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| Soldier beetle pollinating a flower. |
The vast majority of flowering plants are arranged by botanists into two classes, wind-fertilized (anemophilous), and insect-fertilized (entomopkilous), that is, plants whose pollen is brought to their stigmas by the wind, and plants for which insects perform this duty. One striking feature of wind-fertilized plants is the absence of bright-colored leaves and of scent. The interior of these flowers, too, contains no honey; the visits of insects would be of no use to them, so they do not offer any inducements to these animals to come to them.
Insects are induced to visit flowers in some cases to get shelter from storms ; in others to deposit their eggs, but most commonly of all to procure food. Honey and pollen are the principal foods which they seek for in flowers; but pollen is ordinarily produced in such abundance that much of it can be spared. The brilliant colors of the corolla enable the flower to be seen at a distance, and the various parts of the flower are, as a rule, so shaped as to admit only into the interior the insects that are serviceable. The honey which the flower secretes, and the sweet smells do not, as far as is known, serve any other purpose save that of attracting insects.
The modes in which the flower adapts itself to the visits of special insects, the appliances by which it covers these with pollen, to be transferred to stigma of another flower, are wonderfully various, and seem mostly intended to favor cross-fertilization.
Required for Observation in The Classroom: This lesson should be illustrated by means of a variety of flowers, including species that are small and inconspicuous, and others brightly colored, flowers that sleep by day (evening primroses, tobacco, &c.), flowers that sleep by night (daisy, dandelion, pimpernel, &c.), and odorless and sweet-scented flowers. Diagrams showing the sucking-tubes of insects.
Method of Student Observation:
- Various flowers should be examined in order to see and taste the sweet nectar produced by them.
- Diagrams showing the sucking-tubes of insects should be shown, and the insects themselves should be observed as they visit the flowers in a garden.
This information should be acquired, if possible, by the observation of insects at large, and not given by the teacher in the school-room. - Examples of flowers (primrose, canterbury bell, carnation, etc.) illustrating the accompanying notes may be found in most flower-gardens, or in hedgerows and banks.
- These facts should be verified by the actual observation of flowers and insects at different periods of the day and evening, and the children should be encouraged to make notes of their own independent observations, carried on at any time.
How to Grade Study Notes For Student Journals: Every student will need a
journal to write in weekly for this online nature study series. Teacher
will assign the weekly content in advance.
- Make
sure the facts are: written in complete sentences, the first word of
each sentence capitalized, and a period should be included at the end of
each sentence.
- Spell check your vocabulary and write the words correctly.
- Dress up your journal entries with student clip art, drawings of your own in color or in black and white.
- Student may also include photographs of their own taking for extra credit.
Look
for the following facts about insects and flowers
inside of student journals. Assign a point value to the quality of the
content.
- Why Insects visit Flowers. - Many flowers produce sweet fluids on which certain insects (bees, butterflies, etc.) delight to feed. Such insects are provided with long sucking-tubes, which can be thrust down the cups and tubes of flowers for the purpose of obtaining these fluids, and some (bees) are also provided with jaws by which they can bite through the lower parts of the flowers when their sucking-tubes are not long enough to reach the sweet juices from above.
- Some insects (bees, &c.) feed on the pollen, or else collect the pollen to feed their young.
- How Insects help Flowers. - When an insect visits flowers, some of the pollen adheres to its body. Then, as it flies from flower to flower in quest of food, the pollen it carries is transferred to the stigmas, thus assisting in the work of fertilization.
- Insects generally fly from flower to flower of the same species, thus adding to their usefulness, for the ovule of one species can only be fertilized by pollen from the same species or from one closely allied.
- Some flowers cannot possibly fertilize themselves, either because their anthers and their stigmas are so situated, relatively, that pollen cannot be transferred from one to the other (e.g. the primrose); or because the anthers and the stigmas are never mature at the same period. Such flowers must have their pollen transferred, and this work is carried on by insects or by the wind.
- How Flowers attract Insects. - Those flowers which are fertilized by the wind are, as a rule, very inconspicuous, and have no scent ; but those which require the aid of insects generally have brilliant corollas, or emit sweet odors to attract them.
- Again, some flowers seem to prefer the aid of particular species of insects, and remain closed except at the hours during which those insects are on the wing. Hence we find some flowers sleeping during the day, and others during the night.
- The flowers which require the aid of day -flying insects usually have corollas to attract them. Those which prefer the visits of night-fliers often remain closed till the evening, and attract the insects either by their sweet perfume, or by their large white or pale-yellow corollas, which are readily distinguished at a distance after dark.
Video at Youtube for Students to Watch + articles to read:
- Pollen and Nectar Carriers - article
- Insect Mimicry and Protective Coloration - article
- Video Attracting Beneficial Insects by Gardener Scott
- Video Building A Host Environment for Beneficial Insects by Paul Zimmerman
The Insect and Flower Anchor Chart and Classroom Discussion: Direct
discussions, develop vocabulary and demonstrate correct sentence
writing. Anchor charts are used in many different grades the following
example below may be used in 2nd through 4th grade during a group
discussion.
- The insect visits flowers to seek for honey.
- The honey lies at the bottom of the flower-cup.
- The insect sucks up the honey from the bottom of the flower with its long sucking tube.
- The insect visits flowers to seek for honey, which lies at the bottom of the flower-cup.
- The yellow dust inside the flower is called pollen.
- The insects gather the pollen and make it into a kind of bread for their young.
- The pollen sticks to the insect when it is seeking for honey in the flower.
- The yellow dust inside flowers is called pollen, and sticks to the insect, when it is seeking for honey in the flower.
- When the insect leaves a flower its body is covered with pollen.
- The insect carries the pollen to the next flower.
- This helps the flower to produce seed.
- When the insect leaves a flower its body is covered with pollen , which it carries to the next flower , and so helps the flower to produce seed.
Insect and Flower Frame Printables: Print, color and write your favorite nature poem inside the boarder printable. For student use, not for resale.
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Click to download the largest available size before dragging to your desktop.
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Poems to Copy, Credit the Author Please:Extended Learning Content:
Free Student Clip Art: Clip
art may be printed from a home computer, a classroom computer or from a
computer at a library and/or a local printing service provider. This
may be done from multiple locations as needed because our education blog
is online and available to the general public.
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1. Section of Flower, showing honey secreted at bottom of tube ;
2. Insect-fertilized Flower; 3. Insect at work, sucking honey;
4. Sucking-tube of insect enlarged,
and section of same ; 5. Wind-fertilized Flowers. |
