G. C. Crampton.
The Mecopteron Notiothauma reedi.
Psyche 37:83-103, 1930.

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19301 The Mecopteron Notiothuumu reedi
THE WINGS OF THE REMARKABLE ARCHAIC
MECOPTERON NOTIOTHAUMA REEDI
McLACHLAN WITH REMARKS ON THEIR
PROTOBLATTOID AFFINITIES
Massachusetts Agricultural College, Amherst, Mass. Through the great generosity of Dr. Edwyn P. Reed, the distinguished Chilean surgeon, I have had the privilege of making an anatomical study of the remarkable archaic Mecopteron Notiothauma reedi, McLachlan. In presenting me with the only known specimen of the hitherto unde- scribed male of Notiothauma for dissection and description, Dr. Reed has placed me deeply in his debt, and I would use this opportunity of thanking Dr. Reed for the rare privi- lege of studying this unique specimen.
The male of Notiothama conforms to the general de- scription of the female in having a castaneous body, but the wings of the male, and those from a specimen which had been damaged by pests (presumably a female, though the sex could not be determined from the remaining frag- ments) are ochreous, shot through with brown, giving a "brindled" appearance to the incumbent wings. The male has a remarkable median dorsal process on what appears to be the fourth abdominal tergite (the speci- men has not yet been softened for study) and on the next tergite is a pair of rather small lateral tergal processes, while the tergite behind this bears a pair of longer lateral tergal processes, which give a remarkable appearance to the flattened abdomen. The abdomen does not taper like that of a typical Panorpid, and is somewhat suggestive of the abdomen of the Mecopteron Merope, which is rather closely allied to Notiothauma.




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Psyche
[March
The genitalia are rather "bulbous" and the basistyles or basal segments of the claspers of the male are rather short and stout; and the dististyles or distal segments of the claspers, unlike those of Mwope (which has long slender dististyles) are shorter and stouter, and are somewhat fur- ate, with the exterior terminal branch curving outward (laterad) to' some extent, apparently for the purpose of lying on either side of the median dorsal process (described above) when the genitalia are held forward in repose. I would designate this hitherto undescribed male as the allotype of Nofiothauma re&, McLachlan, and a detailed description of it will be presented in a later paper dealing with the morphology of this remarkable Mecopteron, which is the only scorpionfly with flat incumbent wings (see Plate 2).
There is no fundamental difference between the wings of the male and those of the damaged specimen (presumably a female), so that the accompanying description of the wings of the supposed female will serve to illustrate the later description of the venation of the male, in describing the alar ossicles and other features of the basal region of the wing, in discussing the morphology of the male insect. The measurements of the wings are as follows: Length of fore wing, 23.5 mm.; greatest width of fore wing, 10 mm.; length of hind wing, 22 mm.; greatest width of hind wing, 9 mm. The fore wings are more deeply pigmented and are ochreous, while the hind wings are more hyaline, and have a yellow tinge. The fore wings are like delicate tegmina, apparently derived from Protoblattoid (Proto- blattid-like) or Protorthopteroid (Protorthoptera-like) prototypes, but the hind wings have lost the anal fan char- acteristic of the Protoblattids, etc., as likewise have the Isoptera (except Mastotermes), for that matter, which are the direct descendants of Protoblattoid forbears. The fore wings are somewhat broader in the distal half of the wing, and are broadly rounded apically, resembling in these re- spects the fore wings of the Protoblattids Asyneritus, Adiphlebia, etc., figured by Handlirsch, 1925 ( Schroeder's "Handbuch," Band 31, or the Protorthopteroid insect Metropator, figured by Handlirsch, 1909 (Die Fossile Insekten). These are Protoblattoid features pointing to a



