Our Immigrant Insect Faunal
By REECE 1. SAILER
Dept. of Entomology and Nematology, University of Florida, Gainesville 32611
From the time of Asa Fitch in the .mid-19th century
American entomologists have known that many of our
most serious crop pests were not native to North America.
It is also common knowledge that a very large number of
crop pests, present in other countries, have not yet gained
entry to the United States. Each year the U.S. Department of Agriculture spends several million dollars on
plant quarantine activities designed to insure that these
foreign pests are not added to our North American fauna.
species that must be added to my list. Also a comparison
of numbers shown on my charts and graphs will reveal
certain discrepancies. These result from incomplete information concerning many of the species included in the
list.
Before commenting further on the foreign element of
our fauna I would like to say a few words about the native fauna. The most recent estimate I have seen indicates that there are 104,000 named species of insects resident in the 48 contiguous states. Thus, the introduced
species comprise only slightly more than 1.3% of the
total fauna. Certainly we also have reason to be interested in the origin and history of the native species for,
as indicated later, these indigenous species have and will
continue to influence the ability of foreign species to successfully invade the United States.
In view of the importance of foreign species as pests
and of other foreign species as natural enemies of insect
pests and weeds or as pollinators of many crops, it would
seem highly desirable to know how many are present in
the United States. For many reasons it is also desirable
to know where they came from, how long they have been
here, and how they arrived. Also, while we are painfully
aware of those species that are pests, and know something
of those that are beneficial, few people, aside from taxonomists, are aware of the large number having little or
no known importance. Unfortunately there is no single
source from which to
obtain such information.
While much information
is available, it is scattered
through literally hundreds
of publications.
Again, thanks to the work of taxonomists, zoogeographers are able to tell us something of the history of this
indigenous fauna. Some species have been present, or
more likely descendent from species present, on the North
American land mass when it fractured off and drifted
away from the great super-continent known as Pangaea.
Although a subject of much past controversy, most knowledgeable people now accept Continental Drift as a fact
(Hallem 1973, Kurten 1973). Many biologists, including
entomologists, now explain many faunal similarities between widely distant continental areas as the result of
early occupation of contiguous portions of the ancient
super-continent.
For several reasons I doubt that more
than a few North American species can boast of such ancient lineage. North America is believed to have started
splitting off from Europe 150,000,000 years ago. The last
land connection across the North Atlantic was broken
about 30,000,000 years later. To assume that the many
indigenous North American species known also to occur
in Europe and Asia owe their present distribution to continental drift implies that they are living fossils unchanged
for 120,000,000 years.
About 5 years ago I
decided to try to rectify
this
situation
partially
through compilation of a
list of insects and mites,
resident in the 48 contiguous states and known to
be of foreign origin. Species to be included in the
list were those believed to
have become established
REECE1. SAILER
in North America subsequent to 1620. In assembling the list I wish to acknowledge the assistance of
many people without whose help such a task would have
been impossible. First and foremost are the taxonomic
entomologists of the Agricultural Research Service's Systematic Entomology Laboratory and their colleagues of
the Smithsonian Institution's Department of Entomology.
Secondly, there are the several secretaries and more recently, graduate students who have prepared file cards,
tabulated data, worked up charts and graphs and typed
manuscripts.
Such an assumption also ignores the consequences of
climatic change resulting from latitudinal and longitudinal
position. It also ignores the catastrophic effects of glaciation that has repeatedly obliterated the biota of much of
North America and Europe during the past million years
(Flint 1957). In my opinion the intermittent land connection between North America and Asia known as Beringia
has had a much greater influence on our insect fauna.
Within the past 200,000 years Beringia was a broad 1200
mile wide isthmus of dry land connecting Asia and North
America. At the same time much of present-day Alaska
was ice-free while most of Canada and much of the
United States was buried by a vast continental glacier.
In this discussion it is not my intention to present lists
of names, but rather the orders to which they belong,
where they came from, how they arrived and what influence they now have as components of our fauna. I should
also point out that while I have been able to record 1,385
species as of foreign origin, the list is still far from complete. Almost without exception each new monographic
treatment or review of some sizeable genus or larger
group of North American insects will include one or more
1 Pr~sid~ntial
addr~ss : Entomological
Washington, D. C., Nov=b~r 28, 1977.
