species composition and diversity of mosquitoes in neka county, mazandaran province, northern iran

background: regarding to the significant of the possibility of the malaria epidemic and nuisance of mosquitoes dur­ing the active season, the fauna and some ecological activities of mosquitoes in related to tree holes were investi­gated from april to december 2009 in neka county of mazandaran province, northern iran. methods: larval collection was carried out from natural, artificial breeding places, and tree holes inside the forest in neka county, mazandaran province in 2009. in addition, human bait net trap collection was conducted using suction tube several times during this investigation. results: four genera and five species were found in tree holes. anopheles plumbeus, culiseta annulata , culex   pipiens , and ochlerotatus geniculatus were collected by larval collection whereas, ochlerotatus pulcritarsis was found by adult collection. overall cx. pipiens 44.6%, oc. geniculatus 32.6%, an. plumbeus 22.5%, and cs. annulata 0.3% were collected by larval collection. during the bait net collection five specie were identified including: oc. genicula­tus 55.87%, oc. echinus 1.33%, oc . pulchritarsis 8.8 %, cx. pipiens 33.8%, and an. plumbeus 0.2%. cs.   annu­lata larvae was detected for the first time with a low abundance in tree cavity. conclusion: tree holes were found the main habitat for the species of oc. geniculatus . the species of cs.   annulata was found in tree holes