A curious adaptation of habit to its 

 environment of a Malayan mosquito, 



By C. Strickland, m.a., b.c. 



Travelling Medical Entomologist, F. M. S. 



During a recent visit to the Gap, on the Selangor-Pahang 

 boundary, which is at 2,800 feet, I observed a curious and interest- 

 ing fact in the life of mosquito which seems worthy of record. 



This mosquito, kindly identified for me by Dr. Stanton as 

 Chaetomyia (Leicesteria) flava, Leicester, which had been caught 

 in the resthouse and was kept in a test-tube, was observed to have 

 attached to a hind-leg a mass which until closer examination, seemed 

 to be one of those Ceratopdgon which have a habit of attaching 

 themselves to mosquitoes to suck out their body-juices. On ex- 

 amination however with a microscope it proved to be an ova-mass, 

 and what was very interesting, from each ovum the head of a young 

 larva, was sticking out, the whole thing looking like a miniature 

 nest of young sparrows. 



The mosquito was introduced to a bottle in which was some 

 water, when it immediately flew down to the water and dipped its 

 hind-leg methodically into it. Immediately all the larvae came 

 out of the ova-mass and swam away as livelily as a crowd of child- 

 ren coming out of school on a holiday. 



On two occasions I observed this phenomenon and on another 

 I caught a specimen of the mosquito with the ova-mass on its leg 

 from which all the larvae had gone. 



I think it seems clear that the mosquito ovideposits on its own leor 

 and that the phenomenon represents a device by which the mosquito 

 is enabled to deposit its larvae in collections of water which are 

 inaccessible to it for ordinary deposition; perhaps in bamboos, or 

 in the leafy axils of plants like common hladi or pig-lily, 1 or it 

 may be to save the eggs from some danger which they might incur 

 if they were laid on water. 



I am much indebted to Mr. de la Mare Norris of the Agri- 

 cultural Department, F. M. S., for the drawing which is given. 



1. Leicester in his monograph on Culictdae of Malaya 1908 says that he 

 has found the adult larvae in bamboos and in coconut shells lying in the 

 jungle. 



Jour. Straits Branch R. A. Soc, No. 75, 1917. 