Society of
Obviously, the climatic conditions prevailing in Siberia,
Alaska and the connecting land bridge are critical considerations if this route is to be accepted as a major factor in explaining faunal relationships of North America
and Asia. Even as dry land, the Bering Sea area is likely
to be associated in the minds of most people with igloos
and Eskimos mushing across the tundra behind a dogteam. Today the region is a formidable ecological barrier
America,
3
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4
Vol. 24, no.1
BULLETIN
1978
1300
V)
1100
w
V
w
a..
V)
900
u..
0
et:
W
d:l
700
~
::>
Z
UJ
>
-
500
I-
4:
...J
::>
~
::>
300
V
100
1640
1700
1800
1860
1900
1940
1977
TIME
Accumulation
FIG.
I.-Number
of Immigrant
Species
of exotic species of insects and mites resident in the 48 contiguous
states at time intervals from
1640-1977.'
to insects of the temperate zones. But with cold water of
the Arctic Ocean blocked off from the North Pacific, the
southern coast of Beringia would have been swept by a
warm ocean current with an effect similar to that of the
present Atlantic Gulf Stream on the British Islands and
Scandanavia.
That plants and animals did move freely
across this land bridge is evidenced by the present fauna
and flora of Alaska. My own unpublished list of Alaskan
Hemiptera shows that 80% of the species are of Old
World origin. Clearly Alaska has served as a beachhead
and staging area for invasion of North America by plants
and animals that first evolved in Asia.
There is another consequence of Asian species' access
to Alaska. At the time these animals and plants migrated
across Beringia, the vast North American ice sheets had
obliterated or driven the New World flora and fauna far
to the south. Later, as this flora and fauna followed the
retreating ice sheets north, it found access to Asia blocked
by the physical barriers of climate and the Bering Sea.
But perhaps of equal or greater importance, northward
movement of New World species was also blocked by
the presence of the invading Old World species of plants
and animals.
The Bering land bridge has therefore functioned as a
valve that tended to admit Asian species to North Amer'All
figures prepared by Scott R. Yocom.
ica but deny North American species access to Asia. As
one consequence of this valve effect there are more than
500 species of Diptera in the United States that are also
known to occur in temperate Europe and Asia, but are
not now found in Alaska and northern Canada (Stone
et al. 1965). These species almost certainly originated in
the Old World and their presence now in central and
eastern United States is strong evidence that the Bering
Sea land bridge at some time had a climate not too different from that of the present day Smoky Mountain area
of North Carolina.
During the 15,000± years since the ice sheet retreated from our northern borders, the fauna and flora of
North America settled into the biomes and life zones that
characterized the continent when the first European colonists began to arrive on its eastern shores. Their arrival
marked the beginning of an ecological revolution that has
not only affected the biota of North America but even
the physiography of the continent.
Beginning with the Age of Discovery, geographic and
ecological barriers that isolated islands, continents, and
inter-continental areas have been breeched by commerce.
In the 1;nited States natural ecosystems have been displaced by agro-ecosystems over much of the land surface.
The remainder has in one way or other been influenced
by our modern industrial civilization.
Vol. 24. no.1
1978
5
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Now having in a most general and superficial manner
covered the origin of the indigenous insect fauna of the
48 states, we will look at what has happened since 1620.
I think we can safely assume that several species of insects were on board the Mayflower when it tied up at
Plymouth Rock. Some would most certainly have gone
ashore with the little band of 102 Pilgrims. There is a
good chance that some of our stored product pests can
trace their lineage to the Mayflower. If not, it is because
they were eaten by the Pilgrims during the near famine
conditions that the colony experienced in its first year.
United States from all parts of the world. None-the-Iess,
comparatively few foreign species had become established
in the U.S. by 1800. Distance and time were still formidable barriers. Only species that lived on man himself or
his domestic animals and those that lived in stored products could survive the trip. The one important exception
were those long-lived forms carried in ballast of ships.
As agriculture expanded, commerce increased and time
in transit diminished, opportunities for foreign insects to
gain entry and become established increased exponentially.
