Glossary

a

• abdomen: one of the three body segments in insects; the most posterior segment containing the heart, reproductive organs, and digestive organs
• alate: winged
• antenna (pl. antennae): pair of segmented, sensory structures (feelers) projecting from the heads of insects
• anterior: situated near the front of the body; nearer to the head
• apical: far from the base, the tip of a structure
• appendage: any limb or organ that is attached to the insect's body by a joint
• apterous: without wings
• arista: a large bristle located on the apical antennal segment for dipteran species
• axil: the upper hollow where a leaf or flower attaches to a stem

b

• basal: at or near the base of a structure
• bronzing: smooth, dark brown discoloration to plant tissues as a result of insect damage

c

• calyx: whorl of residual flower parts that include the sepals, found at the stem end of a fruit
• canopy: referring to the crown of a tree that includes the leaves, stems, and branches
• caterpillar: common name for larval lepidopterans (butterflies and moths)
• cauda: a v-shaped structure extending from the rear of the aphid abdomen
• cercus (pl. cerci): segmented, paired appendages at the rear of the abdomen, usually triangular and short in grasshoppers
• chewing mouthparts: mouthparts designed for biting and chewing; mandibles move from side to side with overlapping edges that cut like scissors as well as surfaces for grinding; characteristic of orthopterans
• chlorosis: yellow or white spotting on leaves and fruit resulting from feeding by certain pests
• chrysalis: another term for the pupa of a butterfly
• cilia: slender hairs that outline the forewings and represent modified setae; a diagnostic characteristic of thrips (order Thysanoptera)
• clavate: word used to describe antennae in which the last, terminal segments are wider towards the tip forming a club-like shape
• clypeus: a sclerite on the head of the insect positioned below where the antennae attach and articulated with the labrum on the other side
• cocoon: the protective covering around the pupa of some insects
• compound eye: an eye comprised of many individual eye elements called ommatidia that each have a lens; the main visual organ in insects
• concave: shaped or curved like the inner surface of a sphere
• convex: shaped or curved like the outward surface of a sphere
• cornicles: paired, triangular-shaped tubes projecting from the rear of an aphid abdomen; also referred to as siphunculi
• costal fold: a fold along the leading edge of the lepidopteran forewing that contains scent scales used to attract members of the same species
• coxa: basal segment of insect leg that is connected to the body by a joint
• crawler: the mobile first instar of many scale species
• cremaster: a hook or series of hooks at the terminal end of the abdomen in some lepidopterans, used to attach the butterfly or moth to the pupation site
• crochet (pl. crochets): small, hook-like structures that extend in a circle from the prolegs found on larval lepidopterans

d

• diapause: temporary cessation of development caused by a physiological response to unfavorable conditions
• distal: appendage or part farthest from the body
• dorsal: the upper surface of an insect

e

• eclosion: the emergence of an insect from an egg or pupa
• elytron (pl. elytra): hardened or sclerotized pair of forewings in beetles
• emergence: used to describe the completion pupation that culminates in the appearance of the adult form of an insect
• ensiform: word used to describe antennae that are sword-like and broad at the base, but narrowing to the tip
• epidermal cells: layer of plant cells immediately beneath the waxy covering on the surface (the cuticle)
• exudate: fluid released naturally from the body openings of insects or from wounds in insects or plant tissues
• eyespots: markings on an insect, usually the wing, that resemble a large eye

f

• femur: from the base of the insect body, the femur is the third segment of the insect leg, situated between the trochanter and tibia
• filament: long thread-like structures extending from the body of insects, typically from the abdominal segments (e.g., mealybugs)
• filiform: type of antenna that is uniformly thin and threadlike throughout its length
• flagellum (pl. flagella): the outermost part of the antenna, beyond the scape and pedicel, usually divided into many subsegments (flagellomeres)
• flush: period of rapid growth in the terminal shoots of citrus trees that may be associated with flowering or may be vegetative
• foliar: relating to foliage (leaves)
• forewing: the anterior (closest to the head) pair of wings in insects
• frass: pellets of very dry excreta produced by some insects
• furcula: forked projection from the posterior edge of the abdomen and overlying the supra-anal plate of male grasshoppers

