OF THK NATIVE DOMESTIC WATER-RECEPTACLES AT LAGOS, &C. 131 



Seasonal Variation of Mosquito Laroce in Domestic Water- Vessels at Lacjos 

 and at Ebute 3Ietta (1910-1911). 



1910. 



Stegomi/ia 

 foiiciaia. 



Peciinopolpus 



ftiSCUS. 



Cnlex 

 (hdton !, 



(-'ulex tifffipcs 

 ■va,i.ftisca. 



Culex 

 niffrocostaUs. 



Pi/retophorus 

 costalis. 





Lagos. 



B. 



Metta. 



Lagos. 



E. 



Metta. 



Lagos. 



E. 



Metta. 



Lagos. 



E. 



Metta, 



Lagos. 



E. 



Metta. 



Lagos. 



E. 



Metta. 



August 



.99-4 



34-4 



8-6 



G-8 



1-8 9G-5 



3-8 



10-3 



0-3 



0-0 



1-7 



0-0 



September ... 



97-6 



.88-4 



12-4 



0-0 



5-3 1 92-3 



0-7 



15-3 



0-0 



15-3 



0-7 



0-0 



October 



99-0 



30-0 



12-8 



10-0 



3-5 



90 



8-2 



10-0 



1-8 



0-0 



0-9 



0-0 



November ... 



1000 



- 



20-9 



- 



0-0 



- 



0-0 



- 



0-0 



- 



2-3 



0-0 



December 



93-4 





16-3 — 



6-5 



- 



8-1 



- 



IG 



- 



0-0 



0-0 



1911. 

























January 



92-7 



44-4 



42-7 



222 



1-0 



GG-G 



31 



0-0 



0-0 



O-O 



31 



00 



February 



901 



64-2 



22-3 



7.1 



2-1 



50-0 



2-1 



14-2 



1-0 



21-4 



6-3 



0-0 



March 



920 



83-3 



45-4 



25-0 



3-4 



75-0 



9-0 



33-3 



3-4 



25-0 



1-1 



00 



Aver, monthly 

 percentages 



95-5 



49-1 



22-7 



11-8 



2-9 



78-4 



4-4 



13-8 



1-0 



10-3 



2-0 



0-0 



Mosquito Larv;e. 

 Stegomyia fasciata, F. 



This larva was present in an average of 92"5 per cent, of the total water- 

 receptacles examined. It is the comnaouest 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. tit/ripes var. fiiscu, Theo. At Ebute Metta the species is 

 apparently less common, but the number of samples i-eceived 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 



