Glossary - Pests of Ornamental Trees, Shrubs and Flowers - page 438

frass Solid excreta produced by an insect, especially a
caterpillar.
frons The upper part of the face of an insect, lying
between and below the antennae and usually
including the central ocellus.
fundatrix ( pl. fundatrices ) A parthenogenetic, vivipa-
rous, usually wingless female aphid that emerges
from an overwintered egg, and typically establishes a
colony in the spring.
gall Abnormal growth of plant tissue, induced by certain
insects, mites, fungi and other organisms.
gallicola ( pl . gallicolae ) A winged female adelgid that
emerges from a gall whose development it helped (as
a nymph) to induce.
galligenous tissue Tissue produced by a plant in
response to an external stimulus.
gaster In certain Hymenoptera, that part of the abdomen
located behind the petiolus.
geniculate Abruptly bent, elbowed.
genu The fourth segment of the leg of a mite, located
between the femur and the tibia.
genus The main taxonomic category between family
and species, including one or more species
considered to be of a single evolutionary origin.
glabrous Without hairs, hairless.
gnathosoma The first (anterior-most) of the two main
sections of the body of a mite, comprising the
mouthparts and bearing the paired chelicerae and
pedipalps (q.v.).
gravid Pregnant.
grub A colloquial name for an insect larva, such as a
'chafer grub'.
haemolymph The blood-like fluid filling the body
cavity of an insect.
haltere One of a pair of club-shaped or drumstick-like
balancing organs on the metathorax of a true fly,
formed from the modified hind wings.
hemelytron ( pl . hemelytra ) An elytron that is mainly
hardened but is membranous distally.
hemimetabolous insect An insect with incomplete
metamorphosis, i.e. no pupal stage in the lifecycle
(cf. holometabolous insect).
heteroecious Species whose 'summer' and 'winter'
hosts are different, as in certain aphids.
hibernaculum ( pl . hibernacula ) The structure or
shelter (e.g. a cocoon) in which hibernation takes
place.
hibernation Winter diapause.
Holarctic The area encompassing the Nearctic and
Palaearctic zoographical regions.
holometabolous insect An insect with complete
metamorphosis, i.e. with a pupal stage in the

lifecycle within which transformation from the larval
stage to adulthood takes place (cf. hemimetabolous
insect).
honeydew A sugary fluid excreted through the anus of
certain polyphagous bugs, including aphids,
mealybugs, psyllids, scale insects and whiteflies.
horn As in hawk moth caterpillars, a term of
convenience to describe an often spinose outgrowth
arising from the eighth abdominal segment.
hyaline Transparent and translucent.
hypha ( pl . hyphae ) The long, filamentous structure that
forms the mycelium of a fungus.
hypocotyl That part of a seedling below the cotyledons
which gives rise to the roots.
hypodermis In a plant, the layer of cells immediately
below the epidermis.
hypopal Pertaining to a hypopus.
hypopus ( pl . hypopi ) The morphologically distinct,
often phoretic, dispersal stage of a mite.
hysterosoma The hind section of the idiosoma of a
mite, bearing the third and fourth pairs of legs.
idiosoma The main body section of a mite, divided into
the propodosoma and the hysterosoma.
idiosomal Pertaining to the idiosoma.
inflorescence A flower cluster.
inquiline An animal that lives in the habitation (e.g. a
gall or a nest) of another and shares its food.
instar One of usually several larval or nymphal growth
stages in the development of an insect.
internode The part of a plant stem between adjacent
nodes.
intersegmental Between segments.
interveinal Between the veins, as in a plant leaf.
keel In certain slugs, a distinct dorsal ridge running
down the body.
knee In certain flies (e.g. family Agromyzidae), a term
of convenience to describe the differentially coloured
section at the base of the tibia which demarcates the
point of articulation with the femur.
labial Pertaining to the labium
labium The 'lower lip' of the mouthparts of an insect.
labrum The 'upper lip' of the mouthparts of an insect.
lamella ( pl . lamellae ) A thin, leaf-like flap or plate.
lamellate Composed of several lamellae.
lanceolate Spear-shaped.
larva ( pl . larvae ) The immature growth stage of a
holometabolous insect, which is very different in
appearance from the adult into which it
metamorphoses during a quiescent, non-feeding
pupal stage; compound eyes absent (cf. nymph).
Also, the first immature, six-legged growth stage of
a mite.