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19301 The Mecopteron Notiothauma reedi 85 Protoblattoid ancestry for the Mecoptera, instead of indica- ting an ancestry for the Mecoptera in forms like the Me- gasecoptera or even the Palseodictyoptera. The Megasecoptera and Palseodictyoptera are Archip- terygota, or insects incapable of folding the wings along the abdomen in repose, while the Protoblattids and Protor- thoptera are Neopterygota, or insects capable of laying the wings along the abdomen in repose, and the Protoblattids and Blattids typically hold the wings in the recumbent posi- tion in repose (i. e., the wings laid flat, one on top of the other, on the top of the abdomen) and it is a very signifi- cant fact that Notiothauma holds its wings in the incumbent position in repose, so that this archaic Mecopteron must have been descended from Neopterygotan ancestors rather than from Archipterygotan ancestors such as the Megase- coptera, etc., regarded by Handlirsch and Tillyard as the ancestors of the Mecoptera. (See Plate 3) The basal arch (ha of Figs. 1 and 7)
of the first anal
vein, forming a typical "basoplica," together with the fold- like depression, like that described by Crampton, 1927 (Psyche, 34, p. 59) and 1928 (Bull. Brooklyn Ent. Soc., 23, p. 113) in the Blattids, Isoptera, Orthoptera, Cicadas, Tri- choptera, etc., which have developed these structures in. connection with laying the wings along the abdomen in re- pose, likewise indicates a Neopterygotan ancestry for the Mecoptera.
The formation of cellules in the wings of the Protoblat- tids Asyncritzis, Adiphlebia, etc., suggests the beginnings of a tendency to form cellules in the fore wings-a ten- dency which has been carried to an extreme in Notiotha- uma. It should be noted that it is not necessary for all of the Protoblattids or for all of the Mecoptera to exhibit this tendency in order to derive the Mecoptera from a Proto- blattoid ancestory, since, according to the adumbration theory, some members of an ancestral group may exhibit tendencies which later reappear in some members of a de- rived group without these features being exhibited by all, or most, of the members of either group, as has been dis- cussed elsewhere. It is therefore illogical to demand that all of the Protoblattoids shall exhibit a tendency toward the formation of numerous cellules, in order to derive such a



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86 Psyche [March
Mecopteron as Notiothauw (with its many cellules) from Protoblattoid ancestors.
In both the fore and hind wings of Notiothauma, there is a postero-basal lobe, or jugalula, labelled a in Figs. 1 and 2, which is called the alula in Coleoptera, etc., but the term alula was long ago used by Oaten-Sacken, 1896 (Berlin Ent. Zeit., 41, p. 285) to designate an entirely different struc- ture, namely the anal lobe of the Dipterous wing (i. e., the lobe distal to the calypteres) ; and it is preferable to refer to the jugalular lobe as the jugalula, since it is homologous with the jugalula of the roach. Esben-Petersen, 1921 (Me- coptera in Coll. Zool. Selya Longchamp) calls these jugal- ulse the "claviT in Notwthauma, but the clavus is an en- tirely different region, homologous with the anal region presently to be described, and there is no excuse for apply- ing the term clavus to any structure other than the region homologous with the clavus of the Hemiptera. The juga- lula a is bordered by a fringe of hairs labelled af in Figs. 1 and 2, and when the jugalula a of the fore wing (Fig. 1) is folded forward under the fore wing, it engages the bris- tles labelled bsc in Fig. 2 of the hind wing, thus serving as a primitive type of jugurn. In my specimens, the jugalula was folded forward, and it was very difficult to make out its structure in the mounted wings.
The basicostal bristles bcs of Figs. 1 and 2, are borne on a thickened, antero-basal, marginal structure in both wings; and these bristles in the hind wing are apparently the forerunners of the frenulum of higher insects, although they can hardly be called a frenulum on the fore wing. These bristles are unusually stout and long, and belong to the type of bristle which may be called dinotrichia, or powerful bristles, such as those occurring- on the veins, etc., at the base of the fore wings (Fig. 7) or on the thorax, etc., Macrotrichia occur on the costal margin of the wings in the neighborhood of the hurneral veinlet h of Figs. 1 and 2, and gradually become smaller toward the middle of the wing, (they are not drawn in this region of the wing in Figs. 1 and 2). The "dinotrichia" occurring on some of the veins in the basal region of the fore wing are shown in Fig. 7, and the sockets or pits, which are left when such bristles are broken off, are shown in the figure. Macro-



