Marisia - Maros Megyei Múzeum Évkönyve 29-30/2. (2010)

Zoology

Boris VERESCEAGHIN, Svetlana BACAL, Galina BUSMACHIU

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In scientific literature on forest entomology, including specialized academic books are usually included only insects living on trees and shrubs and particularly the pest species and their entomophags, which creates a false and incomplete impression about the role of insects in forest ecosystems. Such data are included in manuals for university forestry, for example: Forest entomology (Vorontov, 1975), Biological basis of forest protection (Vorontsov, 1963, 1975); Biogeocenological study of phytophagous forest insects (Rafes, 1980). In the last book there is no data on phytophagous insects of herbaceous plants in forests. However, among the great diversity of dendrophylous insects, the pests, including the potential ones, represent a very small percentage; the other species are only one component of forest ecosystems that maintain their ecological balance.

Material and methods

The material discussed in the paper was collected during many years of scientific research (1960-2010), within various forest ecosystems of the Republic of Moldova. In order to obtain rich faunistic material different entomological methods of collection, preservations, treatment, preparation of museum collection were used for the studied groups (Collembola, Homoptera, Coleoptera), with the specific procedures for each group of invertebrates.

Results and discussions

A result of accomplished studies in forest zones of the Republic of Moldova invertebrates from 3 orders were collected and identified (Collembola, Homoptera and Coleoptera).

Order Homoptera (order to which belong the aphids) is a very important group of insects, widespread and very diverse. In deciduous forests of the Republic of Moldova there are no harmful aphids species. Aphids are only one of the components of the food chain. In total, according to data accumulated over many years of research, on the territory of Republic of Moldova 350 species of aphids are known at present, including 190 species that develop on 209 species of herbaceous plants, which occur mainly in forests and their outskirts, of which 156 are perennial plant. Aphids are numerous, varied and quite widespread, are an important component of forest entomofauna serving in general as food source for many other groups of insects.

The flora of Moldova includes 2000 species of vascular plants [8], but currently the natural vegetal cover has only been preserved on an area of approximately 10% of the country territory [6, 7]. The most rare and vulnerable species of flora are included in the Red Book of Moldova [4], second edition, where 117 plant species are cited. We have to mention that without considering the human impact on ecosystems, due to the diversity of habitats, the diversity of flora and climatic features; in Moldova can be meet approximately 12,000 species of insects, of which about 1,400 species are dendrophylous.

Among insects as rare species are included 37 species of eight orders of insects. Aphids are not included in this list, but among them are already identified 32 rare species whose host plants are not only rare, but also common species. All the aphids are phytophagous. The biocenologic role of aphids in the regional fauna is characterized by a variety of functions; they are not only consumers in the first degree. The sweet excrements eliminated by aphids after their biochemical qualities represent valuable natural food for many parasite species and entomophagous predators of the orders Hymenoptera and Diptera (especially Syrphidae andTachinidae). In Moldova there are 145 species of aphids that produce sweet excrements (honey dew), which is a trophic resource exploited by 31 species of ants.

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