Field Trip Report: Orthoptera present at Sierra La Demanda

The area was located almost on the outside of Barbadillo de Herreros. We began searching in an open area of dry pasture, where woody vegetation was scarce. In this habitat, mainly thorny bushes composed the spare shelters for fauna: wild blackberrys (Rubus sp.) and dog roses (Rosa canina) were the dominant species, along with several blackthorns (Prunus spinosa) and may blossom (Crataegus monogyna). The common broom (Cytisus scoparius) and some thistle species were present as well. Crossing this most open area, we arrive at the Vía verde from Barbadillo de Herreros. A contrast between soil-level and woody vegetation was still evident in this area, however bushes and trees were the dominant portion.

This first sampling allowed us to detect the most common Orthoptera for the time of year and typical of the herbaceous habitats dotted with bushes, so abundant in the area. To a greater or lesser extent, we found the same community of Orthoptera in almost all the points visited during the workshop.

Abundant grasshoppers that tolerate dried-up herbaceous vegetation: blue-winged grasshopper (Oedipoda caerulescens), Elegant Straw Grasshopper (Euchorthippus elegantulus), Jago’s Cross-backed Grasshopper (Dociostaurus jagoi), Lesser Toothed Grasshopper (Stenobothrus stigmaticus) species with lower density, Eurasian Pincer Grasshopper (Calliptamus barbarus), Broad Green-winged Grasshopper (Aiolopus strepens), Iberian Field Grasshopper (Chorthippus jacobsi), Heath Grasshopper (Chorthippus vagans), Pantel’s Grasshopper (Omocestus panteli). Among the Ensifera, the Common Grey Bush-cricket (Platycleis albopunctata) is typical of grasslands.

Add to this list three caelíferos: the Red-legged Grasshopper (Chorthippus binotatus), a common species in La Demanda and typical of bushes of the Fabaceae family, with important coverages in the area; the Meadow Grasshopper (Pseudochorthippus parallelus) more localized in the sampling and in need of non-exhausted pastures; and the Common Pincer Grasshopper (Calliptamus italicus) in very low densities.

Finally, we should point out the typical ensiferans of forest edges: the Speckled bush-cricket (Leptophyes punctatisima), a species that is more difficult to detect than others that frequently stridulate in a manner audible to the human ear, such as the Wood-cricket (Nemobius sylvestris) and the Great Green Bush-cricket (Tettigonia viridissima).

Two zones were visited during the second sampling session. Both of them relied in mid-mountain habitats, inside a range of 20 km from the base camp. Moreover, the two spots showed microhabitat heterogeneity, with open areas and dense scrub zones.

Puerto del Manquillo, the first stop, consisted of a firebreak surrounded by Mediterranean scrub. Substrate in the central area contained numerous fragments of weathered slate, along with some heather bushes. On either side of the firebreak we found medium-sized shrub vegetation, growing larger and more diverse on the shady part. On the sunny side, heathers were dominant (tree heather Erica arborea, Spanish heather E. australis, common heather Calluna vulgaris); on the shaded side, these species combined with Scotch brooms (Cytisus scoparius) and scattered specimens of Pyrenean oak (Quercus pyrenaica), common beech (Fagus sylvatica), and Scots pine (Pinus sylvestris). Here and there, the yellow-flowered broom (Adenocarpus complicatus)  could be spotted in the sunnier areas.

The second stop took place at the Valle del Sol Ski Station, abandoned since 2005. Long abandoned, the ski slopes showed signs of habitat regeneration, creating a mosaic of grasslands and scrub areas. Woody species consisted of Scots pine and large shrubs such as Scotch brooms or tree heaters. Along the forest ecotone, small individuals of heather were scarcely present. Finally, a small patch of wet, tall grassland growing near the ski station hosted an important diversity of insect species.

