Article beginning on page 28.
Psyche 6:28-29, 1891.

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PSYCHE. [February 1891.
ON THE LIFE-HISTORY OF DIABROTICA I Z-PUNCTATA OL1V. BY H. GARMAN, LEXINGTON, KY.
This insect is deserving of especial
attention just now because it appears to be undergoing a change of habit similar
to those undergone in the past by sev-
eral other native American insects, and
probably due to the destruction, by the
cultivation of land and by grazing, of
the wild plants upon which it has hith-
erto subsisted. This explanation of its
sudden appearance recently over a wide
extent of territory as a corn-infesting
insect seems to me the only one war-
ranted by the published facts of its his- tory.
Until I 888 Diabrotica 12-functata
did not appear in the literature of eco- nomic entomology as an important en-
emy of any of our staple crops. Mr.
B. D. Walsh, writing in 1866 (Pi-act.
ent., v. I, no) and referring to the
beetle, states that "it is very injurious to flowers especially to Dahlias," and in-
fers that it is in part responsible for an injury to the leaves of melons, cucum-
bers and other plants, of which one of
his correspondents complains.
In 1868 Walsh and Riley (Am. ent.
v. I, 227) in reply to a correspondent in Bushberg, Missouri, wrote of the same
beetle, "The yellow beetle with twelve
black spots which we herewith illustrate (Fig. 168, twice natural size) and
place in reply to R. D. Parker of Man-
hattan, Kansas, these authors state that insects sent to them for determination
are also D. 12-functata.
In 1870 Prof. C. V. Riley (zd Mis-
souri Report, 66) wrote that the beetle
'*may often be found embedded in the
rind of both melons, cucumbers and
squashes," a statement which is re-
peated in 1872 by Mr. E. B. Reed (Ent.
soc. Ont., Report for 1871, 91).
Prof. S. A. Forbes somewhat extends
the knowledge of the food-habits of the
beetle by recording in his first report as State Entomologist of Illinois (p. 104)
that it was observed Aug. I, 1882, feed- ing on the pollen of corn and on the
blossoms of clover.
One of the most notable cases of in-
jury. by the beetle is that reported in 1888 by the editors of Insect life (v. I, 58). In an orchard at Hernden, Virginia,
planted chiefly in 1887, young apricot
and plum trees are stated to have been
badly injured in late April and early
May by the beetles, which devoured
the leaves as they unfolded. The land
on which the trees were planted was
mostly in corn in 1887, but a half acre
had been in melons. In concluding
their notice the authors use the follow- ing words :
which has been so destructive to your
'It is safe to say, however, that this occur- water melons and Hubbard squashes, is
rence is exceptional,
and that it depended
the 12-spotted Diabrotica." In the same
almost entirely upon the peculiar circum- Ps\&e 6 028-10 (pre- 1903). hfp //psyche aitclub orgW6-0028 htinl



