THE LADY-BEETLE
"_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._"
--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 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.
[Illustration: The spotted lady-beetle; a, larva; b, pupa; c, adult;
enlarged. (After Chittenden, U. S. Dept. Agri.)]
The lady-beetles, or lady-birds as they are often called, are fairly
uniform in shape and color. They are 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.
[Illustration: The convergent lady-beetle; a, adult; b, pupa; c, larva;
all enlarged. (After Chittenden, U. S. Dept. Agri.)]
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 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.
OBSERVATIONS AND STUDIES
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
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
help greatly in the fight on our insect foes. Make drawings of and
describe briefly the different stages of the lady-beetles.