94 MQNTBLY WEATHER REVIEW. FEBRUARY, 1920
values, and (b), the mean variability, i. e., the mean difference between successive absolute values of the variable. (a) Our fomulse are exact in both the very different
caaes where all values are equally robable and where they follow the law of Gauss, as w& as in still different cases. Hence, i t can not be doubted that they possess a very Feat degree of ’generality, and no matter what law whch the quant.ihes occurring in meteorological applications might follow, the application of these formu- lee would not lead us into serious error; as a niatter of fact, such quantit.ies usually follow the law of Gauss quite closely. (6) The successive values of the mat-hematical vari- able are independent of one another, and the mean variability is #- times the mean departure; but for the
meteorolo ‘cat elements, particularly for a series of suc-
the mean veriabilit is usually somewhat ess than the above quantity.’ Hence we should impose on the free mathematical variable the su lomentary condition that it have the same mean varia&ty as has the element bdng considered; unfortunately, one encounters here ti
mathematical difliculty (also met with in the theory of
an imperfect gas) which has not yet been surmounted. If we arbitrarily k e d the mean variability it would amount to admitting that the probability of the occur- rence of a value is a function of the preceding value, which is exactly contrary to the fundamental assumptiom upon which the theory of robability resta, and according
However, the mean variability does not play such mi important rBle as it would at first sight seem to; and some sim le considerations show that the introduction of a con ition reducin the mean variability somewhat would not modify the in ‘cations of our formds.
F
cessive da s y values, the values are not inde endent, and
to which all our formuls 1 ave been derived.
I $
WATERSPOUTS ON THE SOUTHERN CALIFORNIA COAST.
“Visitors at the beaches (Port San Luis, Avila, Pismo, and Oceano) Sunday afternoon about 5 o’clock had the ortunity of observing,” says the San Luis Obispo %%une, “a most unusual phenomenon, that of an im- mense waters out traveling a t a hiwh rate of speed toward the beach. $he spout was shape3 like a funnel, and is said to have been about 2,000 feet high, extending as high as the clouds and spreading out into a fine mist. The spout was first visible from Avila and Pismo when it was about 4 or 5 miles distant from the shore, and from that time traveled rapidly until it broke on the beach between Shell Beach and the old Oil ort refinery. “Fishermen who landed at Avila Y ater in the evening stated that they had seen three spouts at one time, two of which were travelin in the direction of the Pecho and
one of those going toward Pocho, and robab y covered
In describing these waterspouts the San Francisco Call says :
The phenomenon waa followed by a tremendous downpour of rain. Fishermen at sea. 1101th of the port viewed the three spouta simul- taneously. As they approached the shore the two larger ones mounted the headlands. but the third ~ras diverted. It swept mxnd the buoy and proceeded across the bay a t a speed estimated to be in excess of 40
miles an hour. Water within a diameter of from 150 to 200 yards waa violently
agitated and appeared to be siphoned upwmd to a mass of clouds some
2,OOO feet above. As the spout approached the shore persons near state that there was a tremendoiis roar. The funnel apparent,ly de- tnched itaelf from the water and w~ts drawn gradually up into the maas of overhan ‘ng. rapidly moving, cumulo-nimbus clouds. Violent gusts
of Wind folfwed the appemnce of the spouts and continued for several hours. According to J. E. Hiasong, United States weather observer here, the spouts were due to the overrunning o€ eurface air by a layer of colder air aa weather control passed from an area of low to an area of high preeeure. The spouta are the first to appear on this coast. within the memory of the oldest inhabitant.
P
one toward Shell Beac f . The largest of the s outs was
about 5 acres in area, according to the P shermen.”
INFLUENCE OF THE WIND ON THE MOVEMENTS OF INSECTS.
By WLus EDWIN HURD.
[Weathw B ~m u , Washington. Jan. f3,lsaO.l
The weather perha s hes more to do with the control
significance of this meteorological espect is varied. Cold, heat, rain, hail, humid ty, drought, sunshine, electricity, and wind are factors. Temperature, rain, and wind movement are of utmost economic importmce. Sudden cold and ra.in. in early summer may more or less completely destroy the incubating or newly hatched members of what would otherwise rove to be a vast swarm of destructive crop eaters. &ought may retard or destroy numbers of insects in their metamorphoses. Frosts at the moment of appearance of the imago may wreak untold disaster to the tender brood. And pre- vailing winds may so accelerate or retard the direction of movement of many injurious species at the time of their seasonal advance as to cause or avert great eco- nomic disasters. Thus the winds may upon occasions become the ara-
fields and orchards. When we see butterflies and other large-win ed, small-bodied insects flutterh hither and the lmpresaion is stron that any extended flight opsuch
of insect life than a K other factors comhined., and the
mount issuo of l i e or death for the little fliers o P our
yon, bu P eted about in the air on a win 3 y da
creatures must con B o m with the direction of the wind.
