Threats Posed to the Rediscovered and Rare Salvia ceratophylloides Ard. (Lamiaceae) by Borer and Seed Feeder Insect Species

Abstract

The effects of herbivorous insects on a plant population are not always well tolerated. This is especially true if the herbivorous actions are directed toward rare plant species. Salvia ceratophylloides Ard. is a rare endemism of southern Italy. Observations of the plants in situ revealed that many of them were under severe stress and did not produce seeds. Therefore, to find out which factors affect the reproductive activity as a whole, an observational study was carried out. We found bottom-up and top-down effects on plant health and reproduction associated with herbivorous action. Squamapion elongatum (Coleoptera, Curculionoidea, Apionidae), in all monitored sites, infested plants non-uniformly but was able to threaten the health condition, flowering, and seed production of sage by digging tunnels into the sage branches (bottom-up action), and then secondarily by seed feeder Systole salvia Zerova (Hymenoptera, Eurytomidae) predating sage seeds (top-down action). Mainly, chalcid parasitoid wasps such as Trichomalus spp. (Hymenoptera, Pteromalidae), as well as Eupelmus vesicularis and E. muellneri (Hymenoptera, Eupelmidae), limited the herbivorous S. elongatum population and the seed herbivore S. salviae emerged with its parasitoid Ormyrus diffinis (Hymenoptera, Ormyridae). Overall, this study showed how ecological interactions among herbivores, their host, and their natural enemies act on this sage species in all sites investigated. Among the herbivores, mainly S. elongatum affected this rare sage species, which should be taken into consideration, especially in the formulation of biological control solutions and for improving operating practice aimed at reproducing the species. This study provides the molecular characterization of the herbivorous species involved, in order to support future projects to evaluate the intra- and interspecific genetic variability of insects, their evolutionary relationships, and phylogeny studies.

The Assessment and the Within-Plant Variation of the Morpho-Physiological Traits and VOCs Profile in Endemic and Rare Salvia ceratophylloides Ard. (Lamiaceae)

“…Only six compounds were differently affected by sites: p-cymene, α-terpineol, α-copaene and α-cubebene, emitted in Pu more than Mo site which, conversely, produced more β-tujone and dimethyl sulfide ( Table 5). Salvia ceratophylloides Ard., an endemic, rare, and critically endangered plant species, has been recently rediscovered on some sites around the Reggio Calabria hills [2,3]. The knowledge of its morphological and ecophysiological traits is very important for understanding the habitat requirements for the conservation [24] and providing its capacity to adapt to climate change conditions and, consequently, to the plant communities distribution [25].…”

“…is a perennial herbaceous species endemic to Southern Calabria, Italy, which was declared extinct in 1997 [1] and recently rediscovered a hundred mature individuals distributed in two sites, 2 Km apart, around the Reggio Calabria hills [2,3]. Nowadays, the S. ceratophylloides populations are threatened with extinction because of the habitat modification and destruction by wild urbanization and agriculture [3]. Spread of alien species, such as Cascabela thevetia, Ipomoea setosa subsp.…”

Crop Wild Relatives (CWRs) Threatened and Endemic to Italy: Urgent Actions for Protection and Use

“…Taxa that are known to be endemic to a country or those that occur in only a few countries or regions may be considered vulnerable. Species with a restricted distribution should therefore be given higher priority than species occurring more widely [ 8 , 11 , 12 ].…”

Behavioral and Physiological Plasticity Provides Insights into Molecular Based Adaptation Mechanism to Strain Shift in Spodoptera frugiperda

“…Herbivorous insects are engaged in a very intimate and challenging relationships with their host plants. Plants are the key components of the ecological niche for herbivorous insects being a food resource, mating site, egg-laying site and habitat essential for the insects survival and reproduction [ 8 , 9 , 10 , 11 ]. Therefore, the use of plant hosts involves key morphological, behavioral and physiological adaptations that are essential for development and survival [ 9 , 10 , 12 , 13 , 14 ].…”