Glossary - Agricultural Entomology - page 280

metathorax; also, in a mite the fourth pair of
legs.
Hindwings The pair of wings arising from the
metathorax.
Holometabolous insect An insect with complete
metamorphosis, i.e. with a pupal stage in the life-
cycle (cf. Hemimetabolous insect).
Honeydew A sugary fluid excreted through the anus
of certain phytophagous Hemiptera, notably
aphids, mealybugs, psyllids and scale insects.
Horn A term of convenience to describe a spinose
outgrowth arising from the eighth abdominal seg-
ment of certain caterpillars.
Hyaline Clear and colourless, as in the wings of cer-
tain insects.
Hypermetamorphosis A kind of life-cycle which in-
cludes two or more distinct types of larvae.
Hyperparasitoid A parasitoid whose host is itself a
parasitoid.
Hypognathous With a vertically directed head and
the mouthparts directed ventrally.
Hypopal Pertaining to the hypopus.
Hypopharynx Part of the insect mouthparts.
arising behind the mouth but just in front of
the labium. Typically short and tongue-like in
insects with biting mouthparts but often
enlongated and tube-like in insects with sucking
mouthparts.
Hypopleural bristles A distinctive curved row of
bristles present on each side of the thorax of cer-
tain flies.
Hypopus The

Knee A term of convenience to describe, in certain
flies (e.g. Agromyzidae), the differentially col-
oured section at the base of the tibia which
demarcates the point of articulation with the
femur.
Labial palp One of the pair of palps arising from the
labium.
Labium The lower lip' of the mouth.
Labrum The 'upper lip' of the mouth.
Lamella {pi, lamellae) A thin leaf-like flap or plate.
Lamellate Composed of several lamellae.
Larva The immature growth stage of a holo-
metabolors insect, which is very different in
appearance to the adult into which it me-
tamorphoses during a pupal stage; the first (typi-
cally six-legged) juvenile stage of a mite between
the egg and first eight-legged nymphal stage.
Larval paedogenesis Parthenogenetic reproduction
in which the adult and pupal stages are omitted
from the life-cycle and the larva gives rise directly
to a 'new' generation of larvae.
Larviform An adult with larva-like body features.
Lateral At or close to the sides.
Lateral penellipse A penellipse with the 'missing
sector' directed mesally.
Macropterous Wings fully developed.
Maggot A colloquial term, often applied to the larva
of a fly.
Malpighian tubules The thin, blind-ending tubules
that arise between the mid-gut and hindgut of an
insect, and which are concerned with the regula-
tion of nitrogenous waste, salt and water.
Mandible Jaw.
Mandibulate With mandibles suitable for biting or
chewing.
Maxilla {pi. maxillae) One of two parts of the
mouthparts of an insect, located just behind the
mandibles.
Maxillary palp One of the pair of palps arising from
the maxillae.
Meconium The excreta produced by a fully-
developed insect larva which does not defaecate
during its development; also, the excreta dis-
charged by an adult insect on emerging from the
pupa.
Melanin A collective term for various black, brown
or yellow pigments which may be incorporated
into the skin.
Mesal At or pertaining to the mid-line of the body.
Mesal penellipse A penellipse with the 'missing sec-
tor' directed laterally.
Mesonotum The dorsal surface of the second tho-
racic segment.
Mesoseries A series lying mesally.
Mesothorax The second of the three main sections
of the thorax of an insect.
Metasternum The ventral surface of the metathorax.

morphologically distinct, often

phoretic, dispersal stage of a mite.
Hypostome The beak-like part of the mouthparts of
a mite.
Hysterosoma That part of the idiosoma of a mite
lying beyond (posterior to) the sejugal furrow and
bearing the third and fourth pairs of legs.
Idiosoma The hinder-most of the two main sections
of the body of a mite, bearing the legs (cf.
Gnathosoma).
Imago {pi. imagines, imagos) The adult stage of an
insect.
'Imago' larva In cecid midges, a larva which will
eventually develop via a pupal stage into an adult
(cf. Paedogenic larva).
Inquiline An animal living in the "home' (e.g. a gall
or a nest) of another and sharing its food.
Instar The stage in the development between two
moults or stages - a first-instar larva or nymph is
that which emerges from the egg.
Integument The outer covering (cuticle plus epider-
mis) of an insect or mite.
Intersegmental Located between two segments.
Juguin A narrow lobe at the base of the forewing of
Certain Lepidoptera which overlaps the hindwing
and serves to couple the wings together.