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Abstract: A survey on the present distribution of the horse chestnut leafmining moth, Cameraria ohridella Desch. & Dimic 1986, in Europe and in Italy is given: In Europe, within a period of 15 years, the leafminer – recently introduced into Central Europe – has settled in an area that spreads over 13 latitudinal and about 20 longitudinal degrees; in Northern Italy, an area of approximately 50,000 km² has been afflicted in the 5 years since the leafminer’s introduction in South Tyrol and Julian Venetia in 1993.

The development of the distribution in the region of South Tyrol and Trentino is shown: In the province of Bozen-South Tyrol, between 1995 and 1999 the moth has spread in all the three principal valleys (Eisacktal, Pustertal, Etschtal); in the Trentino province, first local attacks began only in 1998, near Trento and Riva, but spread over the entire Etschtal/Adige Valley in 1999. While in South Tyrol C. ohridella was introduced from the North (North Tyrol), the introduction into the Trentino occured from the South (Verona).

At present the attacks in Trentino province are preponderantly low (resulting heavy only in the city of Trento and in Riva del Garda) and limited to altitudes ranging from 70 to 700 in. In South Tyrol, attacks are mainly heavy in altitudes ranging from 250 to 900/950 m, while they are low in the increasingly affected higher altitudes of 1,000 to 1,230 m. Numeric attack parameters are given to show attack intensities.

The number of generations per year depends on the respective climatic conditions: in lower-altitudes, usually three generations develop in a year, but in higher altitudes (800 to 1,100 m) only two generations; in the climatically favoured area around the Lake Garda a (partial) fourth generation appears possible.

The question of host plants (Aesculus sp., Acer sp.) and the larval parasitism of C. ohridella is discussed. The parasitism of the larvae, principally by Eulophidae (Hym., Chalcidoidea), was ascertained already in the first years of attack: In South Tyrol, 16 species of parasitoids appeared, and 8 in the Trentino province, but only two species were dominant: Minotetrastichus sp. and Pnigalio sp. The level of parasitism reached was low, comparable to other Central European countries.

Abstract: Cereal aphid flight was monitored by 12.2 m suction traps at Szolnok in the middle of the Great Hungarian Plain and at Rothamsted, UK. Flight activities of Rhopalosiphum padi, Metopolophium dirbodum and Sitobion avenae were compared by the cross correlation function (CCF) between Hungary and UK. There was significant synchrony between flight a-tivity in Hungary and UK of R padi, M. dirbodum and S. avenae based on the eight years weekly sample data. The peak flight occurred 1, 3 and 2 weeks later at Rothamsted than at Szolnok for the three species (the CCF values were at – 1 week lag, r = 0.854, – 3 week lag r = 0.809, – 2 week lag r = 0.883, P < 0.05 respectively). When the flights in individual years were compared within species and between places the syn-chrony was lowest for R. padi: – in 4 years out of 8 and there was no synchrony, in the other years when synchrony occurred the time lag varied between – 1 week and – 4 weeks. For M. dirhodum the time lag varied between 1 and – 5 weeks, the synchrony was the best for S. avenae the week lag varied between 0 and – 3 weeks.

Our results show that flight activity of cereal aphids at Szolnok occurs 1-3 weeks earlier than at Rothamsted. The crop season is earlier in Hungary than in England.

Modes of passive dispersal of the grape rust mite Calepitrimerus vitis (Eriophyoidea) were investigated in a vineyard of South-Western Germany. More than 200 Eriophyoidea per month were trapped in a wind chamber during summer (32,1 % C. vitis) suggesting long-distance dispersal by air currents. Rain washed part of the adult C. vitis population from the foliage. SE micrographs suggest that quiescent nymphs are affixed to the leaf by a substance of unknown nature. However, the role of rain in C. vitis colonisation of uninfested vineyards is still unclear, as is the role of phoretic transport by arthropods. For the first time, evidence of rust mite dispersal by human activity is presented. A large number of C. vitis was found adhering to clothes and hands of workers carrying out customary cultural practices in the vineyard. Other arthropods, including Typhlodromus pyri, the main predator of C. vitis, were also passively transported by wind, rain and human activity.