And yet the facts do not always bear out such a conclu- sion, since in reality the unsteady butterfly is much more capable of forcing itself against the air current than is the heavy locust or the more projectile-like beetle. The dispersion of insects by means of winds is a matter of constantly increasing a icultural
and as i t affects the agricultural sta les, interests the farmex innsmuc F as i t may
interest all of us, who need to % e The question was formerly more discussed by the student of geographical zoology, as it affected his plan regarding the spread of a ty e of life from region to region within coasts or across t f: e seas. The South American locust, for instance, is believed in some scientific circles to be descended from the survivors of an African swarm of identical genus which, following more or less passively in the steadv currents of the northeast trades, succeeded in crossin h e Atlantic Ocean. The flig % ts, or migrations, may be largely voluntar quite the opposite. 2 though R good nearly all cases most insects the direction of the air currents, although some are inclined to quarter the
an important part, and
FEEaRuAltY, 1920. MONTHLY WEATHER REVIEW. 95
wind or orient themselves against it in flight-some- times, it seems, out of pure perversity. This orientation, or apparent anemotropic instinct, however, is frequently only the effort of the insect to kee itself on the wing whether poising or in flight while t Yl e wind is blowing. Many flies and midges turn to face every passin breeze, ,poismg themselves with wings edaed to the win%, and if it becomes too stron , falling to tge pound
are icked up boddy and carried from local haunts by the
larva and mosquitoes, or the insects while migratinp may-be blown from their course by the strong winds 02 passmg storms. Indeed, on some of the tropical islands, nature seems to have stepped in with a s ecial means of protecting some of her tinier creatures.yl) She has padually dwarfed or eliminated the wings of certain lnsectq and hence they are unable to fly too high aud thus nsk being caught in powerful winds and blown to sea. a determin-
ing factor in the flights of all insects, ancertain types may be swept by hurricanes from one island to another, or to a mamland where they had not previously ap- peared. After the southwest gales of Au st 26, 1901,
numbers of the “blue page” moth of ginidad were found to have been blown to the Barbados, a distance of 160 miles, and some to Dominica, still more remote.(2) Harmful insects may also be introduced, as has fre- quently ha pened in our Southern States, through the agenc%of %e tropical storm. The Argentine Pam ero
Sometimes eat numbers of calosoma beetles, or, in particular, t f e light blue dragonflies which inhabit the am as, are found in advance of the westerly wind in Ea &at* and elsewhere, instinctively seeking to escape the tempest, and when caught by it are tumbled in downlike confusion by the 70 or 80 mile ale. But while some insects are thus caug a t up involun-
tarily, others of a more helpless type instinctive1 place themselves in the athway of the air current. eurious insects, notably ap Yll ‘ds, are then known to crawl to the tops of planta just before a thunderstorm, and when the first onrush of the wind occurs, dro into i t and are
breeze from a neighboring food supply is sufficient to cause a flight of winged stragglers against the wind toward the agreeable scent. The plum curculio, for instance, flies to its food su ply, the neighboring plum tree, ageinst the breeze. I n 1’ e manner the resence of a female moth is communicated to the male uring the mating season. Many experiments dong this line have been conducted. The female moth has been confined in a cage during ti
breezy period and of the number of male insects observed fluttering about the captive by f a r the gre.ater proportion of them came to her against the wind. In connection with the colonization instinct and the influence of the wind upon it the home-returning instinct is so pronounced that the insects will fly a ainst head
scent of the home colony may be brought to them. The veteran naturalist, Fabre, cites an instance of his
own observation (31 in the case of some identified mason bees which he carried from the home swarm to a place between two and three miles distant. U on their releas
so stiff a wind was blowing from the Jrection of the
The involuntaq f ights are those in which the insects
win 3 a, as in the case of buffalo gnats, scales, gipsy moth
So air movements of gale force are alwa
at its urst often carries swarms of insects along wit 1 it.
