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

SIMPLE SUMMARY: Orthoptera, with more than 28,930 described species, is one of the most diverse groups of insects in the animal kingdom. They are divided into two suborders: Caelifera and Ensifera. They have very diverse habits, ranging from epigean to endogean species so that some species exhibit troglomorphic characteristics. A comparative morphological study was carried out by scanning electron microscopy of the different structures of eight species of micropteran crickets whose tegmina had lost their flight and song functionality (Orthoptera, Gryllomorphinae, Petaloptilini, and Gryllomorphini). Special emphasis has been placed on the tegmina and their possible relationship with reproductive functions. In addition, to evaluate troglomorphism in the genus Petaloptila, the biometric parameters of six other species have been considered. The existence of structures not previously described in this group (gland openings, setae, pores, or group of campaniform sensilla) was documented, and the relationships between flight loss and stridulation in favor of secretory structures were established. In addition, it has been detected that species of the subgenus Zapetaloptila exhibit troglomorphic traits, unlike those of the subgenus Petaloptila. This information represents an advance in the knowledge of the morphology of the studied species, especially within tegmina. This also provides information on their degree of troglomorphism and relates to their mode of life. It is a starting point for future research on phylogenetic and histological studies or to find out if the species also inhabit yet undescribed environments. ABSTRACT: 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.