OF THE NATIVE DOMESTIC WATER-RECEPTACLES AT LAGOS, &C. 131 
Seasonal Variation of Mosquito Larve in Domestic Water- Vessels at Lagos 
and at Ebute Metta (1910-1911). 
Stegomyia | Pectinopalpus Culex Culex tigripes 
Culex Pyretophorus 
Sasciata. Suscus. duttoni. var. fusca. 
nigrocostalis. costalis. 
1910. ft Pel . 
E. ewe oe spell ihe See || 12t Pee ee see | aE 
Lagos.! wetta| 428°: metta.| 498°S-| Metta) 428°! Metta) 42°: Metta. duaEee| Metta. 
-— — \ J 
| 15:31 0-7 | 0-0 
| H 
August rents OO 4: | O44 cron mor. se) | 967>) 1 a8 lO Ors | OO Ee 0:0 
September ... | 97°6 | 38-4] 124 | OO] 53 | 92:3] 0-7 | 153] 0-0 | 
October 99:0 300 | 12:8 | 10:0 | 3:5 | 900 | 82 | 10:0} 1:8 0-0 | 0-9 0-0 
November ... 100:0 == || 20) — | 00 — 0-0 _— 0-0 —_ 2 0:0 
| | | 
December... | 93°4 — | 16:3 — 65 | — 81 — 16) — 0-0 0-0 
| 
1911. 
January see | 92rd (444 42% | 22:2 |) 1:0 1 66:6} ol 0:0 | 0-0 OOM 32 70:0 
Poa |e) ED 
~~) 
co 
ir) 
wb 
Fepruary ... | 90°1 | 64:2 | 223] 7.1) 21 | 50: 
5 
0 
March weet | O20 Sars 4074 | 2070) | 34 1 5°01" 9-0) | 3373 a4 
bo 
x 
pan 
rear 
S 
| | oe 
Aver. monthly | 95.5 | 49-1 | 22-7 | 118] 29 | 784] 44 | 138] 1-0 103] 20 | 0-0 
percentages | | 
Mosquito LARVA, 
Stegomyia fasciata, F. 
This larva was present in an average of 92°5 per cent. of the total water- 
receptacles examined. It is the commonest species of larva, is widely distributed 
over the township, and is found in all varieties of water-vessels. It is hardy and 
not much affected by environment, living in both clean and foul water with equal 
facility. Its chief natural enemy in these water-receptacles is the large car- 
nivorous larva of C. tigripes var. fusca, Theo. At Ebute Metta the species is 
apparently less common, but the number of samples received from that locality 
was too small for certainty. A slight monthly variation in numbers is shown in 
the tables. 
Pectinopalpus fuscus, Theo. 
This larva was present in an average of 21°6 per cent. of the total receptacles. 
It is, therefore, the next commonest larva to S. fasciata. Usually it is found in 
vessels containing foul water contaminated with animal excreta, or in water that 
