Terrestrial invertebrates - Udine Cultura

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98 ■ Orthopterans and mantids The orthopterans and their allies are very well represented on the grasslands of both fresh- and brackish-water areas. Among the characteristic species of freshwater marshlands is Metrioptera marmorata, endemic to the northern Adriatic and found in coastal locations between Trieste and Chioggia, where it is associated with sedges and rushes. This is a highly endangered species: Metrioptera brunneri previously regarded as extinct, it was recently rediscovered at Monfalcone, between the two above cities. The dainty Conocephalus fuscus and the larger and sturdier Paracinema tricolor bisignata are much more common on the Italian peninsula and islands, and are typical of hygrophilous vegetation. The adults frequent grasses like Phragmites, Puccinellia and Agropyron, on which they feed and which, at least in the case of Xiphidion discolor, they also use as a refuge for their eggs, which are laid inside leaf sheaths. Small tetrigids are also typical of wet areas, and are extraordinarily well camouflaged on bare ground. The two Italian representatives of the tropidopolan acridids are Tropidopola cylindrica cylindrica, widespread in rushes and reed-beds on the Tyrrhenian coast and the islands, but increasingly rare everywhere because of the reduction of its exclusive habitat, and T. graeca transjonica, known only at the mouth of the river Lato in Apulia. Brackish-water environments are also rich in typical species. Some of the most significant are those of the genus Epacromius: E. coeruleipes and E. tergestinus, two acridids with a discontinuous but very ample Palaeo-Arctic distribution. In Italy they are found in lagoon areas in the northern Adriatic, and, only E. tergestinus, also in Latium. Their close ties with brackish water make them good indicator species of sandbanks. The habits of Chrysochraon dispar giganteus, a species with Adriatic distribution, little known and considered endangered, are probably similar. Aiolopus thalassinus, allied with the Epacromius, is less specialised. This halophilous and hygrophilous species, despite its name, is not exclusive to either brackish-water or coastal areas. Its less stringent requirements are also reflected in its more widespread distribution over most of Italy, although it is becoming rarer. Conocephalus dorsalis has similar ecological characteristics, but is limited to central-northern Italy. Endemic species are also found here: on the northern Adriatic coast, between the Lagoon of Venice and the Valli di Comacchio, further south, lives Metrioptera brunneri, a species exclusive to brackish water, found in sea-lavender and glasswort communities on sandbanks, and on the banks of channels with Phragmites and Agropyron. It is difficult to observe as it is very elusive. It was practically unknown until recently, and is still of uncertain systematic status. The southern fauna includes Pterolepis elymica, a tettigoniid endemic to Sicily, so far only found along the western coast, from the salt-pans of Trapani to Mazara del Vallo, where it is exclusive to brackish and retrodunal environments. This is another little-known species, identified only a few decades ago. Haloxene species, being thermophilous, appear on higher drier ground. Examples are Acrida ungarica mediterranea, generally rare elsewhere, and a few mantids, such as the common Mantis religiosa and the elegant Empusa fasciata, an oriental species recorded at the mouth of the Tagliamento in the Gulf of Trieste. The large Gryllotalpa also lives on raised clay banks, safe from exceptionally high tides. Difficult to find, it is often identified by its shallow tunnels. In the Lagoon of Venice, some species of the G. sedecim/G. octodecim group have been recorded, but can only be precisely identified by chromosome counts. A less well-known excavating orthopteran is Xya variegata, only about 0,5 centimetre long, rare, and exclusive to sandy or silty sedimentary soils, mainly coastal, in which the adults live and reproduce. Orthopteran of the genus Gryllotalpa 99