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[February 1891. PSYCHE. 2 9
stance of a young orchard having been
planted close to a last year's melon patch, which was not replanted this year. The bee- tles undoubtedly bred upon the melons last season and hibernated in large numbers.
The present spring, finding no more appro- priate food at hand they took to the young plums and apricots merely as a substitute. We have little fear, therefore, that a new habit has been formed."
What basis the authors had for the
positive statement that the beetles bred upon the melons I am unable to say,
but it is more than probable from what
is now known of the life-history of the
insect that many of the beetles had de-
veloped instead on the roots of the corn. These references and quotations will
serve my purpose of presenting the in-
sect as it was known to entomologists
during the time which they cover. It is
to be noticed that no reference is made
to the larva except that implied in the
statement made by the editors of Insect
life to the effect that the beetles breed upon melons. If these authors had
known at the time their notice was writ- ten that larval Biabrotica 12-@nctata
feed on the roots of corn we may assume
that they would have mentioned it in
reporting a case in which the relation
between the injury to the trees and the
corn-infesting habit is so evident.
During the years 1882 and 1883 Prof.
S. A. Forbes made a thorough study of
the related D. longicornis, which
affects the roots of corn in Illinois and other middle states. In this region D.
12-$.wzctata is a very common species,
occurring everywhere in gardens and
fields on flowers. With the thoi-ough
examination of insects from the roots of corn which to my knowledge was made
by him, it is altogether unlikely that it would have escaped notice if its larvae
had then been present in any numbers
in corn fields.
In the report for 1887 (published in
1888) of the Entomologist of the Na-
tional Department of Agriculture, Mr.
I?. M. Webstel states in a brief notice
that while in Louisiana in I 886 :
"We frequently heard of fields of young
corn being seriously injured, during some seasons, by a small white worm which at- tacked the roots, usually during April. From the description given us of the pest and its manner of attacking the plants, we first thought it might be the larva of D. mi-
cornis, as the habitat of that species is known to extend southward to Central America. On April 12 of the present year [1887] we were enabled to solve the problem by finding con- siderable numbers of these larvae in a field of corn in Tensas Parish, La., where they were working considerable mischief by killing the young plants. As observed by us, their
mode of attack differed from that of their northern congener in that they did not ap- pear to attack the fibrous roots or bury them- selves in longitudinal channels excavated in the larger roots. On the contrary, they bur- rowed directly into the plants at or near the upper whorl of roots, which almost invariably resulted in the death of the plant. . . . Both ofthese fields had produced cotton the pre- ceding year. The adult beetles were fre- quently seen before we observed the larvae, but they were not abundant about the plants in the corn fields, beingusually on the yellow blossoms of a species of Aster which springs up in cultivated grounds early in the spring in great abundance. No pupae were found, although careful search was made for them."



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30 PSYCHE. [February 1891.
The above is the earliest notice of D.
12-@nctata as a corn insect of import-
ance which I have seen. Unfortunately
the writer does not state whether his
conclusion as to the author of the injury was the result of inference, or was - ar- rived at by carrying the larvae through
their transformations. From the fact
that he had not found pupae up to the
time of writing, it is proper to assume
that the transformations were not ob-
served. As a possible clue to one of the original food-plants of the larva atten- tion is directed to the fact that he found the beetles abundant on an Aster
growing on cultivated ground. (From
its yellow color the plant would appear
to belong to some other genus.) If, as is not unlikely from an observation made
by Prof. Lugger and reported farther
on, the plants observed by Mr. Webster
are attacked by the larvae, the fact
may liave an important economic
bearing.
During the years 1889 and 1890 the
injury from larvae to corn attracted at- tention over a wide area ofcountry. To
my knowledge it has been witnessed in
Virginia, Alabama, Mississippi, Louis-
iana, Arkansas, Kentucky, Illinois,
Indiana and Ohio.
My own observations began July 15,
1889, and have continued, as other work
permitted, to the present time. A brief
notice of the insect, its habits and stages, was printed in the Louisville Home and
Farm, Sep. I, I 889, and in November
of the same year was followed by a more
elaborate account of the transformations and descriptions of the stages, presented before a meeting of the Association of
official economic entomologists at Wash- ington. (See Insect life, v. 2, 179.)
The latter paper is embodied in what
follows, with the addition of observa-
tions made during the winter of 1889-
go, and the spring of 1890.
(To be contim~ed.)
THE PARTIAL PREPARATORY STAGES OF HETEROPACHA RILEYANA HARVEY.
BY G. H. FRENCH,
In 1887 I found larvae of this species
feeding on the honey locust in two
stages of their growth. At the time I
was feeding quite a number of other
larvae and did not make so full notes of these as could be desired, but what I
did make are as follows :
Length, .45 inch.
The body flattened be-
neath, the backrounded, head small, a fringe of white hairs on each side ofthe body. Color CARBONDALE, ILL.
reddish brown with an indistinct dorsal stripe of a more distinct red, a stigmata1 blackish stripe ; head black, with a longitudinal fulvous line each side of the middle and a transverse line of the same about the middle of the front.
Next to last stage :-Length at moult .60 inch. Shape as in the preceding. Brownish red on the dorsum, but joints 8 and 9 gray on the sides leaving only a narrow dorsal brown- ish red stripe; joint 6 gray but less distinct,



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