Oviposition and post-embryonic development of Aglaoctenus lagotis (Araneae: Lycosidae)

Abstract

ABSTRACT. The present study describes the life history of Aglaoctenus lagotis Holmberg, 1876 from oviposition to adulthood, analyzing the number of eggs in each egg sac, birth rate, number of instars, sex ratio, cephalothorax size of all instars, and developmental time in laboratory. The results indicate that the studied species can produce two egg sacs during the reproductive period, and that the post-embryonic phase includes 12 nymphal instars. A higher mortality rate was observed during the first three instars, featuring a Type III survival curve. The sex ratio was geared towards the female in the adults and no significant difference was observed in the length of the cephalothorax between male and female. This species can therefore be considered monomorphic. Sexual dimorphism was observed in the cuticle color, with males being light brown whereas females are dark brown.KEY WORD. Birth rate; number of instars; sexual dimorphism.

The effects of forest fragmentation on the population ecology and natural history of a funnel-web spider

“…According to Lubin (1978), orb-weaving spiders are more susceptible to desiccation and require greater amounts of energy to rebuild their webs daily, while more permanent webs enable spiders to persist during periods when food is scarce. Our results show that the abundance of A.lagotis declines from October onward, indicating high mortality during development in the natural environment and corroborating the laboratory-based observations of Moreira and Del-Claro (2011). Various factors that do not exist in artificial environments (such as the laboratory) may influence spider mortality in natural environments, including temperature variations, disease, food scarcity, the availability of web-building sites, competitive interactions, predation, and parasitism.…”

“…The life history of A.lagotis is marked by seasonal events (Moreira and Del-Claro 2011), and some components of its life cycle occur within a well-defined period. For example, the number of individuals was largest and the cephalothorax length was smallest during October in both areas and in all quadrats.…”

“…Genetic data can illustrate spatial population differentiation (Ramirez and Haakonsen 1999;Kronforst and Fleming 2001) or demonstrate that habitat fragmentation has reduced gene flow (Knutsen et al 2000). Members of Lycosidae generally have one or two generations per year (Schaeffer 1987); A.lagotis has only one (Moreira and Del-Claro 2011). Hence, several generations have already passed between the studied fragments since their isolation.…”

Cryptic diversity of Aglaoctenus lagotis (Araneae, Lycosidae) in the Brazilian Atlantic Rainforest: evidence from microsatellite and mitochondrial DNA sequence data

“…One of its habitats, the Brazilian Atlantic Forest (BAF), is a highly fragmented and threatened domain [13], considered to be a conservation hotspot [14]. Human-caused forest loss and fragmentation have been changing landscape configuration of BAF, with important consequences on the community structure and population dynamics [15,16,17,18,19] including significant effects for the spider taxa [20] Despite being an abundant and singular species, Aglacotenus lagotis has been poorly studied [21], furthermore is still lacking information that could reveal more about population dynamics in this species, including familiar aggregation and connection between forest patches. Thus, this study proposes to investigate the genetic distribution of Aglaoctenus lagotis populations in forest fragments in the BAF of southeastern Brazil using microsatellite and mtDNA markers.…”

História natural de Ischnothele Annulata (Araneae, Dipluridae), em Cerrado sensu stricto: reprodução, alimentação, fenologia e densidade populacional

“…Os conhecimentos adquiridos com estudos de história natural suprem informações para serem usadas em sínteses de teorias ecológicas e modelos a testes e experimentos e a análises de mecanismos biológicos (Bartholomew, 1986). Com essas informações, podemos chegar a um entendimento mais real sobre a biodiversidade e seu estado de conservação (Moreira & Del-Claro, 2011).…”