It is not worth repeating the names of the most common and typical Orthoptera of open environments already sighted on the first day. Among the grasshoppers, we can mention some additions, species of the subfamily Oedipodinae associated with the least vegetated habitats: Azure Sand Grasshopper (Sphingonotus azurescens), Iberian Band-winged Grasshopper (Oedipoda coerulea), Handsome Cross Grasshopper (Oedaleus decorus), Western Band-winged Grasshopper (Oedipoda charpentieri), and nymphs of Iberian Digging Grasshopper (Acrotylus fischeri), adults in turn 2. Add Yersin’s Grasshopper (Chorthippus yersini).

Among the Ensifera, the very common Common Slender Bush-cricket (Tessellana tessellata) can be added to the community of common Orthoptera despite being missing from the first survey. The most interesting observations and recordings of bradyporines, commonly known as cicadas: Lluciapomaresius spec., Neocallicrania selligera, and the remarkable Anvil’s Saddle Bush-cricket (Pycnogaster jugicola).

During the evening, the group set up for a night excursion between Monterrubio de la Demanda and Barbadillo de Herreros. The plot, designated for cattle grazing, featured short, dry xerophytic vegetation on mostly bare soil. Scattered throughout the landscape, we observed several plant species, including Spanish brooms (Genista hispanica), various thistles (Eryngium campestre, Centaurea calcitrapa), wild roses, and blackberry bushes.

La Hoya Ranas was one of the most interesting places we visited, with a good abundance of orthopterans. Among the herbaceous vegetation of these communal hills, we were able to observe grasshoppers in a resting state (asleep?), adding the Western Cross-backed Grasshopper (Dociostaurus genei) and the Common Maquis Grasshopper (Pezotettix giornae), a species that had curiously gone unnoticed until then.

We were able to observe the spectacular behaviour of the Common Mountain-cricket (Eugryllodes pipiens) with its elytra raised at the time of the song. Not easy to locate in the field and always a good thing to take photos of.

The Ensifera were in full action, as they are mostly nocturnal. Again the bradyporines caught the attention: Ephippigerida sp., Neocallicrania selligera, Lluciapomaresius sp., and Pycnogaster jugicola. Three Grey Bush-crickets were also active: Platycleis albopunctata, Platycleis affinis and Tessellana tessellata, as well as the European Tree-cricket (Oecanthus pellucens). We only found nymphs of the Common Field-cricket (Gryllus campestris). Despite being very discreet and difficult to observe, the ultrasonic detectors indicated the great abundance of Antaxius spinibrachius.

We end this inventory with two of the most interesting observations: the Sickle Bush-cricket Phaneroptera laticerca, a recently described species whose identification was verified in situ by its discoverer Julien Barataud. We could not have had better information about the species.

On this day, the group conducted a field sampling around an assemblage of lagoons called Lagunas de Neila.

The ascent followed a trail crossing the collinean level. This area remained predominantly populated by Scots pines and junipers (mainly Juniperus communis), interspersed with various heather species (Erica australis, E. arborea, Calluna vulgaris). Woolly thistles (Cirsium eriophorum), foxgloves (Digitalis purpurea), and willows (Salix salviifolia) were scarcely present. Herbaceous vegetation did not hold importance along this stretch. 

Further down the trail, the closer groundwater allowed for the presence of rushes (Juncus sp.) and wild blueberries (Vaccinium myrtillus). The journey ended at the northeastern edge of Laguna Negra, 1,920 meters above sea level, studying a bog with sundews (Drosera sp.) and cross-leaved heath (Erica tetralix) surrounded by junipers and pines. 

Very few species were detected in this high altitude location. Obviously in the high mountains, the conditions are more adverse and the richness (=number of species) of Orthoptera can be impoverished… although at 1,800 – 2,000 m above sea level, they should be jumping everywhere. Therefore, something is wrong in an area of ​​great environmental protection. On the one hand, there is a clear problem of overgrazing in the reserve, leaving very low densities of Orthoptera in its meadows. It was difficult to find corners with “reasonable” densities of Stenobothrus stigmaticus, Chorthippus jacobsi, Omocestus panteli and Pseudochorthippus parallelus. Of course, on the paths there were species of bare ground such as Oedipoda coerulea and Oedipoda caerulescens. In the forest area, we found specimens of Chorthippus vagans and especially the striking Common Club Grasshopper (Myrmeleotettix maculatus), new to the expedition. We were also quite successful in locating the Large Marsh Grasshopper (Stethophyma grossum) among the sparse vegetation of the bog.