Fig. 1, in at least an approximate manner, shows how the
number of established foreign species accumulated during
the past 350 years. According to my most recent and
still far from complete list the total number now stands
at 1385. This includes all categories-those
that were
introduced intentionally as well as those that arrived accidentally. The vertical axis of the graph shows number
of species and the horizontal axis, time. The line connects points that show the number of species known to
have been present at the end of each time interval. Because of the paucity of data, intervals of 20 years are
shown up to 1860. After that date each interval is 10
years.
Several things are immediately evident from the graph.
Certainly reinforcements arrived with every ship bringing additional people and supplies from England. However, it is unlikely that any crop pests were among the
foreign species that date from this early period. Most
would not have survived the long sea voyage. Any that
did would have found conditions for establishment of a
population extremely hostile. Prospects improved as the
human colonists expanded their numbers and established
gardens, farms and orchards. As the human settlements
grew, the trickle of commerce between Europe and America turned into a torrent. At first limited to England,
commerce was soon established with other European
countries and by 1800 commodities were reaching the
Major
Orders
~o~o2o
-
Hymenoptera:
--
Coleoptera:
~
Lepidoptera
"0"'0"'0
'0°0°0
300
Homoptera
:
272
295
:
;~~~1.Acarina:
al
~
w
U
w
79
80
: 86
Heteropt
era
55
200
Q..
(/)
Minor
Orders
I.L.
0
~
Orthoptera
27
Psocoptera
11
Thysanura
w
a:l
Dermapte
~
:::l
Neuroptera
Z
120
Thysanoptera
............. Diptera
V)
327
100
: 11
ra
8
4
Anoplura
:
2
Araneida
:
2
E mbioptera
Isoptera:
:
2
2
Siphonaptera
Total
2
=
1385
ORDERS
Immigrant
FIG. 2.-Number
states.
Species
of species In each of the Orders represented
by
Order
in the exotic arthropod
fauna of the 48 contiguous
Vol. 24, no. 1 1978
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6
100
RESIDUAL
VI
w
THYSANO
90
HETEROPTERA
U
w
a...
VI
ORDERS
PTERA
01 PTERA
80
HOMOPTERA
lL.
0
LEPIDOPTERA
70
ACARINA
c::
w
~
~
::l
Z
....•
HYMENOPTERA
60
COLEOPTERA
50
<l:
I-
0
I-
40
•..•...
0
30
I-
Z
w
U
c::
w
a...
20
10
0
1820
1840
1860
1880
1900
1920
1940
1960
1977
TIME
Change in Proportional Representation of Species
FIG. 3.-Proportional
by
Order Since 1820
changes in Order composition of established exotic species at time intervals from 1840-1977.
First there was a very slow accumulation of species until
1860. Between 1860 and 1920 number added during each
10-year interval increases almost exponentially. This is
clearly correlated with an exponential increase in Commerce that occurred during this same period. In 1920,
there is an abrupt change to a still ascending but straight
line. This must reflect the deterrent effect of the Plant
Quarantine Act of 1912. This act was not fully implemented until 1920 (Marlatt 1920). Since that time additional species have been recorded at the rate of about 12
per year. Some of these might well have been in the
United States prior to 1920 and escaped notice until a
later decade. Also, on an average, 3 of the 12 are intentionally introduced beneficial species. This leaves an
increment of 9 accidentally introduced foreign species that
are annually incorporated into our fauna.
Obviously, plant quarantines have not proved an insurmountable barrier to invading species. However, the data
also suggest that plant quarantines have prevented the
entry of a very large number. Had foreign species continued to arrive at the accelerating pre-1920 rate, instead
of 682, we might expect at least twice this number would
have gained entry and, based on past performance, 20%
or 286 would have been pest species of significant importance. These would certainly have included the Mediterranean fruit fly and many of the serious crop pests
that so far have been unable to invade the U.S.
Next, I would like to look at who these fellow immigrants are and how they got here. In Fig. 2, the number
of species belonging to each of the Orders is shown by
means of a bar graph. Here we see that Homoptera
takes first place with more than 23% of the total number.
Coleoptera with 21%, Hymenoptera with 20% and Lepidoptera with 9% include 65% of the remaining species.
Diptera stands 5th in number of species, closely followed
by Thysanoptera and Acarina. In aU, 17 orders are represented. Sixteen, if you belong to the school that places
Homoptera and Heteroptera as suborders of Hemiptera.
