Effect of environment on mosquito dispersion

Glavni cilj ovoga istraživanja bio je utvrditi smjer disperzije komaraca vrste Culex tarsalis i istražiti utjecaj okoliša na tu disperziju. Culex tarsalis Coquillett najbrojnija je vrsta komaraca na području jugoistočne Kalifornije i glavni ruralni vektor tih prostora. Prenositelj je mnogih virusa, od kojih su najpoznatiji „Western equine encephalomyelitis“ (WEE), „St. Louis encephalitis“ (SLE) i „West Nile“ virus (WNV). Disperzija komaraca vrste Cx. tarsalis istražena je na širem području naselja Mecca u dolini Coachella Valley u Kaliforniji, u razdoblju od 22. listopada do 6. studenoga 2007. godine „capture-mark-release-recapture“ metodom. Komarci su skupljeni južno od naselja Mecca (23 890), markirani dvjema fluorescentnim bojama (orange i aqua) i pušteni s dvije lokacije: sjeveroistočno i jugozapadno od naselja Mecca. Uzorkovanje markiranih jedinki provedeno je devet puta u dvanaest dana na 40 postaja pravilno raspoređenih na površini od oko 30,6 km2, međusobno udaljenih od 0,2 km do 0,8 km. Korištene su CDC-klopke uz CO2 kao atraktant, ali bez izvora svjetlosti, a postavljene su unutar šest različitih tipova staništa (pustinjsko stanište, plantaže datulja, voćnjaci citrusa, vinogradi, poljoprivredno područje i urbano područje). Ponovno je uhvaćeno 266 markiranih jedinki vrste Cx. tarsalis (1,11%), od čega 90,22% u prva tri dana uzorkovanja. Više od 50% markiranih jedinki uhvaćeno je u pustinjskom staništu, a tek 3,4% u urbanom staništu. Utvrđeno je kako broj markiranih jedinki značajno raste s porastom udjela pustinje, a značajno opada s porastom udjela urbanog područja u okolici točke hvatanja komaraca, dok o udjelu poljoprivrednih površina, voćnjaka citrusa, vinograda i plantaža datulja ne ovisi statistički značajno. Na temelju provedene statističke analize dokazano je da nije bilo razlike u disperziji između orange i aqua-komaraca (ovisnoj o udaljenosti od točke puštanja i kutnom otklonu od sjevera). Zabilježena je značajna tendencija disperzije komaraca u smjeru juga, s obje točke puštanja, vjerojatno stoga jer je ondje većina pogodnih mjesta za hranjenje i polaganje jaja, a relativna vlažnost zraka je u porastu zbog blizine ribnjaka i umjetnih jezera. Moguće je također da je kretanje komaraca usmjeravao vjetar koji je u razdoblju istraživanja bio dominantno sjeverni. Srednja dnevna prijeđena udaljenost razlikovala se za aqua (0,79 km) i orange (1,06 km) komarce. Faunističkom obradom ukupnoga broja jedinki (34 708) utvrđeno je osam vrsta komaraca, od kojih je Cx. tarsalis najzastupljenija i čini udio od 86,09%. Ona je jedina eudominantna, eukonstantna i ekskluzivna vrsta u svim zastupljenim staništima. Ustanovljeno je da ukupan sastav populacija komaraca i njihova brojnost koleba u odnosu na tip staništa. Uspoređujući disperzije ruralnih i poplavnih vrsta komaraca, utvrđeno je da se razlikuju u brzini, ali i da su slične po tome što isu dominantno usmjerene prema urbanim staništima. Spoznaje o kretanju komaraca, dobivene istraživanjima u Kaliforniji i istočnoj Hrvatskoj, mogu unaprijediti programe kontrole komaraca-vektora, uzimajući u obzir okolišne faktore koji utječu na smjer leta ženki komaraca.The purpose of the study was to determine direction of mosquito dispersal for species Culex tarsalis and to examine the environmental effect on dispersion. Culex tarsalis Coquillett is the most abundant mosquito species in southeast California and the primary rural vector of the area. It transmits a wide variety of viruses; the most outstanding are Western equine encephalomyelitis (WEE), St. Louis encephalitis (SLE) and West Nile virus (WNV). The investigation of dispersal of Cx. tarsalis was performed in the area of Mecca town in Coachella Valley, California, in the period October 22 – November 6, 2007, using capturemark-release-recapture methods. First, the mosquitoes (23,890) were collected at traps placed south from Mecca, then marked with fluorescent dust (orange and aqua) and, finally, released at two locations: northeast and southwest of small town Mecca. Recapture was performed nine times in twelve days at 40 CO2 baited CDC-traps without lights and placed across the area (30.6 km2) in six different habitats (desert, date gardens,citrus orchards, vineyards, agricultural area and urban area). The sampling points were between 0.2 km to 0.8 km away from each other. During the first three days of investigation 90.22% of the total 266 Cx. tarsalis females (1.11%) were recaptured. More than 50% of the marked mosquitoes were collected in the desert while only 3.4% in urban habitat. The analysis indicated that in the surroundings of the trap site the number of marked mosquitoes significantly increases along with the raise in the portion of the habitat characterised by the desert and significantly decreases with the raise in the portion of the habitat that is urban. However, the portion of agricultural area, citrus orchards, vineyards and date gardens has no statistically significant bearing. Statistical analyses confirmed that there were no differences in dispersion between orange and aqua mosquitoes (dependent on the distance from the release point and on the angle of deflection from the North). A significant tendency of mosquito dispersal to the south was recorded for both release points, probably due to the most favourable feeding places and oviposition sites and potentially increase humidity caused by the vicinity of large ponds. Furthermore, there is a possibility that the wind, predominantly northern during the investigation period, had an influence on mosquito dispersal direction. The mean distance travelled was different for aqua (0.79 km) and orange (1.06 km) mosquitoes. Eight species emerged through faunistic analysis of the adult mosquitoes captured (34,708), the most common being Cx. tarsalis (86.09%). This is the only eudominant, euconstant and exclusive species in all habitats. It was determined that mosquito population structure and mosquito abundance oscillate in accordance with the habitat type. The comparison of dispersion of rural and floodwater mosquito species identified differences in dispersal rates. However, similarities were detected with regard to the direction (the prevailing direction was away from urban habitats). Knowledge of mosquito movement obtained by the investigations in California and Eastern Croatia can improve mosquito and vector control programs by taking into account environmental factors that influence female mosquito flight direction

