SPECIAL PKOBLEMS OE INSECT CUMlii)L 151 



Water will not do this, because the openings are protected 

 agaiiist its entrance by oily secretions. Compare the effect 

 of dipping an insect into water and into kerosene. 



Next, beginning at the head, study all organs and mov- 

 able parts {(ippendages) : the eyes, feelers ( antennas rci)la(ing 

 Head Prothorax Mesothomx Metathorax Abdomen 



Comppiind Ey^ \ I / / 



Simpt^ Eye/ | ^^.^ ^,.^^^ / / ^/„,; j,^„j, / 



Ear / d* 



Spiracles 

 'Trochanter 



Mandible 

 Maxilla 



'Femur 

 ■.Tibia 

 '■ .Tarsus 



Labium 



Oripositor 



Mouth-Farts 



Fi<;. 77. External anatomy of the grasshopper 



ears and nose as sense organs, at least partly), moulli i>arts 

 (very complicated, consisting typically of an upper and lower 

 lip (labrum and labium) and two pairs of jaws (mandibles 

 and maxilhe), which move sidewisc instead of up and down). 

 Watch a caterpillar or grasshopper eat a leaf and see if you 

 can discover why the jaws move side wise. A study ol mouth 

 parts is again important with ref(M-ence to methods of destroy- 

 ijicr insects. Tliose that bite and chew can be killtMl by spraying 



