1. (ARTHROPODA: Chelicerata)
In Mesostigmata, the dorsal plate on the body.
2. (ARTHROPODA: Crustacea)
In Decapoda, a spindle-shaped division of the carapace.
In Coccoidea, the outlet of wax glands; the ceratubae.
2. (ARTHROPODA: Insecta)
a. The wax and exuviae cover resting tentlike over the body of armored scale. b. Usually two peglike cibarial setae borne lateral and/or ...
2. (ARTHROPODA: Insecta)
Usually two peglike cibarial setae borne lateral and/or posterior to the anterior hard palate of the clypeopalatum of mosquitoes.
In Ophiurida, the ossicles along the mid-line of the aboral arm surface; dorsal arm plate.
2. (ARTHROPODA: Insecta)
The blood space enclosed by the dorsal diaphragm and the heart; dorsal pericardial sinus; pericardial cavity.
2. (ARTHROPODA: Crustacea)
In Ostracoda, sometimes prominent, solid or hollow, pointed projection on the dorsal valve margin.
2. (ARTHROPODA: Insecta)
In Syrphidae larvae, a pointed spine or ridge-like elevation of the posterior spiracular plate mesad to the circular plate.
In some Comatulida, a stellate hollow around the aboral pole of the centrodorsal ossicle.
In Anoplura, one of two stylets that are retracted within the trophic pouch.
dorsal tentorial arm
Thought to be an outgrowth of the anterior arm, which it joins near the junction of the anterior and posterior arm; frequently reduced or more or less ...
In mosquito larvae, a tuft of long setae on the dorsum of the ninth segment of the abdomen.
1. The dorsal blood vessel.
see contractile vessel.
n. pl. [L. dorsum, back]
Paired sensory bristles found dorsally on the head.
adj. [L. dorsum, back; ferre, to carry]
Carrying young or eggs upon the back.
In Diptera, that area between the transverse suture and the scutellum, and the base of the wing and the dorsocentral region.
The line of separation between the dorsum and the limb bases of the body, often marked by a fold or groove.
adv. [L. dorsum, back; cauda, tail]
Toward the dorsal surface and caudal end of the body.
adj. [L. dorsum, back; centralis, midpoint]
1. Pertaining to the mid-dorsal surface.
Pertaining to the aboral surface.
In Diptera, a longitudinal row of bristles on the mesonotum, laterad of the acrostichal bristles; absent in many groups.
adj. [L. dorsum, back; medius, middle]
Pertaining to the true middle line on the dorsum of an individual.
In certain Decapoda, a longitudinal groove extending from the tip of the rostrum to the posterior carapace margin dorsomedially.
adj. [L. dorsum, back; Gr. mesos, middle]
Being at the top and along the midline.
n. [L. dorsum, back; Gr. mesos, middle]
Where the meson meets with the dorsal surface of the body.
In Diptera, a suture separating the mesonotum from the pleuron.
In Diptera, a pair of bristles on the dorsal portion of the scutellum, one on each side of the midline.
n. [L. dorsum, back; tentorium, tent]
The dorsal arms of the tentorium.
adj. [L. dorsum, back; venter, belly]
In the axis or direction from the dorsal toward the ventral sufaces; bifacial; dorsiventral.
In Decapoda, a prominent muscle connecting the head apodemes with the inner surface of the carapace posterior to the cervical groove.
n. [L. dorsum, back]
The back or upper surface of an organism.
n. [Gr. dory, spear; aner, male]
A large male form of the driver and legionary ants, characterized by large, modified mandibles, long cylindrical ...
n. [Gr. dory, spear; philos, loving]
Any obligatory guest of army ants belonging to the Dorylini.
A haploid possessing a complete genome from each of two species; see snyhaploid.
Form of DNA proposed by Watson and Crick, made of two chains of nucleotides arranged spirally around each other.
n. [F. doublure, lining]
The reflected margin of a carapace, as in mantis shrimp, horseshoe crabs and trilobites.
The final conical termination of a nerve fiber entering a muscle; an end plate.
adj. [Gr. drepane, sickle]
Sickle-shaped; falcate; drepaniform.
n. [D. drillen, to bore, drill]
A snail that preys upon other mollusks by penetrating the shell with a drilling apparatus; see radula.
adj. [Gr. dromos, race; tropein, to turn]
1. Bent in a spiral.
2. An influence affecting the conductivity of a nerve fiber.
n. [A.S. dran, the male bee]
A male social bee, especially a male honeybee or bumblebee.
n. [L. ductare, to lead]
1. The tubular outlet of a gland for external secretion.
2. Any tube that conveys fluids or other substances.
n. [L. dim. ductare, to lead]
A small duct, or the beginning portion of a duct.
n. [L. ductare, to lead]
A tube in female Lepidoptera connecting the ostium with the bursa copulatrix.