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19301 The Mecopteron Notiothuumu reedi 87 trichia occur on the ventral surface of the basicostal structure labelled be in Fig. 4, and on the ventral surface of the humeral veinlet h of Fig. 4; and a row of macrotri- chia occurs on the ventral surface of the subcostal vein shown in Fig. 4. This row of macrotrichia may aid in hold- ing the wings in place in repose.
Forbes, 1924 (Ent. News, 35, p. 232) in describing the nygmata of Holometabolous insects, states that in "Merope and apparently Notiothuuma nygmata are absent," but I find in the basal costal cell, for example, what appears to be the homologue of a nygma, similarly located to that of Panorpodes (see n of Fig. 7), and nygmata are thus apparently present in the fore wings of Notiothauma, although I have not examined Merope to determine if they are present in this insect also.
The venation of the hind wings is quite easily homo- logized, but the tangle of cellules in the distal portion of the fore wings makes it extremely difficult to trace the course of the veins in this region of the fore wings, so that the course of the distal portions of such veins as the second, third and fourth branches of Media is merely suggested, although the basal portions of these veins are quite easily homologized.
The fore wing has preserved a suggestion of a humeral lobe in the curved contour of the basal portion of the wing just anterior to the label h in Fig. 1 (which is a Proto- blattoid or Protorthopteroid feature) and the costal vein has become interrupted just basad of the humeral veinlet h of Fig. 1. The detached basal portion of the vein becomes broadened (to accommodate the large bristles bsc) and forms a structure homologous with the sclerite called the basicosta in the roach, Mantids, Trichoptera, Cicadas, etc. (Psyche, 34, p. 59, and Bull. Brooklyn Ent. Soc., 23, p. 113). The occurrence of such a basicostal sclerite in Notiothauma indicates that its fore wing was derived from a Blattoid or Protoblattoid prototype rather than from a wing of the type occurring in the Archipterygotan insects (which have no such sclerite). I find a trace of the basi- costal sclerite even in the hind wing of such a highly spe- cialized insect as the monarch butterfly Danaus archippus ("Anosia plexippus") in which the costal vein fades out



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88 Psyche [March
and the humeral veinlet is retained to support the weak- ened humeral lobe. In the hind wing of Muhcoso~ and . other Lasiocampids there are two veinlets called the humeral cross veins by Cornstock, 1924 (An Introduction to Entomology) but I think it preferable to restrict the term humeral veinlet to the first veinlet h of Figs. 1 and 7, and to refer to the one diatad of it as the posthumeral veinlet (i. e., 'ph. of Fig. 7). These structures are referred to as veinlets rather than as cross-veins, since they are homologous with the veinlets of the Neuroptera, etc. The humeral veinlet h of Visa. 1 and 7, is much stouter than the other veinlets; and the weaker posthumeral veinlet ph is more pronouncedly curved.
The veinlets in the broad costal area of the fore wing have branched or are connected by cross veins in an irregular fashion causing a distortion of the veinlets and producing numerous cellules, which are irregularly pen- tagonal or hexagonal in the basal region and are more elongated and suhquadrate in the distal region of the costal area. The broad costal area apparently represents a con- dition inherited from Protoblattoid ancestors resembling Asyncfitus in some respects, and the curve in the costal margin of the fore wing may also represent the retention of a tendency more markedly developed in the Protoblattoid insects, instead of these features representing a type of specialization peculiar to Notiothauma,
As is true of Mecoptera in general, the subcostal vein Se , of the fore wing (Figs. 1 and 7) is a concave vein, and a minus sign (-) has been placed above it in Figs. 1 and 7, to '
indicate this fact. The base of Sc dips below the base of the radius R, as is indicated in Fig. 7. After paralleling R for some distance, Sc ends at the pterostigma pst of Fig. 1, although some of the branches of Sc appear to penetrate the pterostigma for a short distance. The wide separation of Sc from the costal margin, and its paralleling R for such a considerable distance are Protoblattoid features appar- ently inherited from a Protoblattoid ancestry. The radial vein R is higher than the concave vein Sc, and appears to have much the same character as that of Ri which is a convex vein, so that R may be regarded as a convex vein, although its sector RE seems to be a concave