carried to new amas for the urpose o P mating. The sense of smefl is highy Y specialized, hence every
R 1%
winds to gratify it. Indeed, i t seems probab 5 e that the
hive that the bees could not fly aloft where they might have seen the country, but were com elled to fly low.
home laden with ollen, and 15 or 20 uninjured insects
The fliihta of insecta may sometimes aytend over hundreds of miles, and in this way the faunal zones of many, notably locusts or so-called grasshop ers, and some
swarms of locusts, especially, have been seen far from land over the Atlantic Ocean, floating swiftly with the northeast trade winds, and on various occasions they have been known to alight upon the sails or decks of vessels. A recent instance of this nature waa reported to the Weather Bureau by Capt. B. Morthensen of the Norwegian bark Robert Scraftorc. On the 7th of October,
1916, when in latitude 20’ 57’ N., lon ‘tude 39’ 28’ W.,
this vessel met with numerous specimens of the genus Srhistoaercu flying on board in a steady northeasterly wind. (4)
Nearly all naturalists and many travelers have had occasion to comment upon the power of the locust and it is unquestionably the most common example of the migratory insects. Cowm relates many a ewsome tale
873 A. D., according to Wanley’s Wonders, a swarm that darkened the sun visited France with the south winds from Africa. They ate all the em vegetation and were
ashore in great windrows and there decayed. It was estimated that one-third of the o ulation of France died from the resulting famine anfpyafue. In 1649 a swarm of locusts was Carrie by the northeast trades from the Barbary coast to the island of Tene- riffe.(6) During the passage the insects rested at night in a great heap on the surface of the water, where many
which
the priests tried to drive them away through enances.
the plague lasted for four months. In the days before the practical extermination of the Rocky Mountain locust (Sc7~istoqrm arnericuna). OUT o m
country was often terribly beset by t-his multitudinous pest. In 1855 for instance, i t devastated the region around Great 8alt Lake, (7) devouring all the
cro s and the rairie grass. A high wind swe t t e place
into the lake, whence they wero afterwards washed ashore. When Mr. Julea Remy, the traveler, arrived he saw dead locusts piled a foot hi h along the beach.
“proof of t % e truth of their religion, because it had hap- pened (1.9 among the Israelites, in the seventh year after their settlement in the count .”
ublished a report upon the mi ations of the locusts of
a Feat breeding place for the 8ch&tocercaJ and that from this territory they descended in vast swarms to the south- eastward as far as Missouri, taking all possible advantage of the comparatively infrequent northwesterly winds that blew on fair days, for the prevailing wind over much of the stretch of country along the route during the summer
Yet, in 40 minutes, two of the released ! ees had returned
had returned by t i e following morning.
bugs and beetles, have been widely exten 3 ed. Immense
or about 1,200 nautical miles from % e African coast,
of the locust hordes.(5) He tells us that a T out theyear
finally blown int,o the sea, w f? ence they were washed
drowned, but in the morning the survivors littered in the sun, and on the
for two months by 7,000 or 8,000 soldiers, upon f’eneriffe. There they were fought
But in spite of all &orb directed toward its a g atement
at t 7l e end of B e summer, blowing myriads o P the $owing insectg
The ensuin famine was held by t!i e Mormons to be a
In 1878, the United States % ntomological Commission
gorth America. It was there s %- own that Montana was
96 MONTHLY WEATHER REVIEW. FEBRUARY, 1990
season is from the southeast. On a day with favorable winds the locusts were known to fly over the prairie for a distance of 200 to 300 miles. These creatures in common with some other insects
diminished. Nearlv all locusts evidentlv Drefer to flv with the wind, since t h h a flight of many h&k’ duratioi is accompanied by an inappreciable loss of energy. Then, too, they are not fashioned to fly readily against the wind. The swarms, by instinct, mi ate in the direction followed by their ancestors. But r efore taking a general fliuht, if the air is calm, numbers of the insects, actuated t-y the
same instinct, are often observed to rise evidently to determine the direction of the u per currents: if favorable
unfavorable, they await a more opportune morning.@) It has often been observed that locusts are high fliers, and the have been reported at elevations of 13,000 to 15,000 get. At Bismarck N. Dak., they have been noted above the cumulus cfouds, and Byers tells of two swarms, one above the other, that were seen going in o posite directions with differing air currents. (9) A
to such a degree that they will fall helplessly to the ground before they can recover their e uilibrium.
