[R] Refers to the insects for which a pupal stage is interposed between the larval and the adult form. Holometabolous development occurs in endopterygotes and a few exopterygotes, for example, whiteflies, thrips, and male scale insects. Larvae are generally of quite different structure and habit from adults.
Perhaps no concept in entomology has resulted in more polarization of thought than that of categorizing development into types. One classification includes insects that have immatures with external wing pads, the Exopterygota, and species that have internal wing pads as larvae, the Endopterygota. Another classification agrees with the previous demarcations but substitutes Hemimetabola for Exopterygota and Holometabola for Endopterygota. Another view separates the Exopterygota into Paurometabola (for those whose immatures develop terrestrially) or Hemimetabola (whose immatures inhabit water) and retains the endopterygota as a single unit, the Holometabola. However, the terms Hemimetabola and Holometabola seem to have a more worldwide usage.
Major hemimetabolous insects important in plant protection include the Orthoptera, the Thysanoptera, the Heteroptera and the Homoptera.
Major holometabolous insects important in plant protection are the Lepidoptera, the Coleoptera, the Diptera and the Hymenoptera.
* Development of hemimetabolous insects (INRA)
Exemple of a weewil (Curculionidae).
From left to right: new-borne larva, fully grown larva, pupa, adult.
HYPPZ on line: Species (scientific names), Pests (common names), Glossary, Crops.