Dissemination of Stegomyia albopicta (Skuse 1895) in Istria

Vrsta komarca Stegomyia albopicta - azijski tigrasti komarac (Diptera, Culicidae) otkrivena je na području poluotoka Istre tijekom rujna i listopada 2005. godine. Budući da je otada ta vrsta prisutna u Italiji, moglo se očekivati širenje prema Hrvatskoj. Terenskim istraživanjima na području Istre prisutnost vrste evidentirana je u čak osam gradova. Vrsta je zabilježena uglavnom uz obalno područje jugozapadnog dijela Istre: u Puli, Rovinju, Funtani, Poreču, Novigradu, Bujama, Umagu i Savudriji. U gradovima u unutrašnjosti poluotoka još uvijek nije evidentirana. Pretpostavljamo da je vrsta prenesena na dva načina, morskim transportom te uvozom rabljenih guma iz Italije i Slovenije. Ličinke vrste Stegomyia albopicta pronađene su isključivo u umjetnim leglima kao što su spremnici za vodu, gume i vaze, dok su odrasle jedinke uhvaćene u blizini navedenih legala. Ukupno je uhvaćeno 85 jedinki komaraca tj. 45 odraslih i 40 ličinki. Ostale vrste koje se pojavljuju u istraživanim leglima su Culiseta longiareolata, Culex pipiens i Culex hortensis. Hrvatska je osma zemlja u Europi u kojoj je počelo širenje ove izrazito invazivne vektorske vrste.From September to October 2005 the species Stegomyia albopicta, an Asian tiger mosquito (Diptera, Culicidae), was discovered in several places in the Istrian peninsula. As it has been present in Italy for the preceding 15 years, its spread to Croatia was expected. Preliminary studies in Istria show the presence of this species in eight towns. The species was mainly discovered in the southwestern part of the coastal region of Istria: in Pula, Rovinj, Funtana, Poreč, Novigrad, Buje, Umag and Savudrija. In the towns located in the interior of the peninsula the species has not yet been observed. We assume that the species has been transferred in two ways: by marine traffi c, and the used-tire trade from Italy and Slovenia. The mosquito larvae of the Stegomyia albopicta were discovered only in man-made breeding sites such as water reservoirs, tires and vases. Adult mosquitoes were caught in the surroundings of the breeding sites. A total of 45 adult mosquitoes and 40 mosquito larvae were caught. Other species appearing in the breeding sites in addition to the Stegomyia albopicta are as follows: Culiseta longiareolata, Culex pipiens and Culex hortensis. Croatia is the 8th European country where the dissemination of this extremely aggressive vector species has started

