340 



Marvels of Insect Life. 



h^ 



Phoiu by] [H. Main, F.h.S. 



Grub of Lady-Bird. 



Few persons who see this grub crawhngon 

 their rose-bushes have any idea that it is 

 the early — and to them the most important 

 — stage in the hi?tory of the lady-bird. 

 During the four or five weeks that this 

 stage lasts its sole food is the apliis, or 

 green-fly, and it consumes from thirty 

 to forty sreen-flv in an hour. 



twenty eggs in a close cluster, and when these hatch the minute grubs at once 



set to work on their mission in life. 



It is a singular thing, but these Insects appear to 

 have no enemies at all. The conspicuous colour spots 

 on the grub and chrysahs, and the strongly con- 

 trasted colours of the beetle, warn Insect-eating birds 

 that they are not palatable ; but many Insects so pro- 

 tected fall victims to other Insects that deposit their 

 eggs in them. The lady-birds appear to be immune 

 from the attacks e\ en of ichneumon-wasps. It maybe 

 that these are kept off by an unpleasant odour emana- 

 ting from the blood of the Insect. If a ladv-bird be 

 touched it will be seen to exude from certain joints of 

 its legs a yellow fluid — really blood -^\•hich has a 

 strong, unpleasant smell. 



Something like two thousand species of the lady- 

 bird family are known from various parts of the world, 

 and of this number more than forty are British. A few 

 of them are vegetarians. Even among our native species 

 great variety in the matter of spots will be found. In 

 some, yellow takes the place of red in their li\'ery, and 

 instead of definite spots we may have an elaborate 

 labyrinthine pattern. The commonest species in our 

 gardens are the two-spotted ^ and the seven-spotted 

 lady-birds.'^ In seasons when green-fly are abnormall\- 

 abundant, the grubs appear to get through their feeding 

 more quicklv, and soon the perfect beetles are in 

 evidence everywhere. It is more than probable that 

 on such occasions vast swarms migrate from the Con- 

 tinent, for over and over again they ha\^e been found 

 washed up by the sea in millions along our southern and 

 eastern shores. These, of course, were only the few 

 weak or unfortunate members of the host that chanced 

 to fly too near the surface, and were caught by the 

 crests of the waves. The vast body has flown on and 

 settled on the green lands of Kent, Sussex, and Surre}', 

 where the extensive hop-gardens have been suffering 

 so badly from green-fly that beer-drinkers have feared 

 a future when all the bitter flavour of their staple 

 beverage would have to be supplied b\' the chemist. 

 Then, by some means, the lady-birds at a great distance 

 have learned that their services are required here, 

 and they gathered in enormous swarms, and descending 

 sickly hop-bines have cleared them of the pest and so saved the 

 for the hop-merchant and the beer-drinker. W'e can remember 



' Adalia biimnctata. - Coccinclla scptcmpunctata 



Plioto by] \H. Main, F.E.S. 



Chrysalis of Lady-Bird. 



When tlie grub has sucked to the full of 

 green-fly juice, it suspends itself by the 

 tail to a leaf — as shown to the left of the 

 photograph— contracts in length, and turns 

 to Uie chrysalis shown on tlie rigiit side of 

 the ni:drib. 



upon ih( 

 situation 