A duct between osmium and uvette in the demanian system.
In Siphonaptera, a primitive genital character of certain females that functions as a spermathecal duct.
A duct between the uterus and the demanian system.
In Hymenoptera, an abdominal gland of the sting apparatus that supposedly secrets a liquid which when applied to cell walls, forms a thin, ...
n. [Gr. doulosis, servitude]
Ant slavery in which a parasitic ant species raids the nests of another species to capture brood (usually pupae) to rear ...
adj. [L. duodecim, twelve; Gr. theke, case]
Pertaining to having 12 spermathecae, usually in 6 pairs.
n. [ML. duodenum, the first part of the small intestine]
The anterior intestine.
n. [F. doupion, double]
In Lepidoptera, a double cocoon spun by two silkworms; the silk from such cocoons.
n. [L. duplex, double; Gr. glossa, tongue]
A forked or divided glossa.
adj. [L. duplex, double]
Pertaining to a polyploid having two dominant alleles for a given genetic locus (AAa); doubled.
adj. [L. duplex, double]
A bipectinate antenna with branches alternately long and short.
n. [L. duplex, double]
1. A doubling; a fold.
2. (ARTHROPODA: Crustacea)
In Ostracoda, the calcified inner lamella of a shell that extends along the free margin of the ...
duplicature muscle fibers
Muscle fibers that widen the anterior end of the tentacle sheath, through which the lophophore passes during protrusion and serves as fixator ligaments for ...
A ligament consisting of a series of bands attaching it to narrow grooves in the cardinal area of the valve.
adj. [L. durus, hard; Gr. phagein, to eat]
Pertaining to animals that break shells to eat the animal inside; sclerophagus.
n. [Gr. dyas, two]
1. Two chromatids that make up one chromosome in the first meiotic division.
2. A pair of cells caused by aberrant meiotic division.
The theory that various parts of the body increase in linear dimensions by a ratio that is constant for the species.
adj. [Gr. dynamis, power]
Producing motion or activity; see static.
adj. [Gr. dys, bad; odos, tooth]
Having small, weak teeth close to the beak.
adj. [Gr. dys, bad; phos, light]
Dim; zone between euphotic and aphotic zones in light penetration of water.
n. pl. [Gr. dys, bad; sappros, putrid; bios, life]
Microbiotrophic nematodes able to invade and obtain nourishment from healthy plants.
adj. [Gr. dys, bad; trophein, to nourish]
1. Defective nourishment.
2. A lake high in undecomposed organic matter.
In social Hymenoptera, sex determination in which fertilized eggs become females and unfertilized eggs become males.
Composition of the shell that forms the eaves; either porcelaneous or riddled with microscopic tubules (spongy).
n. pl. [A.S. efes, lower border of a roof]
Portions of the tegmentum just over the line where the insertion plates and the sutural laminae ...
adj. [L. eburneus, ivory]
Made of, or like ivory; ivory white.
adj. [Gr. ek, out of; L. calcar, spur]
Lacking spurs or calcaria.
adj. [Gr. ek, out of; L. carina, keel]
Without a keel or carina.
adj. [Gr. ek, out of; L. cauda, tail]
Lacking a cauda or tail-like process or structure; excaudate.
A wing lacking a tail-like process.
adj. [Gr. ek, out of; kentron, center]
1. Deviation from the regular.
Having an operculum with growth on one side of the nucleus only, and to one side of ...
adj. [Gr. ekdemos, away from home]
Disease brought into a region from outside; neither endemic nor epidemic.
A thin membrane formed from the lateral lamellae of the old procuticle that is tanned by the polyphenols and phenoloxidase associated with the new outer ...
In some Diptera and Coleoptera, a simple cuticular tube formed around the old spiracle and through which the old spiracle and trachea are pulled ...
n., pl. -ses [Gr. ekdysis, getting out of]
Molting, the process of shedding cuticle or exoskeleton; see molt, apolysis, endysis.
n. [Gr. ekdysis, getting out of]
A hormone that initates changes in cells associated with molting, produced by a secretion of the prothoracotrophic hormone ...
Alternation of blood feeding and molting in mites, ticks, and hemimetabolous insects.
n. [Gr. ek, out of; -esis, denotes action]
The migration of organisms into a new habitat.
adj. [Gr. echinos, spiny]
Set with prickles; spinous; having some or all of the surface of the body covered with spines.
n.; n. pl. [Gr. echinos, spiny; derma, skin]
Phylum of marine coelomate animals with basic pentaradiate symmetry in the adult, with a calcareous endoskeleton and a ...
