The structure of the larval visual system has been examined closely in the larva of tiger beetles, in attempts to understand their predatory and escape behaviors, which are visually guided (Friederichs, 1931; Toh & Mizutani, 1994a, 1994b). The photoreceptor organ of the tiger beetle larva consists of six stemmata (larval single-lens eyes) on either side of the head, two of which are much larger than the others (Friederichs, 1931). Behavioral experiments suggest that the two pairs of the large stemmata, which are referred to as anterior and posterior large eyes, are concerned with such visual behaviors (Mizutani & Toh, 1998).