Habitat use and phenology of the large insular endemic grasshopperAcrostira euphorbiae(Orthoptera: Pamphagidae)

Abstract

The habitat use and the phenology of the large grasshopper Acrostira euphorbiae García and Oromí endemic to La Palma (Canary Islands) are studied. This grasshopper is entirely dependent on the Canarian endemic shrub Euphorbia lamarckii both for food and to avoid predation. Adults stay on subapical branches during the day, probably to reduce the risk of predation, and climb up to the apex at night to feed. While females seem to ensure the genetic diversity of offspring by waiting for visits by different males, the latter have to move to guarantee their reproductive success. Monophagy in this species may be related to the year-round presence of tender shoots, and to the predator-repellent toxic latex found in the host plant. Unlike related species from continental areas, adults and nymphs of A. euphorbiae are present almost all year round, probably in adaptation to the particular climate of the islands. Nymphs are more abundant in winter, when Euphorbia leaves are most available. However, adults are more abundant than nymphs in spring, summer and autumn. Males develop more quickly than females, an apparent reproductive strategy based on achieving sexual maturity to coincide with females undergoing imaginal moulting. Matings start immediately after adult females emerge. Densities oscillated between 73 and 193 individuals ha(-1), which can be considered a low value compared with other continental pamphagid species.

Mobility and microhabitat utilization in a flightless wetland grasshopper, Chorthippus montanus (Charpentier, 1825)

“…The mean daily movement was comparable to other flightless Orthoptera (e.g. Mason et al 1995;Kindvall 1999;Gardiner and Hill 2004, Diekötter et al 2005, López et al 2007). In contrast, alate Orthoptera species usually move larger distances (e.g.…”

“…We found no significant difference in the movement distances between male and female individuals. This result is rather surprising as the mobility of male grasshoppers is usually higher than in females (Mason et al 1995;Maes et al 2006;Walters et al 2006;López et al 2007). The main reason for this is that male grasshoppers actively search for females, while females invest more time in feeding .…”

Genetic, morphological, and dietary changes associated with novel habitat colonisation in theCanaryIsland endemic grasshopperAcrostira bellamyi

“…Asteraceae) (0.34% observations) and Retama rhodorhizoides (Fam. Fabaceae) (1.7%) (López et al, 2007b); A. tenerifae Pérez & López has been observed on R. rhodorhizoides (27.5%) (López et al, 2005); Purpuraria erna Enderlein and P. magna López & Oromí on Euphorbia balsamifera, K. neriifolia and annual dry grass (López et al, 2013;D. Hernández-Teixidor, pers.…”

A taxonomic revision and species delimitation of the genusPurpurariaEnderlein, 1929 (Orthoptera: Pamphagidae) using an integrative approach

“…A specific ecological study like that carried out with Acrostira euphorbiae (López et al. ) should be performed to confirm these observations.…”

“…Like other Canary pamphagids, the phenology of Purpuraria is probably highly affected by rainfall (López et al. ), because in Lanzarote and Fuerteventura, precipitations are scarce, highly varying along the year and also depending on altitude and orientation of the localities.…”