[Received by Editor, July 3, 1946.]

Issued separately as Bulletin No. 3, Royal New Zealand Air Force Entomological Surveys, South-west Pacific, 1945. Authorised by Chief of Air Staff.

This record was made in the course of a collection of day-biting mosquitoes in shady jungle at Palmalmal, New Britain, on the afternoon of 23rd August, 1945.

A mosquito was observed to be flying slowly and in unusually erratic fashion about 3 ft. from the ground. It was captured, and proved to be an engorged female of Armigeres lacuum Edwards. A ceratopogonine midge was in the act of biting this mosquito, its mouth-parts penetrating the lateral part of the fourth abdominal segment of its host. The abdomen of the midge was distended with blood, which showed through the cuticle as a reddish mass.

Both insects were chloroformed and preserved in formalin. Even after death the ceratopogonid remained in the biting position, so firmly were its mouth-parts embedded in the tissues of the mosquito. The midge was subsequently identified as a female Culicoides anophelis Edwards (Edwards, 1922). The figure was drawn from the preserved specimens, and shows the appearance of the engorged midge. The distal part of the latter's proboscis is buried in the side of the mosquito's abdomen.

C. anophelis has not previously been reported from the Australian Region. Earlier records of attacks on mosquitoes by this insect are from India, Ceylon, Burma, Malaya (type), Indo-China, and Sumatra. The records to date are summarised in Table 1, in so far as attacks on identified mosquitoes are concerned. Other accounts of such attacks are those of Fearnside (1900), who reported a Culicoides as biting an unidentified Culex at Rajahmundry Gaol, India; Rutherford (Knab, 1914) and Carter (1927), who collected Culicoides (queried by Carter as C. anophelis) from several species of Anopheles in Ceylon; and Stanton (Edwards, 1922), who obtained C. anophelis from an unspecified host at Deli, Sumatra.

As many as three specimens of C. anophelis have been found on one mosquito (Galliard and Gaschen, 1937). Lamborn (Edwards, 1922) and Galliard and Gaschen (1937) observe that midges may remain attached to the mosquito host for several hours without causing any apparent ill effects. However, Leon (1924) cites the case of an engorged female Anopheles maculipennis Meigen suffering from an external abdominal hernia at the site of a puncture made by a midge when the mosquito's stomach was empty.

The present instance is the second on record of an attack by Culicoides on a non-anopheline mosquito. The earlier observation is that made by Fearnside (1900) concerning a midge found biting an unidentified Culex. Thus it is established that C. anophelis does not restrict itself to Anopheles as a host.

Sinton (1925) mentions that there is no evidence that C. anophelis bites man. He suggests that if it should prove to do so this midge might become at least a potential mechanical carrier of Plasmodium. In view of the life-cycle of Plasmodium, it seems highly improbable that this could occur. It is more likely that C. anophelis might become a potential carrier of the virus that causes dengue fever, by feeding from a mosquito harbouring this organism. Further information concerning the habits of C. anophelis, particularly as to whether or not it is capable of biting man, is much to be desired.