Pest Biology & Identification
Effective pest management begins with understanding your target pest. This section covers pest identification, life cycles and vulnerable stages, pest ecology and behavior, damage thresholds, beneficial organisms and natural enemies, and how biological knowledge informs treatment timing and method selection.
Study Guide: Pest Biology & Identification
Review these sample questions before starting the practice test.
Q1: What are the four stages of complete metamorphosis in insects?
- A. Egg, nymph, pupa, adult
- B. Egg, molt, growth, adult
- C. Birth, growth, maturity, death
- D. Egg, larva, pupa, adult â
Complete metamorphosis (holometabolous): egg, larva, pupa, adult. Examples: butterflies, beetles, flies, wasps. The larval stage looks completely different from the adult.
Q2: What is "incomplete metamorphosis"?
- A. Three-stage development: egg, nymph, adult â where nymphs resemble small wingless adults â
- B. Development without eggs
- C. Metamorphosis that fails
- D. Development with only two stages
Incomplete (hemimetabolous) metamorphosis has three stages: egg, nymph, adult. Nymphs look like small adults without wings. Examples: grasshoppers, cockroaches, aphids, true bugs.
Q3: What is the difference between an insect and an arachnid?
- A. No difference
- B. Insects are always bigger
- C. Arachnids have wings
- D. Insects have 6 legs and 3 body segments; arachnids have 8 legs and 2 body segments â
Insects: 6 legs, 3 body segments (head, thorax, abdomen), usually wings, antennae. Arachnids (spiders, mites, ticks): 8 legs, 2 body segments, no wings, no antennae.
Q4: What is "host specificity" in pest biology?
- A. A pest that lives everywhere
- B. A hosts immune response
- C. The degree to which a pest is limited to specific host plants, animals, or environments â
- D. A pesticide property
Host specificity ranges from monophagous (one host species) to polyphagous (many hosts). Understanding host specificity is crucial for predicting pest occurrence and designing control strategies.
Q5: What is a "disease vector" in pest management?
- A. A direction of disease spread
- B. A disease symptom
- C. A type of pesticide
- D. An organism (usually an insect or mite) that transmits a pathogen from one host to another â
Vectors transmit pathogens between hosts. Examples: mosquitoes (malaria, Zika), ticks (Lyme disease), aphids (plant viruses), whiteflies (tomato yellow leaf curl virus).
Q6: What is the difference between "annual" and "perennial" weeds?
- A. Annuals complete their life cycle in one year or less; perennials live for more than two years and regrow from roots â
- B. Only size difference
- C. Annuals are always smaller
- D. Perennials only grow in summer
Annual weeds (crabgrass, pigweed) complete seed-to-seed cycle within one season. Perennials (dandelion, quackgrass) persist through underground storage organs and regrow each year, making them harder to control.
Q7: What is a "biennial" weed?
- A. A weed that takes two growing seasons to complete its life cycle â vegetative growth first year, flowering and seed second year â
- B. A weed that grows twice a year
- C. A weed from two continents
- D. A weed that dies twice
Biennials (wild carrot, bull thistle) grow vegetatively in year one, forming a rosette. In year two, they bolt, flower, produce seed, and die. Control in the rosette stage is most effective.
Q8: What are "broadleaf weeds" versus "grasses"?
- A. Only leaf width differs
- B. Grasses are always smaller
- C. Broadleaf weeds (dicots) have net-veined leaves and two seed leaves; grasses (monocots) have parallel-veined leaves and one seed leaf â
- D. Broadleaves only grow in shade
This distinction is critical for herbicide selection. Broadleaf-selective herbicides (2,4-D) kill broadleaf weeds while leaving grass crops unharmed. Grass-selective herbicides (sethoxydim) do the opposite.
Ready to practice all 80 questions? Start the interactive quiz below.