Determinação do número de ínstares de insetos utilizando modelo de regressão segmentado

Abstract

Data from populations of Anticarsia gemmatalis Hübner larvae, and simulated data considering fixed and variable proportions of larvae head capsules sizes of successive instars, were fit into a segmented polynomial regression. The joint points corresponded to the change of instars and the larvae growing process was represented by a sequence of submodels. This allowed the accurate estimation of the mean size of larvae head capsule, and the confidence interval for each instar. KEY-WORDS: Insecta, head capsule, insect development.

Comparison of Biology betweenHelicoverpa zeaandHelicoverpa armigera(Lepidoptera: Noctuidae) Reared on Artificial Diets

“…The variables biomass, head capsule size, and body length were subjected to ANOVA and to polynomial regression at a probability level of 5% (P < 0.05) using the software SISVAR® (Ferreira 2003). The regression model was used because the linearized model rule (Dyar 1890) is not robust enough to explain the head capsule growth of H. zea, according to Ambrosano et al (1997).…”

Morphological characterization of immature stages of Habrobracon hebetor (Hymenoptera, Braconidae) ectoparasitoid of Ephestia kuehniella (Lepidoptera, Pyralidae)

“…The existence of four larval instars of H. hebetor was found by adjusting the total length and width of the cephalic capsule measurements data by a segmented regression model (Ambrosano et al 1997) differing from the previous assessment by Magro et al (2006), who, based on the size of jaws, recorded the existence of only three larval instars for this parasitoid using the same host. This was also opposite to the result observed by Sudheendrakumar et al (1982), in which the authors reported the occurrence of five larval instars according to length of mandible and diameter of prothoracic spiracle.…”

“…For the determination of the number of larval instars, a segmented regression model was used according to Ambrosano et al (1997), with an r 2 = 99%. Twenty individuals at each stage (egg, larva, prepupa and pupa) were evaluated.…”

Trail‐following behaviour and biological aspects of the gregarious caterpillar Brassolis sophorae (Lepidoptera: Nymphalidae)

“…Thus, the number of larval instars corresponds to the number of peaks in homogenous groups in a multimodal distribution of head capsule width, during post‐embryonic development (Parra & Haddad ; Calvo & Molina ). Confirmation of the number of instars can be established using linear regression models (Parra & Haddad ; Ambrosano et al ). The present study was undertaken to determine the nature of trail following and describe development parameters of the larval stage based on cephalic capsule measurements.…”