Impatto dell'introduzione di insetti predatori esotici sulle "guilds" locali

The research theme concerned the undesirable effects of exotic predatory species introduced to control harmful species, and their impact and possible interaction on the local communities and the environment. Studies have been carried out on three different species of insects: 1) Harmonia axyridis (Coleoptera Coccinellidae) which have been assessed for ecological aspects such as interspecific predation and sperm survival in overwintering females. The results obtained show, in the first case, larvae belonging to the species Chrysoperla carnea as a superior intraguild predator on aggressive invasive and large Multicolored Asian ladybird H. axyridis larvae while, in the latter case, a very high survival ability of sperm over winter was recorded. 2) the Chestnut gall wasp Dryocosmus kuriphilus which has been evaluated for its degree of infestation and arthropod associated fauna in Sardinia. Results show a rapid parasitoid recruitment by D. kuriphilus. 3) Neuroptera crisopids belonging to the genus Chrysoperla, for which a hybridization test between criptic species has been carried out. The results show that an absolute post-zygotic incompatibility does not exist among the species investigated, representing a risk factor to the species reared and sold in various countries around the world. Biological invasion by alien species is one of the factors that poses problems on biodiversity therefore understanding its mechanisms may allow us better use of biological control which is an essential component of sustainable agriculture.</br

Alien vs . Predator - the native lacewing Chrysoperla carnea is the superior intraguild predator in trials against the invasive ladybird Harmonia axyridis

The alien invasive ladybird Harmonia axyridis (Pallas) (Coleoptera Coccinellidae) is a biological control agent of aphids and in the larval stage it is a very voracious and superior intraguild predator over most native ladybirds studied, except the large species Anatis ocellata (L.). We report the first aphidophagous insect - lacewing Chrysoperla carnea (Stephens) (Neuroptera Chrysopidae) - which is a superior intraguild predator, despite its smaller size, over the aggressive invasive ladybird H. axyridis in larval stage. We also observed high survival rate of hoverfly larvae Episyrphus balteatus (De Geer) and Epistrophe eligans (Harris) (Diptera Syrphidae), when exposed to ladybird larvae. Ladybird larvae were killed by lacewing larvae, individually paired in an empty Petri dish without food and water, in 50% of the cases when second instar larvae of both species were tested, in 94% of the cases with third instar larvae, and in 52% of the cases when third instar larvae of the lacewing were paired with much heavier fourth instar ladybird larvae. Larvae of the hoverflies E. balteatus were partially (27% of cases) and E. eligans strongly (76% of cases) protected against intraguild predation (= were not killed during experiment) by H. axyridis, but they never killed ladybird larvae. These results suggest that high biological diversity could be retained in crops and natural habitats, with possible synergistic effects on pests

Synthesis and study of polyhydroxylated phenol derivatives with potential cosmetic and phytoiatric applications

Tyrosinase (polyphenol oxidase, E.C. 1.14.18.1) and laccase (phenol oxidase, E.C. 1.10.3.2) are multifunctional copper-containing enzymes, that are keys in melanin biosynthesis, melanisation in animals and browning in plants. Our study is aimed to prepare new monomer and dimer phenol derivatives as potential inhibitors of melanin production starting from natural hydroxylated aromatic units

Valutazione biologica di inibitori di tirosinasi nei confronti di larve e pupe di Tenebrio molitor L. (Coleoptera Tenebrionidae)

Tyrosinase plays an important role in cuticle tanning and sclerotization in insects. Use of selective inhibitors active toward this enzyme could offer the opportunity to elaborate new sustainable biological control techniques. These substances might also act as a synergistic increasing target species susceptibility to pathogen agents or insecticides

