Immature stages of Spodoptera albula (Walker) (Lepidoptera: Noctuidae): Developmental parameters and host plants

Abstract

This study aimed to detail the temporal and morphological parameters of the immature stages of Spodoptera albula (Walker 1857) under controlled conditions (25 ± 1°C, 70 ± 10% RH and 14 hour photophase) and to gather information about their larval host plants. For this purpose, a new rearing method and artificial diet was employed and validated. The viability of the egg, larval, pupal and pre-pupal stages was 94.54, 97.33, 93.84 and 92.34%, respectively. The average duration of the egg, larval, pupal and pre-pupal stages was 4.14, 16.37, 1.69, and 9.34 days, respectively. During the larval stage, 80.85% of females and 93.99% of males passed through six and remaining through seven instars, with significant larval protandry. The larvae that developed through six and seven instars exhibited a mean growth rate of 1.58 and 1.48, respectively. Fifty five host plant species belonging to 29 families are listed. The female pupae were significantly larger, exhibiting protogyny. Both the rearing methods as well as the larval diet proved adequate, providing more detailled observations of the biological cycle, especially the larval stage, and resulting in an overall survival of almost 80%.

Biotic potential, fertility and life table ofSpodoptera albula (Walker) (Lepidoptera: Noctuidae), under controlled conditions

“…However, these values were higher than those described by Martin Zequeira (1982) Comparison of male and female mean longevity using Student t test, considering different variances, at a 95% level of significance (* p < 0.05). Considering the Montezano et al (2013) data, which indicates a mean duration of the immature stages as 31.52 days, the average longevity of S. albula corresponds to 28.32%, or more than one quarter of their life cycle. These results are similar to other studies involving Spodoptera (i.e.…”

“…Information on the origin of insects, rearing methodology and data on immature stages are described in detail by Montezano et al (2013) and all procedures were carried out according to the international practices for animal use and care under the control of an internal committee of the Universidade de Caxias do Sul, Brazil.…”

“…Considering the previously described incompatibilities between biotypes of the fall armyworm, from different host plants or localities, during copulation (Murúa and Virla 2004, Sadek and Anderson 2007, Murúa et al 2008, the insects used in the experiment belong to the first generation obtained from a female collected in the field (see Montezano et al 2013). Adults were kept in pairs (n = 13) within cylindrical plastic containers, 10 cm in diameter and 15 cm high, with tops closed using plastic film, to which container long filter paper strips were attached, to stimulate oviposition.…”

“…After gathering the biological parameters, the Biotic Potential (BP) was calculated considering the resistance of the environment as being null, using the equation described in Silveira Neto et al (1976) The fertility life table was developed using data from the immature stages of S. albula provided by Montezano et al (2013) and is presented graphically by plotting the probability of survival values at the midpoint of each interval, or survival (lx), and the total number of eggs per female per week, which became females, or specific fertility (mx).…”

Lepidoptera (Insecta) associated with soybean in Argentina, Brazil, Chile and Uruguay

“…However, it is important to take in consideration the importance of the identification of the caterpillar due the different capacity for leaf consumption of different species (BEACH & TODD, 1988;NAVA & PARRA, 2002;FRANCO et al, 2014), their reproductive potential (MONTEZANO et al, 2013), and the spatial distribution of the different species in the host plant (PANSERA DE ARAÚJO et al, 1999).…”