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19301 The Mecopteron Notiothauma reedi 89 vein. R fuses with M basally, and is contiguous with M until it forks-or rather, the space between R and M is sclerotized giving the appearance of a union between the two veins, although the veins themselves are not as closely contiguous as this pigmentation or sclerotization of the intervening membrane would suggest (See Fig. 7). Rs is given off in the basal fifth of the wing, and is richly branched, being- somewhat like the radial sector of the Protoblattid Stenoneura, in this respect, though it is of course much more like the venation of such primitive fossil Mecoptera as "Protomerope," or the primitive fossil Neuropteron Perrno-rapisma (particularly the latter) than it is like the Protoblattids, since the Mecoptera and Neuroptera are naturally more closely related to Notio- thauma than the Protoblattids are. The convex vein Ri is apparently unbranched and extends distally below the pterostigma pst almost to the margin of the wing, although a short backward extension of the pterostigma in this region intervenes between the margin of the wing and the tip of Ri. The concave radial sector Rs is given off in the basal fifth of the wing, and is richly branched with numerous cellules between the distal portions of its branches, and the cellules tend to become elongated and more quadrilateral than the cellules of the costal or cubital regions. It is quite easy to trace the branching of the radial sector, and the branching of its forks into Ra and Rs or into R4 and R5, in the basal portion of the wing, but the tracing of the courses of these branches in the distal por- tion of the wing is not as easy a matter as it is in such forms as Merope or even Perrnorapisma, due to the fact that the course of these branches is obscured by the tangle of cellules in Notiothauma, and on this account the inter- pretation of the branches of radius in the figure of the fore wing is purely tentative, although in the hind wing of Notiothaurna the course of these branches can be followed with ease.
M seems to be a concave vein, although it fuses with R basally and is contiguous with R in the basal region of the wing. The branches of M are also concave veins, so that it should be an easy matter to distinguish the course of these veins from that of Cui which is a convex vein, but



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90 Psyche [March
the course of the median veins is so extremely aberrant, that I am the least confident of my interpretations in this region of the fore wing, although of course it is an easy matter to interpret the median veins of the hind wing. I have figured the median veins of the wings of Notiothauma from all available sources, using the original photograph (which is much clearer than the published figure) from which the illustration of Dr. C. E. Porter's note on Notiothauma was made (Revista Chileana Hist. Nat., 1929, XXXIII, p. 288),-Dr. Porter having very kindly sent me the original photograph-and I have also used Esben- Petersen's figure of the wings of Notiothauma, but even with these figures to aid me, in addition to examining the wings of two specimens of Notiothazima, I am not very sure of the course of the branches of M in the fore wing! In his review of Imms' book, Tillyard, 1926 (N. Z. Jour. of Science and Technology, 8, p. 127) states that the "thyridium is a hyaline area on M just before it forks" in Trichopterous wings, and there is a clear spot at the fork- ing of M in Nannochorista, Sisyra, etc. Since there is a hyaline area (resembling the so-called bullse) labelled b in Figs 1, 3, 4, 5 and 6 at the base of what Esben-Petersen (1. c.) considers as the first fork of M in the fore wing of Notiothauma, I feel almost certain that the forking of M is at the point labelled b in these figures. This interpreta- tion, however, would leave a whole vein unaccounted for (can this be M5?) but lying between the concave anterior branch of M and the convex anterior branch of Cu (i. e., Cul, whose course is indicated by a + sign in Fig 1) in these figures. Unlike the typically short M5 of most insects (although M5 is longer in some Psychopsidse), the vein in question is of considerable extent, and joins the rest of the branches of M instead of extending across to Cul as the vein M5 usually does, and as is done by the vein labelled M5 in Fig. 1, etc. I am therefore inclined, purely pro- visionally, to interpret as the first forking of M, the fork which is located just distad of the dotted line running up from the label M in Fig. 1. This fork occurs in all of the wings, and figures of wings, which I have seen; so it can hardly be an added cross vein that has taken on the appear- ance of a fork in one specimen: furthermore, it is continued