For obvious reasons, it serves my purpose here to treat
theme separately, and since I would otherwise prefer to
place them together under Hemiptera, I have used suborder designations.
Fig. 3 indicates the changes that have occurred in the
kinds of foreign insects gaining entry and becoming established during the past 350 years. This graph actually
starts with those present in 1820 and shows the proportional representation of the major orders at each of the
later time intervals. You will note the early dominance
of Coleoptera. These are species that for the most part
arrived in ship ballast. After 1860 Homoptera took the
lead by a wide margin. The explanation for this remarkable invasion of homopterous species is obvious and well
documented.
Following the Civil War the steamship
greatly reduced the time required to cross the Atlantic.
At the same time, growing affluence of Americans created
a demand for nursery stock available in Europe. This
traffic continued to grow through the end of the century.
At the same time private individuals and the U.S. De-
Vol. 24, no.1
1978
7
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partment of Agriculture were searching the world for
new crop plants. An indication of the magnitude of this
traffic is provided by Fairchild (1945) who was head of
the l:nited States Office of Plant Introduction.
In a
book about travel in the tropics he mentions that nearly
200,000 named species and varieties of plants were introduced from all over the world by this agency of the Department of Agriculture.
I can now look over my list
of immigrant species and confidently label at least fifty
Homoptera as having been brought in by plant explorers.
Well before 1900, entomologists of the U.S. Department of Agriculture and those of California and several
Western
other States were aware of the problem involving both
nursery stock and plant exploration
(Howard
1897).
Efforts to obtain Plant Quarantine legislation were finally
successful in 1912 but not fully operational until 1920.
By administrative order, the USDA had instituted quarantine inspection of all plant material imported for Department use in 1906 (Weber 1939, p. 3). The effectiveness of these measures appears to be reflected by an immediate leveling off and later drop in the number of species of Homoptera recorded as newly established in the
United States.
In more recent years, the Hymenoptera
have taken the
Palearctic
721
c
'.p>
t..
0
C
~
0
-0
N
c:
0
III
~
C
~
c
:::>
Origin
FIG. 4.-0rigins
of Immigrant
Fauna
of exotic arthropod fauna showing number of species contributed by each biogeographic
region.
8
Vol. 24, 110.1 1978
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Oceania
.<;
Oc eania
World
FIG. 5.-Biogeographic
lead. This, I am happy to say, is the result of intentional
introduction of beneficial species. You will note an expansion in the Diptera band about 1910. This results
from similar introductions primarily against the gypsy
moth.
The Acarina show a marked increase during the years
1910-30 and reflects a different factor-taxonomic
activity. Prior to that time, there was no one able to identify
mites. Work of one taxonomist active in this period resulted in the first reported presence of most of these foreign species.
Without having delved beyond numbers and order
names, we have now covered the questions of how many
of what kinds, as well as when and how they arrived.
Now we will see where they came from. Fig. 4 provides
a pie graph showing the percent of species coming from
the major biogeographic regions of the World. You will
note that more than 50% came from the Western Palearctic. This means Europe. The Eastern Palearctic and
Oriental Regions account for more than half the remainder. Fig. 5, a map of the biogeographic regions of the
world, shows the location of these regions in relation to
the United States. The number of species each has contributed is clearly correlated with similarity of climate
and crops but even more with amount of commerce. Until
Regions
regions of the world.
very recently most commerce has been with Europe. Since
World War II, Japan and Southeast Asia have become
increasingly important. However, the importance of Europe as a continuing source of invading species is indicated by data for species recorded as established since
1970. Of 68 listed for this period, 40 came from Europe
while only 10 came from the Eastern Palearctic and Oriental regions combined. During the same period, II are
recorded as coming from Mexico, the West Indies or
other areas of Central and South America.
Economic and Ecological Consequences
In 1958 the English ecologist, Charles Elton, published
a book that should be in the library of every entomologist.
The title of this book is "The Ecology of Invasions by
Animals and Plants." In this book Elton uses the term
"ecological explosions" to describe the effect on both
natural and agroecosystems that so often results from
invasion of a system by organisms of an alien system. He
draws on examples from all plant and animal groups as
well as from all parts of the world. He concludes that
thanks to the activities of one dominant organism-man,
the entire world biota is undergoing a convulsive change
more drastic than any that have occurred in the past
million years. The United States has experienced more
than its share of such explosive invasions. There is little
Vol. 24, no.1
1978
ESA BULLETIN
need to enumerate them here. The gypsy moth, European
cornborer, Japanese beetle, oriental fruit moth, European
pineshoot moth, and alfalfa weevil are examples. However, not all invading species cause disruptive effects in
their new habitat. Actually, they run the gamut from
catastrophic importance through no known importance to
highly beneficial.