in the wind. Strange to say, it is the butterfly that has most frequently been observed flyin a st the wind,
Yet, as has reviously been observed, it is far more capable of mahng headway against a fairly strong breeze than is the apparently more powerful-winged beetle, or the locust. However, it is the method of presentation of the win surfaces to the wind that seems to give superiority
of the P M s , Danuids, and NympM&, which pay as little attention to the wind direction as ossible during
insects the condition is dserent, and in commenting upon the South American beetles, the naturalist Bates says: “It is an admitted fact, I believe, that the stearing power of beetles is not great, whilst the horny elytra act as vanes, putting the insect at the mercy of strong winds. ”
In the histor of butterfly migrations-and this insect
to a reat hei ht-it is foun that certain species, notably the %Xt? 05 Ceylon,(lO) seem invariably to fly directly against or quartering to the monsoon, some moving northward in the fall with the approach of the northeast monsoon, and others, according to some observers, moving southward in the spring when the winds of the southwest monsoon are becoming prevalent. Over Co- lombo incalculable numbers of white butterflies have been seen fluttering against the stiff northerly winds, and sur- prised witnesses have claimed that the stronger the air current the swifter is the snowy flight.’
to help them along their way, t R e migration begins, but if
c E ange of wind, it is said, will often unbalance the insects
But not all insects content t 1 emselvea with passivity
although it too does not disdain t %P e riendly current.
to t % e butterfly in this respect. This is articularly true
the fever of the migration flight. Wit R coleopterous
f
is sometimes o B served flyin in vast clouds which reach
1 &me of the observations of butte*- ggfiying against the wind” may be due to a return current aloft-perhaps the occurrence was during a 8ea breeze.-C. F. B.
InSeptember, 1872, Marott observed at sea near Java a column of Pyrameis cardzli fluttering boldly against the wind, impelled by their strange instmct which seeks to over-come all obstacles. They were constantly buffeted about and beaten back into the water, where the la
bri h t leaves. #warms of butterflies have also been met with in our own country, and their movements have been tabulated with reference to the wind. On the 23d of September,
1886, at 7 a. m., Dr. Ellsey (12) saw at West River, Md., (‘the whole heavens swarming with butterflies.” The lower insects were flying about 100 feet from the ground and the upper ones beyond the limit of vision. They were proceeding at the rate of 20 miles an hour against a stiff northeast wind.’ Butterflies have been seen in the North Atlantic 500 miles or more from land, and are frequent1 carried on
whde in 25’ S. latitude and 1,000 rn es from the coast of Brazil, he saw several species of buttedies and moths caxried in light wind and rain squalls from the westward. Many forms of insects migrate for some cause or other, but these journeys are usually taken along the path of least resistance. Over the English Channel it is not so unusual as it might seem to discover a swarm of mixed insects, winged ants, syrphus flies, sawflies, and lady- birds floating on the breeze. In White’s “Natural His- tory of Selborne,” page 366, one reads an account of a shower of aphids that fell in the village on the afternoon of August, 1785, while the wind was in the east from the
dead in such numbers that the sea appeared covere 2 2 wi
shipboard in hurricanes. Accordin5 to E ucas (13),
Western States, winds and hurled
A few p a r s ago Dr. E. Everling, of Halle, Germany, tried to interest aeronauts in making observationk of insects that mi ht be found several thousands of feet in the air. (14) f h e doctor himself, during a balloon PO
e had found at a considerable hei ht one butter i- y %ch he believed had been carried soft by a strong vertical current, since it is unnatural for such insecta to rise to great heights voluntarily, unless the am forced
swarms that extend far Joft. & all robability they may sometimes be carried to considera f le elevations in thunderstorms, or they may be caught in the fairly stron convection currents which are common even to severa thousand feet elevation on warm summer days over land surfctces. These currents often have an upward velocity of 5 miles or more an hour. The economic distribution of insects, however, is the vitally important portion of the subject to all peoples; and as has developed, of the several controls, the wind is
