水蟑螂

**龍蝨科**（Dytiscidae），亦作**龍虱科**，為水甲蟲的一種，隸屬於鞘翅目之下的肉食亞目。生活在田野、水溝、小溪等水體中，是一種掠食性水生昆蟲。其學名源於希臘文 _δυτικός_（_dytikos_），意思就是「肉食性的潛水甲蟲」。本科物種幾乎見於全世界所有淡水棲境，但亦有部分於落葉堆中棲息。成蟲體長一般在 1 和 2.5 cm（0.4－1.0 英寸）之間，儘管物種間的差異會比較大。當中見於歐洲的 _Dytiscus latissimus_ 及巴西的 _Megadytes ducalis_ 有最大的體型，可分別長至 4.5 cm（1.8 英寸）到 4.75 cm（1.9 英寸）。與之相反，擁有最小體型的物種應當為棲息於澳大利亞地下水中的 _Limbodessus atypicali_，只有約 0.9 mm（0.035 英寸）長。
大多數物種的顏色都在深棕色、黑色或深橄欖綠，某些亞科的物種會在其邊沿帶有金黃色的條狀斑紋。

## 食用

本科物種的成蟲，特別是 _Cybister_ 屬的物種，均為可食用昆蟲。在美國內華達州洪堡乾湖的一個山洞內，還在當地史前人類遺下的糞化石內發現有 _Cybister explanatus_ 被食用的殘骸。在墨西哥，他們在吃 _C. explanatus_ 時會以墨西哥夾餅夾著來吃。在日本多個地區（例如：長野縣）有以日本龍蝨（_Cybister japonicus_）為食的習慣；在中華人民共和國廣東省，除了日本龍蝨以外，亦會食用 _C. bengalensis_、_C. guerini_、_C. limbatus_、_C. sugillatus_、_C. tripunctatus_ 等物種。_D. marginalis_ 很可能也包括在內，但這個物種的肉很少。也有報告指在台灣、泰國及新幾內亞亦有食用本科物種的習慣。

大但在陸地上很慢，成年後也不是特別兇猛，它們也被許多中型鳥類、哺乳動物和其他大型捕食者津津樂道地吃掉。幼蟲通常比較安全，由於它們的保護色和通過水柱逃跑的能力；它們可能相當難抓，可能成為小池塘的頂級掠食者。

