EFFECT of SOME ABIOTIC FACTORS on the POPULATION DYNAMICS of TABANIDAE

(DIPTERA: INSECTA) SPECIES in ESKİŞEHİR in TURKEY

Ferhat ALTUNSOY and A. Yavuz KILIÇ Department of Biology, Faculty of Science, Anadolu University , Eskişehir, Turkey.

tabanidae@msn.com INTRODUCTION :INTRODUCTION :

Tabanidae consists of about 4300 species of medium to very large biting flies; indeed, it contains some of the largest blood-sucking insects. The sheer size of tabanids and the pain their bite can cause mean they are not easily ignored. Large accumulations of flies do occur in some areas, and with their painful bite tabanids can be pests of both livestock and humans. Livestock worry can reach a level at which economic losses occur. Females of most Tabanidae species attack mammals and human. Like other blood-sucking flies, Tabanids have a negative economic effect on milk production where they commonly live. Moreover, Tabanids are known worldwide as important mechanical vectors to cause of diseases in some wild and domestic animals.

Understanding changes in the size of populations is a central objective in ecology. The issue has important theoretical and practical implications related to the nature of biological complexity (Zimmer, 1999), conservation of threatened species (Dennis et al. 1991), regulation of exploited populations (Higgins et al. 1997) and management of pests (Logan et al. 1998). These applications often require forecasting population changes. So, the purpose of this study was to investigate the seasonality, relative abundance and fluctuations of population of horseflies species.

Correlation coefficient data has shown that the average, maximum and minimum temperatures had a significant immediate effect on the population (To= 0,689, P= 0,01; To= 0,631, P=0,001 and To= 0,536, P=0,001) (Figure 1)

MATERIAL AND METOT :MATERIAL AND METOT :

Populations of horseflies species were monitored for a 2-y period (May 2005-October 2007) on a marshy area in Eskişehir (39o 53’ 936” N, 30o 37’ 747” E) (1171m) in Turkey. Sampling was conducted fourtimes every week between from 07:00 to 19:00 (May to October every year) using Malaysia and water traps. Weekly population data of species were converted to monthly means for analysis. Monthly means of abiotic factors, maximum and minimum temperature, rainfall and relative humidity, were obtained from the Regional Meteorological Station, Eskişehir. Population dynamics of tabanids were examined for correlations with the abiotic factors.

All data were transformed to normal variants z=(X-μ)/α. A nonparametric Kendall’s correlation coefficient test (SPSS) was done to compute correlation between the monthly population of horseflies and the corresponding month’s abiotic factors.

RESULTS :RESULTS : A total 9. 865 tabanids belonging to eighth genera and 49 species was collected (Table 1).

Photo: Silvius alpinus, copyright by Altunsoy

Relative humidity had no significant immediate or delayed effects on the population of tabanids (Figure 2). As for the influence of rainfall, it usually supported a high population and so, soon after the monsoon, a significant population increase was always observed (To= -0,611, P= 0,003 ).

Rainfall had a significant positive correlation with population within a short period (To= -0,226, P= 0,270) (Figure 3)

Figure 1: Population-temperature

Figure 2: Population-relative humidity

Figure 2: Population-rainfall

DISCUSSION :DISCUSSION :

The studies of the seasonal abundance of tabanids are very important from standpoint of medical and veterinary parasitology, because some species of tabanids participate in transmission of agents of various diseases (Foil, 1989; Krcmar, 2005). Moreover, It will be helpfull for human to get knowledge about ecology, seasonal and daily activity and chances in population density of these vector insects. So, In this study we declared the yearly chances in population density of Tabanidae species.

It can be concluded that different abiotic factors imposed delayed effects of varying durations on the populations of horseflies species. Rainfall alone had an immediate negative effect on the population and seasonality of tabanids. Minimum temperature and relative humidity had no effects at all on the populations of tabanids. Most importantly this study has demonstrated a method by which such differential effects of weather on insect population can be analyzed.

REFERENCES :REFERENCES :

11. Dennis B. Munholland P.L. and Scott J.M. (1991) “Estimation of growth and extinction parameters for endangered species” Ecol. Monogr. 61:115-143.

2. Foil, L.D. (1989) “Tabanids as vectors of disease agents” Parasitol. Today 5:88-96.

3. Higgins K. Hastings A. Sarvela J.N. (1997) “Sthocastics dinamics and deterministic skeletons: population behavior of dungeness crab. Sci. 276:1431-1435.

4. Krcmar, S. “Seasonal abundance of horse flies (Diptera: Tabanidae) from two Locations in Eastern Crotia,” J. of Vector Ecology, 30(2), 316-321 (2005).

5. Logan J.A. White P. Bentz B.J. Powell J.A. (1998) Model analysis of spatial patterns in mountain pine beetle outbreaks Theor. Popul. Biol. 53:236-255.

6. Zimmer C. (1999) Life after chaos. Science 284:83-86

Species 2005   2006   2007

 May

.June July

Aug.

Sep.  

May.

June

July

Aug.

Sep.  