Dryocosmus kuriphilus (Hymenoptera cynipidae) in Sardegna

The chestnut gall wasp Dryocosmus kuriphilus was detected in Sardinia in 2007. Two years later its biological control agent, Torymus sinensis, was released and was started the monitoring of native oak gall wasp parasitoids recruited by D. kuriphilus. Five years after its introduction the exotic parasitoid T. sinensis established itself in the study sites and more than 25 morphospecies of native parasitoids emerged from D. kuriphilus galls

Impact of alien insect pests on Sardinian landscape and culture

Geologically Sardinia is a raft which, for just under thirty million years, has been crossing the western Mediterranean, swaying like a pendulum from the Iberian to the Italian Peninsula. An island so large and distant from the other lands, except for its "sister" Corsica, has inevitably developed an autochthonous flora and fauna over such a long period of time. Organisms from other Mediterranean regions have added to this original contingent. These new arrivals were not randomly distributed over time but grouped into at least three great waves. The oldest two correspond with the Messinian salinity crisis about 7 million years ago and with the ice age, when, in both periods, Sardinia was linked to or near other lands due to a fall in sea level. The third, still in progress, is linked to human activity. Man has travelled since ancient times and for many centuries introduced allochthonous species to Sardinia which radically modified the native flora and fauna, but always at a very slow and almost unnoticeable rate. The use of sailing or rowing boats, with their low speeds, hindered the transport of living organisms from one place to another. The use of the steam boat, introduced around 1840 but widely diffuse around 1870-1880, opened the doors to more frequent arrivals and also to organisms from the American Continent. This technical innovation had an influence over the whole world economy, with its well-known grain crisis, and coincided in Sardinia with the arrival of Roman dairymen, producers of pecorino cheese and the beginning of the expansion of sheep farming which would continue uninterrupted until the present day. In this period of sudden social and environmental change, an insect was introduced which would turn out to be probably the most economically devastating agricultural pest in Europe: the Grape Phylloxera. The vineyard and wine business collapsed first in France then in Italy. The Phylloxera arrived in Sardinia in 1883 and wine production crashed a very short time later and only resumed after the distribution of American vine rootstock at the beginning of the 20th Century. From then, vine cultivation in Europe was modified with the essential use of this rootstock. Since then methods of transport have increased enormously in number and speed. The number of allochthonous and invasive species has increased proportionally: some of them along with exotic plants which are cultivated on the island, others following man in his activities. Often these new pests attack and destroy ornamental plants which have become part of the Sardinian landscape, causing it to change; just as often their presence requires methods of pest management which are different from the traditional methods on specific crops; finally in at least one case (the Asian tiger mosquito) they pose a threat to our health

An Individual Marking Technique for Green Lacewings (Neuroptera: Chrysopidae)

We present a new technique developed to uniquely mark individual adult green lacewings (Neuroptera Chrysopidae) with a durable, quickdrying ink applied by a very fine tipped pen. This marking method is particularly suitable for use in laboratory experiments. It is reliable, cheap, and easy to apply and to decode

Rilascio e insediamento di Torymus sinensis (Hymenoptera Torymidae) in Sardegna

The classical biological control based on the release of the parasitoid Torymus sinensis Kamijo (Hymenoptera, Torymidae) is considered to be the only effective method of controlling Dryocosmus kuriphilus ((Hymenoptera, Cynipidae), a major pest of Castanea species worldwide. In our multi-year study, performed between 2009 and 2015, we confirm the establishment of T. sinensis in Sardinia (Italy) and its effectiveness in controlling gall wasp infestation

Sustainable dyeing methods for managing Tineola bisselliella (hummel) infestations of woolen fabrics

This work studies the possible functionalisation provided by natural dyes to wool fabrics against moths attacks. Wool flannel samples were dyed with extracts from Daphne gnidium L., Helichrysum italicum (Roth) G. Don, Rubia peregrina L., Castanea sativa Mill.. Tests on the textile resistance to mature larvae of T. bisselliella were performed together with the quantitative characterization of second metabolites of the plants extracts. The test allowed to preliminary elicit the contribute of natural dyes and mordants to protect wool textile