Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

FNZ 57 - Apoidea (Insecta: Hymenoptera) - Morphology of adult

Donovan, BJ 2007. Apoidea (Insecta: Hymenoptera). Fauna of New Zealand 57, 295 pages.
( ISSN 0111-5383 (print), ; no. 57. ISBN 978-0-478-09389-6 (print), ). Published 07 Sep 2007

Morphology of adult

The following measurements and ratios for up to 20 specimens of each sex and caste establish basic numerical data for the species. For measurements the smallest and highest values are presented, and the mean and standard deviation, while the ratio of malar length/malar width is of the mean of up to 20 measurements of each value. Because the values for the majority of species are small, standard deviations are not presented for these latter measurements.

Length: Measured from the front of the face to the tip of the metasoma, with the face vertical and the metasoma horizontal; where these body parts were not so aligned their lengths were measured separately and then summed.
Width: Widest part of the metasoma viewed from directly above or below.
Forewing length: Distance between the apex of the tegula and the apex of the marginal cell, with the wing lying lengthwise along the body.
Facial length: Distance between the ventral margin of the median ocellus and the ventral median margin of the clypeus.
Facial width: Greatest distance between the inner margins of the compound eyes, or if inner margins diverging throughout their length, the distance between immediately below the antennal sockets.
Malar length and width: Shortest distance between the lower margin of the compound eye and the mandible (Fig. 53n); greatest width of the base of the mandible.

The basis of modern descriptions of the external morphology of adult bees was established by Michener (1944). Other works of note relevant to this revision of New Zealand bees are Snodgrass (1956) on the honey bee, and Stephen, Bohart & Torchio (1969) primarily on bees of Northwestern America, including the alkali bee Nomia melanderi. The terminology used in the major publication of Michener (2000) is that of Michener (1944) modified in various ways. This terminology is certain to be the standard for the foreseeable future. Michener (2000) should be referred to for details of bee morphology. The characters below are listed in the order in which they are used in the descriptions of the species of bees that occur in New Zealand.


The sclerotised head presents many features of taxonomic value, however in some species, and particularly in males, these can be obscured by dense vestiture.
Length of scape: Greatest length of scape, the 1st segment of the antenna.
Length of 1st flagellar segment: Measured from base to apex of 1st segment beyond the pedicel, the 2nd segment of the antenna.
Penultimate flagellar segment of antenna: The 2nd to last distal segment of the antenna.
Length of compound eye: Maximum length measured from frontal view.
Width of compound eye: Maximum width measured from frontal view.
Ocellocular distance: Distance between lateral margin of lateral ocellus, 1 of 3 simple eyes on the central dorsal aspect of the head, and closest part of compound eye.
Interocellar distance: Shortest distance between the margin of a lateral and the median ocellus.
Distance of antennal sockets from vertex: With face in frontal view, the distance from upper margin of antennal socket to upper edge of vertex above the lateral ocellus on the same side of the face.
Distance of antennal sockets from apex of clypeus: With face in frontal view, the distance from the lower margin of the antennal socket to the apex of the clypeus directly below.
Supraclypeus: Usually raised area above the clypeus and between the antennal sockets.
Frontal ridge: Raised very narrow ridge-like area of the frontal line extending dorsally from supraclypeus between antennal sockets.
Frontal line: Depressed area of frontal line extending from the frontal ridge towards median ocellus.
Frons: Area between the antennal sockets and ocelli.
Vertex: Area between ocelli and dorsal margin of face, to about half way between lateral ocelli and compound eyes.
Paraocular area: In frontal view area of face beside compound eye.
Clypeus: Large lower central plate of face, separated laterally from the paraocular areas and dorsally from the supraclypeus by the epistomal suture. May be variously shaped and sculptured.
Anterior tentorial pit: A depression in the epistomal suture more or less about half way along the clypeal boundary.
Labrum: Central usually transverse plate below clypeus.
Labral process: raised median area of labrum, from which rises the keel.
Keel: Very narrow prominent median area of labrum.
Mandible: ‘Jaw’ which articulates with the head below or near the lower margin of the compound eye. May have teeth and cutting edges.
Galea: Large lateral sclerotised plate of the proboscis.
Facial macula: Yellow, pale or light yellow, or orange area of face.
Facial fovea: Depressed linear area on the paraocular area parallel and close to about the dorsal 3rd of the compound eye.
Gena: In lateral view, area of head posterior to the compound eye. Width is measured at widest part. The width of the compound eye with which the width of the gena is compared is here measured in the same way, and differs from the width of the compound eye measured in frontal view.

