No abstract

The study evaluated the response of pea (Pisum sativum cv. Avola) to arbuscular mycorrhizal fungi (AM) species Glomus mosseae and Glomus intraradices and Rhizobium leguminosarum bv. viceae, strain D 293, regarding the growth, photosynthesis, nodulation and nitrogen fixation activity. Pea plants were grown in a glasshouse until the flowering stage (35 days), in 4 kg plastic pots using leached cinnamonic forest soil (Chromic Luvisols -FAO) at P levels 13.2 (P1) and 39.8 (P2) mg P/kg soil. The obtained results demonstrated that the dual inoculation of pea plants significantly increased the plant biomass, photosynthetic rate, nodulation, and nitrogen fixation activity in comparison with single inoculation with Rhizobium leguminosarum bv. viceae strain D 293. On the other hand, coinoculation significantly increased the total phosphorus content in plant tissue, acid phosphatase activity and percentage of root colonization. The effectiveness of coinoculation with Rhizobium leguminosarum and Glomus mosseae was higher at the low phosphorus level while the coinoculation with Glomus intraradices appeared to be the most effective at higher phosphorus level.

Gypsy moth, Lymantria dispar L., is one of the most important pests of deciduous trees in Europe. In regular cycles, it causes large-scale defoliation mostly of oak, Quercus spp., forests. Government authorities in the most infested countries in Europe conduct large-scale applications of pesticides against gypsy moth. In 1999, a new natural enemy, the entomopathogenic fungus Entomophaga maimaiga, was successfully introduced into a gypsy moth population in Bulgaria. Recent investigations suggest that now E. maimaiga is quickly spreading in Europe. Herein, past studies are reviewed regarding this fungus with special emphasis on its potential for becoming an important factor regulating gypsy moth populations in Europe, focusing on the host's population dynamics in relation to the fungus, the influence of environmental conditions on fungal activity, the influence of E. maimaiga on the native entomofauna, including other gypsy moth natural enemies, and spread of the fungus. Based on this analysis, the potential of E. maimaiga for providing control in European gypsy moth populations is estimated.

During the period 1986-1988 the parasitoids of smaller poplar borer Saperda populnea L. (Coleoptera, Cerambycidae) The tachinid fly B. irrorata decreased the smaller poplar borer larvae frequency by 9.3 % up to 18.9 %, while the iehneumonoid D. populneus, and the braconoid L impostor destroyed insignificant percentages of these larvae --0.5 % up to 1.7 % and 0.5 % up to 2.5 % resp.The flight period of the pest preceded or almost coincided with the ones of D. populneus, and L impostor. The fly B. irrorata always appeared last and its flight period was expanded.