After the second larval moult, he passes through a passive stage comparable to the pupa-stadium of an b insect, and during this stage, which occurs inside the root, the reproductive organs are perfected.
The pupa stage of the ant-lion is quiescent.
The wing, when not in use, is folded d Pupa of Dyticus.
Fixed to the body as in the pupa of a moth, and the likeness of pupa to perfect insect is very close.
A, Calandra granaria; b, larva; c, pupa; d, C. oryzae.
- A, Wireworm; B, pupa of Click Beetle; C, adult Click Beetle (A griotes lineatum), b c a FIG.
After a resting (pseudo-pupal) stage and another larval stage, the pupa is developed.
The majority of authors, however, follow Brauer in dividing the order into two sections, Orthorrhapha and Cyclorrhapha, according to the manner in which the pupa-case splits to admit of the escape of the perfect insect.
In the Orthorrhapha, in the pupae of which the appendages of the perfect insect are usually visible, the pupa-case generally splits in a straight line down the back near the cephalic end; in front of this longitudinal cleft there may be a small transverse one, the two together forming a T-shaped fissure.
In the Cyclorrhapha on the other hand, in which the actual pupa is concealed within the hardened larval skin, the imago escapes through a circular orifice formed by pushing off or through the head end of the puparium.
A, Female; b, female after loss of wings; c, male; d, worker; e, larva; g, pupa (magnified four times); f, head of larva more highly magnified.
- A, Wireworm; B, pupa of Click Beetle; C, adult Click Beetle (Agriotes lineatum).
- e,f, Owl moth (Heliothis armigera); a,b, egg, highly magnified; c, larva or caterpillar; d, pupa in earthen cell.
Other writers apply the term to a " free " pupa (see infra).
A gnat pupa swims through the water by powerful strokes of its abdomen, while the caddis-fly pupa, in preparation for its final ecdysis, bites its way out of its subaqueous protective case and rises through the water, so that the fly may emerge into the air.
Some pupae are thus more active than some nymphs; the essential character of a pupa is not therefore its passivity, but that it is the instar in which the wings first become evident externally.
This, however, is not the case, because the greater part of the transformation precedes the disclosure of the pupa, which, as L.
The difference between the nymph or false pupa and the true pupa is that in the latter a whole stage is devoted to the perfecting of the wings and body-wall after the wings have become external organs; the stage is one in which no food is or can be taken, however prolonged may be its existence.
Amongst insects with imperfect metamorphosis the nearest approximations to the true pupa of the Holometabola are to be found in the subimago a From Chittenden, Bull.
- a, Saw-toothed Grain-Beetle (Silvanus surinamensis); b, pupa; c, larva, magnified 12 times; d, feeler of larva.
But even at present we can correctly state that the true pupa is invariably connected with the transference of the wings from the interior to the exterior of the body.
Only a brief reference can be made here to the fascinating subject of the life-relations of the larva, nymph and pupa, as compared with those of the imago.
An interesting feature is the difference often to be observed between an aquatic larva and pupa of the same insect in the matter of breathing.
But the pupa hangs from the surface by means of paired respiratory trumpets on the prothorax, the dorsal thoracic surface, where the cuticle splits to allow the emergence of the fly, being thus directed towards the upper air.
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.
Pupa incompletely obtect or free, and enclosed in the hardened cuticle of the last larval instar (puparium).
Cuticle of pupa or puparium splitting longitudinally down the back, to allow escape of imago.
The sub-imago of the Ephemeroptera suggests that a moult, after the wings had become functional, was at one time general among the Hexapoda, and that the resting nymph of the Thysanoptera or the pupa of the Endopterygota represents a formerly active stage in the life-history.
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.
Weismann (1863-1864) traced details of the growth of embryo and of pupa among the Diptera, and A.
Pupa is named from its resemblance to a chrysalis, the apex being rounded.
These gradually become larger, and when so the creature may be said to have entered its "nymph" stage; but there is no condition analogous to the pupa-stage of insects with complete metamorphoses.
F, B, Pupa of Anopheles.
G, D, Pupa of Culex.
Through this temporary protection the active pupa, which closely resembles the mature insect, subsequently bites a way by means of its strong mandibles, and rising to the surface of the water casts the pupal integument and becomes sexually adult.
With the appendages not fixed to the body, as is the case in the pupa of most moths.
- a, Pear Saw-fly (Eriocampoides limacina); b, larva without, and c, with its slimy protective coat; e, cocoon; f, larva before pupation; g, pupa, magnified 4 times; d, leaves with larvae, natural size.
D, Its head more highly magni- c, Pupa of male.
- Passive Nymph or " Pupa " of male scale-insect (Icerya).
He even noted the fact that the pupa of the flea is sometimes attacked and fed upon by a mite - an observation which suggested the well.
When the larva is fully mature, and ready to change into the pupa condition, it proceeds to spin its cocoon, in which operation it ejects from both glands simultaneously a continuous and reelable thread of 800 FIG.
The whole cocoon with its enclosed pupa weighs from 15 grains for the smaller races to about 50 grains for FIG.
The insects complete their cocoons in from three to four days, and in two or three days thereafter the cocoons are collected, and the pupa killed to prevent its further progress and the bursting of the shell by the fully developed moth.
- Pupa of Lepas pectinata in optical section.
It is important to note that the scales are present when the moths first emerge from the pupa-case, but are loosely attached and fall off with the first flight.
- Larva and Pupa of Apis (magnified four times).
It hides itself in the ground during the winter, and in the spring it passes into the pupa stage, from which it emerges about August as the full-grown insect.