COMPLEXUL MUZEAL DE ŞTIINŢELE NATURII „ION BORCEA” BACĂU STUDII ŞI COMUNICĂRI 2006 Vol. 21: 274 – 279 THE SINECOLOGICAL ANALYSE OF A FEW POPULATIONS OF CREPUSCULAR AND NOCTURNAL SCARAB BEETLES (INSECTA, COLEOPTERA, SCARABAEOIDAEA) FROM THE MEADOW OF SIRET RIVER AREA MIHAELA ARINTON* ABSTRACT ARINTON M., 2006 - The sinecological analyse of a few populations of crepuscular and nocturnal scarab beetles (Insecta: Coleoptera: Scarabaeoidaea) from the meadow of Siret river area. Studii şi Comunicări, Compl. Muz. Şt. Nat. „Ion Borcea” Bacău, vol. 21: 274-279. For studying the crepuscular and nocturnal scarabeoid fauna from the meadow of Siret River area, the author analyzed 323 scarab beetles. The insects were collected in 2004-2006, with the help of a lighting trap. Systematically speaking, the 323 specimens belong to 4 families, 6 subfamilies: Geotrupidae (Bolboceratinae, Geotrupinae), Ochodaeidae (Ochodaeinae), Trogidae, Scarabaeidae (Scarabaeinae, Aphodiinae, Melolonthinae), 14 genera and 19 species. According to the sinecological analyze realized for the 19 species collected in this area, Oxyomus sylvestris Scop., Melolontha melolontha L. and Aphodius (Acanthobodilus) immundus Creutzer are the eudominant species; Geotrupes spiniger Marsh. is the only dominant species. For the studied area, Oxyomus sylvestris Scop., Melolontha melolontha L., Aphodius (Acanthobodilus) immundus Creutzer, Geotrupes spiniger Marsh. and Pleurophorus caesus Creutzer are the characteristic species. The other 14 species are accessories. Studying the cenotic affinities between the species, the results indicate that the highest affinity is between Copris lunaris L. and Pleurophorus caesus Creutzer – 96%. Other groups of species are represented by: Ochodaeus chrysomeloides Schrank – Odontaeus armiger Scop. (92%); Aphodius (Acanthobodilus) immundus Creutzer – Geotrupes spiniger Marsh. (89%); Aphodius (Calamosternus) granarius L. – Aphodius (Bodilus) lugens Creutzer (approximate 85%). Another group is represented by Euheptaulacus sus Herbst, Aphodius (Nialus) varians Duftsch. and Polyphylla fullo L. In this case, the value for the affinity indicator is 80%. Key words: nocturnal, crepuscular scarabeoids, sinecological analyze Introduction active during the day, when the sun is shining, but Scarabs are heavy-bodied, oval beetles, many species are nocturnal or crepuscular. The insects which are included in a large suprafamily of insects included in first group can be collected during the day, – about 30,000 species distributed throughout most directly from the flowers, or by using the of the world. A large group of scarab beetles are entomological net. For studying the nocturnal or scavengers, feeding on decaying vegetation or on the crepuscular scarabs it is necessary to use lighting traps. dung of grazing animals. Other species of scarab beetles feed on living plants. Members of these Material and methods groups include such major crop and garden pests as The material analyzed in this paper work was the Japanese beetle, the rose chafer, and the May collected with a lighting trap placed in the meadow beetle. Adult plant-eating scarab beetles attack of Siret River area (in Holt Village from Letea leaves, flowers, and fruits, while the larvae, which Veche Commune). The researches were made in develop from eggs, laid in the ground, attack roots. 