Mesosoma (Fig. 35)

In bees the area between the articulations of the head and metasoma consists of the 3 segments of the thorax, the pro-, meso-, and metathorax, plus the propodeum (Michener 1944).
Prothorax: Anterior segment of mesosoma, immediately behind the head.
Pronotal sulcus: Angled depression on lateral aspect of pronotum.
Pronotal suture: In Osmia coerulescens a vertical suture laterally which extends across the dorsal aspect of the pronotum, so dividing the pronotum more or less into 2 halves.
Pronotal collar: Raised dorsal posterior area of the pronotum
Pronotal lobe: Large rounded lobe on the postero-lateral margin of the pronotum.
Mesothorax: 2nd segment of the mesosoma.
Scutum: Large subrectangular dorsal plate of the mesothorax.
Parapsidal line: Longitudinal line on the lateral aspect of the scutum.
Scutellum: Transverse dorsal plate of the mesothorax immediately posterior to the scutum.
Axilla: Sclerite lateral to the scutellum.
Metathorax: 3rd segment of the mesosoma.
Metanotum: Transverse dorsal plate of the metathorax.
Propodeum: 4th segment of the mesosoma, lying anterior to the articulation with the metasoma.
Propodeal triangle: Triangular median dorsoposterior area of the propodeum, with broad base adjacent to the metanotum and narrowing posteriorly to nothing towards the articulation with the metasoma. If in lateral view the propodeal triangle is angled, the dorsal area is the dorsal face of the propodeum, and the area below the angle which narrows posteriorly is the posterior face of the propodeum. If in lateral view the propodeal triangle slopes directly to the posterior, it is declivous.
Lateroposterior area of propodeum: Lateroposterior area adjacent to the propodeal triangle.
Lateral area of propodeum: Lateral area adjacent and anterior to the lateroposterior area.
Metepisternum: Lateral area of the metathoracic segment; a rectangular, narrow, almost vertical area on the lateral aspect of the mesosoma immediately anterior to the lateral area of the propodeum, and posterior to the mesepisternum.
Mesepisternum: Lateral area of the mesothoracic segment; large lateral area of the mesosoma immediately anterior to the metepisternum and posterior to the prothorax.
Scrobal groove or suture: Longitudinal groove near the dorsal aspect of the mesepisternum, above which lies the hypoepimeral area.
Episternal groove: More or less dorsoventral groove nearly dividing the mesepisternum in half.
Strigilis: Spur on the distal end of the protibia, and semicircular comb-like structure on base of probasitarsus, together forming antenna cleaner.
Trochanteral floccus: Area of long, fine, branched hairs on the metatrochanter which carry pollen.
Basitibial plate: Depressed area on the outer basal aspect of the metatibia.
Carina: A ridge or sharp line.
Scopa: Area of stout hairs used for carrying pollen, primarily on the lateral aspect of the propodeum, the metatibia, the metabasitarsus, or ventrally on the metasoma.
Corbicula: Wide flat outer face of the metatibia surrounded by stout spines; carries pollen.
Inner metatibial spur: The inner of 2 spurs on the apex of the metatibia.
Arolium: Protruding pad-like structure between the tarsal claws.
Tegula: Rounded plate over the wing articulation.
Pterostigma: Thickened, usually elongate area about 2/3 the way along the anterior margin of the forewing (Fig 36a).
Marginal cell: Distal marginal cell of the forewing just beyond the pterostigma.
Submarginal cells: 2 or 3 cells immediately posterior to the pterostigma and the marginal cell.
1st, 2nd, and 3rd submarginal crossveins: Veins that lie between the 1st and 2nd submarginal cells, the 2nd and 3rd submarginal cells, and the outer border of the 3rd submarginal cell respectively.
Vein 1st m-cu: The vein that joins the posterior margin of the submarginal cells.
Jugal lobe: The lobe on the posterior margin of the hind wing near the wing base (Fig 36b).
Vannal lobe: The lobe between the jugal lobe and the more-or-less distal 1/2 of the hind wing on the posterior margin (Fig. 36b).
Vein cu-v. The crossvein in the hind wing against which the reach of the jugal lobe is evaluated.


