When taken in the hand, it has the habit, common to
most grasshoppers, of pouring out an inky fluid from
its mouth; only the discharge is unusually copious
in this species. It has another habit in defending
itself which is very curious. When captured it
instantly curls its body round, as a wasp does to
sting. The suddenness of this action has more
than once caused me to drop an insect I had taken,
actually thinking for the moment that I had taken
hold of a wasp. Whether birds would be deceived
and made to drop it or not is a question it would not
be easy to settle; but the instinct certainly looks
like ’one of a series of small adaptations,
all tending to make the resemblance to a wasp more
complete and effective.
DRAGON-FLY STORMS.
One of the most curious things I have encountered
in my observations on animal life relates to a habit
of the larger species of dragon-flies inhabiting the
Pampas and Patagonia. Dragon-flies are abundant
throughout the country wherever there is water.
There are several species, all more or less brilliantly
coloured. The kinds that excited my wonder, from
their habits, are twice as large as the common widely
distributed insects, being three inches to four inches
in length, and as a rule they are sober-coloured,
although there is one species—the largest
among them—entirely of a brilliant scarlet.
This kind is, however, exceedingly rare. All
the different kinds (of the large dragon-flies) when
travelling associate together, and occasionally, in
a flight composed of countless thousands, one of these
brilliant-hued individuals will catch the eye, appearing
as conspicuous among the others as a poppy or scarlet
geranium growing alone in an otherwise flowerless
field. The most common species—and
in some cases the entire flight seems to be composed
of this kind only—is the Aeschna bonariensis
Raml, the prevailing colour of which is pale blue.
But the really wonderful thing about them all alike
is, that they appear only when flying before the southwest
wind, called pampero—the wind that
blows from the interior of the pampas. The pampero
is a dry, cold wind, exceedingly violent. It
bursts on the plains very suddenly, and usually lasts
only a short time, sometimes not more than ten minutes;
it comes irregularly, and at all seasons of the year,
but is most frequent in the hot season, and after
exceptionally sultry weather. It is in summer
and autumn that the large dragon-flies appear; not
with the wind, but—and this is the
most curious part of the matter—in advance
of it; and inasmuch as these insects are not seen
in the country at other times, and frequently appear
in seasons of prolonged drought, when all the marshes
and watercourses for many hundreds of miles are dry,
they must of course traverse immense distances, flying
before the wind at a speed of seventy or eighty miles
an hour. On some occasions they appear almost