May.

June July

Aug.

Sep.

Atylotus fulvus 0 0 25 8 0   0 0 2 0 0   0 11 8 0 0

Chrysops caecutiens 0 3 8 1 0   0 0 5 2 0   0 15 16 2 0

Chrysops viduatus 0 1 2 1 0   0 0 2 0 0   0 3 5 1 0

Dashyrhamphis carbonarius 0 1 0 0 0   0 2 0 0 0   0 2 0 0 0

Dashyrhamphis umbrinus 10 157 22 0 0   7 26 0 0 0   9 116 0 0 0

Haematopota bigoti 0 2 1 0 0   0 0 0 0 0   0 0 1 0 0

Haematopota crassicornis 0 1 4 0 0   0 0 0 0 0   0 0 1 0 0

Haematopota grandis 0 0 2 0 0   0 0 1 0 0   0 0 1 0 0

Haematopota longantennata 0 0 1 0 0   0 0 1 0 0   0 0 1 0 0

Haematopota ocelligera 0 7 0 0 0   0 4 0 0 0   0 0 0 0 0

Haematopota pluvialis 0 18 13 0 0   0 16 8 0 0   0 2 0 0 0

Haematopota scutellata 0 6 0 0 0   0 6 0 0 0   0 3 0 0 0

Haematopota subcylindrica 12 434 686 68 10   7 76 61 30 10   15 117 204 8 0

Hybomitra caucasica 7 3 0 0 0   5 4 0 0 0   6 4 0 0 0

Hybomitra ciureai 0 0 2 0 0   0 0 0 0 0   0 0 1 0 0

Hybomitra pilosa 0 3 0 0 0   1 0 0 0 0   0 2 0 0 0

Philipomyia aprica 0 15 204 22 5   0 15 34 12 3   3 257 484 7 0

Philipomyia zizaniae 0 0 0 0 0   0 0 0 0 0   0 1 5 0 0

Tabanus armeniacus 0 0 2 0 0   0 0 0 0 0   0 0 1 0 0

Tabanus autumnalis 0 32 12 0 0   0 0 4 0 0   0 7 3 0 0

Tabanus bifarius 0 44 29 8 0   0 8 6 2 0   0 277 29 3 0

Tabanus briani 0 0 1 0 0   0 0 0 2 0   0 0 0 0 0

Tabanus bromius 1 138 513 85 12   3 35 76 53 15   2 143 376 42 10

Tabanus cordiger 0 13 0 0 0   0 6 6 0 0   0 4 5 0 0

Tabanus cuculus 0 0 1 0 0   0 0 0 1 0   0 0 2 0 0

Tabanus eggeri 0 0 1 0 0   0 0 0 0 0   0 0 2 0 0

Tabanus exclusus 0 5 30 8 0   0 0 5 6 0   0 8 6 0 0

Tabanus glaucopis 0 0 11 14 2   0 0 2 8 2   0 0 10 5 3

Tabanus golovi 0 0 0 0 0   0 0 0 0 0   0 0 2 0 0

Tabanus indrae 0 0 0 0 0   0 0 3 3 0   0 0 2 0 0

Tabanus laetetinctus 0 0 1 0 0   0 0 0 0 0   0 0 2 0 0

Tabanus leleani 0 2 0 0 0   0 0 8 0 0   0 5 0 0 0

Tabanus lunatus 0 3 35 3 0   0 0 25 10 2   0 11 162 13 2

Tabanus maculicornis 0 4 1 0 0   0 0 0 0 0   0 0 1 0 0

Tabanus martinii 0 0 0 7 1   0 0 0 0 2   0 0 0 5 2

Tabanus miki 0 0 20 3 0   0 0 6 4 0   0 6 10 7 0

Tabanus porchinskii 0 0 32 10 0   0 0 11 12 0   0 0 42 8 0

Tabanus prometheus 0 0 9 0 0   0 0 2 0 0   0 0 14 0 0

Tabanus quatuornotatus 8 385 8 0 0   8 96 0 0 0   6 87 3 0 0

Tabanus regularis 0 0 0 0 0   0 0 0 3 0   0 0 0 2 0

Tabanus rupium 0 46 2 0 0   0 16 18 0 0   0 25 3 0 0

Tabanus spodopteroides 0 0 2 0 0   0 0 2 0 0   0 0 1 0 0

Tabanus spodopterus 0 0 25 1 0   0 0 6 4 0   0 0 8 3 0

Tabanus sudeticus 0 2 2 3 0   0 0 0 0 0   0 0 0 1 0

Tabanus terterjani 0 0 0 0 0   0 0 0 0 0   0 0 0 2 0

Tabanus tinctus 0 0 3 0 0   0 0 0 0 0   0 0 1 0 0

Tabanus unifasciatus 3 145 35 8 3   3 18 27 15 3   4 68 0 5 10

Therioplectes tricolor 0 12 0 0 0   0 0 8 0 0   0 6 0 0 0

TOTAL 41148

2174

5 250 33   34 328 329 167 37   45118

0141

2 114 27