The metasoma is the area lying posteriorly to the articulation with the mesosoma.
Terga: Dorsolateral plates of the segments.
Post-spiracular gland: A small depression on the lateral aspect of terga 2–3 posterior to the spiracle of female Hylaeus.
Tergal fovea: A small circular depression just above and behind the post-spiracular gland on tergum 2 of female Hylaeus.
Gradulus: A transverse line near the anterior of the tergum.
Premarginal line: A transverse line near the posterior of the tergum.
Pseudopygidium: Bare, longitudinal, usually narrow area of tergum 5 in female Lasioglossum, often fringed with short hairs. Some male Leioproctus (Nesocolletes) have a pseudopygidial-like area on tergum 7.
Pygidial plate: Distinct, usually more or less dorsal triangular plate at the apex of tergum 6 of some females. More or less triangular in Leioproctus and Nomia, and narrow in Euryglossina.
Sterna: Ventral plates of the segments.
Sternum 7: 7th metasomal sternal plate, internal and much modified compared to plates 2–6.
Sternum 8: 8th metasomal sternal plate, internal except for elongated median posterior process.
Genital capsule: The male intromittent apparatus, usually concealed within the apex of the metasoma.
Basal ring: Sclerotised ring around the base of the gonobase.
Gonobase: The base of the genital capsule.
Gonocoxite: Lateral, posteriorly directed process distal to the gonobase.
Gonostylus: Apical area distal to the gonocoxite. Often there is no obvious distinction between the gonocoxite and the gonostylus.
Retrorse lobe: In male Lasioglossum, lobe arising from the lateral ventral surface of the gonocoxite.
Volsella: structure near the base of the penis valves.
Penis valve: 1 of 2 lateral median posterior processes between the gonocoxites, which together form the penis.

Descriptive terms

Punctures: Rounded depressions in the cuticle. Punctures may be small, medium, or large, with the sizes relevant to those on the specimen being described. Dense punctures are contiguous.
Sulcus: A broad, usually shallow depression in the cuticle.
Tessellation: Cuticular surface chequered with regular, close-set ridges, often appearing hexagonal.
Shagreening: A close-set roughness of the cuticle, like the rough-surfaced horse leather called shagreen; or shark leather (LaBerge 1967).

The descriptions ‘light’, `medium’, and `dense’ for tessellation or shagreening refer to the range found on the specimen being described. Sometimes other descriptions such as `faintly’ may be used.

Sometimes light tessellation and light shagreening may approach and intergrade with each other.


Apical fimbria: Narrow transverse band of very short appressed hairs, apical on terga and sterna.
Prepygidial fimbria: Dense hairs across the apex of tergum 5 in females.

Many bees are clothed in hairs, the density, length, and colour of which may vary widely. Because the cuticular surface of much of the body may be almost entirely obscured by vestiture, the distribution of the colour of the vestiture can be very important for identification of species. Some male Leioproctus are keyed to species on characters of the vestiture. In females hairs may form pollen-carrying structures, the scopae, which can occur on the lateral aspect of the propodeum, the metasomal trochanter, femur, tibia, and basitarsus, and the venter of the metasoma.

The vestiture of males is described on the understanding that males are entirely without the structures of females that carry pollen.

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