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Elementary Study of Insects

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<h2>Chapter XII THE LADY-BEETLE</h2> <div class="cpoem" style="width:15em;"><div class="poem"><div class="stanza"> "Hurt no living thing: Ladybird, nor butterfly, Nor moth with dusty wing, Nor cricket chirping cheerily, Nor grasshopper so light of leap, Nor dancing gnat, nor beetle fat, Nor harmless worms that creep." </div> </div></div> —Christina Rossetti. The lady-beetles comprise one family of small beetles, which is famous for the number of beneficial forms it includes. With but two exceptions the American forms feed upon other insects, in most cases pests such as plant-lice and scale insects. From the time they hatch from the egg until they pupate and again after the beetle stage is reached they are regular tigers[88] after plant-lice. They catch and hold their prey between the front feet while they devour it bodily. The larva of the lady-beetle has an astonishing capacity for in one day it will eat several times its own weight of plant-lice. Farmers and fruit growers could hardly get along without the help of these small beetles and yet unfortunately thousands are often destroyed by those who do not know of their beneficial work. <div class="cpoem" style="width:700px;"><div class="figleft"> <ANTIMG src="images/038.png" width-obs="287" height-obs="200" alt="" title="" /> The spotted lady-beetle; a, larva; b, pupa; c, adult; enlarged. (After Chittenden, U. S. Dept. Agri.)</div> <div class="figright"> <ANTIMG src="images/039.png" width-obs="380" height-obs="200" alt="" title="" /> The convergent lady-beetle; a, adult; b, pupa; c, larva; all enlarged. (After Chittenden, U. S. Dept. Agri.)</div> </div> The lady-beetles, or lady-birds as they are often called, are fairly uniform in shape and color. They are[89] oval or round in outline with the back rounded or elevated and the underside flat. In color they are usually either orange or yellow, checkered or blotched with black or black with yellow or bright orange markings. They closely resemble small tortoises. Unfortunately several plant feeding beetles are similar in shape and color which casts reflections on the lady-beetles. The grub of the lady-beetle is usually black or dull colored with red or yellow markings which make it very conspicuous. It runs about over foliage and is broad in front and tapers to a point behind. When the grub is full fed it attaches the top of its body[90] to a leaf, twig or other object and pupates. In the pupal stage it is often protected with spines and is able to lift the front end of the body up and down when disturbed, producing a light tapping sound. The lady-beetle usually hides in rubbish about the base of trees or in some cases even enter homes for the winter months, coming out with the spring to deposit small masses of oval yellow or orange eggs on plants infested with lice. They breed rapidly and with the help of parasites and other beneficial insects usually control the plant-lice pests. <h3>Observations and Studies</h3> Examine about fruit trees, shade trees, truck crops and in wheat fields for the brightly marked beetles. Watch them move about the plant in search of food. Can they fly? Do you find them eating the leaves? Do you find any green lice near them? See if they feed on these lice. Examine[91] also for the soft bodied, tiger-like grubs. Do they eat the lice? Do they travel fast? Have they wings? See if you can find any of the pupae attached to limbs or twigs and if so, tickle them with a straw or a pencil and see them "bow." Keep a record of the different trees and plants on which you find lady-beetles. 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[92] help greatly in the fight on our insect foes. Make drawings of and describe briefly the different stages of the lady-beetles. <hr style="width: 65%;" />[93] <div style="break-after:column;"></div>

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