Issues


Issues: 1-5 | 6-10 | 11-15 | 16-20 | 21-25 | 26-30 | 31-32
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Morphological analysis of Wood mouse (Apodemus sylvaticus)  zoomonitor for human impact on the environment in Bulgaria: Sexual dimorphism of craniometrical variation

Georgy Markov1, Ivanka Atanasova2, Milena Gospodinova1, Ivaylo Raykov2

1Institute of Zoology, BAS; 2Konstantin Preslavsky University of Shumen

Abstract:

Morphological analysis of specimens of the wood mouse (Apodemus sylvaticus) from agricultural region in Northeastern Bulgaria was carried out. The degree of sexual dimorphism of the studied craniometrical measurements was revealed through: (a) variation flow, (b) assessment of degree of comparative variation and (c) morphological profiles. The obtained results extend the knowledge about population characteristics of the zoo-monitor A. sylvaticus in regard to the assessment of phenotype population variation of the two sexes under agricultural conditions. The established characteristics represented substantial morphological basis for further eco-physiological investigations of this zoo-monitor species in agricultural ecosystems in Bulgaria.

 

(Forestry Ideas, 2009, Vol. 15, No. 1) [Download]
Downloads: 1195

Study of the Ichthyofauna of Ivailovgrad Dam

Nikolay Kodjabashev, Vasil Kolev, Gradimir Gruitchev

University of Forestry  Sofia

Abstract:

The subject of the current article is the ichthyofauna and the ichtyocenosis of Ivailovgrad dam. Eleven species of fish have been identified, one of which has been registered for the first time for this dam. Two species of asp fish and eel can be considered extinct since they haven't been caught for the last 30 years. On the basis of the coenosis results the contemporary state of the fishing stocks in Borislavtsi Bay has been established. The rates of growing and predominance have been found, leading to the conclusion that the ecological balance has been seriously disturbed as a result of the illegal catch. The predominant species in the region such as Roach and Dark Vimba are of little value. The commercially important European catfish, Carp and Pikperch have a very irregular size and age structure and make up a small percentage of the total catch. The structure of Vardar Nase has also been disturbed, probably due to changes in the spawn areas. The results of our research lead to the conclusion that a stricter control over the catch must be imposed especially during the spawn season. Dramatic changes have occurred as a result of the cascade of the three dams. They constitute an insurmountable barrier to fish populations and cause for genetic isolation. Lack of fish passages along the river have led to complete disappearance of the asp. and eal. And in a significant reduction of typical reofil species as maritza barbel vardar nase, dark vimba. With the construction of the dam has significantly increased opportunities for the cultivation of valuable species for industrial and sports fishing. These are carp, pikperch, catfish from the natural species and grass carp and silver carp from intoduction.

(Forestry Ideas, 2009, Vol. 15, No. 1) [Download]
Downloads: 881

Ceroplastes japonicus (Green) (Hemiptera:Coccoidea: Coccidae)  a new pest on Ilex in Bulgaria

Anelya Pencheva

University of Forestry  Sofia

Abstract:

Ceroplastes japonicus (Green) is a new insect species in Bulgaria. It identification was for the first time in 2006, from plant material, collected in greenhouses (Sofia). During monitoring in the period 20072009 this species was found outdoors only along the Black sea coast, (Sozopol, Burgas and Sunny beach), but nowhere else. We noticed mass outbreaks of C. japonicus mainly on Ilex aquifolium, and also on Laurus nobilis and Citrus sp.

The following conclusions were made based on the three year long studies:

 The plants examined in the studies are an important source tor the introduction of Ceroplastes japonicus in Bulgaria.

 During the course of the studies the species has adapted to the conditions of both the region around Sozopol and more barren areas around Burgas and is able to develop sucessfully there.

(Forestry Ideas, 2009, Vol. 15, No. 1) [Download]
Downloads: 1375

THE LEAF-MINER MOTHS AS A PART OF THE BULGARIAN BIODIVERSITY

Rumen Tomov

University of Forestry - Sofia 

Abstract:

In the framework of project "Investigation on leaf-mining insects (Lepidoptera) in Bulgaria", the published information about leafminers of Bulgaria was analized. On the base of new collected insect material the species composition of 10 lepidopteran families was studied.

The establishment of 466 leaf mining species belonging to 29 families from 14 superfamilies of order Lepidopterain Bulgariawas confirmed by our survey. A list of alien leaf-miner moths, review of their spreading pattern and actual population status is presented. The possible threat leafminers to biodiversity and economy of Bulgariais discussed.  

(Forestry Ideas, 2009, Vol. 15, No. 1) [Download]
Downloads: 1289

ALIEN INSECTS AND THEIR TREAT TO BIODIVERSITY OF BULGARIA

Rumen Tomov1, Katya Trencheva1, Georgy Trenchev1, Marc Kenis2

1University of Forestry  Sofia; 2CABI Europe-Switzerland, Delemont, Switzerland

Abstract:

In the framework of the ATARTIB project, the level of knowledge about alien insects and their environmental impact in Bulgaria was assessed. The literature survey, showed that the published information was dispersed among many publications, most of them very old or difficult to be found in the libraries.

The published data about negative environmental impact of alien insects on biodiversity of Bulgaria was not found but the following gaps in our knowledge were detected: (1) for most of the species reported, only faunistic datawere found; (2) for some species only a single report was found with no information on their population status;(3) some species are present in Bulgaria according to Fauna Europea database, but the references ware not available for us, since they most probably ware reported by not local entomologists;(4) the inclusion of such species in the preliminary analysis made, is questionable, since it is not clear whether the species are established or have been intercepted only;(5) only alien species of economic concern and under phytosanitary control are studied (6) the analysis concerns published information about species considered to be of exotic origin and introduced in Bulgaria by means of human activity only.

We propose following investigations to be carried on, in order to be created the general monitoring and management system of alien arthropods of Bulgaria: (1) accurate inventory of alien arthropods filling the gaps in knowledge concerning alien arthropods in Bulgaria detected in framework of conducted projects; (2) study the ecological impact of selected alien species and the mechanisms underlying this impact; (3) assessing the role of natural enemies in the invasion success of alien species; (4) assessing the role of alien arthropods on mammals and birds as vectors of diseases.

(Forestry Ideas, 2009, Vol. 15, No. 1) [Download]
Issues: 1-5 | 6-10 | 11-15 | 16-20 | 21-25 | 26-30 | 31-32