Ultrastructural and quantitative studies of hemocytes in the sugarcane borer, Diatraea saccharalis (Lepidoptera: Pyralidae)

Abstract

Seis tipos de hemócitos circulantes foram caracterizados na hemolinfa de larvas de Diatraea saccharalis (Fabricius) (Lepidoptera: Pyralidae), através da microscopia eletrônica de transmissão e varredura: prohemócitos (PR), plasmatócitos (PL), granulócitos (GR), esferulócitos (ES), oenocitóides (OE) e vermiformes (VE). O PR foi o menor tipo celular; apresentando um núcleo grande, citoplasma com poucas organelas e superfície lisa e homogênea. O PL era polimórfico e abundante, com citoplasma rico em organelas e superfície celular com várias projeções citoplasmáticas. O GR era abundante, apresentando dois tipos de grânulos envoltos por membrana (denso e estruturado), glicogênio, gotas de lipídio e projeções citoplasmáticas filopodiais. O ES era uma célula grande, com citoplasma carregado de esférulas intracitoplasmáticas. O OE foi o maior tipo de hemócito encontrado, apresentando citoplasma grande, homogêneo e escassas organelas. O VE era discóide e apresentou grânulos elétrons-densos.

Six circulating hemocytes cell types from Diatraea saccharalis (Fabricius) (Lepidoptera: Pyralidae) larvae were identified by transmission and scanning electron microscope: prohemocytes (PR), plasmatocytes (PL) granulocytes (GR), spherulocytes (SP), oenocytoids (OE) and vermicytes (VE). The PR was the smallest cell type with a large nucleus, a cytoplasm with few organelles and a homogenous smooth surface. The PL was polymorphic and abundant, with a cytoplasm rich in organelles and a cellular surface with several cytoplasmic projections. The GR was abundant, showing two types of membrane-bounded granules (dense and structutered), glycogen, lipid droplets and a surface with philopodial projections. The SP was a large cell, with a cytoplasm full of intracytoplasmic spherules. The OE was the largest hemocyte type with a large and homogeneous cytoplasm and scarce organelles. The VE was discoid in shape and showed electron-dense granules.