588 



Color and Pattern and their Uses 



Chemical 

 colors 



Physical 



colors 



TABLE OF INSECT COLORS. 

 Bv W. L. Tower. 



Cuticular 

 colors 



r Black 



Dark brown 



Brown 

 . Straw yellows 



Located 



in 

 primary 

 cuticula 



Hypodermal 

 colors 



Chrome 



yellows 

 Red 



\"ermilion 

 Scarlet 

 Blue 



Green 



WUow 



White 



Located in 

 or between 

 the hypo- 

 dermal 

 cells 



Sub- r Green 



hypodermal -i Yellow 

 colors I White 



Located in 



the body- 



cavity in 



hiTmolymph 



or fat-body 



Permanent. Insoluble in water, 



alcohol, ether, oils, weak acids, 



or alkalies 

 Soluble in strong concentrated 



mineral acids with dissolution of 



the cuticula 



Permanent. Insoluble 

 in water, oils, alcohol, 

 weak acids, or alkalies 



Soluble in ether or other 

 fatty solvents 



Not permanent. 

 Fade at death or 

 on e.\posure 



Soluble in water, al- 

 cohol, etc. 



Are chlorophyll or 

 xyanthophyll de- 

 rivatives largely 



Not permanent. Fade 

 at death or on ex- 

 posure 



Soluble in usual or- 

 ganic solvents 



Derived 

 pigments 



Derived 

 pigments 



Reflection 



colors 



I WTiite [ 



Caused by air included within scales, etc. The most 

 common, and perhaps the only true physical, color 



Refraction 



colors 



Metallic 

 colors 



Opalescent 

 colors 



Caused by combining white and 

 some metallic refraction color, 

 usually with pigment present. 

 Frequently caused by thin irregu- 

 lar lamella; over pigment, giWng 

 effect of Newton's rings 



Diffraction j Iridescent [ gee next class 

 colors ( colors ) 



Chemico- 

 physical 

 colors 



Reflection 

 pigmental 

 colors (a) 



Colored surfaces 

 with polished ap- 

 pearance 



Caused by a polished lamellar 

 surface over layer of pig- 

 ment. 



Refraction | Almost all 

 pigmental < metallic 

 colors (6) ( colors 



Cause — polished refractive 

 layer of pigment 



lamella overl>ing a 



Diffraction 



Almost all 

 iridescent 



pigmental < 

 colors (c) ( colors 



(Cause — surface structures, pits, ridges on refrac- 

 tive lamella overlying a layer of pigment 



Combination 

 colors 



Various iridescent metallic and 

 opalescent metallic colors, etc., 

 in which colors of groups a, h, 

 and c combine to produce color 

 effects 



This class of color is con- 

 fined largely to Lepi- 

 doptera and almost ex- 

 clusively to scaled in- 

 sects or areas bearing 

 scales 



