stadium.

Institia: stria or furrows of equal width throughout.

Instrumenta cibaria: mouth parts of a mandibulate insect as a whole.

Instrumenta suctoria: mouth parts of a haustellate insect as a whole.

Integer: entire: applied to a margin without incisions.

Integument: the outer covering to the insect body.

Inter: between; among.

Inter-alar space: in Odonata; the terga of meson- and meta-thorax.

Interantennal: between the basal segments of antennae.

Inter-articular: the membranous tissue between joints or segments.

Intercalary -ies: additional or inserted between others; as a vein:
plural; added or supplementary longitudinal wing reins: see under
specific headings; i.e. anterior, etc.: in Ephemerides, certain
longitudinal veins between the 8th (anal) and 9th (1st maxillary) and
not branches of either: in Diptera, the anterior intercalary (Loew) = the
discoidal, and the posterior intercalary = the cubitus 1 of Comstock:
applied to an evanescent sclerite in the embryo between antenna and
mandible; also termed premandibular.

Intercostal: between veins or costae; usually in the narrow grooves
between veins in the costal region of a wing.

Intercostula: those small, vein-like structures between the normal
veins, visible on a wing margin but lost toward the disc.

Intercoxal process: in Coleopteran; a median protrusion of the basal
segment of abdomen between the hind coxae.

Intermediate: lying between others in position or possessing
characters between two other forms.

Intermediate field: of termini is = discoidal field q.v.

Internal area: in Hymenoptera; the posterior of the three areas
between median and lateral longitudinal carina on the metanotum
third lateral area.

Internal cell: in Hymenoptera (Pack.) 2d anal (Comst.).

Internal triangle: in Odonata see triangle.

Internal veins: in Lepidoptera, from one to three in number, run free
from base to outer margin near hind angle; never branched;1a to is
in the numerical series: = anal veins (Comst.).

Interneural: between the nerves (or veins) of wings.

Interno-mandibular: applied to one of the pairs of salivary glands in
bees, situated at the inner side of base of mandible.

Internomedian: in Orthoptera; = cubitus (Comst.); q.v.

Interocular: between the eyes.

Interplical: lying between folds; specifically applied to the alternate
ridges and grooves in anal area of secondaries of Orthoptera.

Interposed sectors: in Odonata;