June, 1909.] 



519 



Plant Sanitation, 



There are several striking instances of 

 introduced lady-bird beetles clearing 

 out, for the time, some particular scale, 

 but of the thousands of specimens intro- 

 duced into California there are a number 

 of species that have died out in a very- 

 short space of time. 



One of the greatest experiments at 

 present being carried on is the introduc- 

 tion ot the egg parasites of the Gypsy 

 and Brown Tail moths from Europe, 

 under the able administration of Dr. 

 Howard working with the Gypsy Moth 

 Commission at Boston. Both these 



forest moths, which have been intro- 

 duced from Europe, have done an 

 immense amount of damage in the 

 forests of North America, while in their 

 native land they are held in check by 

 something. If that something can be 

 transported to America, then thousands 

 of pounds will be saved every year. 



In conclusion, I would point out that 

 the introduction of all kinds of insects 

 should be cautiously undertaken and 

 should not be carried out except by fully 

 qualified Entomologists. 



MISCELLANEOUS PESTS. 



MILLIONS AND MOSQUITOS 



{From the Bulletin issued by the Im- 

 perial Department of Agriculture for 

 the West Indies.) 



Introductory. 



The small fish called "millions "in 

 Barbados have been technically identi- 

 fied as Girardinus poeciloides, De Filippi. 



They are very small in size, the full- 

 grown female measuring about 1| inches 

 in length, while the male is much 

 smaller. The female is dull in colour 

 without conspicuous markings, while 

 the male is marked with irregular red 

 splashes on the sides, and has a circular 

 black spot on each side. 



Millions live for the most part in 

 water too shallow for larger fish, which 

 might prey upon them- They feed ou 

 the eggs, larvae, and pupa3 of mos- 

 quitoes, and probably on most other 

 forms of animal life which occur in the 

 water they frequent. They may be 

 found along the water's edge among the 

 weeds and grass roots, and they are able 

 to swim up stream in the smallest of 

 small rills and against a strong current. 



They increase in numbers very rapidly 

 under favourable circumstances. They 

 are viviparous— that is, they bring forth 

 living young. This is an advautage to 

 the species, for although the number of 

 offspring from one of these females may 

 not be so great as the number of eggs 

 or spawn produced by an oviparous 

 (egg-laying) female, yet a larger propor- 

 tion of them reach maturity since there 

 is exposed to their enemies no inactive 

 egg stage of development. In captivity, 

 in water tanks, reservoirs, fountains, 

 and garden tubs in which aquatic plants 



are kept, they thrive and multiply, and 

 in Barbados they are very much used in 

 this way both in the town and on 

 estates, to reduce the annoyance from 

 mosquitos. 



Allied Species. 

 Millions belong to the group of fishes 

 known astop-minnows. The top-minnows 

 are small carnivorous fish that swim and 

 feed near the surface of the water. 



Closely related to the millions of 

 Barbados are two species of Girardinus, 

 one of which is G. versicolor, Gunther, 

 said to be found in San Domingo, and 

 the other Or. formosus, of South Carolina 

 and Florida. 



Mosquitos at Barbados. 



In Barbados, two of the commonly 

 known species of ' mosquito ' are Culex 

 fatigans and Stegomyia fasciata. Cidex 

 is the mosquito which is responsible for 

 the distribution of filariasis, also known 

 as elephantiasis or ' Barbados leg.' The 

 Siegomijia mosquito is the active agency 

 in the distribution of yellow fever. 



The Anopheles mosquito which trans- 

 mits the malarial parasite is not known 

 to occur in Barbados, but it is found in 

 most other parts of the tropics, and 

 in many subtropical and temperate 

 countries. 



Life-Histroy op Mosquitos. 



The life-history of a mosquito includes 

 the four distinct stages usual in the 

 development of an insect— the egg, the 

 larvse, the pupa, and the imago (or 

 adult). 



The adult female mosquito deposits 

 her eggs on the surface of water where 

 they remain for several days until they 

 hatch. The eggs of Culex are laid in 

 masses or rafts. Those of Anopheles and 

 Stegomyia are laid singly. 



