Can the enemy release hypothesis explain the success of Rumex (Polygonaceae) species in an introduced range?

The enemy release hypothesis states that introduced plants have a competitive advantage due to their release from co-evolved natural enemies (i.e., herbivores and pathogens), which allows them to spread rapidly in new environments. This hypothesis has received mixed support to date, but previous studies have rarely examined the herbivore community, plant damage, and performance simultaneously and largely ignored below-ground herbivores. We tested for enemy release by conducting large scale field surveys of insect diversity and abundance in both the native (United Kingdom) and introduced (New Zealand) ranges of three dock (Rumex, Polygonaceae) species: R. conglomeratus Murray (clustered dock), R. crispus L. (curly dock) and R. obtusifolius L. (broad-leaved dock). We captured both above- and below-ground insect herbivores, measured herbivore damage, and plant biomass as an indicator for performance. In the introduced range, Rumex plants had a lower diversity of insect herbivores, all insect specialists present in the native range were absent and plants had lower levels of herbivore damage on both roots and leaves. Despite this, only R. crispus had greater fresh weight in the introduced range compared to the native range. This suggests that enemy release, particularly from below-ground herbivores, could be a driver for the success of R. crispus plants in New Zealand, but not for R. conglomeratus and R. obtusifolius.

First records of the Palaestes abruptus Sharp, 1899 and P. nicaraguae Sharp, 1899 (Coleoptera: Cucujidae) from South America, with a checklist of flat bark beetles from the continent

Background

The flat bark beetles (Coleoptera: Cucujidae) is a small insect family with only about 70 species. Most of the species are distributed in Holarctic, Oriental and/or Australasian realms, while in South America, only six species have been recorded, including a single one known from Peru.

New information

Two cucujid beetle species, Palaestesabruptus Sharp, 1899 and P.nicaraguae Sharp, 1899, are recorded from South America for the first time. The species are recorded from the Pasco (P.abruptus) and Cusco and Junín (P.nicaraguae) Regions of Peru, based, in part, on data collected through the iNaturalist citizen science database. Habitats of both species are presented in photographs for the first time. A country-level checklist to Cucujidae species currently known from South America is provided.

A revision of the Pediacus Shuckard 1839 (Coleoptera: Cucujidae) of Asia and Australasia

The Pediacus Shuckard fauna of Asia and Australasia is revised. Eighteen species are recorded, described and illustrated from the regions and a key to species is provided. Nine new species are described: Pediacus australis sp. nov. (Australia, Papua New Guinea, Philippines, Thailand), P. carinatus sp. nov. (Indonesia, Malaysia, Thailand), P. fujianensis sp. nov. (China), P. japonicoides sp. nov. (Taiwan); P. leei sp. nov. (Taiwan), P. pendleburyi sp. nov. (Malaysia), P. sinensis sp. nov. (China), P. taiwanensis sp. nov. (Taiwan) and P. thomasi sp. nov. (Taiwan). A checklist of the Pediacus fauna of the world is given, listing a total of 31 species.