LEPIDOPTERA 



169 



Only a minority of the diverse visits of the wasps here mentioned are devoted to 

 plundering flowers and social flowers with fully concealed nectar (C, S), while saw- 

 flies only visit flowers from which they can get nectar by simply bending down 

 their heads. 



As regards the colours they have acquired by natural selection, wasps on the whole 

 are also to be looked upon as but little specialized flower visitors. More than three- 

 quarters of the species of all their families, and in ichneumons (which as a rule 

 only seek for entirely exposed nectar) even nine-tenths, are greenish, white, or 

 yellow. (H. Miiller, ' Alpenblumen,' pp. 519-20.) 



B. Butterflies and Moths (Lepidoptera). 



Hymenoptera are undoubtedly the most important of all our indigenous insects 

 as regards pollination of flowers, and for that reason have been first described. 

 But in respect of adaptation to flowers, they are surpassed by the Lepidoptera, since 

 all these seek for nectar as their only food, whereas many Hymenoptera nourish 



^ 



Fig. 71. Adaptation of Lepidoptera iojloweys {aiier^iervmnnMaWeT). (i) Head of Polyommatus 

 phloeas Z., with proboscis half rolled up. (2) Head of Vanessa \o L.\ the laciniae and the labial palps 

 have been cut off short (x 7). (3) Part of a lacinia of Macroglossa fucifonnis L., seen from the inner side 

 (a, the groove) ; highly magnified. (4) Transverse section through the apposed laciniae of the same 

 species highly magnified, aa, tube formed by the juxtaposition of the two grooves. (5) Tip of a lacinia of 

 Vanessa Atalanta L. References in (2) as in Fig. 64. 



themselves upon animal substances as well as flower-food, and not a few of them 

 even prefer such a diet. 



As the Lepidoptera are exempt from the care of offspring, simply laying their 

 eggs on the food-plant of the caterpillar, their proboscis is exclusively adapted for 

 securing the nectar that serves as their only nourishment. In the mouth-parts of 

 this order (Fig. 71), the labrum (2, Ibr) and mandibles {7Jid) are rudimentary, but 

 the labial palps and first maxillae are well developed. The laciniae of the latter are 

 produced to form two long half-tubes, which lie so close together that they constitute 

 a closed suctorial tube. According to Kirbach, the adjacent edges of the maxillae 

 are provided above and below with sickle-shaped plates lying close together, or are 

 beset on the lower side with a row of double hooks, which interlock and bind these 