Fig. 6 provides a rough indication of the economic impact of the immigrant species. Of the 1379 for which I
have assigned economic importance, 236 are in the category of important pests-species that annually cause some
monetary loss; while 566 fall in a minor pest category.
By minor pests, I have in mind species that are known
to feed on economically useful plants but seldom cause
significant damage. Also included are species of nuisance
value as well as species that are parasites of beneficial
forms. Species of no known importance account for 21%
of the total and an equal number are assigned to the
beneficial category. The latter include parasites, predators, pollinators, dung feeders, and weed feeding species.
With closer scrutiny of these species, several interesting aspects of the immigrant fauna are evident. First, the
important pest species constitute only 350/0 of the estimated 700 species of important arthropod pests present in
the U.S., yet this 35% includes species responsible for
50% of all insect pest losses. A second important point
relates to quarantine strategy. If we had undertaken to
predict the economic importance of each of the 236 spe-
Number of Immigrant Species to the 48 States
FIG. 6.-Economic
9
importance of exotic species showing number represented in each category.
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10
BULLETIN
cies in advance of their arrival we would have been wrong
2 times out of 3, the reason being that we would have
relied on evidence of economic importance in the countries of origin. As a result we would not have anticipated
the importance of such species as the Japanese beetle, the
citrus blackfly, and the cereal leaf beetle. From this
knowledge it appears that accurate prediction of any
foreign species' potential importance as a pest in the
United States requires that we know what factors are
responsible for lack of importance in the country of origin. Undoubtedly, these factors are, more often than not,
natural enemies that will be left behind when the species
invades the U.S. I can only conclude that any plant feeding insect is potentially dangerous to American agriculture if it is found in a foreign country to be associated
with one of our crop plants.
The beneficial immigrant species also fall into 2 subcategories-those
that were intentionally introduced and
those that came in as accidents of commerce. As an entomologist specialized in introduction of beneficial insects,
I find it disconcerting that of 271 beneficial immigrants,
118 are accidental introductions.
These include many
valuable species such as the parasite of San Jose scale,
Prospaltella perniciosi Tower, and the alfalfa seed pollinator, Megachile rotundata (F.).
On the other hand,
beneficial insect introduction activities during the past 90
years have contributed only 2 species to the injurious
species list and these are of negligible consequence.
Future Prospects
Originally, I became involved in this immigrant species
subject because of assignment to a task force charged
with review of USDA Quarantine Inspection program.
The objective was to determine how effective this program was and how it might be improved. I concluded
that one means of determining effectiveness would be a
retrospective view of our immigrant insect fauna. Secondly, it seemed that a comparison of the immigrant fauna
of the 48 states with that of Hawaii would be useful.
As indicated earlier, it is evident that quarantine restriction activities, while not altogether stopping entry
of inj urious foreign species, have served as an effective
deterrent and considerably reduced the probability that a
foreign plant feeding species will gain entrance to the
United States. It was with the view of determining the
magnitude of this deterrent effect that I undertook the 48
states-Hawaii comparison. Hawaii has only 0.8% of the
land area of the 40 contiguous states and essentially only
one port of entry for foreign commerce. More man hours
of quarantine inspection effort per unit of commodity are
expended at Honolulu than at any of the other U.S. ports
of entry. Other things being equal, one would reason
that fewer foreign insects should gain entry to Hawaii
than to the 48 contiguous states with their vastly greater
area, more diverse environments, and a vastly greater
amount of commerce that arrives through more than 30
ports of entry. However, from even a preliminary review
of the data it is evident that other things are not equal.
Instead of the annual increment of 12 foreign species for
the continental states, 16 are being added to the Hawaiian
fauna (Mitchell 1975).
