Comparison of forensically important species of flies in area of the cities of Split and Omiš

Abstract

Entomologija je znanost koja proučava insekte, a forenzična entomologija insekte pronađene na mrtvim tijelima. Točna identifikacija vrste muha iznimno je važan korak u forenzičnoj entomologiji, s obzirom na činjenicu da insekt prikupljen na truplu može omogućiti korisne informacije za procjenu postmortalnog intervala (PMI) tj. procjenu vremena kada je smrt najvjerojatnije nastupila. Ciljevi ovog diplomskog rada su prikupiti, identificirati i utvrditi brojnost i raznolikost strvinarskih vrsta muha te ih usporediti između dva grada, u ovom slučaju Splita i Omiša. Osim navedenog, namjera nam je bila i ustanoviti utjecaj temperature, vlažnosti zraka i oborina na razlike u brojnosti i raznolikosti vrsta. Proteinska klopka za hvatanje muha napravljena je od plastične boce na kojoj je po sredini izrezan otvor kroz koje bi muhe ulazile, a u bocu smo još ulijeli 70%-tni alkohol. Na vrh čepa s unutarnje strane boce smo objesili mamac, svježe meso (pileća jetrica) i kao takvu objesili konopom za granu stabla. Istraživanje je trajalo tri mjeseca (travanj, svibanj i lipanj), klopka je bila postavljena tijekom tri dana u razmaku od pet tjedana. Primjenom proteinske klopke ukupno je prikupljeno 366 jedinki koje pripadaju redu Diptera, kasnije identificirane u pet porodica i devet vrsta. Najbrojnija porodica bila je Calliphoridae (muhe zujare) sa 6 identificiranih različitih vrsta, dok je druga najbrojnija bila Psychodidae kojoj nismo uspjeli identificirati točnu vrstu, a treća je Sarcophagidae (muhe mesaruše) s 3 različite vrste, zatim Anthomyidae s 2 i Phoridae s 1 jedinkom koju također nismo uspjeli identificirati. Na kraju istraživanja ustanovili smo da se porodice i vrste razlikuju i po brojnosti i po raznolikosti vrsta kako između oba proučavana područja tako i između samih mjeseci na istom području. Razlike su nastale zbog utjecaja temperature zraka, vlažnosti zraka i oborina na navedenim lokacijama te zbog različitosti okoliša. Dodatni faktor koji je utjecao na njihovu međusobnu brojnost i raznolikost krije se u činjenici da su ta dva područja sama po sebi različita. Lokacija u gradu Splitu nalazi se u blizini brze ceste s malim brojem stabala, dok s druge strane područje omiške lokacije bogato je borovom šumom te ga karakterizira netaknuta priroda i poprilična udaljenost od civilizacije.Entomology is the science that studies insects and forensic entomology examines insects found on dead bodies. Accurate identification of fly species is an important step in forensic entomology, given the fact that an insect collected on a carcass can provide useful information for estimating postmortem interval (PMI) i.e. estimating the time when death most likely occurred. The objectives of this master thesis are to collect, identify and determine the number and diversity of carnivorous species of flies and compare them between two cities – Split and Omiš. Also, the goal was to establish the influence of temperature, humidity and precipitation on the differences in the number and diversity of species. The protein trap for catching flies was made out of a plastic bottle with a hole cut in the middle through which the flies would enter, and at the bottom of the bottle we poured 70% alcohol. At the top of the cap on the inside of the bottle we hung the bait, fresh meat (chicken liver), and as such we hungit with a rope for a tree branch. The survey lasted three months (April, May and June), during three days and five weeks apart. Using the protein trap, a total of 366 individuals belonging to the order Diptera were collected, later identified in five families and nine species. The most numerous family was Calliphoridae (buzzard flies) with 6 identified different species, while the second most numerous was Psychodidae, whose species could not be identified, the third was Sarcophagidae (butcher flies) with 3 different species, followed by Anthomyidae with 2 and Phoridae with 1 unit that we also failed to identify. At the end of the research, we found that families and species differ in both number and diversity of species, inluding between the two studied areas and between the months in the same area. The differences are due to the influence of air temperature, humidity and precipitation in these locations and due to the diversity of the environment. Moreover, an additional factor that influenced their mutual number and diversity lies in the fact that the two areas are different per se. The location in the city of Split is located near the highway with a small number of trees, while on the other hand the area of location in Omiš is rich in pine forests and is characterized by untouched nature and considerable distance from civilization