Cuticular Structures in Micropterous Crickets (Orthoptera, Gryllidae, Petaloptilini, Gryllomorphini)

Orthoptera is a very diverse group that has colonized practically all terrestrial ecosystems on the planet. They have adapted to live in the endogenous environment as well as in caves so that some species exhibit troglomorphic characteristics. This group has been extensively studied due to its economic and social importance; however, many basic morphological and biological questions remain to be solved. In this study, a comparative morphological study by scanning electron microscopy of different structures of eight species of micropteran crickets of the tribes Gryllomorphini and Petaloptilini, whose tegmina had lost their flight and song functionality was carried out. Special emphasis was placed on the tegmina and their possible relationship to reproductive functions. In addition, to assess troglomorphism in the genus Petaloptila, the biometric parameters of six other species have been considered. Actualization of the lifestyle of the studied species has also been carried out. The results show structures not previously described in this group (gland openings, setae, pores, or group of campaniform sensilla). Structures not previously described in this group have been detected, and tegmina (glandular openings and devoured tegmina) seem to confer a role in reproduction. Troglomorphisms are only observed in species of the subgenus Zapetaloptila. Statistically, significant differences have been found in characters such as cephalic elongation, ocular reduction, greater length of appendages, and depigmentation.

The color pattern inducing gene wingless is expressed in specific cell types of campaniform sensilla of a polka-dotted fruit fly, Drosophila guttifera

A polka-dotted fruit fly, Drosophila guttifera, has a unique pigmentation pattern on its wings and is used as a model for evo-devo studies exploring the mechanism of evolutionary gain of novel traits. In this species, a morphogen-encoding gene, wingless, is expressed in species-specific positions and induces a unique pigmentation pattern. To produce some of the pigmentation spots on wing veins, wingless is thought to be expressed in developing campaniform sensilla cells, but it was unknown which of the four cell types there express(es) wingless. Here we show that two of the cell types, dome cells and socket cells, express wingless, as indicated by in situ hybridization together with immunohistochemistry. This is a unique case in which non-neuronal SOP (sensory organ precursor) progeny cells produce Wingless as an inducer of pigmentation pattern formation. Our finding opens a path to clarifying the mechanism of evolutionary gain of a unique wingless expression pattern by analyzing gene regulation in dome cells and socket cells.

Stinging apparatus of apoid wasps and bees as never seen before

The stinging apparatus is expected to vary depending on the type of prey taken and the way it is carried in apoid wasps and the purpose of defense it serves in bees. To understand the differences in sting morphology, members of two apoid wasp families (Ampulicidae and Crabronidae) and a bee family (Halictidae) were studied. Scanning Electron Microscope images of lancets revealed tooth like projections on dorso-lateral aspect in Ampulex compressa (Fabricius, 1781) and blunt barbs on the lancets of Liris aurulentus (Fabricius, 1787) and Tachysphex bengalensis Cameron, 1889 whereas, in Halictus fimbriatellus Vachal, 1894 barbs are arranged in two rows on lancet, which includes four barbs on one side and three barbs on the other side of lancet which are not acutely pointed. The SEM images also indicated the presence of campaniform sensilla on the lancets of compressa. These findings help us to know the possible relationships of hunting behavior and modification of the sting in accordance.