Bulletin UASVM serie Agriculture 69(2)/2012 Print ISSN 1843-5246; Electronic ISSN 1843-5386

Parameters Researches Regarding the Structural Parameters of the Populations of Rhynchitidae and in Romania

Iuliana ANTONIE

“Lucian Blaga” University, The Faculty of Agricultural Sciences, Food Industry and the Protection of the Environment, Sibiu, 7-9 Dr. Ion Raţiu, 550012, Sibiu, Romania: [email protected]

Abstract. The study of the two families took into account the economic factor, because there are not few species of Rhynchitidae and Attelabidae that produced important damages in the vine, orchard, and forest areas as well as in the agricultural cultures. The researches took place during 1996-2006. The fauna material was collected during the travels to different localities in the country. In some investigated localities the collecting and the observations in the field were extended for at least 2-3 days and for the vine ecosystems with a great attack of Byctiscus betulae the researches lasted for 3-4 years, at regulated intervals of 3-4 weeks. In order to establish the structural parameters there was processed a rich material of over 1300 adult samples belonging to 17 species from a total of 29, which are to be found in Romania. The material comes from 42 localities. The way of collecting was: directly with the hand, with the entomologic net, by drillings in the soil and by using the device of obtaining the zoophagous parasites.

Keywords: Ecology, structural parameters, Rhynchitidae and Attelabidae

INTRODUCTION

The species Rhynchitidae and Attelabidae (Coleoptera, Curculionoidea) are a relatively small group of , whose research represents both a scientific and practical interest (Becker, 1954). The main reason of approaching these two families was an economic one, because not few of the species of Rhynchitidae and Attelabidae produce important damages in the vine, orchard and forest areas as well as in the agricultural cultures.

MATERIALS AND METHODS

In order to establish the structural parameters of the populations of Rhynchitidae and Attelabidae in Romania, there was processed a rich material of over 1244 adult samples belonging to 17 species, from the total of 29 species met on the Romanian territory. This material was collected by the authors during the travels to different localities in the country during 1996-2000. The collecting points were 42. The way of collecting: the direct collecting with the hand; the use of special instruments: the entomologic net, the entomologic jar.

RESULTS AND DISCUSSION

The size of the population is the main parameter of structural state that characterizes any natural population (Botnariuc and Vădineanu, 1982). The adults of the species of Rhynchitidae and Attelabidae don’t make journeys on long distances, flying nearby the ecosystems with plants on which they develop their larva. These at their turn are entophyte. Taking into account that the migration and emigration have a minor role in the number of these populations of rinchitidae and atelabide, the size of these populations depends mainly on two factors: the birth rate and the mortality. The absence of some high population effectives

469 and of some obvious territorial behavior, as well as the fact that the species within the Rhynchitidae and Attelabidae families are bound by a certain kind of ecosystem (through the host plant where the larva develops), make the distribution in space of the individuals within the population to be of a group type in the case of all the species we found in the field. The populations of Rhynchitidae and Attelabidae have distinct generations (that don’t superpose), that make that at some moment the entire effective to belong to a certain class of age. Till now there are no arguments to allow the discussion of some fundamental difference from a genetic point of view within the populations of Rhynchitidae and Attelabidae. As concerning the other insects also in the study of the populations of Rhynchitidae and Attelabidae, the genetic structure is reduced to the structure on sexes. Studies regarding the structure on sexes of the population of this coleopteron are rare due to the small series of captured individuals from different ecosystems, which generally don’t allow getting to conclusions. The data obtained by us are the same with those given by Fenili (1952), Daanje (1956) and Mărgărit (1967).

CONCLUSIONS

The size of these populations of the species of Rhynchitidae and Attelabidae depends mainly on two factors: the birth rate and the mortality. The absence of some high population effectives and of some obvious territorial behaviour make the distribution in space of the individuals within the population to be of a group type in the case of all the species we found in the field. The populations of Rhynchitidae and Attelabidae have distinct generations (that don’t superpose). Till now there are no arguments to allow the discussion of some fundamental difference from a genetic point of view within the populations of Rhynchitidae and Attelabidae.

ACKNOWLEDGEMENT

This work was cofinanced from the European Social Fund through Sectoral Operational Programme Human Resources Development 2007-2013, project number POSDRU/89/1.5/S/63258 ”Postdoctoral school for zootechnical biodiversity and food biotehnology based on the eco-economy and the bio-economy required by eco-san-genesys”

REFERENCES

1. Becker, H. (1954). The Contribution to the Knowledge of the Byctiscus (Byctiscus betulae L. ) Entomological Contributions, 4, (2), 158-172. [Ger.] 2. Botnarciuc, N. and A. Vădineanu (1982). Ecology. Ed. Didactică şi Pedagogică, Bucureşti [Rom] 3. Daanje, A. (1956). The Technique of Twisting of the Leaves at coryli L. and nitens Scop. (Coleoptera, ), Behaviour, XI, 86-155. [Ger.] 4. Fenili, , G.A. (1952). Contributions to the Knowledge of dell' Scop. (Coleoptera, Curculionidae), “Redia” Giornale de Entomologia, 38: 193-281. [Ital.] 5. Mărgărit, Gr.(1967). Observations regarding the Mass Multiplication of the Bug Byctiscus populi, (Coleoptera, Curculionidae), Studies and Researches of Biology, Zoological Series, 19 (6): 493-500.

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