The function of nuptial gifts has generated longstanding debate. Nuptial gifts consumed during ejaculate transfer may allow males to transfer more ejaculate than is optimal for females. However, gifts may simultaneously represent male investment in offspring. Evolutionary loss of nuptial gifts can help elucidate pressures driving their evolution. In most katydids (Orthoptera: Tettigoniidae), males transfer a spermatophore comprising two parts: the ejaculate-containing ampulla and the spermatophylax-a gelatinous gift that females eat during ejaculate transfer. Many species, however, have reduced or no spermatophylaces and many have prolonged copulation. Across 44 katydid species, we tested whether spermatophylaces and prolonged copulation following spermatophore transfer are alternative adaptations to protect the ejaculate. We also tested whether prolonged copulation was associated with (i) male cercal adaptations, helping prevent female disengagement, and (ii) female resistance behavior. As predicted, prolonged copulation following (but not before) spermatophore transfer was associated with reduced nuptial gifts, differences in the functional morphology of male cerci, and behavioral resistance by females during copulation. Furthermore, longer copulation following spermatophore transfer was associated with larger ejaculates, across species with reduced nuptial gifts. Our results demonstrate that nuptial gifts and the use of grasping cerci to prolong ejaculate transfer are functionally equivalent. K E Y W O R D S :Genitalia, nuptial feeding, sexual conflict, sexually antagonistic coevolution, spermatophore, spermatophylax.

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Loss of vegetation cover is a major factor that endangers biodiversity. Therefore, the use of geographic information systems and the analysis of satellite images are important for monitoring these changes in Natural Protected Areas (NPAs). In northeastern Mexico, the Natural Protected Area Altas Cumbres (NPAAC) represents a relevant floristic and faunistic patch on which the impact of loss of vegetation cover has not been assessed. This work aimed to analyze changes of land use and coverage (LULCC) over the last 42 years on the interior and around the exterior of the area, and also to propose the time of succession for the most important types of vegetation. For the analysis, LANDSAT satellite images from 1973, 1986, 2000, 2005 and 2015 were used, they were classified in seven categories through a segmentation and maximum likelihood analysis. A cross-tabulation analysis was performed to determine the succession gradient. Towards the interior of the area, a significant reduction of tropical vegetation and, to a lesser extent, temperate forests was found, as well as an increase in scrub cover from 1973 to 2015. In addition, urban and vegetation-free areas, as well as modified vegetation, increased to the exterior. Towards the interior of the NPA, the processes of perturbation and recovery were mostly not linear, while in the exterior adjacent area, the presence of secondary vegetation with distinct definite time of succession was evident. The analysis carried out is the first contribution that evaluates LULCC in this important NPA of northeastern Mexico. Results suggest the need to evaluate the effects of these modifications on species.

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