In addition to the continuous presence of cows trampling the ground throughout the year, it is likely that the droughts of recent years have had a very negative effect on insect populations in the sierra. It seems clear that climate change is raising the minimum altitude where high mountain species can survive and it is very likely that species with no possibility of migrating to higher altitudes will sooner or later disappear from the mountain system. This is clearly the case of the Iberian endemic Podisma carpetana ignatii and the Club-legged Grasshopper (Gomphocerus sibiricus) in the Sierra de La Demanda. It was our disappointment not to see either of these two species, which were quite common in the 1980s, as demonstrated in the doctoral thesis of González (1989).

We spent a lot of time looking for the elusive Callicrania without success. However, we did locate Lluciapomaresius spec. again, which is not rare, although it requires a great deal of patience.

In short, a fascinating location for its landscapes and high altitude lagoons, although somewhat disappointing in terms of Orthoptera observation.

The first sampling site consisted of a sunny area with a small stream running through it. The riparian zone showed a high density of roundhead bulrush Scirpus holoschoenus and Juncus species, followed by flowering specimens of purple loosestrife Lythrum salicaria. Habitats surrounding the stream showed diverse species, including multiple thistles (such as Eryngium campestre, Dipsacus fullonum, Centaurea calcitrapa among others) and St. John ‘s wort (Hypericum perforatum). Woody species occupied around 30% of the area, with oaks (Quercus ilex), willows (Salix purpurea), and ashes (Fraxinus angustifolia). The elephant grass (Arundo donax) was also observed, though not relevant.

Later, the group moved to the El Torcón recreational area: an arid juniper woodland (Juniperus sabina) with sparse grassy cover and a few underdeveloped shrubs. Among the latter, the dominant species included blackthorn, young holm oaks and wild roses. The yellow-flowered broom was scarcely present. Approaching the banks of Aranza River, the habitat evolved to a watercourse protected by black poplars (Populus nigra), alders (Alnus glutinosa), ash trees (F. angustifolia), and willows (S. purpurea, S. atrocinerea). Bare gravel areas combined with densely vegetated surfaces, mainly by roundhead bulrush and pennyroyal (Mentha pulegium). Nearby, occasional green grasslands hosted species such as alfalfa (Medicago sativa) and chicory (Cichorium intybus).

We added two species of wet grasslands to the project: the Long-winged Cone-head (Conocephalus fuscus) and the Tricolor grasshopper (Paracinema tricolor).

The main interest of the second stop was the observation of the courtship of the blue-winged grasshopper Oedipoda caerulescens, among other common species observed in the area.

The final field excursion of the course took place in the early evening at Collado de Canales. During the trip, the group passed through a small section of collinean forest and ended in a semi-open area with large shrubs.

The habitat closest to the parking area was largely shaded, densely vegetated with woody species on either side of the trail. Notable species included Scots pine and holm oak, with a shrub layer composed of thorny plants such as blackthorn, blackberry, wild rose and Spanish broom.

At higher elevations, a Mediterranean mountain meadow became visible, mostly exposed due to the sparse tree cover, but with a significant density of shrubs. Dominant species included Spanish broom, wild rose and hawthorn (Crataegus monogyna) along with common juniper. Other smaller herbaceous plants typical of Mediterranean environments were also present, such as the thyme (Thymus zygis), Spanish golden thistle (Carlina hispanica), Spanish oyster thistle (Scolymus hispanicus), and lavender cotton (Santolina rosmarinifolia). In smaller quantities, holly (Ilex aquifolium), Scots pine, and young holm oaks were observed as well.

We repeated species at this last sampling point in both shifts.

This project has received funding from the European Union’s Horizon Europe Research and Innovation programme within the framework of the TETTRIs Project funded under Grant Agreement Nr 101081903.

Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or REA. Neither the European Union nor REA can be held responsible for them.