100 ■ Heteropterans The typical heteropterans, or true bugs, of brackish-water areas include the saldids and several halophilic or halobiontic species found in lagoon and rivermouth areas in Italy. Halsosalda lateralis is widespread, although discontinuously, along the entire peninsula and on the islands, often in large numbers. In the north, they are often found associated with Salda adriatica, a species with Pontic-Mediterranean distribution which is not found south of the Po Delta. They are highly active daytime predators which frequent the damp mud of banks, able to hunt both by sight - they have very large eyes - and by making use of their sense of smell, as revealed by their capacity to poke in the mud with their rostra until they reach any small annelids or insect larvae. Some species can tolerate prolonged immersions, in response to tides in their elected habitat. The phytophagous heteropterans include various plant-bugs (mirids) specialising on halophytes, including Phytocoris salsolae and several species of Orthotylus, such as O. palustris, and O. divisus, in Sicily and Sardinia, and O. curvipennis, only in Sicily. They are typical species of glasswort and sea-lavender communities. The fauna of freshwater environments consists of a large number of more or less ubiquitous species. Among the most characteristic are the lygaeids of the genus Cymus, associated with rushes, and the pentatomids of the genus Eysarcoris, frequent mainly among sedges. Salda adriatica ■ Coleopterans Carabid beetles are well-represented in damp environments. Among the large Carabus, two species are worthy of mention: C. granulatus, very widespread and still relatively common at the edges of reed-beds, along hedgerows and in damp riparian woodlands, where it takes refuge and overwinters in rotten tree trunks, and the larger and more eye-catching C. clathratus, which is also able to hunt underwater but is very sensitive to environmental change - to the extent that it is now extinct in many areas, including the marshlands in Latium and the Lagoon of Venice. Typical of damp environments are Carabus granulatus species of the Chlaenius and Chlaeniellus genera, almost all of which Chlaenius spoliatus are brightly coloured. The large Chlaenius spoliatus is a voracious predator of talitrids, which it finds in the fissures of damp clay soils. The many small species grouped until recent times in the vast genus Bembidion are also richly represented in damp environments. Among the most common and widespread are B. quadrimaculatum and Ocydromus tetragrammus illigeri, with their characteristic yellow-marked livery, and the more sober Philochthus lunulatus, Notapus varius and Emphanes axillaris occiduus (previously known as E. rivularis). Other typical species of this environment are the highly abundant Agonum afrum, the elegant and unmistakable Drypta dentata, which is common beneath detritus in reed-beds but also to be found in marsh woodlands, under the bark of trees, and a group of species, long and flat in shape - a fact which allows them to find refuge in the hollow stems of reeds: examples are Odacantha melanura, the species of the genus Demetrias, Paradromius linearis and the rare P. longiceps. Lastly, characteristic of freshwater marshes are various species of Brachinus, known for an extraordinarily sophisticated technique aginst attack: small quantities of hydrogen peroxide and of an enzyme (catalase) capable of very rapidly reducing the former to water, are introduced, with a sudden release of 101
Page 1 and 2: Terrestrial invertebrates MARCO ULI
Page 3: 96 ■ Molluscs The malacological f
Page 7 and 8: 104 the wet mud on the coastline, a
Page 9 and 10: 108 ■ Dipterans The dipterans of
Page 11 and 12: Terrestrial vertebrates MAURO BON
Page 13 and 14: 116 117 Great crested grebe (Podice
Page 15 and 16: diver (Gavia arctica) and red-throa
Page 17 and 18: 124 Recent artificial environments:
Page 19 and 20: 128 aquatic birds, especially dabbl
Page 21 and 22: 132 Lesser white-toothed shrew (Cro
Page 23 and 24: agriculture and livestock farms sur
Page 25 and 26: 140 These environments are protecte
Page 27 and 28: Teaching suggestions MARGHERITA SOL
Page 29 and 30: 148 How to identify molluscs More t
Page 31 and 32: 152 RELINI G., BERTRAND J., ZAMBONI
Page 33 and 34: 156 Gibbula - 49, 52 Heterocerus -
Page 35: The authors wish to thank the follo

Terrestrial invertebrates - Udine Cultura

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