Padronização de metodologia de criação de Spodoptera eridania (Stoll) e Spodeptera albula (Walker) visando detalhar parâmetros biológicos

Abstract

The genus Spodoptera, Guenée 1852, (Lepidoptera: Noctuidae) is represented by 30 species of great importance to encompass most of the insects that cause significant damage to several economically important crops cult ivated by man. However, there are few detailed studies of biology, especially related to reproductive aspects. This study aimed to develop and validate a methodology to detail the biological parameters of representatives of Lepidoptera, particularly S. eridania and S. albula to allow comparisons intra and interspecific under controlled condit ions (25 ± 1 º C, 70 ± 10% RH and 14h photophase) and gather informat ion about the host plants for their larvae. For both were employed and validated new methods of creation and artificial diet. In the immature stages was observed that the viability of the egg, larva, pupa and pre-pupae were 94.54, 97.33, 93.84 and 92.34% for S. albula, and 97.82, 93.62, 96.42 and 97.03% for S. eridania, respectively. The average duration of the stages of egg, larva, pupa and pre-pupa was 4.14, 16.37, 1.69, and 9.34 days for S. albula and 4.00, 16.18, 1.58, and 9.17 days for S. eridania. At the stage of larvae was observed that for both species passed through six instar, with significant larval protandry. 55 host plants were related for S. albula and 202 for S. eridania. The longevity of females was significant ly higher than in males for both species. The average periods of pre, post and oviposit ion were 2.615, 1.769 and 9.385 days, respectively for S. albula and 2.067, 0.600 and 8.133 for S. eridania. The average fecundity was 1.417,69 egss 1.340,401 larvae per female for S. albula and 1.398.00 and 1.367.50 to S. eridania. On average females mated 1.2 times. There was a strong posit ive correlation between the number of mat ings and fecundity, and a strong negat ive correlat ion between the number of copulations and duration of pre-oviposit ion and longevity. The biot ic potential of S. albula and S. eridania was estimated at 8,768 x 1022 and 1,894 x 1025 individuals / female / year respectively. The net reproductive rate (Ro), mean generat ion time and intrinsic rate o f increase (rm) for S. albula and S.eridania were respectively 353.904, 560.531 times per generation, 37.187, 35.807 days and 1.105, 0.177, with a finite rate of increase (λ) and 3.019 (λ) of 1.193. Both the methodology of creation as the larval diet were suitable, because they enabled high survival, fert ility and much more detail of the observat ions related to the biological cycle, especially the larval stage.