Assessing the role of taxonomic impediment in the knowledge on geographic distribution of Physidae (Gastropoda: Hygrophila) in South America, using an intensive-data approach

Abstract There is a marked disparity in the state of knowledge of Holartic x Neotropical species of the freshwater snail family Physidae; the incipiency of data on Neotropical physids reflecting the lower number of dedicated specialists. The gaps in the knowledge on Neotropical physids have led to historical uncertainty about species validity. Revisiting the species is essential to reduce taxonomic impediment and delineating their probable distribution is the first step to attain this purpose. We aimed at critically analyze occurrence records of South American physids, compiled through an intensive search in the literature, biodiversity and molecular databases. We present a provisional characterization of the distribution of this family in South America, considering the probable versus the poorly documented distribution of the species. The critical underrepresentation of South American physids in collections, molecular databases and literature reinforces the role of taxonomic impediment in delaying the advance of the knowledge on species diversity. Malacological collections represented the main source of records, evidencing the relevance of unpublished data associated to specimens to assess distributional information on neglected groups. As most of the species are represented by shells, the reassessment of species identity and distribution must be done, using molecular and anatomical criteria for species delimitation

Morphological characterization of pollens from three Apiaceae species and their ingestion by twelve-spotted lady beetle (Coleoptera: Coccinellidae)

Abstract Larvae and adults of certain species of predator lady beetles feed on pollen, guaranteeing their survival, and at times, reproduction in the absence of preferred prey. Palynology, therefore, may contribute in the investigation of botanical families visited by these predators in order to obtain this floral resource. There are records of the visitation of Apiaceae flowers by Coleomegilla maculata DeGeer, 1775 (Coleoptera, Coccinellidae), but not the ingestion of their pollen grains by this lady beetle. The external morphology of pollen grains of three Apiaceae aromatic species (Anethum graveolens L., Coriandrum sativum L., Foeniculum vulgare Mill.) was characterized, and it was evaluated the ingestion of these pollens by fourth instar larvae and adults of C. maculata upon confinement along with flowers of these Apiaceae for 24 and 48 hours. The pollen grains of those species presented similar external morphology. In the two times of exposure, the larvae ingested the same amount of pollen from the three Apiaceae species, and the amount of C. sativum pollen ingested was the same between larvae and adults. The amount of A. graveolens pollen grains ingested by the adults was significantly greater than the pollens of C. sativum and F. vulgare, in 24 hours, with the opposite occurring in 48 hours. In the first 24 hours, the adults ingested more A. graveolens pollen than the larvae, with the opposite occurring with F. vulgare. There was no significant difference in the amount of Apiaceae pollen ingested between larvae and adults in 48 hours. The results suggest that the pollen-eating habits of certain aphidophagous lady beetles may be crucial in their preservation within agro-ecosystems