SPOLIA ZEYLANICA. 
159 
ON TOXORHYNCHITES IMMISERICORS (WALKER), THE 
ELEPHANT MOSQUITO. 
By E. Ernest Green, F.E.S., 
Government Entomologist , Ceylon . 
With Plate. 
Megarhinus immisericors , Walk. (Journ. Proc. Linn. Soc., 
Lond., IV., p. 91, 1860 ; and VII., p. 202). 
Gulex regius , Thwaites (?). 
Megarhinus immisericors (8), Theobald, Mono. Culic., I., p. 225, 
pi. VII., fig. 28. 
Megarhinus gilesii (?), Theobald, Mono. Culic., I., p. 227, 
pi. IX., fig. 33. 
Megarhinus subulifer , Dolleschall, Nat. Tijdschr. v. Ned. Ind., 
Y0l. XIV., p. 382. 
Toxorhynchites immisericors (Walker), Theobald, Mono. Culic., 
vol. III., p. 123. 
rpHE genus Toxorhynchites of Theobald (Monograph of the 
^ Culicidse, vol. I., p. 244) differs from typical Megarhinus , 
to which it is otherwise very closely allied, in the short palpi of 
the female. It resembles Megarhinus in the unusually large size, 
brilliant colouring, and angled proboscis of both sexes (see fig. 1). 
The lateral margins of the terminal segments (more particularly 
in the male) are often densely tufted in both Megarhinus and 
Toxorhynchites (fig. 2). 
T. immisericors , though by no means so plentiful as many other 
Culicidse, is not an uncommon insect in the Royal Botanic 
Gardens, Peradeniya (altitude 1,500 feet). I have taken it also in 
Pundalu-oya, at an elevation of over 4,000 feet. The adult insect 
may be found resting on the trunks of trees and—still more 
frequently—upon the stems of the Giant Bamboo (Dendrocalamus 
giganteus). It occasionally flies in at the open window of a room 
(always in the daytime), when its loud deep hum immediately 
attracts attention to its presence. It appears to be a distinctly 
day-flying insect. 
Though this species is popularly known by the names of 
“ Elephant Mosquito ” and “ Stinging Elephant Mosquito,” I have 
8(25)04 Y 