## 系統分類

本科包括下列各屬：

* _Acilius_ Leach, 1817
* _Aethionectes_ Sharp, 1882
* _Africodytes_ Biström, 1988
* _Africophilus_ Guignot, 1948
* _Agabetes_ Crotch, 1873
* 豆龍蝨屬 _Agabus_ Leach, 1817
* _Agametrus_ Sharp, 1882
* _Agaporomorphus_ Zimmermann, 1921
* _Aglymbus_ Sharp, 1882
* _Agnoshydrus_ Biström, Nilsson & Wewalka, 1997
* _Allodessus_ Guignot, 1953
* _Allomatus_ Mouchamps, 1964
* 彩斑龍蝨屬 _Allopachria_ Zimmermann, 1924
* _Amarodytes_ Régimbart, 1900
* _Andex_ Sharp, 1882
* _Andonectes_ Guéorguiev, 1971
* _Anginopachria_ Wewalka, Balke & Hendrich, 2001
* _Anisomeria (beetle)_ Brinck, 1943
* _Anodocheilus_ Babington, 1841
* _Antiporus_ Sharp, 1882
* _Australphilus_ Watts, 1978
* _Austrodytes_ Watts, 1978
* _Barretthydrus_ Lea, 1927
* _Batrachomatus_ Clark, 1863
* _Bidessodes_ Régimbart, 1900
* _Bidessonotus_ Régimbart, 1895
* _Bidessus_ Sharp, 1882
* _Borneodessus_ Balke, Hendrich, Mazzoldi & Biström, 2002
* _Brachyvatus_ Zimmermann, 1919
* _Bunites_ Spangler, 1972
* _Calicovatellus_ K.B.Miller & Lubkin, 2001
* _Canthyporus_ Zimmermann, 1919
* _Capelatus prykei_ Turner & Bilton, 2015
* _Carabdytes_ Balke, Hendrich & Wewalka, 1992
* _Carabhydrus_ Watts, 1978
* _Celina (beetle)_ Aubé, 1837
* _Chostonectes_ Sharp, 1882
* _Clypeodytes_ Régimbart, 1894
* _Coelhydrus_ Sharp, 1882
* _Colymbetes_ Clairville, 1806
* _Comaldessus_ Spangler & Barr, 1995
* _Copelatus_ Erichson, 1832
* _Coptotomus_ Say, 1830
* _Cretodytes_ Ponomarenko, 1977
* _Crinodessus_ K.B.Miller, 1997
* _Cybister_ Curtis, 1827
* _Darwinhydrus_ Sharp, 1882
* _Deronectes_ Sharp, 1882
* _Derovatellus_ Sharp, 1882
* _Desmopachria_ Babington, 1841
* _Dimitshydrus_ Uéno, 1996
* _Dytiscus_ Linnaeus, 1758
* _Eretes_ Laporte, 1833
* _Geodessus_ Brancucci, 1979
* _Gibbidessus_ Watts, 1978
* _Glareadessus_ Wewalka & Biström, 1998
* _Graphoderus_ Dejean, 1833
* _Graptodytes_ Seidlitz, 1887
* _Haideoporus_ Young & Longley, 1976
* _Hemibidessus_ Zimmermann, 1921
* _Heroceras_ Guignot, 1950
* _Herophydrus_ Sharp, 1882
* _Heterhydrus_ Fairmaire, 1869
* _Heterosternuta_ Strand, 1935
* _Hoperius_ Fall, 1927
* _Hovahydrus_ Biström, 1982
* _Huxelhydrus_ Sharp, 1882
* _Hydaticus_ Leach, 1817
* _Hyderodes_ Hope, 1838
* _Hydrocolus_ Roughley & Larson, 2000
* _Hydrodessus_ J.Balfour-Browne, 1953
* _Hydrodytes_ K.B.Miller, 2001
* _Hydroglyphus_ Motschulsky, 1853
* _Hydronebrius_ Jakovlev, 1897
* _Hydropeplus_ Sharp, 1882
* _Hydroporus_ Clairville, 1806
* _Hydrotrupes_ Sharp, 1882
* _Hydrovatus_ Motschulsky, 1853
* _Hygrotus_ Stephens, 1828
* _Hyphoporus_ Sharp, 1882
* _Hyphovatus_ Wewalka & Biström, 1994
* _Hyphydrus_ Illiger, 1802
* _Hypodessus_ Guignot, 1939
* _Iberoporus_ Castro & Delgado, 2001
* _Ilybiosoma_ Crotch, 1873
* _Ilybius_ Erichson, 1832
* _Japanolaccophilus_ Satô, 1972
* _Kintingka_ Watts & Humphreys, 1999
* _Kuschelydrus_ Ordish, 1976
* _Laccodytes_ Régimbart, 1895
* _Lacconectus_ Motschulsky, 1855
* _Laccophilus_ Leach, 1815
* _Laccoporus_ J.Balfour-Browne, 1939
* _Laccornellus_ Roughley & Wolfe, 1987
* _Laccornis_ Gozis, 1914
* _Laccosternus_ Brancucci, 1983
* _Lancetes_ Sharp, 1882
* _Leiodytes_ Guignot, 1936
* _Leuronectes_ Sharp, 1882
* _Limbodessus_ Guignot, 1939
* _Liodessus_ Guignot, 1939
* _Lioporeus_ Guignot, 1950
* _Liopterus_ Dejean, 1833