A cercaria having a collar with spines around the margin of the head and a long slender tail.
n.; n. pl. [Gr. echis, serpent; oura, tail]
A phylum of soft-bodied, unsegmented, sac-like almost exclusively marine invertebrates with a large fluid-filled body cavity; ...
adj. [NL. Eciton, a genus of ants; L. philos, loving]
An obligatory guest of the tribe Ecitonini.
adj. [Gr. eklektos, selected]
Selecting from various systems, doctrines, or sources.
An antigen borne by a parasite that is common to both the host and the parasite, genetically of parasitic origin.
n. [F. eclosion, emerge]
The act or process of emerging from the egg or pupal case; to eclose.
adj. [Gr. oikos, house; klima, region]
Total of meteorological factors within a habitat.
n. [Gr. oikos, house; klinein, to slope]
Continuous gradient of characters in response to variation in ecological conditions.
The formulation of regularities in geographic variation of characters correlated with environmental conditions.
Interbreeding between two or more sympatric populations is prevented by mating in different ecological niches; see geographic isolation/barriers isolate.
n. [Gr. oikos, house; logos, discourse]
The study of interrelationships among organisms themselves and their environment; bionomics; hexicology; mesology; poikology.
n. [Gr. oikos, house; morphe, form]
A growth form caused by a special environment; infraspecific variation.
The number of individuals per unit of habitat space; also called specific density.
n. [Gr. oikos, house; phainein, to appear]
The range of phenotypes produced by one genotype within the limits of the habitat under which it is found in nature.
n. [Gr. oikos, house; phainein, to appear; typos, type]
A nongenetic modification of the phenotype by specific ecological conditions, esp. habitat variation; ecophenotypic ...
n. [Gr. oikos, house; sitos, food]
A microparasite to which its host is immune under normal conditions; ecoparasite.
n. [Gr. oikos, house; L. species, kind]
A group of populations in an ecological niche that are among themselves, and with other ecospecies, capable of interbreeding without ...
n. [Gr. oikos, house; systema, an ordered arrangement of things]
Any entity or natural unit that includes living and non-living parts interacting to produce a stable system in ...
n. [Gr. oikos, house; tonos, stretch, brace]
A transition area between two adjacent ecological communities or biomes; usually containing many organisms from both, as well as ...
n. [Gr. oikos, house; typos, type]
A local race arising as a result of genotypical response to a particular habitat; an ecospecies.
n. [Gr. ek, out of; soma, body]
The telescoping posterior part of the body.
adv. [Gr. ektos, outside; L. ad, toward]
From within toward the exterior; see entad.
n. pl. [Gr. ektos, outside; aden, gland]
A male accessory gland, ectodermal in origin; ectodene glands; see mesadenia.
adj. [Gr. ektos, outside]
Exterior; outer surface of the body or body parts.
adv. [Gr. ektos, outside]
Near to or towards the body wall; see ental.
n. [Gr. ektos, outside; blastos, bud]
The outer wall of a cell; ectoderm; epiblast.
n. [Gr. ektos, outside; chone, funnel-shaped hollow]
A funnel-shaped chamber into which the ostia empty.
n. [Gr. ektos, outside; L. cum, together; mensa, table]
A commensal symbiont that lives on the outer surface of its host.
adj. [Gr. ektos, outside; krinein, to separate]
Any chemical released into the environment that includes allelochemics, pheromones, foods, and respiratory gases.
n. [Gr. ektos, outside; kystis, bladder]
The outer layer of the zooecium.
n. [Gr. ektos, outside; derma, skin]
The outer embryonic layer from which the epidermis of the body wall and nerve tissue are derived; ectodermal a; see choanoderm.
Mouthparts external to the head, not enclosed; ectotrophous; see entognathous condition.
adj. [Gr. ektos, outside; lekithos, yolk of an egg]
Having cleavage modified by a special condition whereby yolk is stored in separate cells ...
n. [Gr. ektos, outside; meros, part]
A blastomere forming the ectoderm.
n. [Gr. ektos, outside; mesos, middle; chyma, anything poured]
1. A structure with organized cells that functions in epithelial interfaces, muscular sheets, and neuroid ...
n. [Gr. ektos, outside; mesos, middle; derma, skin]
Mesoderm derived chiefly from the ectoderm during early embryology of animals; forming mesenchyme predominently in ...
adj. [Gr. ektos, outside; neuron, nerve]
Pertaining to the oral part of the nervous system (sensory and motor).
n. [Gr. ektos, outside; oikos, house]
The outer layer of the oecial wall; usually calcified.
n. [Gr. ektos, outside; para, beside; sitos, food]
A parasite feeding on a host from the exterior; ectoparasitic adj..