upward by reason of bein the u per mem l ers of deep
ei
3 The usuol, southerly, overrunning wlnd msy not have been far up.-C. F. B.
h U A R Y , lsao. MONTHLY WEATHER. REVIEW. 97
by no mesns the leasf considerable. Entomologista agree
as to ita value among the dispersion factors, as a prme means in spreading insecta at the time when they are most susceptible to being carried. This means generally when the insect is in wing, but it is also sometimes true even of the caterpillar stage of existence, and is well known as a dominant factor in the movements of certain other minute insects that can be carried by even light air currents and which, being able neither to crawl nor fly at will &om place to place by reason of their physical limitations, are dependent upon some exterior method of transportation. This dispersion, however, is not always advantageous
to the insect nor injurious to the farmer. A cold wind- storm with driving rain may almost completely destroy a thriving colon of young bugs or flies en route, or a fortuitous win i may blow it away from its natural food instead of toward it, and thus cause it to starve because of sheer inability to use the plenty in its Frail insects, like the Hessian fly and the wheat mid e, are especially liable to destruction in fight, althou h t % e7 depend upon the wind prevailing at the time w%en mgration must take place to conduct them to the roper food supply. d s t cro -eating insects of the South are migrants
isting at the time of their appearance. Thus it is seen that the generally prevailing southerly winds of this region in s ring spread the fbes, weevils, aphids, scales, and plant Pice to the northward, whence it sometimes happens that they o too far and are caught unprepared for the vigorous cf!matic conditions which may assail and destroy them in a single night. The more northern farmer, too, may well rejoice if the hated depredator at the beginning of its peregrinations is caught by a nor- therly wind, as sometimes occurs, and prevented at the outset from making an further migratory attempt for that season. Webster 8 5 ) hinted broadly at the possi- bilities of conditions of this sort when he said that the prevailing southerly winds during the breeding season m s ri spread the “green bug” from Taxas north- warcf. % strong north wmds prevailed at this time the ed females would be dnven southward, and the
One of the most destructive pests of the South is the common Mexican cottonboll weevil, which entered extreme southern Texas in 1892. Thence annually the insect spread northward and eastward until in 1917,
according to the leaflets of Hunter and Pierce of the Bureau of Entomology, 488,240 square miles of the
609,540 square miles com rising the extent of the cot- ton belt were infested. L o of the greatest fully de- fined spreads of the weed were in 1915 and 1916, largely due to the sweepin winds accompanyin the hurricane
Gulf, carryi the insect westward into 29,400 s uare
then in the storm’s eastward pro ess over the already infested area of Mississippi and Eabama, scattered the Over a considerable forward portion of this Geor ‘a mea, the result of the
lowing gear, when the new broods appeared. In 1919 a further immanrje territory of the cotton belt was invaded and for the first time the weevil a peared in centrai
son for the extraordinary spread has not yet been deter- mined, although the generally prevailing southerly to southwesterly winds over much of this region during
and depen a ent upon the meteorological conditions ex-
T pro lem north of the Red River rendered simpler.
of August, 1915. %Ius storm entered I exas from the
miles that h 3 previously been free from it in the 2 tate;
1915 invasion was practic 2 y unknown until the fol-
Tennessee and southeastern North 8 arolina. The rea-
est for the h t time into Georgia.
July and A t may have been a considerable factor.
the p r e c e k mild winter. Last seasun the forces of the Department of Agricul- ture were closely watchin for the possible reap emanc-e of a still more formidab f e p e s t t h e pink bo1 P worm- members of which had been swept in cotton debris from Mexico into Trinity Bay, Texas, by the 1915 hurricane.