Mosquitoes of Istria, a contribution to the knowledge of Croatian mosquito fauna (Diptera, Culicidae)

Background and Purpose: Although Istria was endemic of malaria up to the mid 20th century, the mosquito fauna was studied in detail. Our investigation of mosquitoes in Istria, a very specific region with a highly diverse breeding site types, was conducted in order to gain insights into the mosquito fauna and abundance, as well as to establish the possible presence of new species. Material and Methods: The sampling took place from May to September over a seven-year period, from 1999 to 2005. Mosquito larvae were trapped in medium and small breeding sites using a net 25 or 10 cm in diameter and a dipper. Adult specimens were sampled in both urban and forest areas using CO2 baited CDC traps, and the man – aspirator method for 15 minutes. Results and Conclusions: The research in the area of Istrian peninsula was conducted in 74 sites. We collected 3087 specimens and established the presence of 27 mosquito species. The most abundant mosquito species in the Istrian fauna is Culex pipiens complex with 43.34%, Ochlerotatus sticticus with 9.55%, and Culex hortensis with 9.32%. The remaining 24 species have the share of 37.79%. The largest number of species, 12, were recorded in two sites, Motovun and Pula. In other sites we determined from one to ten species, and the distribution of themost abundant species is presented on UTM maps. Our systematic investigation of mosquitoes in Istria, taking into account the specificities of the terrain and favorable climatic conditions, recorded the mosquito fauna of Istria, species distribution and dominance. The fauna includes 27 mosquito species and shows a great faunistic diversity (54% of the total Croatian mosquito fauna)

Equine Seroprevalence Rates as an Additional Indicator for a More Accurate Risk Assessment of the West Nile Virus Transmission

The West Nile Virus (WNV) is a zoonotic arbovirus that has recently been causing outbreaks in many countries in southern and Central Europe. In 2012, for the first time, it caused an outbreak in eastern Croatia with total of 7 human clinical cases. With an aim of assisting public health personnel in order to improve survey protocols and vector control, the high risk areas of the WNV transmission were estimated and mapped. The study area included cities of Osijek and Slavonski Brod and 8 municipalities in Vukovarsko-Srijemska County. Risk estimation was based on seroprevalence of WNV infections in horses as an indicator of the virus presence, as well as the presence of possible WNV mosquito vectors with corresponding vector competences. Four mosquito species considered as possible WNV vectors are included in this study: Aedes vexans, Culex modestus, Culex pipiens and Ochlerotatus caspius. Mosquitoes were sampled using dry-ice baited CDC trap, twice a month, between May and October. This study suggests that the two mosquito species present the main risk of WNV transmission in eastern Croatia: the Culex pipiens – because of good vector competence and the Aedes vexans – because of the very high abundances. As a result, these two species should be focus of future mosquito surveil- lance and a vector control management

