Morphometric study of the midgut epithelium in larvae of Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae)

Abstract

PALAVRAS-CHAVE: Morfometria, célula epitelial, inseto, broca da cana, mesêntero ABSTRACT -The sugarcane borer, Diatraea saccharalis Fabricius, has great economical interest as it affects the culture and industrial use of the sugarcane. However, there are few studies concerning the internal morphology of this insect. This work aims to study morphometrically the midgut and the epithelium along their lenght, trying to characterize different regions. Midgut of last instar larvae was divided in three regions: anterior, middle and posterior, and the fragments were processed for light microscopic observation. Histological sections were analyzed in a computerized system concerning the length, width and area of the epithelium, their cells, and the midgut lumen. The obtained data were statistically analyzed by the Kruskal-Wallis test and by multivariate analysis. Our results showed that the midgut has two different regions, the anterior and the posterior; the middle region presents values that are coincident with the ones of either the anterior and the posterior portions, suggesting that there is an intermediate region between the other two ones. The epithelial cells (columnar, goblet and regenerative cells), when evaluated by multivariate analysis, do not present significant morphometric differences in the different midgut regions. However, the analysis of variance for separate variables show that the regenerative cells present wide morphometric variability along the midgut.

Ultrastructure of two Types of Endocrine Cells in the Midgut Epithelium of Spodoptera Exiqua Hűbner, 1808 (Insecta, Lepidoptera, Noctuidae)

“…Lepidopteran midgut is composed of four types of cells: columnar, goblet, endocrine and regenerative (ANDRIÉS and TRAMU, 1985;LEHANE and BILLINGSLEY, 1996;PINHEIRO et al, 2003;LEVY et al, 2004). Endocrine cells have been observed between epithelial cells in the midgut epithelium of the majority of insects, but they have been described mainly for Lepidoptera, Ephemeroptera, Trichoptera and Plecoptera (MONTUENGA et al, 1989;NISHIITSUTSUJI-UWO and ENDO, 1981;ROST-ROSZKOWSKA, 2008).…”

Morfologia do canal alimentar de lagartas de Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) alimentadas com folhas tratadas com nim

“…A disposição da musculatura por todo o canal também seguiu padrão uniforme (Chapman 1998). Segundo Cavalcante & Cruz-Landim (1999) e Pinheiro et al (2003), no epitélio do mesêntero dos insetos há predominância de quatro tipos de células: colunares, caliciformes, regenerativas e células endócrinas. Essas células predominaram ao longo do epitélio do mesêntero das lagartas de S. frugiperda, as quais são consideradas responsáveis pela absorção do alimento digerido, mostrando aspectos morfológicos similares a outros lepidópteros (Cavalcante & Cruz-Landim 1999, Levy et al 2004a.…”

“…As células regenerativas são indiferenciadas e responsáveis pela renovação do epitélio do intestino médio, substituindo as células que se desgastam e se perdem durante o processo de digestão, além de possibilitar o crescimento do canal alimentar a cada ecdise. São encontradas na base do intestino médio, isoladamente ou em grupos formando ninhos, não havendo diferenças em sua abundância ao longo do mesêntero (Pinheiro et al 2003, Wanderley-Teixeira et al 2006, Martins et al 2006.…”

“…Com o objetivo de verifi car a interferência do nim na renovação do epitélio do mesêntero, foi realizada a quantificação das células regenerativas baseando-se em Pinheiro et al (2003). Foram utilizadas cinco secções de cortes obtidas da região mediana do mesêntero de cinco lagartas.…”

Toxicology of the Bioinsecticides Used in Agricultural Food Production

“…The regenerative cells are undifferentiated and are responsible for the renovation of the midgut epithelium, substituting the cells that wear out and are lost during the digestive process -they also make it possible for the alimentary channel to grow larger at each ecdysis. They are found at the base of the midgut, alone or in groups, and there are no differences in their abundance along the midgut (16,17,18). Changes in the alimentary canal, especially in the region of the midgut, can affect the growth and development of insects, as well as all the physiological events, because these processes depend on adequate food, on its absorption and transformation in the alimentary canal (9,11).…”