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19301 Th,e Mecopteron Notiothama reedi 91 in the vein labelled M3 in Fig. 1-although it may possibly continue on down and fuse with Cul instead, but the latter view is not very probable (although it should be considered as a possibility), because it would leave the vein labelled M3 unaccounted for. I am therefore inclined purely pro- visionally to interpret the fork of M just distad of the dotted line running up from the label M in Fig. 1 as the forking of M into and M3,4 as is indicated by the labelling. The fork at the hyaline spot labelled 5 in Figs. I, 3, 4, 5 and 6, would then be the forking of into Mi and M2. Where the forking of M3+4 into Ma and M4 is, I do not know, although I am inclined to think that it may be just basad of the dotted line running up from the label Ma in Fig. 1. If this be correct, N3 would be the vein so labelled in the Figure, while M4 would be the short vein extending to and fusing with Cii1 in Fig. 1. On the other hand, this short vein may be merely a cross vein between vein and Cul, in which case the vein labelled M3 in Fig. 1 would in reality be vein I have provisionally followed the former view and have labelled the median veins as though M4 had fused with Cul in Fig. 1. There is such a discon- certing tangle of cellules (which are more elongate and quadrangular in the medial region than in the cubital region) in the medial region, however, that I would not insist on the interpretation of the courses of the branches of M indicated by the labelling, and the final interpretation of these veins must await the study of the pupal trachea- tion, or the comparison with some less complicated vena- tion in the fore wing of some as yet unknown Mecopteron. Merope and "Pr~tomerope,'~ however (both of which are related to Notiothauma) are primitive Mecoptera with a less complicated venation which shows no indication of a fusion of M4 with Cui, and this fact makes me suspect that the vein labelled M3 in Fig. 1 is in reality vein M3+* and the forking of this vein into M3 and M4 occurs further out toward the distal half of the wing, and the labels should therefore be shifted accordingly in Fig. 1. The develop- ment of the medial field is much greater in Notiothauma than in most Protoblattids, but some of the Protoblattids, such as Eucaenu,s, have a four branched media such as the ancestors of the Mecoptera must have had.



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92 Psyche [March
The cubital field
of Notiothauma is filled with broader
irregular pentagonal or hexagonal cellules and the cubital field is remarkably like that of such Protoblattids as Asynerytus. The extremely short basal portion of Cu (i. e., before it forks) is another feature strongly suggestive of these Protoblattids, and is an added feature pointing to a Protoblattoid ancestry for Notiothauma (and hence for the Holometabola in general). As was mentioned above, Cui is a convex vein (as is indicated by a + sign in Fig. 1) and Cua is a concave vein (indicated by a - sign in Fig. I), and this seems to be characteristic of all Mecoptera. As occurs in the wings of some fossil, but no other Mecoptera, Cul branches into Cul a and Cul b judging from the condition exhibited by the hind wing, but I am not certain where this occurs in the fore wing unless it be at or just beyond the point where the dotted line running up from the label Mi in Fig. 1 crosses Cui. As is also true of the Mecopteron Panorpodes, a nygma or wing spot, occurs in the basal cubital cell, as is shown in Fig. 7, where the nygma is labelled n. Just behind Cu is the preclaval rima or crack- like line demarking the anterior limits of the claval or anal area.
This crack frequently interrupts the basal portion of Cu, and may have been formed in connection with the developing ability to lay the wings back in the incumbent position.
The anal or claval area (i. e., the clavus of Herniptera) extends from the above-mentioned claval rima to the jugalula labelled a in Fig. 1, and contains the three anal veins which are convex veins in Mecoptera'in general. The first anal, labelled 1. A. in Fig. 1, has a well developed basal arch labelled ba which occurs as a basal ridge, with an
accompanying pocket or fold developed in connection with the ability to lay the wings back along the abdomen in repose. The weakening of the costal margin and the conse- quent detachment of the basicostal sclerite or protuberance be of Fig. 1, is probably also developed in connection with the folding of the wings along the abdomen in repose, so that all of these features are of importance from the phylogenetic standpoint, and it is surprising that no one has referred to such features in the wings of insects. I have found them in the Blattids, Isoptera, Cicadas,



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19301 The Mecopteron Notiothauma reedi 93 Gryllacridae, Panorpids, etc. (Psyche, 34, p. 59 and Bull. Brooklyn Ent. Soc., 23, p. 113), and when such an im- portant form as the fossil Metropator is figured with a basal arch in the first anal vein by Tillyard, 1926 (Arner. Jour. of Science, 11, p. 161)
I think that this (together
with the outline, venation, etc. of the wing) indicates that Metropator is more closely related to the Protorthopteroids than to the Palaeodictyoptera, although Handlirsch places Metropator in his order Palaeodictyoptera, and not in the order Pr~torthopte~a as Tillyard states. Eubleptzis (order Eubleptoptera) may be nearer the Palaeodictyoptera, but Metropator (Metropatoroptera) evidently represents a type worthy of ordinal rank, closely related to the Protorthoptera. and with a venation approaching that of