West Nile Virus Outbreak in Humans in Croatia, 2012

During August and September 2012, seven cases of West Nile neuroinvasive disease were identified in three north- -eastern counties of Croatia. Four cases were reported in Osijek-Baranja County, two in Brod-Posavina County and one in Vukovar-Srijem County. The median age of the patients was 62.7 years. All patients were hospitalized for 2–5 weeks. The patients from Slavonski Brod had more severe clinical presentation of disease with prolonged hospitalization. Medi- cal entomological research was carried out in 64 localities, where 1785 mosquitoes were captured. Among the analyzed mosquitoes, 114 were determined to be Culex pipiens and subjected to molecular characterization for the presence of vi- rus. No viral RNA was detected in mosquitoes. Subsequent public health measures taken include mosquito control in all settlements where disease was detected

Utjecaj nekih klimatskih elemenata na reprodukcijska svojstva romanovske ovce na području Bilogore

The study aimed to determine the influence of air temperature, amount of precipitation and sunlight duration on the reproductive traits of the Romanov sheep in the Bilogora region, Croatia.Animals were kept in a fenced rotating pasture with access to stables during the night. Sheep were naturally mated. During three consecutive years (2019-2021), reproductive performance data were collected for four sheep flocks (n=26-57). Data on air temperature, sunlight duration, and daily precipitation volumes were obtained from the Croatian Meteorological and Hydrological Service (CMHS), Zagreb, Croatia, from the nearest meteorological recording station, located within 5-15 km of farms. A total of 425 ewes were mated, of which 399 successfully conceived and 851 lambs were born, with an average litter size of 1.63. The average fertility during the study was 93.88%. Lambing distribution was not equally distributed throughout the year as 73% of all lambs were born during winter and spring (winter 51.88%; spring 21.31%; summer 13.53% and autumn 13.28%). Sexual activity was lowest from the end of March to May, while the peak of sexual activity was from the end of August to October. There was a positive or negative correlation (P<0.0001 (Kruskall-Wallis)) between air temperature, sunshine duration and amount of precipitation with certain reproductive traits (number of pregnant and non-pregnant ewes). Daily average air temperatures were highest in summer but drop suddenly at the start of the breeding season in early autumn. Also, the day begins to shorten, and night begins to become longer which is crucial for shortday breeder species such as sheep and goats. Other factors, such as relative humidity and rainfall, can also directly or indirectly impact sexual activity and significantly affect fertility. The results indicate that air temperature, amount of precipitation, and sunlight duration during different months or seasons could influence the reproductive traits of Romanov sheep in Bilogora region, Croatia.Cilj je istraživanja bio utvrditi utjecaj temperature zraka, količine dnevnih oborina i trajanja sunčeve svjetlosti na reprodukcijska svojstva romanovske ovce u području Bilogore, Hrvatska. Životinje su držane na ograđenom rotirajućem pašnjaku s pristupom stajama tijekom noći. Ovce su bile prirodno pripuštane. Tijekom 3 uzastopne godine (2019.-2021.) prikupljeni su podatci o reproduktivnoj učinkovitosti četiri stada ovaca (n=26-57). Temperaturu zraka, trajanje sunčeve svjetlosti i dnevne količine oborina prikupio je Hrvatski meteorološki i hidrološki zavod (CMHS), Zagreb, Hrvatska, u najbližoj meteorološkoj postaji za mjerenje, koja je udaljena nalazi unutar 5-15 km od farmi. Pripušteno je ukupno 425 ovaca, od kojih je 399 uspješno koncipiralo i ojanjilo 851 janje. Prosječna veličina legla bila je 1,63; prosječna plodnost tijekom istraživanja bila je 93,88 %. Rasprostranjenost janjenja nije bila tijekom cijele godine ravnomjerno raspoređena, jer je 73 % svih ovaca ojanjeno tijekom zime i proljeća (zimi 51,88 %, u proljeće 21,31 %, u ljeto 13,53 % i u jesen 13,28 %). Spolna aktivnost bila je najniža od kraja ožujka do svibnja, dok je vrhunac spolne aktivnosti bio od kraja kolovoza do listopada. Postojala je pozitivna ili negativna korelacija (P<0,0001 (Kruskall Wallis)) između temperature zraka, trajanja sunčeve svjetlosti i količine oborina s određenim reproduktivnim svojstvima (brojem gravidnih i negravidnih ovaca). Prosječne dnevne temperature najviše su ljeti, no početkom jeseni i početkom sezone razmnožavanja temperature zraka naglo padaju. Isto tako, dan postaje kraći, a noć postaje duža što je ključno za rasplodnju vrsta tzv. short day breeder kao što su ovce i koze. Osim temperature i sunčeve svjetlosti, drugi čimbenici, poput relativne vlažnosti i padalina, mogu izravno ili neizravno utjecati na spolnu aktivnost i znatno utjecati na plodnost. Možemo pretpostaviti da temperatura zraka, količina oborina i trajanje sunčeve svjetlosti tijekom različitih mjeseci ili godišnjih doba mogu utjecati na reproduktivne osobine romanovske ovce na Bilogori u Hrvatskoj

