Collect several of the beetles and the grubs and keep them in a bottle or jelly glass. Leave them without food for a day and then give them some green plant-lice and watch them devour the lice. How many lice can one eat in a day? How do they go about devouring a louse? Do they simply suck out the blood, or is the louse completely devoured? Supposing that for each apple tree in Missouri there are one hundred lady-beetles and that each beetle devours fifteen lice in a day, does it not seem worth while protecting them and encouraging such work? A little time spent in acquainting one's self with the good work of such forms as these will help greatly in the fight on our insect foes. Make drawings of and describe briefly the different stages of the lady-beetles. CHAPTER XIII THE DRAGON-FLY What child is there that is not familiar with the insect commonly known as the dragon-fly, snake doctor or snake feeder? Every lover of the stream or pond has seen these miniature aeroplanes darting now here, now there but ever retracing their airy flight along the water's edge or dipping in a sudden nose dive to skim its very surface. At times it is seen to rest lazily, wings out-stretched, perched on some projecting reed or other object. But when approached how suddenly it "takes off" and is out of reach. The dragon-fly is an almost perfect model of the modern monoplane. Its two long wings on either side are the planes, its head the nose, its thorax the fuselage and its long projecting abdomen the tail or rudder. On wing the dragon-fly is one of the swiftest and most powerful insects. The dragon-flies are found all over the world being most abundant in the warmer regions where rainfall and bodies of water are abundant. For breeding they require water, their immature stages living under water feeding on aquatic animal life. Our present order of dragon-flies is the remains of an ancient race of insects of immense size. From fossil remains we learn that ancient dragon-flies had a wing expanse of three feet. [Illustration: Cast off skin of dragon-fly nymph, showing shape and position taken on a twig when the adult winged form emerged from the last nymph stage.] The dragon-fly is a beneficial insect thruout life. The young feed on mosquito wigglers and similar life in ponds and streams while the adults dart here and there over ponds, fields or lawn catching mosquitoes and other winged insects. Many look upon the dragon-fly as a dangerous stinging insect but it is entirely harmless and can be handled without the least danger. They vary greatly in size and appearance. The so-called damsel-flies form a group of dragon-flies or Odonata which rest with the wings in a vertical position and the young aquatic stages are more slender. In color markings dragon-flies include all hues of the rainbow tho as a rule they do not have such extravagant colors as the butterflies. [Illustration: One of our common dragon-flies found about ponds and streams.]