The Muzzana woods are a “treasure chest” of biodiversity also thanks to the great variety of insect species. This diversity thrives in the dead wood and other organic material produced by the numerous species of trees and shrubs. Lepidopters, beetles and hymenopters are the most present species.
Lepidopters include some common species of leafrollers (Tortrix viridana, Lymantria dispar, Operophtera brumata, Euproctis chrysorrhoea and others) whose larvae nest in oaks and other hardwood trees in May and June.
Strolling along the edge of the woods, one may easily come across several other diurnal species including some that are typically of forests. These include Gonepteryx rhamni, Apatura ilia, Limenitis camilla, Argynnis paphia, Pararge aegeria, Maniola jurtina. Other rarer and protected species such as the Zerynthia polyxena e Lycaena dispar are common along the banks of the river Cormor and of the neighbouring lagoon.
There is a considerable amount of coleoptera or beetles, including many that gnaw the leaves of trees and bushes. Phyllobius sp., Polydrusus sericeus, Galerucella luteola, Agelastica alni, Apoderus coryli, Melolontha melolontha are among the most common species.
The Xylophagans deserve a special mention, especially the Curculionidae among them, the ‘true’ weevils, and the Cerambycini, a tribe of longhorn beetles. Their importance is due to their role with the process of recycling of wood residual remains and also because they constitute the main source of nourishment for several species of birds, including woodpeckers. Among them, the stag beetle (Lucanus cervus), is one of the few insects to be well-known among the lay audience for its size and peculiar appearance. Its larvae live in decaying oak trunks. This magnificent coleoptera has become a rare species.
Un piccolo insetto, un immenso valore
All’interno del bosco Selva di Arvonchi è stato rinvenuto Gasterocercus depressirostris, un raro coleottero curculionide associato alle foreste primarie (Querco-carpineti) ancora presenti in Europa.
Among the most interesting species there is the Gasterocercus depressirostris, a rare Curculionidae whose presence is linked to oak trees. The species is locally extinct in many areas of Europe because of the disruption of its habitat. Therefore its presence is considered an indicator of a primary forest.
The several species of Carabidae (ground beetles), are also worth mentioning for two reasons . The first one is that they prey on insects harmful to crops. The second one is that their distribution is linked to microclimatic parameters, to the point that one can determine cases of ‘localised extinction’ in case of derangements of the woodland portions and soil moisture.
Hymenoptera include various species of Cynips (Cynips quercus, Neuroterus sp.), which are responsible for the formation of crown galls on the leaves and young branches of the oak trees; Vespidae including, the wasp, the Vespula, the Polystes, and several other wild bees.
Last but not least, there are Dipterae typical of humid areas. Among them forest mosquitos of the genus Aedes, and some species of Tabanids, bloodsucking marsh horse fly (gen. Tabanus Chrysozona) which are all common on clearings and along the woods borders.
This text is based on Fabio Stergulc, “Boschi di Carlino, aspetti naturalistici e di tutela ambientale” (1990). The original refers to the Carlino woods, a a short distance away from the Muzzana woods.
Many lowland woods in Friuli share common features, and hence this text is relevant to the Muzzana woods as well.