Diatomaceous earth has been demonstrated in Australia, Germany, and the USA to protect stored products from infestation by insect pests. However, application of diatomaceous earth has rarely been used in Asian countries for the protection of stored grain from insect damage. These facts and the paucity of existing data from the tropics prompted the present study of storage with diatomaceous earth. We exposed rice treated with the diatomaceous earth product Fossil Shield® to infestation by Tribolium castaneum Herbst. During the dry season, when tests were conducted, the mean temperature was 29 ± 2 °C and relative humidity was 80 ± 3 %. The population of T. castaneum in rice was significantly reduced after treatment with Fossil Shield®. Diatomaceous earth at 1 g and 2 g per kilogram rice reduced population growth of T. castaneum to a coefficient of 0.27, and 0.02 respectively after 42 days. Fossil Shield® at 0.5 g per kilogram rice increased the mortality of T. castaneum, but did not stop population growth.

Host plant preference of the Russian wheat aphid Diuraphis noxia (Kurdj.) was studied on 11 cultivars of 9 plant species: winter barley, spring barley, winter wheat, spring wheat, rye, oat, Triticale, canary grass, red millet yellow millet and maize. Seeds of the host plants were sown in a circle near the edge of pots. The host plant choice was evaluated 24 hours after releasing 55 Diuraphis noxia female adults in the middle of each pot. The suitability of different hosts for aphid development was evaluated 2, 7 and 14 days after infestation based on the mean number of Russian wheat aphid individuals per plant. Red millet, yellow millet and maize were chosen by significantly fewer aphids than grain crops. Winter and spring barley were chosen as hosts most frequently, and the progeny production was also the highest on these plants. The growth rate of D. noxia was significantly affected by the host plants and the date of assessment and their interaction.

Analytical studies were conducted on the species composition of galls occurring on the leaves of Salix purpurea L. in the Ojców National Park in 1999 – 2000. The species composition of galls was identical in two consecutive years. Galls were caused by 5 species (a total of 480 galls). The most numerous species in both years was Pontania viminalis (L.). Index of occurrence frequency and Agrell’s index of species co-existence have been calculated. This index reached the highest values in case of Pontania dolichura (Thoms.) and P. viminalis (L.) in 1999 as well as Phyllocolpa leucaspis (Tischb.) and P. viminalis (L.) in 2000.

The possibility for the combined control of Ophiostoma novo-ulmi and Scolytus multistriatus was tested in Italy. Two elm clones [U. pumila×U. minor (clone B) and U. glabra var. pendula grafted onto U. pumila×U. minor pollards (clone A)] were treated by stem injection of different blend or concentrations of fungicides and insecticides. Then, adults of S. multistriatus, either loaded with spores of two isolates of O. novo-ulmi (H328 and 182) or provided of their natural load of conidia, were forced to feed in twig crotches of the treated trees. After 48 hours all insects were checked (dead or alive). One month later, the same twigs were cut off and brought to the laboratory. From each twig, three discs almost 1 mm thick were then taken (0, 3 and 6 cm over the point where the insect fed). The wood discs were inoculated in selective substrate and stored until the development of O. novo-ulmi colonies. All thesis containing insecticides give good results against S. multistriatus. Similarly, all thesis containing fungicides show a good fungus control independently from the fungal isolated. The percentage of fungal transmission obtained from insects carrying the natural load of conidia was lower than percentages obtained from beetles artificially loaded. Both beetle sex and position on the foliage never influence insect mortality or O. novo-ulmi infection. The best results were obtained injecting the Carbendazim + Acephate blend in the clone A. High chemical concentrations did not improve the general results.

The ambrosia beetle Gnathotrichus materiarius, which originally came from North America, was discovered in southern Finland in 1996. In 1997, using Norwegian drainpipe traps baited with pheromones of Gnathotrichus retusus and G. sulcatus, we collected beetles in the region where the first specimen had been caught in order to determine whether this potential pest species had become established in the area. Samples from a total of 16 traps included 79 species of beetles and 719 individuals, but no specimens of G. materiarius. The most abundant species in the samples were the ambrosia beetles Xyleborus dispar and Trypodendron lineatum. Several predators and other associates of bark beetles were also captured. The majority of the beetles caught were saproxylic species.