g

• gall: a distorted area of stem or leaf tissue arising from the plant's response to attack by certain pests and pathogens
• gaster: the bulbous part of the ant abdomen located behind the waist (petiole)
• generation: the time it takes for an insect to develop from egg to adult
• geniculate: adjective used to describe antennae in which there is an abrupt bend or 'elbow' along the length of the antennae
• genitalia: external reproductive structures
• girdling: removal of the bark, phloem, and cambium tissues around the entire circumference of the effected plant part (branch, root, or trunk) that results in the death of the wood beyond that point; characteristic damage inflicted by specific insects like beetle larvae
• gravid: female that is bearing eggs
• gregarious: exhibiting the behavior of moving or feeding in a group of individuals of the same species; early instars of many insects feed in groups
• grub: an immature stage in the life cycle of insects; larvae of beetles are often referred to as grubs

h

• haltere (pl. halteres): the club-shaped, modified hindwing of flies (order Diptera) that plays a role in moderating balance and stabilization in flight
• head: one of the three main body segments in insects; the anterior-most segment containing the many sensory structures including the eyes, antennae, and mouthparts
• hemelytra: the forewings typical of many hemipterans; the base of the wing is leathery and the tip of the wing is membranous
• hemimetabolous: simple metamorphosis that consists of a series of molts and lacks a true pupal stage
• hindwing: the posterior or rear pair of wings in insects
• holometabolous: complete metamorphosis that includes egg, larval, pupal, and adult phases
• honeydew: the sugar-rich waste product excreted by aphids, mealybugs, and scales insects as a result of feeding on the phloem of plants
• host plant: the plant the provides sustenance for an insect
• host range: the range of species that a particular organism can feed on to achieve successful growth and reproduction
• hyaline: transparent and glassy

i

• imago: the adult stage of an insect
• immatures: term used to describe the sub-adult stages of insects that do not undergo complete metamorphosis; see also nymph
• instar: immature stages (larva or nymph) of insects in between molts
• integument: the outer covering of an insect's body
• invasive: term used to describe species that are not native and have the ability to adversely effect habitats they invade either ecologically or economically

l

• larva (pl. larvae): the immature or juvenile stage of certain groups of insects that undergo complete metamorphosis that includes a pupal stage; these juveniles often look very different from the adult form and are missing structures (e.g., wings) that are found in the adult
• lateral: with an orientation pertaining to the side

m

• maculate: spotted
• maggot: an immature stage in the life cycle of insects; fly larvae are often referred to as maggots
• mandibles: the jaws of insects with chewing mouthparts
• medial: situated in or closest to the middle
• membranous: with the same character as a membrane, typically used to refer to structures like wings that are clear and translucent like a membrane
• mesothorax: the second or middle segment of the thorax
• metathorax: the third and last segment of the thorax
• mobile: able to move
• molt: process of shedding the external skeleton during periods of growth; occurs between successive instars of a larva or nymph
• moniliform: type of antennae where successive round segments make the antenna as a whole appear like a string of beads
• motile: able to move

n

• necrotic: the damage caused by cell death (necrosis) in plants or other organisms, often a result of insect feeding on plants, and displayed as brown or black coloration of tissues
• nymph: the immature or juvenile stages of insects that do not undergo complete metamorphosis; look similar to the adult and develop to the adult stage through a series of incremental changes that does not include a pupal stage

o

• ocellus (pl. ocelli): the simple eye of an insect that consists of a single, bead-like lens, typically located at the top of the head in insects that undergo complete metamorphosis; absent in lepidopterans and reduced in many other species
• oviposition: the act of depositing eggs
• ovipositor: a tubular structure extending from the abdomen of female insects that is used to lay eggs
• ovisac: structure attached to the body that contains eggs; produced by many scale insects

