A field study on Saga pedo (Ensifera, Tettigoniidae, Saginae): Spatial behavior of adult specimens

Abstract

Despite its large size, the protected predatory bush-cricket Saga pedo (Pallas, 1771) is difficult to study in the field. This is mainly due to its strong mimicry, prevalent night activity, and low population density. The aim of this study was to investigate the spatial behavior of some adult individuals through the use of luminescent tags and recording their occurrences at night. The monitored individuals moved considerably during the oviposition period and were found more frequently in small sections of the study area. Two models for count data were implemented to try to explain this behavior. The results indicate that their spatial behavior was predominantly related to the prey availability in the available environment. In addition, predation on the HymenopteraSphex funerarius Gussakovskij, 1934 is reported for the first time.

Ecology and abundance of a relict population of the bush cricket Saga pedo in the Northern Apennines, Italy

“…For example, the stag beetles Lucanus cervus have a detection probability of 56.2% on transects (Della Rocca et al, 2020), while the larvae of Parnassius apollo have a detection probability ranging from 84% to 97% (Fred & Brommer, 2003;Kukkonen, 2021). The low detectability of S. pedo has been previously documented in the literature (Anselmo, 2022;Holuša et al, 2013;Iorio et al, 2019). However, this is the first study that, through extensive repeated samplings and advanced statistical models (N-mixture models), provides robust estimates of the detection probability of S. pedo without the need for handling insects.…”

“…To estimate S. pedo abundance, we initially considered a set of 13 covariates (Table 1 ) ecologically relevant for our target species (Anselmo, 2022 ). Specifically, we derived two topographic covariates from the TINITALY 1.1 dataset at 10 m resolution ( https://tinitaly.pi.ingv.it/Download_Area1_1.html ), tree cover density from the Copernicus Tree Cover Density 2018 dataset at 10 m resolution ( https://land.copernicus.eu/en/products/high‐resolution‐layer‐tree‐cover‐density/tree‐cover‐density‐2018 ), while lad cover covariates from “Land cover Piemonte (2022)” vector dataset ( https://www.geoportale.piemonte.it/cms/progetti/land‐cover‐piemonte ).…”

“…To estimate S. pedo abundance, we initially considered a set of 13 covariates (Table 1) ecologically relevant for our target species (Anselmo, 2022). Specifically, we derived two topographic covariates from the TINITALY 1.1 dataset at 10 m resolution (https:// tinit aly.…”

“…Thus, understanding the ecology of S. pedo studying its habitats is crucial to foster effective conservation strategies for this species. However, to date, ecological studies on S. pedo are limited (Adžić et al., 2023 ; Anselmo, 2019 , 2022 ; Holuša et al., 2013 ) and, due to the strong elusiveness and crypticity of this species, the likelihood of observing it in nature is extremely low, resulting in underestimation of population abundance (Holuša et al., 2013 ).…”