It is also of interest to look at the total insect fauna
of the Hawaiian Islands in comparison with that of the
48 contiguous states. Zimmerman (1948) estimated that
there were 6,000 species of insects in the Hawaiian
Islands. Of these, only 3,722 were endemic, the remain-
Vol. 24, no.1
1978
ing 2,278 being of foreign ong1l1. Thus, we find that
Hawaii is not only acquiring new immigrant species more
rapidly but already has almost 900 more than the 48
contiguous states. As another way of looking at the
foreign element of the 2 areas, 38% of the Hawaiian
fauna but only 1.3% of the 48 states has been introduced
accidentally or intentionally by man.
From this comparison of Hawaii and the 48 states I
can only conclude that environmental resistance is a
powerful deterrent to invading species. In fact, it would
appear to be much more important than Plant Quarantine
Inspection. By environmental resistance I have in mind
the kind of problem facing the tropical insect that finds
itself on the grounds of the Kennedy Airport in New
York. Or, the plight of the insect hitchhiker that leaves
a plane in Miami only to be confronted by a hungry
horde of predatory ants, spiders, birds, and a variety of
other potential enemies. Then, assuming the insect is
lucky enough to have escaped the sharp eyes of the quarantine inspectors and the jaws of potential predators and
to find a niche in which to live and start a family, it may
still have a problem. The niche may already be occupied,
leaving no room for the invader.
Finally, there is another barrier that has received little
attention but one I am convinced is important. This is
inbreeding depression. Most colonizing species arrive in
very small numbers. Relieved of natural enemies and with
other environmental factors favorable, the invading species may increase its numbers rapidly for a few generations and then suffer a drastic reduction in fecundity,
fertility, and general vigor. This I believe to be a consequence of the genetic load of deleterious recessive allelic
genes carried by the founding individuals. As a result of
inbreeding, a portion of the population will soon become
homozygous for these deleterious recessive genes. The
resulting depression of reproductive potential combined
with environmental resistance may result in extinction of
a well established population. At least 10 immigrant species once recorded as established have disappeared, possibly for this reason. In several cases, introduced beneficial species were involved. By comparison, only 6 species have been eradicated by regulatory action and one of
these-the citrus blackfly-is back.
Thus, in its efforts to prevent entry of new pests into
continental United States, Plant Quarantine is really only
the first line of defense. It is backed up by powerful
natural deterrents. This does not mean that I depreciate
the Quarantine effort. Quarantine activities have obviously reduced the rate of new entries and have prevented establishment of many potentially dangerous pests
but it is still a numbers game. There is a certain probability that any foreign species capable of living in the
United States will gain entry and become established.
For some, the probability is so high that we can expect
that they will be discovered and hopefully eradicated
within a year or two. For other species the probability is
so low that they may never make it.
In the case of Hawaii, it appears that environmental
resistance to invading species is so low that the Islands
act almost as a faunal vacuum and will continue to do
so until all available ecological niches are filled. Here,
the barrier provided by Plant Quarantine is of much
greater importance per unit of agricultural
production
than for the 48 continental states. Aside from protecting
Hawaiian agriculture and the Islands' native fauna and
flora from invading species, there is an additional reason
Vol. 24, no.1
1978
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for maintaining the strictest possible plant Quarantine
procedures in Hawaii. Because of their vulnerability to
invading species, the Islands comprise a dangerous stepping stone and staging area for invasion of Asiatic species
into the continental states.
The hazard of invasion by foreign pests has also been
greatly increased by the opening of such airports as those
of Chicago and Kansas City to international traffic. Insect hitchhikers arriving at New York find a generally
hostile urban environment. By contrast, a corn or SOybean insect landing at the Kansas City International Airport finds itself in the midst of corn and soybean fields.
If the dangers posed by these internal centers of foreign
traffic are to be minimized, they will require expenditure
of a proportionately greater quarantine and surveillance
effort. It would also be sound policy to establish land
USe policies that would result in establishment of ecological barriers around such airports.
Finally, my personal interest in immigrant species is
their importance in the field of biological contro\. Based
on both theory and experience, the discovery of a new
foreign pest in the United States should trigger 2 kinds
of response. (1) Immediate surveys and studies to determine feasibility of eradication and (2) initiation of foreign work needed to find and import natural enemies. If
eradication succeeds-fine.
The foreign work will generate information likely to be useful at a future date. If
eradication does not succeed, several years lead-time on
eventual control will be gained.
