Pupa is named from its resemblance to a chrysalis, the apex being rounded.
The pupa stage of the ant-lion is quiescent.
D, Its head more highly magni- c, Pupa of male.
The wing, when not in use, is folded d Pupa of Dyticus.
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.
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.
Mandibles present in pupa, vestigial in imago; maxillae suctorial without specialization; first maxillae with lacinia, galea and palp. Prothorax small.
Pupa incompletely obtect or free, and enclosed in the hardened cuticle of the last larval instar (puparium).
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.
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.
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.
- Passive Nymph or " Pupa " of male scale-insect (Icerya).
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.
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.
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.
After a resting (pseudo-pupal) stage and another larval stage, the pupa is developed.
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.
- e,f, Owl moth (Heliothis armigera); a,b, egg, highly magnified; c, larva or caterpillar; d, pupa in earthen cell.
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.
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.
Weismann (1863-1864) traced details of the growth of embryo and of pupa among the Diptera, and A.
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.
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.
- Pupa of Lepas pectinata in optical section.
- Larva and Pupa of Apis (magnified four times).
After many years the larva is transformed into the pupa or nymph, which is distinguishable principally by the shortness of its antennae and the presence of wing pads.
After a brief existence the pupa emerges from the ground, and, holding on to a plant stem by means of its powerful front legs, sets free the perfect insect through a slit along the median dorsal line of the thorax.
In some cases the pupa upon emerging constructs a chimney of soil, the use of which is not known.
- A, Wireworm; B, pupa of Click Beetle; C, adult Click Beetle (A griotes lineatum), b c a FIG.
- A, Wireworm; B, pupa of Click Beetle; C, adult Click Beetle (Agriotes lineatum).
This, however, is not the case, because the greater part of the transformation precedes the disclosure of the pupa, which, as L.
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.
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.
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.
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 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.
The coleopterous pupa (figs.
Fixed to the body as in the pupa of a moth, and the likeness of pupa to perfect insect is very close.
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 free in the lowest families, in most cases incompletely or completely obtect.
A, Calandra granaria; b, larva; c, pupa; d, C. oryzae.
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.
F, B, Pupa of Anopheles.
Aristotle and Harvey (De generatione animalium, 1651) had considered the insect larva as a prematurely hatched embryo and the pupa as a second egg.
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.
Cuticle of pupa or puparium splitting longitudinally down the back, to allow escape of imago.
The growth of the worms during their larval stage is thus stated by Count Dandolo: - When the caterpillars are mature and ready to undergo their transformation into the pupa condition, they cease eating for some time and then begin to ascend the brushwood branches or echelletes provided for them, in which they set about the spinning of their cocoons.