Hemimetabolous
Definition
A developmental pattern with three stages (egg, nymph, adult) and no pupal stage. Nymphs resemble small adults and moult repeatedly. Cockroaches and crickets follow this pattern.
- Development stages
- Egg, nymph, adult
- Pupal stage
- Absent
- Nymph appearance
- Resembles a small adult
- Growth process
- Repeated moulting
- Example orders
- Cockroaches, crickets, true bugs
Common questions
Why does hemimetabolous development matter for estimating post-mortem interval?+
Since hemimetabolous nymphs already resemble the adult and grow through a series of moults rather than a dramatic pupal transformation, age estimation for these insects tracks nymphal instar stage and size rather than the larval-to-pupal timeline used for flies.
How does hemimetabolous development differ from holometabolous development?+
Holometabolous insects such as flies and beetles pass through a complete metamorphosis with a distinct larval form and an inactive pupal stage before becoming an adult, while hemimetabolous insects skip both and simply grow larger and more adult-like with each moult.
Related terms
- Accumulated Degree Hours (ADH)
- A temperature-corrected measure of developmental time. Calculated by summing (hourly ambient temperature minus the species-specific base temperature threshold) across the period of...
- Binomial Nomenclature
- The two-part Latin naming system established by Linnaeus: genus name followed by species epithet. Used in all scientific and forensic botanical reports...
- Holometabolous
- A developmental pattern with four distinct stages (egg, larva, pupa, adult) and a complete metamorphosis inside the pupal case. Flies, beetles, and...
- Instar
- A developmental stage between moults (ecdysis). Blow flies have three larval instars (L1, L2, L3), each ending when the larva sheds its...
- Spiracle
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