the process of egg sac construction and the factors that determine fecundity in the spider Loxosceles intermedia were analyzed by comparing lab-reared females that had mated only once (n = 180 ovipositions) and females with unknown reproductive histories (n = 76 ovipositions). Among females known to have mated only once (n = 84), the number of viable eggs correlated positively with the duration of mating and with the age of the female at the time of fertilization and decreased significantly with successive ovipositions. In females with unknown (n = 36) reproductive histories, up to three fertile egg sacs were obtained from the same female with a third oviposition being observed only once. Oviposition was more frequent among larger females than smaller females. Among the reproductive variables evaluated, there were correlations between the number of eggs and the weight of the female spiders. More fertile eggs were laid by females with unknown reproductive histories than by females that mated only once. The existence of more stable environmental conditions, abundant food, and multiple fertilizations are probable factors which favor greater fertility of L. intermedia in urban Curitiba, located in southern Brazil, and can partly explain the success of this species in occupying this ecological niche.

Reações da espécie invasora Achatina fulica (Mollusca: Achatinidae) à fatores abióticos: perspectivas para o manejo

Achatina fulica Bowdich, 1822 is an african snail that is invasive in different parts of the world, being characterized mainly by its high adaptability. Our objective was to evaluate the influence of abiotic factors, such as temperature and substrate, on the egg eclosion, adult and juvenile reaction to different abiotics factors, and the resistance of A. fulica to popular methods of control. Three studies were made, including 19 laboratory experiments and observations of free animals in the municipal district of Guaraquecaba, southern Brazil. Eggs were characterized as the most fragile phase, whereas the juveniles and adults were resistant to the immersion in fresh and salt water and little resistant to temperature variation and salt, using burying, aestivation, and muscular force as defense strategies. Those strategies should be considered in management actions and in orientating popular methods of control.

Descrição do comportamento agonístico de Loxosceles laeta, L. hirsuta e L. intermedia (Araneae: Sicariidae)

The evolutionary groups of species of Loxosceles Heinecken & Lowe, 1835, besides having morphological characters in common, may also show similar behaviors. The present study describes the agonistic behavior of males of members of the spadicea group - Loxosceles intermedia Mello-Leitao, 1934 and L hirsuta Mello-Leitao, 1931 - and the laeta-group - L. laeta (Nicolet, 1849) - that occur in the state of Parana. In experiments with paired males, an intruder male was placed in the web of a resident male web, and the motor patterns displayed were described and quantified. Males of all three species showed confrontation, defense and combat behaviors. The combat was ritualized and related to peculiarities of each species, while sharing the signaling of strength and size. The motor patterns shown during agonistic behavior were similar to those used in sexual behavior. The motor patterns of L. intermedia and L. hirsuta were more similar to each other and different from L. laeta, suggesting a relationship to the evolutionary group radiation.