Hinds believe that the paired piercers are the inner lobes of the maxillae, and the unpaired piercer the left mandible, the right mandible being absent.
The maxillae are not piercing organs, and their function is to protect the mandibles and labrum and separate the hairs or feathers of the host.
1, Bd) are very intimately fused together to form what is called the "lower lip" or labium, a firm transverse plate representing the fused basal portions of the maxillae, which may carry a small median "ligula," representing apparently the fused inner maxillary lobes, a pair of paraglossae (outer maxillary lobes), and a pair of palps.
(2nd maxillae Wvrq C ?i t?
The head - carrying feelers, mandibles and two pairs of maxillae - is succeeded by the three thoracic segments, each bearing a pair of strong five-segmented legs, whose feet, like those of the adult, carry two claws.
The root-feeding larvae of the cockchafer and allied members of the Scarabaeidae have a ridged area on the mandible, which is scraped by teeth on the maxillae, apparently forming a stridulating organ.
The inner lobe (lacinia) of the first maxilla terminates in an articulated hook, while in the second maxillae (labium) both inner and outer lobes ("ligula" and "para-glossae") are much Gyrinus sulcatus reduced.
The mandibles are strong, adapted for biting the vegetable substances on which these beetles feed, and the palps of the second maxillae have three segments.
The ventraPscleriteof the head-skeleton (gula), well developed in most families of beetles, is absent among the Rhynchophora, while the palps of the maxillae are much reduced.
The mandibles, which are frequently used for carrying various objects, are situated well to the outside of the maxillae, so that they can be opened and shut without interfering with the latter.
The head of an insect carries usually four pairs of conspicuous appendages - feelers, mandibles and two pairs of maxillae, so that the presence of four primitive somites is immediately evident.
The maxillae of the hinder pair become more or less fused together to form a " lower lip " or labium, and the segment of these appendages is, in some insects, only imperfectly united with the head-capsule.
In their typical state of development, the first maxillae offer a striking contrast to the mandibles, being composed of a two-segmented basal piece (cardo and stipes, fig.
Such maxillae are found in most biting insects.
The second pair of maxillae are more or less completely fused together to form what is known as the labium or " lower lip."
2, IV) in which the slender piercers (mandibles and first maxillae) work to and fro.
This second pair of maxillae (or labium) form then the hinder or lower boundary of the mouth.
In front or above the mouth is bounded by the labrum, while the mandibles and first maxillae lie on either side of it.
Ia, frons; b, clypeus (the pointed labrum beneath it); II, mandible; III, first maxilla; (a, base; b, sheath; c, piercer), III', inner view of sheath; IV, second maxillae forming rostrum (b, mentum; c, ligula).
Organs of similar type on the maxillae and epipharynx appear to exercise the function of taste.
Biting mandibles; minute but distinct - maxillulae; second maxillae incompletely fused.
Biting mandibles; vestigial maxillulae; second maxillae incompletely fused.
Biting mandibles; second maxillae incompletely fused.
Biting mandibles; second maxillae incompletely fused.
Biting mandibles; second maxillae incompletely fused; maxilIulae often distinct.
First maxillae also modified as piercers; maxillae of both pairs with distinct palps.
Mandibles and first maxillae modified as piercers; second maxillae fused to form a jointed, grooved rostrum.
Biting mandibles; second maxillae completely fused.
Biting mandibles; second maxillae very intimately fused.
Mandibles present in pupa, vestigial in imago; maxillae suctorial without specialization; first maxillae with lacinia, galea and palp. Prothorax small.
Mandibles absent in imago, very exceptionally present in pupa; first maxillae nearly always without laciniae and often without palps, or only with vestigial palps, their galeae elongated and grooved inwardly so as to form a sucking trunk.
Mandibles rarely present, adapted for piercing; first maxillae with palps; second maxillae forming with hypopharynx a suctorial proboscis.
Biting mandibles; second maxillae incompletely or completely fused; often forming a suctorial proboscis.
All these orders agree in the possession of biting mandibles, while their second maxillae have the inner and outer lobes usually distinct.
The Hemiptera, with their piercing mandibles and first maxillae and with their second maxillae fused to form a jointed beak, stand far apart from them.
The standing of the Trichoptera in a position almost ancestral to the Lepidoptera is one of the assured results of recent morphological study, the mobile mandibulate pupa and the imperfectly suctorial maxillae of the Trichoptera reappearing in the lowest families of the Lepidoptera.
There seems no doubt that the suctorial mouth-organs of the Diptera have arisen quite independently from those of the Lepidoptera, for in the former order the sucker is formed from the second maxillae, in the latter from the first.
Specialized as they are in form, development and habit, they retain mandibles for biting, and in their lower sub-order - the Symphyta - the maxillae are hardly more modified than those of the.Orthoptera.
The mouth parts are well developed, consisting of an upper lip, powerful mandibles, maxillae with three-jointed palpi, and a deeply quadrifid labium or lower lip with three-jointed labial palpi.
The proboscis of tsetse-flies is without the paired piercing stilets (mandibles and maxillae) possessed by other bloodsucking Diptera, such as the female horse-flies and mosquitoes.
E, First maxilla; a, cardo; b, stipes; c, galea; d, lacinia; e, palp. B, Second maxillae (Labium); a, mentum; b, ligula (between the two galeae); c, c, palps.
B, c) with a deep groove on its anterior face; this organ is formed by the second pair of maxillae and corresponds therefore to the labium or " lower lip " of biting insects.
IV., Second maxillae forming rostrum.
Eugereon is a remarkable Permian fossil, with jaws that are typically hemipterous except that the second maxillae are not fused and with cockroach-like wings.
A, Female from above; d, Jaws, more highly magnified b, From beneath, magnified 5 (tips of mandibles and 1st times; maxillae still more highly c, Vestigial wing; magnified).
Maxillae, and the foot in the fore and intermediate leg having but a single segment.
The second antennae, mandibles and two pairs of maxillae may also be claimed as of malacostracan type.
This " leaf-footed " suborder has the appendages which follow the second maxillae variable in number, but all foliaceous and branchial.
In these the furcal branches are linear or rudimentary, the shell is without rostral sinus, and, besides distinguishing characters of the second 2ntennae, they have always a branchial plate well developed on the first maxillae, which is inconstant in the other tribe.
The variable first maxillae are seldom pediform, their function being concerned chiefly with nutrition, sensation and respiration.
The variability in form and function of the second maxillae is sufficiently shown by the fact that G.