The praying mantids (Insecta: Mantodea) as indicators for biodiversity and environmental conservation: a case study from the Maltese and Balearic archipelagos

The use of mantids as indicators for biodiversity and environmental conservation has been studied on different islands of the Mediterranean Basin, specifically the Maltese and Balearic archipelago. The study focused on three model species: a generalist and cosmopolitan species (Mantis religiosa); a species that is uncommon but widespread in the Mediterranean area, adapted to maquis and garrigue environments (Ameles spallanzania); and a rare species linked to dry and semi-desertic biotopes (Rivetina baetica). Their presence and distribution have been found to be significantly correlated with the species richness of Orthoptera, already known to be sound indicators of biodiversity, as well as other elements of their complementary network. All three species preferred both natural and well-preserved habitats over areas subject to human impacts on the land, such as medium to intensive agriculture or habitat degradation. This therefore qualifies them as sound bioindicators for habitat conservation, and their role as such is discussed within both local and global contexts.
Key policy insights
● Praying mantids proved to be good indicators for biodiversity and environmental conservation in some representative Mediterranean environments and may be used also in some more global contexts.
● Some land-uses and human activities have a significant impact on the biology of at least three wide-spread mantid species and their complementary network.
● Ecological corridors of unmanaged natural vegetation can have a key role in maintaining the presence of these insects and the biodiversity they represent.

以螳螂作为生物多样性与环境保护的指示类群，相关研究已在地中海盆地的不同岛屿开展，具体覆盖马耳他群岛与巴利阿里群岛。本研究聚焦三类模式物种：一类为广食性、广布性物种广腹螳螂（Mantis religiosa）；一类是在地中海区域分布广泛但较为罕见、适应马基灌丛与加里格生境的斯氏螳（Ameles spallanzania）；还有一类是与干旱、半荒漠生境相关的稀有物种贝氏螳（Rivetina baetica）。研究发现，这三类螳螂的存在与分布，与直翅目（Orthoptera）物种丰富度显著相关——直翅目本身已是公认的良好生物多样性指示类群——同时也与其所在的互补生态网络的其他组分密切关联。三类螳螂均优先选择自然且保存完好的生境，而非受人类活动干扰的陆地区域，例如中度至集约化农业区或生境退化地带。据此，这些螳螂可作为生境保护的可靠生物指示类群，其作为指示类群的作用将在本地与全球语境中展开讨论。

关键政策启示
●  螳螂在部分典型地中海生境中可作为生物多样性与环境保护的良好指示类群，其应用价值亦可拓展至部分全球场景。
●  部分土地利用方式与人类活动，会对至少三类广泛分布的螳螂物种及其所在的互补生态网络产生显著影响。
●  未受人为管理的自然植被生态廊道，在维持这类昆虫及其所代表的生物多样性存续方面可发挥关键作用。