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Psyche 8:171-173, 1897.

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PSYGETE.
THE LARVAE OF THE AUSTRALIAN EUCLEIDAE.
BY HARRISON G. DYAR, WASHINGTON, D. C.
fAmnial address of the retiring president of the Cambridge Entomological Club, 14 January, t898,I In looking over the figures of exotic
iepidoptero~~s larvae that havebeen pub- lished, I think one of the most curious
and apparently inexplicable forms is the Doratifera vulncrans of Lewin, This
Eucleid is described as possessing the
power of everting eight little tufts of
stinging spines which are concealed
when the larva is not irritated. I was
at a loss to imagine the origin or mech- anism of this structure and it was there- fore with much pleasure that I received
from Mr. E. A. C. Olive of Queensland
a specimen of a species showing the
eversible spines.
The group seems confined to Austra-
lia. I have examined the descriptions
of the species of India for anything
analogous, but without success. The
Indian larvae are similar to our own,
the Sisyrosea type seeming' to predom-
inate, with a few Euclea-like and smooth forms (the latter not to be interpreted
from the figures). There is nothing
here to suggest the origin of the pecu-
liar structure of the Australian larvae. Kirby lists seventeen species of Eu-
cleidae from Australh in eight genera,
of which I have seen figures of five
larvae of two genera. When all are
known, it may be found that there are
other types of larvae, but at present
there is no evidence of this. The five
figures show a neat gradation in char-
acters, apparently representingone type. The one showing the greatest develop-
ment of the peculiar eversible spines is Lewin's species. Scott figures four
others in which this character gradually declines until the last species is without horns of any kind and has become a
smooth Eucleid." Evidently we have
here a new type of smooth Eucleid,
different from either of the North
American ones, derived, I think, from
the true Australian type. Therefore I
consider the larva received from Mr.
Olive as typical of the Australian ELI-
cleidae.
Before describing the Australian spec-
ies I will review the types already made known. These are all represented in
North America. In Europe there are
but two species, both belonging to one
limited type which is better represented here. In Asia, Moore has figured a good




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172 PSYCHE. [February 1898.
many species from India, but the figures are very rough and often inaccurate?
In some as many as twenty side horns
are shown, although these structures are segmentary and could not possibly ex-
ceed twelve (nine is the normal number). The figures serve only to give a general idea of the larvae and in the case of the smooth ones, where the structure is
obscure, they are worthless in locating
the forms.
The few South American species de-
scribed belong to types represented with us. Therefore, with the exception of
Australia, we have all the types as yet
definitely made known.
The structure of the Eucleid larva is
to be understood by starting from a larva like the Pyromorphid or European
Anthrocerid (Zygaenid) or, still more
exactly, the South American Megalopy-
gid which has warts derived from tuber-
cles i+ii, iii and iv+v. In the Eucleid
the subventral area is reduced, owing
to the formation of the creeping disk,
and all the warts below the stigmata1
region are obsolete. This leaves three
warts on thorax and two on abdomen
for the primitive form.
The warts are variously modified, two
main tendencies appearing. First hy-
pertrophy, resulting in appendages or
horns as they are variously called (spined Eucleids) ; second atrophy, resulting
in the smooth type.
Type I (Tropic hairy Eucleids.).
Illustrated by Phobetrou and Calybia.
Three warts present on the thorax ; the
warts are hairy, not spined ; the first
stage shows single setae with an alter-
nation of strong and weak segments
which persists in later stages. We
have here the original number of warts
and a modified primitive first stage,
followed by wart formation with rela-
tively unmodified setae. This combi-
nation of generalized characters entitles this type to the lowest place. Follow-
ing up this'line of descent we have : -
Types 2 and 3 (Tropic spined Eu-
cleids) . Illustrated by Sibine, Euclea
etc. Only two warts on thorax, the
same as on abdomen. Horns spined,
the simple setae present only in stage I and multiple ; no sign of alternating
weak and strong segments. We have
the formation of spiny setae, the num-
ber of warts reduced, a crowding back
of the simple-haired warts into stage
I with loss of the primitive first stage. A distinctly higher type in all the
characters enumerated. To this be-
long many of the Indian and South
American species figured by authors.
Type 4 (Tropic smooth Eucleids).
Illustrated by Eulimacodes. To return
to the startingpoint for this new phylum there are three warts on the thorax,
small warts present in stage I, afterwards single setae only by degeneration. We
have atrophy of the warts superimposed
upon a crowding back of the wart for-
mation into stage I with loss of the
primitive hrst stage.
Types 5 to 7 (Pnlaearctic smooth Eu-
cleids). Illustrated by Apoda, Hetero-
genea and Packardia. The warts are
absent, being reduced to single setae by degeneration. In stage I single setae
are present, but modified and partly




