Ticks transmit more different kinds of pathogenic organisms than any other hematophagous arthropod. This paper attempts to review the literature available on the cell-mediated and humoral responses of ticks. The cell-mediated defense responses by invertebrates are simpler than vertebrates, but are effective as a second line of defense against invasion by microorganisms. Hemocytes play a major role in this immune response through phagocytosis, nodule formation and encapsulation of invading foreign materials. These mechanisms appear to function in both soft and hard ticks. Humoral immune responses consist of three main types; humoral encapsulation, hemagglutination and production of antimicrobial proteins. Humoral encapsulation is elicited by the prophenoloxidase activating system and has only been shown to function in the soft tick Ornithodoros moubata. However, recent studies show the hard ticks also have prophenoloxidase activating cofactors indicating humoral encapsulation also functions in these ticks. Tick lectins function in hemagglutination of various microorganisms in both soft and hard ticks and also appear to function as recognition molecules of nonself and possibly in the transmission of pathogenic microorganisms. Ticks also have numerous antimicrobial proteins that can attack the invading microorganisms. Lysozymes have been shown to have bactericidal effects in several tick species and work in concert with other antimicrobial peptides to kill invaders. Cystatins, classic cysteine protease inhibitors, have recently been shown to function in innate immune responses of ticks. Hemoglobin fragments have antimicrobial activity in the midgut of ticks. Defensins show expression up-regulated by blood feeding and are effective antimicrobial agents with some differences between soft and hard ticks. Other novel antimicrobial peptides have been isolated from various species of soft and hard ticks, but their functions remain to be elucidated. Understanding these innate immune mechanisms in ticks is essential to develop strategies for reducing the transmission of diseases to man and animals.

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クロシデムシNicrophorus concolor Kraatz は日本から北部インドやヒマラヤにかけて広く分布する大形の甲虫で，小形の脊椎動物の死体を土中に埋めてそれに産卵し孵化した幼虫の給餌を行うなど興味深い習性をもつことが知られている．我々は日本各地と国外の数ヶ所で採集されたクロシデムシ成虫の多数の個体を調べて体表に付着しているヒゲダニ科の第2若虫を集め，つくば市で腐肉トラップからクロシデムシとともに得られた材料も含めて，分類学的に検討した．その結果，現在までに7 種を明瞭に識別することができ，その全てが未記載種であることを確認した．この第1 報では日本，韓国，沿海州およびチベットから得られた1 種をPelzneria uncinata と命名，記載する．この種は宿主の体上では大多数が鞘翅の裏面と下翅に見出され，形態的には1）前体部背面の前縁が明らかに硬化し濃色であること，2）後体部背面のd₁，e₁，h₁の3 対の毛が他の毛よりもかなり長く，末端部に数本の微棘を持つこと，3）第3 脚転節の毛wが短小で長さがその挿入点における転節の幅を超えないことなどで同属の既知種から容易に識別できる．

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