300 Insects and their Surroundings 



a host of insects, others find food in the parts of 

 flowers. Many small Caterpillars and Beetles feed 

 entirely on petals, while honey forms the staple food 

 of Bees, and Moths, and very many Flies. 

 Insects and Flowers. — In their visits to flowers 

 for the purpose of gathering 

 honey, Insects do a service to 

 the plants by transferring pol- 

 len from the stamens of one 

 flower to the stigma of another 

 and so ensuring cross-fertilisa- 

 tion. The honey has been re- 

 garded in the light of a pay- 

 ment made to the insects for this 

 service — while it is believed by 

 many botanists that the bright 

 colours of flowers have been 

 developed in order to attract 

 insect-visitors. The high 

 modification of the jaws in 

 Moths and Bees, enabling them 

 to suck honey from the deeply- 

 placed nectaries of flowers, has 

 been described in Chapter I; as 

 also the " pollen baskets" on 

 the hind shins of Bees. While 

 some flowers can be fertilised 

 by the agency of insects of 

 various kinds, others are 

 dependent on the visits of 

 special sorts of bees or moths 

 (176, 177)- ^ most remark- 

 able instance of the inter-dependence of plants and 

 insects is afforded by the relations between the Ameri- 

 can Yuccas and the small white-winged moths of the 

 genus Pronuba. The female in these moths, has, 



Fig. 161. — Yucca Moth (Fro- 

 nuba), gathering pollen. 

 Magnified 5 times. From 

 Riley, Insect Life, vol. 4. 



