The rhabdom structure in the ommatidia of the Heteroptera (Insecta), and its phylogenetic significance

Abstract

In its plesiomorphic state the insect ommatidium consists of eight retinula cells forming a fused rhabdom. It has long been observed that, in contrast to this pattern, Heteroptera have open rhabdoms. However, there has so far been no comprehensive and comparative study of heteropteran ommatidia. For this reason, we investigated the rhabdom structure in 36 species from all higher groups of Heteroptera, as well as from Coleorrhyncha and Auchenorrhyncha as outgroup representatives. In addition we surveyed the data of earlier authors, which brings the number of examined species to a total of more than 70. All examined Heteroptera do have open rhabdoms, with a system of six peripheral and two central rhabdomeres. Outgroup comparison shows that the open rhabdom is an autapomorphy of the Heteroptera. As for the rhabdom structure within the Heteroptera, we found further autapomorphic patterns in Corixidae (Nepomorpha), Gerromorpha, and Leptopodomorpha. Finally, the Cimicomorpha and Pentatomomorpha share a special pattern of the two central rhabdomeres, which we call V-pattern. This is a new synapomorphy of these two taxa.

Fine structure of the compound eye of the fungus beetle Neotriplax lewisi (Coleoptera, Cucujiformia, Erotylidae)

“…A rather similar type of central rhabdom organization to that in N. lewisi was reported from the Gerromorpha (Fischer et al 2000), but in which the proximally placed R8 instead of the distal R7 forms the bilobed rhabdomere.…”

“…The precise number of rhabdomeres, contributing to the rhabdom at any given level, depends on the place where the rhabdom is sectioned. In numbering the retinula cells, we have followed the system used by Fischer et al (2000). Thus, at the very distal end of the retina, embracing the proximal ends of the cone cells, the peripheral rhabdom appears first ( Fig.…”

Phylogenetic divergences of the true bugs (Insecta: Hemiptera: Heteroptera), with emphasis on the aquatic lineages: the last piece of the aquatic insect jigsaw originated in the Late Permian/Early Triassic

“…Although Nepomorpha is not the basal lineage in these studies, the phylogenetic positions of the three aquatic infraorders are not consistent and are always entangled with Dipsocoromorpha. Therefore, after 35 years of efforts to infer the higher level phylogeny of Heteroptera, the phylogenetic relationships among the seven infraorders remain controversial except for the sister relationship between Cimicomorpha and Pentatomomorpha (Schuh, ; Zrzavý, ; Wheeler et al., ; Fischer et al., ; Xie et al., ; Schuh et al., ; Cassis and Schuh, ; Li et al., ; Weirauch and Štys, ) (Fig. ).…”

Three-dimensional reconstruction on cell level: case study elucidates the ultrastructure of the spinning apparatus of Embia sp. (Insecta: Embioptera)

“…However, some promising studies clearly demonstrate that ultrastructural character complexes can be used with great success for resolving phylogenetic relationships among taxa, e.g. ultrastructure of the rhabdom of Heteroptera [28] or the sperm structure of Embioptera [29]. …”