adj. [Gr. ektos, outside; phagein, to eat]
n. [Gr. ektos, outside; phallos, penis]
The outer phalic wall; see endophallus.
adj. [Gr. ek, out of; topos, place]
1. Occurring in an abnormal place.
2. A parasite in an organ in which it does not normally live; see entopic.
n. [Gr. ektos, outside; plasma, to form or mold]
An external or cortical layer of protoplasm in a cell; see endoplasm.
n. [Gr. ektos, outside; proktos, anus]
In certain Neuroptera, a plate of the anal segment, including the fused anoprocess, cerci and catoprocess.
n. [Gr. ektos, outside; soma, body]
The outer region that consists of dermal membrane and subdermal spaces, but is not supported by any special skeleton; ...
n. [Gr. ektos, outside; sperma, seed; legein, to gather]
In females, one to two cuticular pouches, variable in position, functioning for the reception ...
n. [Gr. ektos, outside; ostrakon, shell]
1. In acarology, the outermost layer of the chitonostracum layer that when sclerotized is normally ...
(t) n. [Gr. ektos, outside; symbiosis, life together; on, being]
A symbiont that lives on or among its hosts; see endosymbiont.
n. [Gr. ektos, outside; therme, heat]
The body temperature is determined by that of the environment; poikilothermal.
n. [Gr. ektos, outside; zoon, animal]
adj. [Gr. oikoumenikos, world-wide]
World-wide in extent; cosmopolitan; see pandemic.
adj. [Gr. edaphos, soil]
Relating to, or belonging to the soil or substratum.
n. [Gr. edaphos, soil]
Soil flora and fauna; see geobios.
adj. [L. ex, without; dens, tooth]
Being devoid of teeth or folds; edentulous adj..
The tendency to have greater variety and density of organisms in the boundary zone between communities.
n. [L. editus, high, lofty]
In male Lepidoptera, a small, rounded, hairy prominence arising from the harpe.
adj. [L. efficere, to execute]
A structure specialized for the activation of a particular form of response, i.e., movement or secretion.
adj. [L. ex, out of; ferre, to carry]
Conducting or carried outward; discharging; see afferent.
Passageways through which water moves away from gills and out of the branchial region.
A nerve that conducts from a nerve center toward the periphery; the axon of a motor neuron that conducts impulses to the effectors.
adj. [L. effetus, exhausted]
No longer capable of fertility; barren.
n.; pl. -via [L. ex, out of; fluere, to flow]
A noxious smell or invisible emanation.
adj. [L. ex, out of; fluere, to flow]
Pertaining to the condition of the shell aperture when the margin is interrupted by a short spout for a ...
adj. [L. ex, out of; flectere, to bend]
Bent outward somewhat angularly.
v.t. [L. egestus, discharged]
To eliminate solid material from a cell or from the enteron.
n. pl. [L. egestus, discharged]
The total amount of substances and fluids discharged from the body.
n. [L. ex, out of; jacere, to throw]
Emitted seminal fluid; ejected fluid from the body.
1. In Lepidoptera, the distal part of the ejaculatory duct, cephalad of the sclerotized aedeagus.
2. In Diptera, a syringe-like, stronglymuscled ...
adj. [L. ex, out of; labrum, lip]
Without a labrum.
n. [Gr. elaion, any oil; kytos, container]
Free fatty globules, yellow or transparent, inodorous or evil-smelling, in the coelom; emitted by the dorsal pores ...
A third protozoeal stage or postnaupliar stage, leading to the acathosoma (mysis) stage.
n. pl. [Gr. elastikos, rebounding]
The abdominal flexion organs of the bristletail apterygote insects.
adj. [Gr. elastikos, rebounding]
Capable of resuming the original shape; flexible.
A membrane between the radular membrane and the pharyngeal epithelium, secreted by the latter and found in the part of the radula which is in use.
adj. [L. elatus, high]
Elevated; lifted up.
n. [Gr. elater, driver]
In Collembola, the furcula or springing organ.
A slender, heavily sclerotized larva with short thoracic legs, and with few body hairs; resembles a wireworm.
n. [Gr. elatton, smaller; stasis, position]
A rare stase of prelarva or larva in which the mouthparts are subject to regression in that though ...
An antenna with the first segment elongated and the remaining segments coming off the first segment in an obtuse angle; a geniculate antenna.
n. [Gr. elektron, amber; trope, turn]
Movement of an organism as determined by the direction of an external electric current; galvanotropism.
adj. [Gr. eleutheros, free; rhabdos, rod]
Pertaining to ctenidia with each filament having approximately two ciliated disks that interlock holding the ...