(16) But fortunately the insect was not found, so the menace is for the present removed. But, a art from what we might term the sudden or
kc spread of an injurious insect, we have plenty of catastmP cumu ative evidence of common wind dispersion. If we watch the history of the distribution of the various scale insects, including the ernicious San Jose scale of the fruit orchards, we find tg at the most frequent winds determine the direction of the s read. Over most of the Middle West and the Rocky !kountain section, the prevailing direction during the period of insect activity 18 from the southwest, and in these winds, especially during times when their velocit is increased, the scales
where they may be deposited upon a heretofore unin- fested host. The spread is also more ra id up a gully than down hill, (17) which indicates t % e considerable ascensional force of the daytime and valle winds. Va- rious experiments have been made to B etermine the value and extent of this spread. Sheets of tanglefoot have been placed at varying distances and hei hts from infested fruit orchards, and scales have been f ound de- osited thereon at distances of several hundred feet rom the trees. Similar ex eriments have been conducted in arts of
moth in the prevailing southwester1 winds during the hatching and early larva eriods. l% e author of a bul- letin on the subject states t lil at “the wind is almost wholly responsible for the eneral s read of this insect in New
are covered with specidized long hairs and spin certain buoyant sillken webs, are camed sometimes to great distances. In the marshes near Lynn, Mass., newly hatched worn were caught in a west mind having a velocity varying from 7 to 19 miles an hour, and some deposited on a wind catch 1,833 feet distant. At va- rious times the cate illars have been carried b the
Shoals, 6 miles distant. &-iously enough, in the case
for flight, hence the importance of such dispersion throug T
of this insect the female moth is unable to use her win
the medium of the cater illar. of t ?I e wind distribution of certain
physically from the incursions of various t pes, partic-
teorological control, for gnats and mosquitoes have car- ried discomfort, disease, and death on the otherwise comfortin breezes. The bu do gnat of the southern swamps and ba ous is sometimes swept miles from its habitat. It is a b ood- thirsty creature and ita visits in considerable numbers on the winds have occasioned a great amount of mortality to various animals. In the days while the street cars in Memphis (19) were still drawn by mules, occasions have been known during the season of development of the gnat in the St. Fhncis bottoms on the opposite bank of the Mimaissippi River that a strong west wind would bring clouds of the dangerous insectg into the city. At such times so great were their numbers and voracity that
Then, too YY t e weeds were very numerous, owing to
are picked up like tiny seeds an c9 carried to the eastward,
I
New Englan 3 in connection with the spread of t B e gipsy
England,” (18) and 9 urther s g ows that the larvae, which
wind from the New ’p1: am hire shore to the Is 9 es of
insects man and t Y e lower animals have not escaped
ularly those of the order Diptma, through t E e same me-
But in the histo
f d
98 MONTHLY WEATHER REVIEW. b V A n T , 1m
the were known to stop the street cars by killing the mu 9 es in their tracks. Like the nat, the mos uito, usudy speaking, i R not in
experiments conducted by the Public Health Service near Augusta, Ga. (20), on marked malaria carriers, found that the maximum natural fli ht from congested areas was one mile, and from less a Q undant communities not over a half mile, though occasionally the coast mosqui- toes, including the New Jersey brand, are borne inland on the wind (21) 20 miles or more from their breedin
when the wind is ri ht to bear them from the breeding
quickly vanish. The Carnegie Institution has made some studies bearing upon this ham of the uestion (22).
son, says that while at Sand Key he occasionall observed a swarm of mosquitoes humming about near d e ground, brought in by a wind from the neighboring mangrove swamps and mainland breeding grounds. At such times it was necessary to take refuge in the top of the lighthouse, 110 feet from the ground, and thus beyond the altitude of flight of the pests, to esca e them.
about the actual spread of the disease thmugh the agency of the wind, but Ealand narrates one notable example (23), stating that while malaria is not a city disease, conditions may thivst it upon a cit as in the
at one time lay a marshy area, the Potomac Flats, in which great numbers of the anophales bred and flour- ished. With the prevailin summer-night breezes from
far,fouiid them-
where they
the habit o f wandering o 1 its own accord far afield, and
marshes in a sinu e night. On various barren keys o B the coast of Flori 3 a mosquitoeg have suddenly appeared
mainland. But wit % a change of direction the insects
A former WEATHER BUREAU o E3 m e r , Dr. 8eorge Pater-
In the history ol the m af nrial mosquito little is said
case of Washington, D. C. To the south of i+ ashington
the south the demzens of % t e marshes, whose voluntary
FLUS Washing-
the redtunation of the Flats.
BIBLIOGRAPHY.
1. Jordan, Kellogg, and Heath. Animal utudiea, 1907, p. 348. 2. The (Barbados) Agricultural News, June 2,1907. 3. J. Henri Fabre. Insect adventuree, 1917, pp. 4950.
4. Monthly Weather Review, January, 1917, p. 11. 5. Frank Cowan. CuriouS facta in the %tory of k c h , 1865, 103.
6, Sir Hans Sloane. Nat. a t . of Jamarcs, quoted in Curious &a in
7. Remy and renchley. Journey to Great Salt Lake City, 1861,
8. L. glBkk:Eh: ’$10 tal@ of the k c t a , 1899, p. 115. 9. J. W. Tutt. Mmtmn and dispersal of ineects. London, 1902,
10. Ibid, p. 70. 11. Ibid, p. 75. 12. Ibid, p. 60. 13. Ibid, p: 38. 14. Scientific American, Ma 2 1914, p. 385. 15. F. M. Webster. Some & farmem &odd know about insecte. Yesrbook of the U. 8. De t. of Agr., 1908, .387.
