154 R. KUDO 



HISTORICAL REVIEW OF THE MICROSPORIDIAN PARASITES OF 



MOSQUITOES 



Careful examination of literature reveals that there have been 

 four Microsporidia recorded as parasitic in this group of dipterous 

 insects, concerning three of which it is doubtful whether they are 

 really Microsporidia or not. 



The first record was Pfeiffer ('95) who merely mentioned the 

 occurrence of a 'Glugea' parasite in the larvae of Culex sp. As 

 no further description is given, its microsporidian nature is 

 doubtful. 



A parasite of the larvae and adults of Aedes calopus ( = Stego- 

 mya fasciata) from Rio de Janeiro was thought by its discoverers, 

 Marchoux, Salimbeni, and Simond ('03) to be a Microsporidian, 

 and was recorded as Nosema stegomyae by these authors. Auer- 

 bach ('10) replaced this form into the genus Glugea on the ground 

 of its polysporogenous character. In their splendid work on 

 mosquitoes, Howard, Dyer, and Knox ('12) mentioned this or- 

 ganism as the only microsporidian parasites of mosquitoes with- 

 out mentioning Thelohania legeri Hesse, which is ciuoted below. 

 The position of Glugea stegomyae in the order Alicrosporidia, is 

 very doubtful, when one takes into consideration the facts that 

 the authors did not observe the polar filament, which is one of the 

 important characters of the order, in the so-called spores which 

 are from 3 to 7m long and 2 to 3m wide, and that the development, 

 as described by the authors, is extremely different from that of 

 the majority of Microsporidia. 



Hesse ('04, '04 a) was the first to observe a true microsporidian 

 parasite (Thelohania legeri Hesse) of the insects under consider- 

 ation. The species infects the adipose cells of the larvae of Ano- 

 pheles maculipennis collected from a marsh between Cavaliere 

 and Saint-Tropez in France. Hesse found two cases of the infec- 

 tion among forty larvae examined. As to the infection in adult 

 mosquitoes, he states that he did not study this Alicrosporidian 

 in adult Anopheles, but it did not seem doubtful that the parasites 

 occur also in this stage, since the infected larvae did not appear 

 to suffer from the parasites. 