p

• parthenogenesis: a form of asexual reproduction in which a female produces eggs without fertilization by a male
• pedicel: from the base, the second segment of the antenna, located between the scape and the flagellum
• petiole: the first segment behind the metathorax that connects the thorax to the gaster of an ant; often referred to as a "waist" because the segments are slender and appear as a constriction between the two body sections
• pheromone: chemical substance secreted by an animal that influences the behavior of another animal
• piercing-sucking mouthparts: labium encloses the mandibles and maxillae, which are modified into stylets for piercing and sucking; characteristic of hempiterans
• posterior: orientation pertaining to the rear of the body
• postpetiole: the second segment of the "waist" which, if present, is located directly behind the petiole; only present in certain familes of ants
• pre-pupa: the non-feeding last instar larva of insects that undergo complete metamorphosis
• probing-sucking mouthparts: mouthparts are modified into a long, slender proboscis specialized to probe flowers and suck out nectar; characteristic of butteflies and moths
• proleg: unsegmented, fleshy, foot-like structure extending from the abdomen of many larval lepidopterans that aids in locomotion, but are not true legs like those found extending from the thorax
• pronotum: the dorsal surface of the first thoracic segment
• propupa: a non-feeding stage in the development of thrips and male scales immediately before formation of the pupa
• prothorax: the first segment of the thorax
• pterostigma: a thickened cell on the outer margin of the wing in some insects
• pulp: the soft, moist, internal part of the citrus fruit, beneath the rind and albedo layers
• pupa (pl. pupae): the non-feeding, immobile developmental stage of holometabolous insects during which the larva develops into an adult that is very different in form
• puparium: the rigid outer shell formed from the discarded larval skin that protects the pupa of certain flies

r

• rasping-sucking mouthparts: mouthparts that are modified to rasp or scrape the surface of plant tissues and suck up the fluid that flows from damage tissues; characteristic of thrips
• ring scar (or halo mark): a circular blemish on fruit caused by pest damage to the rind around the calyx during early fruit development

s

• scape: basal segment of the antenna
• scent gland: a gland which secretes an offensive, odorous fume for protection
• sedentary: not mobile
• sessile: not mobile
• seta (pl. setae): stiff hairs or bristles
• setaceous: word used to describe antennae in which the flagellum is reduced and tapers gradually from the base to the tip
• silk: a natural fiber produced by some insects that can be utilized to construct shelters, leave a trail, build a cocoon, etc.
• siphunculi: paired, triangular-shaped tubes projecting from the rear of an aphid abdomen; also referred to as cornicles
• solitary: insects that feed or move about individually, not in groups
• spine: a thorn-like outgrowth of the integument (exoskeleton) that is not separated from it by a joint
• sponging mouthparts: mouthparts are modified for sponging up liquid food by capillary action; saliva containing digestive enzymes may be used to liquify solid food; characteristic of dipterans
• spur: a spine-like process of the integument (exoskeleton) that is connected by a joint
• stigma (pl. stigmata): prominent, darkened cells on the forewings of some male lepidopterans that produce pheromones to attract females

t

• tarsus (pl. tarsi): the last, distal segment of the insect leg, composed of sections called tarsomeres, usually ending in a claw
• thorax: one of the three main body segments in an insect, located between the head and abdomen, where the wings and legs of the insect attach
• tibia: from the base of the insect body, the tibia is the fourth segment of the insect leg, situated between the femur and the tarsus
• trochanter: from the base of the insect body, the second segment of the insect leg, situated between the coxa and the femur
• tubercle: a small raised bump or rounded protuberance, typically, describing a raised bump on a caterpillar that bears a spine orthe rounded bumps that the antennae of aphids extend from
• tympanum (pl. tympana): a vibrating membrane that serves as an auditory organ in some insects

v

• ventral: bottom surface of the body

w

• wing pads: undeveloped or incomplete wing structures that are found on the immature individuals of insects that do not undergo complete metamorphosis, e.g., stink bugs, leaf-footed bugs, grasshoppers