Based on past performance, foreign species of insects
will continue to gain entry to the United States. Improved quarantine inspection procedures may reduce the
number, but more likely, any increase in the effectiveness
of quarantines will be offset by the effect of increased
Commerce and tourist traffic with foreign countries. Certainly, every economically feasible effort should be made
to prevent additional species of insect pests from becoming established in the United States.
In conclusion, it is my opinion that our best hedge
against the dangers posed by foreign species is intelligence. The more information we have about the world
insect fauna the more likely we are to be able to devise
means of preventing entry of dangerous species and to
take appropriate counteraction against any that do invade
the United States. We need current information about the
status of pests in other countries. But, of greater importance, we need detailed knowledge of the insects and mites
associated with crop plants, forests, and other commodities in all foreign countries with which we have any significant commerce. Much of this knowledge is available
11
and needs only to be collated and incorporated into a computerized information bank from which it could be readily
retrieved. There would remain a much larger body of
needed knowledge that should be the subject of a special
program. This would involve work in foreign countries
either by American entomologists or through contract
with foreign institutions. Insect taxonomists would play
a key role in such a program. Such a program would not
be cheap, nor completed quickly but the long-term savings
to American agriculture would far exceed its cost.
REFERENCES CITED
Elton, C. S. 1958. The Ecology of Invasions by Animals and Plants. Methuen and Co. Ltd. London.
Reprinted as a Science Paperback, 1977. Distributed
in the USA by Halsted Press, a Division of John
Wiley and Sons, Inc. New York.
Fairchild, D. 1945. Garden Islands of the Great East:
Collecting from the Philippines and Netherlands
India in the Junk "Cheng Ho." New York.
Flint, R. F. 1957. Glacial and Pleistocene Geology.
John Wiley and Sons. New York.
Hallam, A. 1972. Continental drift and the fossil
record. Scientific American 227: 56-66. Republished
as Chapter 9, p. 81-90 in "Eocology, Evolution and
Population Biology. Readings from Scientific American." W. H. Freeman and Co., San Francisco.
1973.
Howard, L. D. 1897. The danger of importing insect
pests. Yearbook of Agriculture, 1897. P. 527-52.
Kurten, B. 1969. Continental drift and evolution. Scientific American 220: 54-64. Republished as Chapter
10, p. 90-100 in "Eocology, Evolution and Population
Biology. Readings from Scientific American." W. H.
Freeman and Co., San Francisco. 1973.
Marlatt, C. L. 1920. Federal plant quarantine work and
cooperation with State officials. J. Econ. Entomo!.
13: 179-80.
Mitchell, W. C. 1975. Pers. comm. In paper presented
at 59th Ann. Meeting Pacific Branch, Entomo\. Soc.
Am., Portland, Ore. June 24-26, 1975.
Stone, A., C. W. Sabrosky, W. W. Wirth, R. H. Foote,
and J. R. Coulson.
1965. A Catalog of the Diperta
of America North of Mexico. Agric. Handb. No.
276. USDA, Washington, D. C.
Weber, G. A. 1930. The Plant Quarantine and Control
Administration-its
history, activities and organization. Service Monograph of the U.S. Government.
No. 59. Brookings Institution, Washington, D. C.
Zimmerman,
E. C. 1948. Insects of Hawaii. Vo!. 1.
Introduction. Honolulu.
HOUSTON MEETING DEADLINE
The deadline for the submission of titles of presented
papers at the Houston meeting is July 1. The submission
form is printed elsewhere in this issue of the BULLETIN.
For members planning a symposium, their ideas should
be submitted to the appropriate Section Chairman by
April 1, 1978. See the information sheet referred to
above for more complete information. A reminder: The
privilege of presenting submitted papers at an Annual
Meeting of the ESA is limited to members in good
standing only. ESA member sponsorship of non-mem-
ber entomologists
is not permitted.
Not more than
two submitted papers, including joint authorship, will
be accepted from any member. No member shall be
permitted
to read more than one submitted paper.
Non-entomologist
members of related societies are permitted joint authorship
with ESA members and are
extended membership
privileges on individually
sub·
mitted papers. Member and non-member abuse of the
privilege of presenting papers at ESA Annual Meetings
has necessitated the establishment of these requirements.