16. Weekly News Lettep U. g. Dept. of Agr., feb. 6,1919, p..19 17. F. M. Webster. Wm& and aa agenta 1 ~. the hffutmn’of insects. Am. Nat., vol. 36, 1902, p. 795. IS. C. W. Collins. Disperuion of gipy moth lervse by the wind. Bu. Ent. Bul. No..273, Aug. 24, 1915, p. 22. 19. F. M. Webster. Wm& and utorme m te in the diffusion of insects. Am. Nst., vol. 36, 1902, p. 7 r
#). Scientific American, Bept. 8, 1917. 21. J. B. Smith.’ Our b t frien& and e n d a , 1W9, p. 212.
22. S. C. Bell. Insecta at Rebecca Shoal snd Tortugrre. Papem
23. C. A. Ealand. Ineecte and DW, 19l5, p. 96.
the hi~tmg of insects. C m , 1865, p. 104.
p. 21.
from Dept. of Marine Bio., vol. 12, 1918.
EFFECT OF A FLORIDA FREEZE ON INSECTSC
The disastrous Florida freeze of February 2-4, 1917,
which killed or practically defoliated the a h trees in Putnam, Volusia, and h i o n Counties, and parts of Lake and Orange Counties, and heavily damaged trees
in other sections of the State, was of considerable im- portance in “reducing the numbers of injurious pests which infested the trees.” In the section where tem- peratures as low as 15’ or 20’ F. occurred the freeze or the falling and drying of the leaves nearly exterminated the rust mite and vaneties of white fly and scale insects. Few adult s ecimens of the various species survived ex- cept on fire a or otherwise protected groves or individual trees. Of the red scale it is believed that perhaps not more than 1 in 100,000 remained alive. The almost complete extermination of this species by the freeze and its re roduction to billions in six months is a moat
no need of the usual early spraying yet, singularly enough, in most cases the normd number of insects appeared in the following summer or fall. So, as a rule, the set-
back in insect life, however great even over the area of maximum freeze, was only temporary.- W. E. H.
remarkab P e biological fact. In some instances there was
ANIMAL WEATHER PROPHETS.
[Reprinted from Scientific American, New Ywk, Mar. a0. lm, p. m.1
“Mere su erstition,” so the weather authorities say
on the conduct of animals. No one, so far aa we know, baa compiled a record of these so-called omens, but their number is multiple. They are based on a belief that animals are able to tell months in advance, for example, the character of the coming winter. If hunters bring a story to the effect that squirrels have made heavy storm of nuts, it is taken to mean that a severe winter impends. If early caught fur-bearing animals have a heavy, thick coat, that is another si n of a severe winter, or a thin coat, the contrar . If Eird migrations are delayed after the usual date o the southward fli ht, a sign 18 seen of an open winter. Numerous other be iefs based on fancied ability of animals to foresee weather conditions months ahead, and base their preparations on them, have wide currency. Sometimes signs are taken from the ve e- table world, as for example, the past fall in the Mid !$I e West. Corn husks, it was related, were much heavier than usual-that meant a hard winter. The reasoning, such as it is, in many of these weather sips, is apparent on the surface. In the case of others it isn’t, as with the most famous and well-known of them a l l -t h e r d h o g sign. If Mister Woodchuck on Can-
2--sees his shadow issuingex-
b ht.” Otherwise an early spring impends. b e r v a t i o n over a part of a single lifetime would demonstrate most of these weather signs as unreliable,
yet they cling on, especially in country districb. It is possible that they do so, in part, because they shadow into animal si ns of a dif€ erent class which really are
dependable. from the conduct of animals accurate weather redictions can, within certain limita,.be made.
formly short distance as to prophecy-no longer than the daily newspaper weather forecast. They occur because
are many o P the long-distance weather predictions based
f 9
delmas erimental arFebruY y from hiy en, then “winter will have another
This 2 ependable class of animal weather signs is uni-
~sCTheEffecteoftheFreemofFeb 2-4 1917 ontheIumctPestaandYmCitrua” Ey W W Yothem Boreen of Ent&oldgy, &hado, Fb. Fmar The ZlaElC B d , POL &‘NO: 3, DW. dt 1917.