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February 1898.1
united as in Phohetron, and showing an
alternation of strong and weak segments. We have atrophy of the warts without
the loss of the primitive first stage.
I class this type higher than type 4
because the warts have entirely disap-
peared and the structure is so modified
that there is no evidence in the individ- ual ontogeny of the derivation from wart- bearing ancestors ; but it is difficult to compare the types exactly, as they are
so diverse and have pursued such difter- ent lines of development. To this last
type belong both the European species.
It might have been antecedently ex-
pected that the Australian type would
prove to be an ancient one from- consi~~- eration of the many other generalized
animals found in that country, yet such
is not the case. In fact the Australian
Eucleids are distinctly specialized, be- longing to the highest phylum of the
horned larvae (type 3) and forming a
peculiar branch of that phylum, as the
following characters show : -
The horns (hypertrophied warts) are
present in two rows, subdorsal on joints 3 to 13, lateral on joints 3, 4, 6 to 12; the spiracle on joint 5 moved up into
the place of the missing horn ; skin wit11 irregular clear granules ; caltrope spines present in little elliptical sunken patches at the bases of the lateral horns of joints 6 to 12 and subdorsal of 13. So fir the
larva stands just on a level with Eziclea. indetermina and Adonefa .sftimdoides
which have no detachable spines, lower
than Buclea del9hiniiand SGine sf&-
ulea which have them and again higher
than Sisyrosea textula and S. nason'i*
which do not possess caltropes.
The shape is elongated, spaces equal
except the narrowed subventral space ;
feet as usual, the suckers showing dis-
tinctly on joints 5 to 11, apparently
absent on 12 and 13. Thoracic feet
small, distinct. The horns are unequal
in length as in Euclea, but the inequal- ity is a special one. There are besides
two simultaneous modifications of the
original stinging spines. These are,
first, the formation of the retractile
horns and, second, the conversion of
the other horns into long smooth tenta-
cles.
The first of these is indicated in some
of our own species, as in Sisyrosea
nasoni, where all the subclorsal horns
of joints 4 to 12 can be depressed out-
ward with convergence of all the spines
to a point, or, more exactly in Parasa
chloris where the subdorsal horns of
joints 4, 5, I I and 12 are bent in over the' back with the spines not erected.
In fact this rudimentary condition of
Parasa represents exactly the begin-
nings of the structure of the Australian Eucleids. Not only is the structure
similar, but it is the horns of the same segments that are thus affected. In
Doratifera vitlnerans Lewin the re-
tractile horns arc on joints 4, 5, 11, 12, while in D. leisini Scott and D. casts
Scott they are on joints 4 and 5 only.
The retractile horns consist of a short
fleshy shaft with numerous spines which
*The larvae whidt J call nnsonz'have not yet been bred, hence the determination is not certain.




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174 PSYCHE. [February 1808.
bend inward over the back, the spines
this larva the tentacles are present for becoming converged and the whole con-
all the horns of the lateral row and joint cealed by a triangular fold of skin. The 13 as well as for the subdorsals of 3 and presence of this fold is the only essential difference between these tufts of Dorati- fera and our Parasa. The muscular
function may be slightly present in
Parasa ; it is certainly so in Sisyrosea nuson6 though in this case the horns
bend outward.
The second modification is produced
by the lengthening of the horn and the
reduction of the stinging spines. I find on the tentacles of the larva sent me by Mr. Olive not only a few setae, but
several distinctly formed, though very
short stinging spines, as well as a great number of degenerate irregular lumps,
representing the mass of the spines. In
12 where they are especially long.
The subdorsals of 6 to 11 are very
short, rudimentary, again much as in
our Parasa, but their spines are absent, just as on the long horns, which is not
the case in our species.
To summarize : the Australian Eu-
cleids belong to the group of the horned Eucleids of Asia, Africa(?)* and Amer-
ica, but differ in having the spines
removed from the horns which have
not become eversible. It is a distinct
and peculiar specialization of one of the highest types of larvae and possibly
represents the most modified Eucleid
larva on the earth.
PACIFIC COAST COLLECTING. - 11.
BY ALBERT PITTS MORSE, WELLESLEY, MASS.
LOCALITIES.
Yema, R. R. hotel; drinking-
water detestable. Surroundings chiefly
river-flats covered with willow-thickets, and desert. A rocky hill, chaparral,
and ranches at a little distance. This
place and points in Colorado Desert are
likely to be extremely hot.
India. R. R. hotel. Desert thickly
covered with weeds and chaparral;
fruit ranch with artesian well and run-
ning water. Mesa and foot of moun-
tains 3 to 4 miles distant.
A good
place,
Palm Springs. Five miles from
station of same name and directly at
base of San Jacinto Peak, Inn and
fruit ranches. Desert, ranches wifh
fields and orchards, several canyons
with wild date-palms, streams, water-
falls, etc. An extremely favorable
locality.
Additional places in the Colorado
Desert that would probably repay
visits are Flowing Well - natural
spring, - Salton - 250 ft. below sea-
*I have seen no African larvae, but species of Parasa ire recorded from there.




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