Fine Structure of the Compound Eyes of Male and FemaleHeortia vitessoidesMoore (Lepidoptera: Crambidae)

Abstract

AbstractHeortia vitessoides is a destructive pest of the economically important plant Aquilaria sinensis in China. We investigated the external morphology and ultrastructure of H. vitessoides compound eyes using scanning and transmission electron microscopy. We found that H. vitessoides has superposition eyes, made up of a mean of 3,671 and 3,428 ommatidia in males and females, respectively. The mean ommatidial diameter for males and females was 18.87 and 16.81 µm, respectively. Each ommatidium was capped by a convexly curved corneal facet lens of about 13.85 µm thickness. Corneal nipples measuring 226.36 nm in height in males and 295.48 nm in females, covered the surface of the eyes. Heortia vitessoides eyes are eucone, with each ommatidium having a crystalline cone comprising four cone cells, surrounded by two primary pigment cells. The centrally fused rhabdom of each ommatidium was formed by 8–11 of retinal cells, somewhat more than are typically found in Lepidoptera. The relatively large size of the compound eyes, the large number of ommatidia, large number of retinula cells, and high corneal nipples all suggest that H. vitessoides eyes are adapted to optimize visual sensitivity under dim light conditions.