Insects Found During a Plant's Life Cycle

by Stephanie Bailey<,
Entomology Extension Specialist

PROJECT SYNOPSIS

Observe plant (or crop) of interest, noting the life stages and species of insects occuring throughout the plant's life. This unit is a guideline for a 4-H 5th year project or a classroom project.

KERA Goals for Kentucky USA Schools

• Basic Communication and Math Skills: Reading, observing, quantifying, visualizing, classifying, writing, data collecting, visual arts.
• Core Concept - Science: Patterns, systems and interactions, models, diversity, ecology/environment.
• Self-Sufficiency: Positive self-concept, resourcefulness and creativity, self-control and discipline, independent learning.
• Thinking and Problem Solving: Critical thinking, creative thinking, conceptualizing, decision making, problem solving.
• Integration of Knowledge: Applying multiple perspectives, developing new knowledge, expanding existing knowledge.

MATERIALS NEEDED

• Glass Case (Instructions in 4-H Entomology Unit I, printed copy available at your Kentucky USA County Cooperative Extension Office)
• Pinning materials (pins, spreading board, labels)
• Entomology fact sheets, identification books, entomology books for insects and plant(s) of interest--Check with your county extension agent and the local library for resources.

PROCEDURE

Continuously (i. e. as often as possible) sample a crop or any plant of choice for insects using one or many methods, throughout the growing season. Save plant samples which show distinctive feeding scars or other symptoms of insect presence.

Classroom alternative: collect as many insects as possible in the fall, and start on the display case, then finish it in the spring (teachers can do a final touchup during the summer if interested).

Ways to sample insects include baits, light traps, berlese funnel (for soil insects), pan traps, sweep net, hand picking, pitfall traps, sticky traps and 'beat sheets.' See Collecting Insects, for more information. Make notes of which method(s) were used to obtain insects. Pin, preserve in alcohol, or otherwise preserve the insects as soon as possible, because once they die insects become extremely fragile within a matter of a few days. (See Kentucky 4-H Entomology Units I, II and III for more detailed information on making an insect collection.)

Identify insects, note economic and/or conservation importance (resources at library or county extension office) e. g. whether primary pest, minor pest, beneficial, "just passing through" and not of any economic importance, rare (NOTE: threatened/endangered insects are protected--do not collect them!), which stages are pests (if any). Include researched information in the final report (do one or more of options below, or make up your own format).

REPORT/PROJECT #1

Make an exhibit of the insects found on the crop or plant of choice, displayed in a glass case. Dig up one plant early in the season--when the plant is around 6-9" tall, including roots. Clean off the roots gently under lukewarm running water, then press the plant: lay out the plant carefully and in an aesthetically pleasing fashion on newspaper, then layer more newspaper and then very heavy books on top of the newspaper to help the plant dry flat. Leave for 2-3 weeks, until completely dry.

As the growing season progresses, collect and press samples of flowers, silks (corn), and specific types of feeding damage. Arrange these in the case as well. The case should be labeled, including both common name and scientific name (italics or underlined) of the plant.

Pin insects of interest on the part of the plant they were (or could be) found on. On a separate sheet of paper, list the insects and their importance (major or minor pest, damage, beneficial, or accidental tourist).

REPORT/PROJECT #2

Summarize which insects are on the plant throughout the plant's life cycle, and which occur only at certain times, such as flowering/silking, early stages of plant growth, etc. Also determine which insects are found on the plant throughout the insect's life cycle, research number of generations/year for as many of the collected insects as possible.

REPORT/PROJECT #3

Determine which of the insects collected are also found on other plants--research which feed only on the given plant (monophagous insects), which feed only on a select or related group of plants (oligophagous insects), which are general feeders (polyphagous insects), which are predators attracted to the plant by the other insects, and any economic importance.

REPORT/PROJECT #4

Summarize the types of insect damage (e. g. boring, skeletonizing, scalloping, etc.) that different insects/life stages cause, using all examples collected. Include damage (drawing or actual samples) if possible. Determine how the damage occurred (pests with chewing mouthparts, sucking mouthparts, during egg laying, etc.)