68 



Marvels of the Universe 



instead of living \-oung. \\'hen winter has passed, these eggs provide the lirst brood of 



budding females. 



It is obvious, then, that every " green-fly " seen during the spring and summer months can 



become a mother. Reaumur has estimated that a single green-fly may be progenitor to no fewer 



than five thousand nine hundred and four millions nine hundred thousand individuals during the 



two or three weeks of its hfe. 



The mother Hover-fl}' seems fully acquainted with this state of things, for the moment that 



she detects a green-fly on a leaf or stem, she is content to place an egg there ; probably she is 



instinctively satisfied that the 

 sight of a green-fly is a suffi- 

 cient guarantee that ample pro- 

 vision \\-ill be forthcoming to 

 give her offspring a good start 

 in life. 



In an illustration on this 

 page the egg is shown as 

 placed by the parent insect 

 amongst the green-flies, and 

 more in detail on page 66. 

 Three daj's later a tiny, 

 j'ellowish white grub emerges 

 from the egg, which ^\•hen 

 fully extended is not more 

 than one-sixteenth of an inch 



in length 



but its courage and 



PItoto hyl 



[J. J. Ward, F.E.S. 



BUD OF SWEET-PEA ENLARGED. 



In this enlarged photo the forms of the sreen-fly are clearly seen, 

 of the Hover-flj- on the upper part of the flower. 



strength are as marvellous as 

 its voracity'. 



The grub under observa- 

 tion, when hatched, travelled 

 down the stem until it came 

 to a leaf, on whose surface it 

 met with its first green-fly. 

 One of the legs of the latter 

 touched the grub as it moved 

 towards it. Instantly the 

 grub thrust its head forward. 



Note the egg 



and a moment later it was 

 standing upright on the tail- 

 end of its bodj' with the green-fl3^ elevated in the air — a magnified photograph of the actual 

 incident is shown on the page opposite. 



In this attitude the little grub held the green-fly for over an hour while it sucked its 

 juices, and this in spite of the fact that its victim was much larger than itself and continually 

 struggling to escape. It then cast away the empty skin of- the green-fly and rested for a 

 while. During the first day of its existence it captured and ate two half-grown green-flies and 

 two smaller ones ; and daj^ by day, for ten days, its appetite increased in an astonisliing 

 manner. 



It grew rapidly, and by the end of the second day had become quite an expert in manipulating 

 green-flies. It is interesting to note that the grub is bhnd ; it finds its prey by rapidly thrusting 

 .its head here, there, and everywhere as it travels. Sooner or later its nose comes in contact 