2004-2006. The scarabs are active in different periods of the In order to make a sinecological analyze, it year: some of them emerge from the soil early in the was necessary to calculate some ecological spring (Rhizotrogus aequinoctiale Herbst. – in March, indicators: abundance, frequency, constancy, Rhizotrogus vernus Germ. – in April, Melolontha dominance, ecological significance indicator (W) melolontha L. – in May, Amphimallon solstitiale L., and similarity indicator. Amphimallon caucasicus Gyll., Amphimallon assimile Herbst – in June, Monotropus nordmanni Blanch., Results and discussions Anoxia pilosa F, Anoxia villosa F. – in June-July, The nocturnal and crepuscular scarab fauna Anoxia orientalis Kryn. and Polyphylla fullo L. are from this area has been represented by 323 scarab active in July-August). Also, some scarab beetles are beetles, which, systematically belong to 4 families, * “Ion Borcea” Natural Sciences Museum Complex 274 6 subfamilies: Geotrupidae (Bolboceratinae, followed by Melolontha melolontha L. – 24.86%. Geotrupinae), Ochodaeidae (Ochodaeinae), Other well represented species are Aphodius Trogidae, Scarabaeidae (Scarabaeinae, Aphodiinae, (Acanthobodilus) immundus Creutz. (10.83%) and Melolonthinae), 14 genera and 19 species (table 1). Geotrupes spiniger Marsh. (9.29%). These results The results indicate that for the three years of are also graphically represented in figure 1. study Oxyomus sylvestris Scop. was very well According to the same graphic, for 4 species the represented – 90 specimens (27.86%) and it is percentages distribution are less than 1%. Tab. 1 - Distribution of species and individuals within the families and subfamilies of Scarabaeoidaea No Family Subfamily Specie Total A % 1. Bolboceratinae Odontaeus armiger Scop. 6 1.86 2. Geotrupidae Geotrupinae Anoplotrupes stercorosus Scriba 2 0.62 3. Geotrupes (Geotrupes) spiniger Marsh. 30 9.29 4. Ochodaeidae Ochodaeinae Ochodaeus chrysomeloides Schrank 7 2.17 5. Trogidae Trox scaber L. 5 1.55 6. Scarabaeinae Copris lunaris L. 12 3.72 7. Aphodius (Acanthobodilus) immundus Creutzer 35 10.83 8. Aphodius (Bodilus) lugens Creutzer 4 1.24 9. Aphodius (Bodilus) punctipennis Erich. 1 0.31 10. Aphodiinae Aphodius (Calamosternus) granarius L. 3 0.93 11. Scarabaeidae Aphodius (Chilothorax) distinctus Müll. 1 0.31 12. Aphodius (Nialus) varians Duftsch. 4 1.24 13. Euheptaulacus sus Herbst 4 1.24 14. Oxyomus sylvestris Scop. 90 27.86 15. Pleurophorus caesus Creutzer 13 4.02 16. Maladera holosterica Scop. 9 2.78 17. Melolonthinae Melolontha melolontha L. 79 24.46 18. Miltotrogus vernus Germar 10 3.09 19. Polyphylla fullo L. 8 2,48 4 6 15 323 100 1,86% 0,62% Odontaeus armiger Scop. 2,48% 9,29% Anoplotrupes stercorosus Scriba 3,09% Geotrupes spiniger Marsh. 24,46% 2,17% Ochodaeus chrysomeloides Schrank 1,55% Trox scaber L. 3,72% Copris lunaris L. Aphodius (Acanthobodilus) immundus Creutz. Aphodius (Bodilus) lugens Cretz. 10,83 Aphodius (Bodilus) punctipennis Erich. 1,24% Aphodius (Calamosternus) granarius L. Aphodius (Chilothorax) distinctus Mull. 0,31% Aphodius (Nialus) varians Duftsch. 0,93% Euheptaulacus sus Herbst Oxyomus sylvestris Scop. 2,78% 0,31% 1,24% Pleurophorus caesus Creutz. 