Dinamika bogatstva vrsta komaraca u uzorcima (Diptera, Culicidae) hvatanim metodom CDC klopke uz suhi led na području grada Osijeka

In this paper the results of a ten year investigation of mosquitoes using dry ice baited CDC traps in the city of Osijek, Croatia are presented. In the first year we recorded 16 species. During these ten years the total of 20 species were determined. The single method, dry ice baited CDC traps, makes it possible to determine almost the entire fauna in a given area. The estimated fauna is statistically calculated. Five non-parametric estimators were chosen for evaluation: one-factorial Jackknife (Jackknife-1); two-factorial Jackknife (Jackknife-2); one-factorial Chao (Chao-1); two-factorial Chao (Chao-2) and Bootstrap. The estimated fauna contains between 22 and 29 species. The method used turned out to be very good when used over a long period of time, because new species were registered even in years without many mosquitoes.U ovom radu govori se desetgodišnjim rezultatima istraživanja komaraca, koji su hvatani metodom CDC klopke uz suhi led kao atraktant u Osijeku. Prve istraživačke godine zabilježeno je 16 vrsta. Tijekom deset istraživačkih godina broj poznatih vrsta popeo se na 20. Predpostavka ovog rada je da se korištenjem samo jedne metode uzorkovanja može se doći do skoro kompletne faune nekog područja. Očekivana fauna izračunata je statistički. U tu svrhu korišteno je pet neparametarskih estimatora: jedanfaktorijalni Jackknife (Jackknife-1); dvofaktorijalni Jackknife (Jackknife-2); jedanfaktorijalni Chao (Chao-1); dvofaktorijalni Chao (Chao-2) i Bootstrap. Ovim statističkim metodama je određeno da se broj vrsta komaraca u Osijeku kreće od 22 do 29 vrsta. Korištena metoda se pokazuje kao dobra ako se koristi kroz duže vremensko razdoblje, a naročita joj je vrijednost u tome što su se nove vrste evidentirale u godinama kada i nije bilo puno komaraca. Do otkrivanja kompletne faune ovom metodom, potrebno je uzorkovati još neko vrijeme

Mosquito Survey during West Nile Virus Outbreak 2012 in Northeast Croatia Enrih

During the August and September 2012, seven human cases of the West Nile neuro-invasive disease were reported in Croatia. Medical entomology research on a potential vectors during the outbreak was supported by the Ministry of Health. A mosquito survey has been done in 64 sites in three eastern Croatian counties (Osijek-Baranja County, Vukovar-Srijem county and in Brod-Posavina county). Dry ice baited CDC traps were used for mosquito sampling in a period from the 10th to 25th September 2012. A total of 1785 mosquitoes were collected and 5 species were determined. The most numerous species were Aedes vexans with 1634 specimens, a Culex pipiens c., the potential vector of WNV, was present with 6.39%, in 114 specimens. That species was present in 43 out of 64 investigated sites. Vector control included both the control of mosquito larvae and the adults. Treatments have been done on 184 small breeding sites and on 2900 ha of an urban area

