Hemimetabolism

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Related to hemimetabolous: holometabolous, hemimetabolous metamorphosis

Hemimetabolism

 

incomplete metamorphosis, a type of postembryonic development in insects of several systematic groups (such as dragonflies, mayflies, stone flies, Orthoptera, and Hemiptera). From the eggs come larvae (nymphs), which outwardly are similar to mature insects in that they have faceted eyes and a jointed tarsus, as well as mouth organs just as an adult does. Various orders of insects in the post-embryonic stage have from three to 30 nymph stages. Metamorphosis of the nymph into an adult insect takes place without the chrysalis stage. Sometimes the term “hemimetabolism” is used only for the development of the dragonfly, mayfly, and stone fly, which in the nymph stage have provisional or temporary organs (branchiae, masks); the development of other insects with incomplete metamorphosis, in which the larvae lack provisional organs, is called “paurometabolism.” The opposite of hemimetabolism is holometabolism.

M. S. GILIAROV

References in periodicals archive ?
gregaria, it being a hemimetabolous insect, the cyclical change of serum HA, where the apolysis-ecdysis phase is short and restricted to the formation of new cuticle, cannot be explained on the basis proposed by Komano et al.
Functions of the ecdysone receptor isoformA in the hemimetabolous insect Blattella germanica revealed by systemic RNAi in vivo.
Growth ratios in holometabolous and hemimetabolous insects.
To avoid such ambiguities, an ideal study system should have a fixed number of discrete developmental stages, a condition that is met by many hemimetabolous insects.
The three species are widely distributed in eastern North America (Flint and Wiggins 1961, Strong 1972, Harper 1973), and represent taxa that are widely separated phylogenetically - a hemimetabolous insect, a holometabolous insect, and a crustacean, respectively.
Commonly, size is measured as head-capsule width in the larvae of holometabolous insects, and leg-segment or carapace dimensions in juvenile hemimetabolous insects and spiders.
It will be important to establish whether similar thermal responses in adult body size and cell size occur in other insects, particularly hemimetabolous species, and other ectotherms.