4,02% Maladera holosterica Scop. 1,24% Melolontha melolontha L. Miltotrogus vernus Germar 27,86% Polyphylla fullo L. Fig. 1 - The percentages distribution of nocturnal and crepuscular scarab beetles from the meadow of Siret River area (2004-2006) 275 In table 2 is presented the sinecological scaber L., Aphodius (Bodilus) lugens Creutzer, analyze for all the species of crepuscular and Aphodius (Calamosternus) granarius L., nocturnal scarabs collected in the meadow of Siret Anoplotrupes stercorosus Scriba; and accessory River area. According to this analyze, 13 species are species (Aphodius (Chilothorax) distinctus Müll., euconstant – they were collected in each year of Aphodius (Bodilus) punctipennis Erich.). study. The other species belong to constant – Trox Tab. 2 - Sinecological analyze of crepuscular and nocturnal scarabs collected in the meadow of Siret River area (2004-2006) No Specia 2004 2005 2006 A C D W 1. Oxyomus sylvestris Scop. 35 28 27 90 100 C4 27,86 D5 27,86 W5 2. Melolontha melolontha L. 21 17 41 79 100 C4 24,46 D5 24,46 W5 3. Aphodius immundus Creutzer 15 8 12 35 100 C4 10,83 D5 10,83 W5 4. Geotrupes spiniger Marsh. 13 9 8 30 100 C4 9,29 D4 9,29 W4 5. Pleurophorus caesus Creutzer 2 5 6 13 100 C4 4,02 D3 4,02 W4 6. Copris lunaris L. 2 5 5 12 100 C4 3,71 D3 3,71 W3 7. Miltotrogus vernus Germar 2 5 3 10 100 C4 3,09 D3 3,09 W3 8. Maladera holosterica Scop. 1 2 6 9 100 C4 2,78 D3 2,78 W3 9. Polyphylla fullo L. 4 2 2 8 100 C4 2,48 D3 2,48 W3 10. Ochodaeus chrysomeloides Schrank 2 2 3 7 100 C4 2,17 D3 2,17 W3 11. Odontaeus armiger Scop. 2 1 3 6 100 C4 1,86 D2 1,86 W3 12. Aphodius varians Duftsch. 1 1 2 4 100 C4 1,24 D2 1,24 W3 13. Euheptaulacus sus Herbst 2 1 1 4 100 C4 1,24 D2 1,24 W3 14. Trox scaber L. - 1 4 5 66,66 C3 1,55 D2 1,03 W2 15. Aphodius lugens Creutzer - 3 1 4 66,66 C3 1,24 D2 0,82 W2 16. Aphodius granarius L. - 2 1 3 66,66 C3 0,93 D1 0,62 W2 17. Anoplotrupes stercorosus Scriba 1 1 2 66,66 C3 0,62 D1 0,41 W2 18. Aphodius distinctus Müll. - 1 - 1 33,33 C2 0,31 D1 0,1 W2 19. Aphodius punctipennis Erich. 1 - - 1 33,33 C2 0,31 D1 0,1 W2 15 104 93 126 323 - - 100 - - - Consulting the results presented in table 2, it Aphodius (Chilothorax) distinctus Müll. and was possible to identify the eudominant species: Aphodius (Bodilus) punctipennis Erich. Oxyomus sylvestris Scop., Melolontha melolontha L., For studying the cenotic affinities between Aphodius (Acanthobodilus) immundus Creutzer. the species, it was necessary to calculate the Geotrupes (Geotrupes) spiniger Marsh. is the single similarity indicator – table 3. The dendrogram dominant specie. According to the same table, 6 presented in figure 2 was realized based on the species are subdominant, 5 subrecedent and 4 are values of this indicator. recedent species. According to these data, the affinity between Based on the values of ecological Copris lunaris L. and Pleurophorus caesus Creutzer significance indicator (W), it was possible to is 96%. The affinity between these is not 100% identify the characteristic species. Thus, from the 19 because, although the two species were collected in species of scarabs identified for the meadow of Siret each year of study, in 2004 they were represented by River area, 5 are characteristical (Oxyomus sylvestris 2 specimens each, in 2005 – 3 individuals each, but Scop., Melolontha melolontha L., Aphodius for 2006, the difference between the two species is (Acanthobodilus) immundus Creutzer.