Prvi nalaz invazivne vrste sjemenarki Megabruchidius tonkineus (Coleoptera, Chrysomelidae, Bruchinae) u Hrvatskoj

The invasive seed beetle Megabruchidius tonkineus (Pic, 1904) is an agricultural pest native to the east Asian region that was first recorded in Europe (Germany) in the 1980s. There are further recent reports of this species from Bulgaria, France, Hungary, Russia, Serbia and Switzerland. Megabruchidius tonkineus resides in the seed pods of Gleditsia triacanthos L. (Fabaceae) and is recorded for the first time in Croatia in our study. The general morphological, biological and distributional features of this invasive species are given.Invazivna vrsta sjemenarki porijeklom iz orijentalne Azije Megabruchidius tonkineus (Pic, 1904), nađena je po prvi puta u Hrvatskoj u mahunama gledičije (Gleditsia triachantos L.). Prvi nalaz ove vrste u Europi zabilježen je 80-ih godina prošloga stoljeća u Njemačkoj, međutim odnedavno postoje dokazi da se ta vrsta ustalila u Bugarskoj, Francuskoj, Mađarskoj, Srbiji i Švicarskoj. U radu su prikazana osnovna morfološka i biološka obilježja vrste kao i njezina rasprostranjenost na području Istočne Hrvatske

Očuvanje ptica u urbanom okruženju - fauna divljih ptica u Zoološkom vrtu Osijek, Hrvatska

Zoos are our closest, independent, and continuous link to nature. Apart from providing the opportunity to observe captive and exotic wild animals, they also attract various species of wild birds. For that purpose, the main goal of this study was to provide a list of free-living bird species at the Osijek Zoo. During 2021, fieldwork was performed monthly using a point count transect, except during the breeding season when counts were performed twice a month. A total of 61 species were recorded, belonging to 31 families distributed in 15 orders. The most frequently recorded species were Hooded crow, Corvus cornix and Great tit, Parus major. Five species observed at the Osijek Zoo are listed as endangered species in the Red Book of Birds of Croatia: critically endangered: European roller, Coracias garrulus; endangered: Great egret, Ardea alba and Western marsh harrier, Circus aeruginosus; vulnerable: Little egret, Egretta garzetta and Black stork, Ciconia nigra. It appears that the Osijek Zoo provides a good foundation for a high diversity of bird fauna, indicating that this is a good quality urban area. The Osijek Zoo should also strive to preserve this abundant avifauna, by educating the public on conservation, and forbidding any potentially disturbing behaviours.Zoološki su vrtovi najbliža, neovisna i stalna veza čovjeka s prirodom. Osim što pružaju priliku za interakciju i promatranje egzotičnih i/ili divljih životinja, privlače i mnogo vrsta divljih ptica. Glavni je cilj ovoga istraživanja popis slobodnoživućih vrsta ptica u Zoološkom vrtu Osijek. Tijekom 2021. godine metodom transekta u točki, ptice su osim u sezoni gniježđenja, kada su se brojenja obavljala dva puta mjesečno, promatrane jednom mjesečno. Promatranjem je zabilježeno ukupno 61 vrsta ptica koje pripadaju u 31 porodicu i 15 redova. Najčešće su zabilježene vrste: siva vrana, Corvus cornix i velika sjenica, Parus major. Pet vrsta opažanih u Zoološkom vrtu Osijek uvrštene su kao ugrožene vrste u Crvenu knjigu ptica Hrvatske: zlatovrana, Coracias garrulus ‒ kritično ugrožena, velika bijela čaplja, Ardea alba ‒ ugrožena, eja močvarica, Circus aeruginosus‒ ugrožena, mala bijela čaplja, Egretta garzetta ‒ osjetljiva, crna roda, Ciconia nigra ‒ osjetljiva. Zoološki vrt Osijek dobar je temelj za bogatu raznolikost ornitofaune što ukazuje da je urbano područje Osijeka kvalitetno. Zoološki vrt Osijek trebao bi ulagati u očuvanje bogate faune divljih ptica i educirati građanstvo o biološkoj raznolikosti svoga zavičaja