多鯰ケ池と鳥取市大塚のため池のトンボ相

鳥取砂丘の多鯰ケ池（鳥取市）および湖山池の南岸に近い鳥取市大塚にある2カ所のため池（大塚A池，B池： 大塚B池は正確には鳥取市高住）で2014年の春から秋まで定期的にトンボ相の調査をおこなった。多鯰ケ池では21種，大塚A池は28種（うちコサナエは当地新記録），大塚B池は28種（うち11種は当地新記録）の全部で33種を記録した。多鯰ケ池では鳥取県東部では記録の少ないホンサナエ（鳥取県RDB 2012で準絶滅危惧）が，大塚A池では鳥取県内の記録が少ないハネビロトンボ（南方からの飛来種）が出現した。種多様度指数 (イトトンボ科を除く)は，どの地点でも概ね春季から夏季にかけて増加し秋に下降するが，大塚B池では，人為的な活動（草刈り，水抜きなど）により種多様度指数の変動が大きかった。Odonate communities were surveyed in three lakes and ponds (Lake Tanegaike near Tottori Sand Dunes, Otsuka Pond A in Otsuka, and Otsuka Pond B in Takazumi) in Tottori City, Tottori Pref., Honshu, Japan in 2014. A total of 33 species (21 from Lake Tanegaike, 28 from Otsuka Pond A (Trigomphus melampus is a new record), 28 from Otsuka Pond B (Of these, 11 species are new records) were found. Shaogomphus postocularis, which is rare in eastern part of Tottori Prefecture and listed on the red list (2012) of Tottori Prefecture, was found in Lake Tanegaike. A few individuals of Tramea virginia, which is considered to be an incoming dragonfly species from breeding areas somewhere in Shikoku or Kyushu and its records are scarce in Tottori Prefecture, were found in Otsuka Pond A. Simpson’s diversity indices of odonate communities (excluding Family Coenagrionidae) generally increased from spring towards summer and decreased in autumn, though fluctuation of the index was large in Otsuka Pond B due to mowing and drainage of the pond.