A checklist of the species of leaf beetles (Coleoptera: Chrysomelidae) of El Salvador is presented based on data from literature and a digitization project of the Bechyné collection of the Royal Belgian Institute of Natural Sciences (RBINS). The RBINS collections contain a total of 2797 individual chrysomelid specimens from El Salvador, sorted into 89 species and 132 genera. In total, the current checklist contains 420 species, of which 33 are new records for El Slavador from the Bechyné collection. In these collections, there are also ten nomina nuda named by Bechyné, which need further study. The leaf beetle diversity in El Salvador, partly due to the country’s unstable political history, remains poorly studied, and many (new) species await discovery. This checklist provides a baseline for further study in El Salvador and nearby region.

The balance of costs and benefits is expected to drive facultative associations. Here, we assessed the costs of living in a facultative association, by studying the effect of red wood ants on different fitness correlates of the facultatively associated isopod Porcellio scaber.We demonstrated that P. scaber frequently occurs in and near hostile red wood ant nests and may even outnumber obligate nest associates. However, the facultative association involved different costs for the isopod. We found that the density of the isopod decreases near the nest with higher ant traffic. Individuals in and near the nest were smaller than individuals further away from the nest. Smaller individuals were also found at sites with higher ant traffic. In addition, a higher proportion of wounded individuals was found closer to the nest and with higher ant traffic. We recorded pregnant females and juveniles in the nest suggesting that the life cycle can be completed inside the nests. Lab experiments showed that females died sooner and invested less in reproduction in presence of red wood ants. Although P. scaber rarely provoked a strong aggression response, large numbers of the isopod were carried by the ants as prey to the nest. These preyed isopods were mainly dried out corpses.Our results showed that the ant association involves several costs for a facultative associate.Consequently, red wood ant nests and their surrounding territory may act as an alternative habitat where demographic costs are balanced with stable resource provisioning and protection against enemies.

The bat fauna of the Adriatic islands is relatively poorly known. Seven species were documented so far on the remote Adriatic islands of Vis and Biševo (Croatia). This study aims to increase knowledge on the bat communities on these islands. Bat echolocations were recorded between 30 April and 11 May 2018 at seven sites showing bat presence. Calls were identified to genus and species level where possible, which confirmed the presence of eight bat taxa on the islands. Three taxa were observed for the first time: Tadarida teniotis, Myotis sp. and Nyctalus sp. Results of this study increase the number of documented bat taxa on Vis from seven to ten and on Biševo from one to six. This study highlights the importance and benefits of utilizing passive acoustic devices at remote locations. Our findings suggest that bat communities and diversity might also be understudied on other islands in the Mediterranean, which could have important implications for bat conservation.