Eustala perfida, Mello-Leitao, 1947

Messas, Yuri Fanchini, Souza, Herbert Silva, Gonzaga, Marcelo O. & Vasconcellos-Neto, Joao, 2017, Population dynamics of the bark-dwelling spider Eustala perfida Mello-Leitão, 1947 (Araneidae), Journal of Natural History 51 (45 - 46), pp. 2661-2679 : 2665-2666

Phenology of E. perfida

Although we did not record copulas, we found males and females on the same web, probably engaged in reproductive behaviour, in September 2011, August/ September 2012, and July/ August 2013. Some of these couples had the same coloration (green male and female) and others had different coloration (green male, brown female, Figure 4 (a–c)). In total, we found five egg sacs ( Figure 4 (d)), including one in October and two in December 2012 and one each in January and September 2013. We collected one adult female, which later produced an egg sac in the laboratory ( Figure 4 (e)), but the eggs did not hatch.

The developmental stages presented significant and successive peaks of abundance throughout the year ( Figure 5 ). Peaks of different age classes occurred in January (spiderlings and young spiders), February (juveniles), April (subadults), and June (adults) ( Figure 6 , Table 3). Female spiders reached the adult stage earlier than males, with peaks of abundance for subadult females in March, followed by a peak for subadult males in May, adult females in June, and adult males in July ( Figure 7 , Table 4).

Figures

Figure 4. (a) Adult male (green) and adult female (brown) of Eustala perfida on the same orb web parallel to a tree bark. Close-ups of the (b) adult male and (c) adult female. Green adult females of E. perfida and the spider’s egg sac (d) in natural conditions and (e) in laboratory. Scale bars: 5 mm. Photography: Yuri Fanchini Messas.

Figure 5. Phenogram representing the age structure of the Eustala perfida population.

Figure 6. Circular histograms of age structure established for the population of Eustala perfida. The black vector line inside the circle indicates the mean angle or direction of the data. The transverse line on the external sector of the circle indicates the confidence interval of 95%.

Figure 7. Circular frequency histograms of adult females and adult males of Eustala perfida. The black vector line inside the circle indicates the mean angle or direction of the data. The transverse line on the external sector of the circle indicates the confidence interval of 95%.