* _Matus (genus)_ Aubé, 1836
* _Megadytes_ Sharp, 1882
* _Megaporus_ Brinck, 1943
* _Meladema_ Laporte, 1835
* _Melanodytes_ Seidlitz, 1887
* _Metaporus_ Guignot, 1945
* _Methles_ Sharp, 1882
* _Microdessus_ Young, 1967
* _Microdytes_ J.Balfour-Browne, 1946
* _Microhydrodytes_ K.B.Miller, 2002
* _Miodytiscus_ Wickham, 1911
* _Morimotoa_ Uéno, 1957
* _Napodytes_ Steiner, 1981
* _Nebrioporus_ Régimbart, 1906
* _Necterosoma_ W.J. Macleay, 1871
* _Neobidessus_ Young, 1967
* _Neoclypeodytes_ Young, 1967
* _Neoporus_ Guignot, 1931
* _Neoscutopterus_ J.Balfour-Browne, 1943
* _Neptosternus_ Sharp, 1882
* _Nirripirti_ Watts & Humphreys, 2001
* _Notaticus_ Zimmermann, 1928
* _Onychohydrus_ Schaum & White, 1847
* _Oreodytes_ Seidlitz, 1887
* _Pachydrus_ Sharp, 1882
* _Pachynectes_ Régimbart, 1903
* _Palaeodytes_ Ponomarenko, 1987
* _Papuadessus_ Balke, 2001
* _Papuadytes_ Balke, 1998
* _Paroster_ Sharp, 1882
* _Peschetius_ Guignot, 1942
* _Philaccolilus_ Guignot, 1937
* _Philaccolus_ Guignot, 1937
* _Philodytes_ J.Balfour-Browne, 1939
* _Phreatodessus_ Ordish, 1976
* _Platambus_ Thomson, 1859
* _Platydytes_ Biström, 1988
* _Platynectes_ Régimbart, 1879
* _Porhydrus_ Guignot, 1945
* _Primospes_ Sharp, 1882
* _Procoelambus_ Théobald, 1937
* _Prodaticus_ Sharp, 1882
* _Pseuduvarus_ Biström, 1988
* _Pteroporus_ Guignot, 1933
* _Queda (genus)_ Sharp, 1882
* _Regimbartina_ Chatanay, 1911
* _Rhantaticus_ Sharp, 1882
* _Rhantus_ Dejean, 1833
* _Rhithrodytes_ Bameul, 1989
* _Rugosus_ García, 2001
* _Sandracottus (genus)_ Sharp, 1882
* _Sanfilippodytes_ Franciscolo, 1979
* _Scarodytes_ Gozis, 1914
* _Schistomerus_ Palmer, 1957
* _Sekaliporus_ Watts, 1997
* _Senilites_ Brinck, 1948
* _Sharphydrus_ Omer-Cooper, 1958
* _Siamoporus_ Spangler, 1996
* _Siettitia_ Abeille de Perrin, 1904
* _Sinodytes_ Spangler, 1996
* _Spencerhydrus_ Sharp, 1882
* _Sternhydrus_ Brinck, 1945
* _Sternopriscus_ Sharp, 1882
* _Stictonectes_ Brinck, 1943
* _Stictotarsus_ Zimmermann, 1919
* _Stygoporus_ Larson & LaBonte, 1994
* _Suphrodytes_ Gozis, 1914
* _Tepuidessus_ Spangler, 1981
* _Terradessus_ Watts, 1982
* _Thermonectus_ Dejean, 1833
* _Tikoloshanes_ Omer-Cooper, 1956
* _Tiporus_ Watts, 1985
* _Trichonectes_ Guignot, 1941
* _Trogloguignotus_ Sanfilippo, 1958
* _Tyndallhydrus_ Sharp, 1882
* _Typhlodessus_ Brancucci, 1985
* _Uvarus_ Guignot, 1939
* _Vatellus_ Aubé, 1837
* _Yola (genus)_ Gozis, 1886
* _Yolina_ Guignot, 1936

## 參考文獻

* 聯邦科學與工業研究組織 (CSIRO) (2004): Water for a Healthy Country - Family Dytiscidae （頁面存檔備份，存於網際網路檔案館）. Version of 2004-JUL-02. Retrieved 2008-AUG-04
* De Foliart, Gene R. (2002): Chapter 26 - Eastern Asia: China, Japan, and other countries. _In: The Human Use of Insects as a Food Resource: A Bibliographic Account in Progress_.
* Jäch, Manfred A. (2003): Fried water beetles Cantonese style. _American Entomologist_ **49**(1): 34-37. PDF fulltext
* Larson, D.J., Alarie, Y., and Roughley, R.E. (2000): Predaceous Diving Beetles (Coleoptera: Dytiscidae) of the Nearctic Region, with emphasis on the fauna of Canada and Alaska. NRC Research Press, Ottawa. ISBN 978-0-660-17967-4.

## 外部連結

* 維基物種上的相關資訊：龍蝨科
* YouTube 上的 Video of the dangerous mandibles of a Dytiscidae larva（英文）
* 聯邦科學與工業研究組織「家庭龍蝨」 （頁面存檔備份，存於網際網路檔案館）