Field Trip Report: 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).

Field trip to mid-high mountain areas.

(1) Puerto del Manquillo. Open area (firebreak) with weathered slates, vegetation composed of Q. pyrenaica, F. sylvatica and P. sylvestris (scarce in the sampled area, almost all in the shade). Most vegetation is broom and heather on the sides of the sampled strip. In the sunny area we found mainly E. australis and E. arborea, also some C. vulgaris, C. scoparius and an Adenocarpus that I have not identified (photo). In the shade, mainly E. australis and broom (C. scoparius), some trees, with quite a few ensiferas.

(2) Valle del Sol ski resort, altitude > 1800 m. Substrate is an old ski slope that has not been used since 2005, so some grass recovery. There is a lot of P. sylvestris, but we sampled open areas and forest ecotones, with vegetation composed of very sparse heather (E. australis), some tall brooms. In the flatter area, there is tall grass with thistles and good areas for butterflies. Large brooms and smaller heathers, generally cooler environment.

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).

Night outing to the intermediate area between Monterrubio and Barbadillo. Dry and xerophytic vegetation, arid and bare soil, livestock plot. Many brooms, some thistles, wild rose bushes in valley areas.

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.

We went out into the countryside to high mountain areas.

(1) Mountain track between P. sylvestris with some bushes (see vocal recording). Upper border of the hilly floor, no beech trees are visible. The surface becomes progressively more humid until reaching the upper lagoon, where we see a peat bog. Minimum height 1700. Heather (Erica arborea and E. australis), wild blueberries, juniper with two stripes, Digitalis cf. purpurea and thistles (there are photos), two species of salix or perhaps 3. Rushes / caraceae. I have a photo of everything. In general dry, there are no streams but a path of eroded dirt, there are cattle.

(2) E. tetralis and dragonflies. D. rotundifolia, other Erica in flower. Green grass surrounded by P. sylvestris.

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.

(1) Outside Salas de los Infantes: Open area with rushes, in flood zone. 4 types of thistles, St. John’s Wort, oaks, willows of 2 spp, ash trees, black poplar. Arundo donax and other typhas. We started at 10:30 in the morning.

(2) El Torcón: Very dry juniper forest, open and dry vegetation on the path and low bushes around. Blackthorn, oak shoots, scattered Eryngium campestre, Adenocarpus.

On the river bank there are black poplars, ash trees, wild rose bushes, beech trees, willows of 2 spp, rushes, some green chicory, green but not wet grass.

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.

Clearings in the forest at a high altitude pass.

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.