By 2030, the European Commission intends to halve chemical pesticide use and its consequent risks. Among pesticides, nematicides are chemical agents used to control parasitic roundworms in agriculture. In recent decades, researchers have been looking for more sustainable alternatives with the same effectiveness but a limited impact on the environment and ecosystems. Essential oils (EOs) are similar bioactive compounds and potential substitutes. Different studies on the use of EOs as nematicides are available in the Scopus database in the scientific literature. These works show a wider exploration of EO effects in vitro than in vivo on different nematode populations. Nevertheless, a review of which EOs have been used on different target nematodes, and how, is still not available. The aim of this paper is to explore the extent of EO testing on nematodes and which of them have nematicidal effects (e.g., mortality, effects on motility, inhibition of egg production). Particularly, the review aims to identify which EOs have been used the most, on which nematodes, and which formulations have been applied. This study provides an overview of the available reports and data to date, downloaded from Scopus, through (a) network maps created by VOSviewer software (version 1.6.8, Nees Jan van Eck and Ludo Waltman, Leiden, The Netherlands) and (b) a systematic analysis of all scientific papers. VOSviewer created maps with keywords derived from co-occurrence analysis to understand the main keywords used and the countries and journals which have published most on the topic, while the systematic analysis investigated all the documents downloaded. The main goal is to offer a comprehensive understanding of the potential use of EOs in agriculture as well as which directions future research should move toward.

An alternative approach to notice changes of the nematode community structure was evaluated in five study cases in the Mediterranean Sea. In detail, we suggested a combination of morpho-functional traits (i.e., amphid, cuticle, buccal cavity, and tail shape) as an alternative to the taxonomic identification of nematodes. The results clearly demonstrated that the matrixes made using the trait code numbers perfectly mirror the changes of the nematode community structure at the genus level. The combination of the morpho-functional traits more frequently observed in areas under human pressure were ascribable to genera belonging to Xyalidae, Linhomoeidae and Chromadoridae families. This approach might greatly speed the analyses of nematode fauna in biomonitoring programs and might also be adopted for other meiobenthic organisms that may be categorized in functional groups opening new perspectives in the ecological assessment of meiofauna.

In rocky shore systems, sessile macrobenthic assemblages may act as “ecosystem engineers” for many smaller benthic organisms. Thus, the influence of macrobenthic coverage on the diversity and assemblage structure of the harpacticoid copepod fauna was investigated in the rocky shores of a Marine Protect Area (MPA) in the Ligurian Sea (NW, Mediterranean Sea). Two sampling sites were investigated in two seasons at three different depths on both sub-vertical and inclined reefs. A total of 61 species of copepods mainly represented by Miraciidae, Laophontidae, Longipediidae and Thalestridae were found. The complex micro-topography of these substrata provided a wide variety of niches for many species with different lifestyles that suggests the important role of rocky shores to ensure the functioning of coastal ecosystems. The harpacticoid assemblage structure seemed mainly influenced by season and depth. The temporal spread observed is likely one of the underlying mechanisms of niche segregation that allows many species to co-occur in this specific environment along with a subordinate spatial segregation corresponding to the depth gradient. The results seem to support the hypothesis that the different species composition of the “ecosystem engineer” (and consequently its structure changes) are relevant in structuring the copepod assemblages. The comparison with previous data on general meiofauna underlines that higher surrogacy of the taxonomic identification could be used to study rocky shore communities, but the rich diversity that these systems host can only be understood at the lower taxonomic levels. The same holds for future evaluations of impact of environmental changes (including MPA regulations) on meiofaunal assemblages.