FLIGHTS AND FRIVOLS OF THE APHIDS 
EDITH M. PATCH 
Entomologist, Maine Agricultural Experiment Station 
The Seasonal Migrations of Hosts of “ Green Fly” Bothers the Gardener Who 
Wonders “Where They Come From.” Strange Stories of Alternating Habitations 
E ARE all familiar with at least the main facts concern- 
ing the seasonal travels of certain animals. The purple 
martin, rejoicing in his return to the north with a 
wAT-v triumphant, “ I’m here ! I’m here /”, and that annual 
first Penobscot River salmon, caught in the pool below the falls 
and sent as a gift to the President of the United States, are as 
surely obvious hints that the movements of animal life are 
calendared as the coral tassels of the Maple, or — in those few 
haunts where ruthless depredators have not yet completed its 
destined extermination! — springtime’s sweetest token, the fra- 
grance of Arbutus. 
That insects have a share in the itinerary of the seasons is not 
so generally known, though now and then a northern country- 
man stops in late summer to admire a gathering of Monarch 
Butterflies flocking bird-like about some low tree and taking 
brief hovering flights while biding the long flutter to the south- 
land. It is not, however, journeys from cold climate to warm 
with which the seasonal flight of the aphid has concern; but 
round trips of a mile more or less, from one sort of food plant 
to another with stop-over privilege. For the migratory aphid 
requires a change of conditions entailing a new diet in the spring 
or early summer, and again in the fall in order properly to com- 
plete the life cycle of the species. 
Little as is generally known about the habits of these mar- 
velous insects, the aphids themselves are recognized by every- 
one who has much acquaintance with plants; for they are nu- 
merous in species and abundant in individuals, and common 
enough to attract attention even while the secrets of their lives 
are hidden from all except the detective who has patience enough 
to follow the clue. 
Familiar to all observers of the American Elm are terminal 
clusters of leaves bunched into rosettes at the tip of the branch 
(see illustration). Such a deformation constitutes a shelter 
for a family of aphids during 
their spring residence there. 
The mother of the colony is a 
plump insect of dark com- 
plexion, though by virtue of a 
coat of powder she appears 
much paler. She passed the 
winter in the egg stage hidden 
in the crevices of the Elm 
bark. I n the spring, hatching 
from the egg just as the leaves 
are unfolding, she sought a 
suitable tip. punctured it with 
her beak and by simply re- 
maining and feeding caused it 
to form the protective habi- 
tation for herself and her 
young. These, unlike their 
mother, are born alive instead 
of being hatched from an egg. 
H ER progeny are all fe- 
males. Upon attaining 
their growth these give birth 
in turn to living young, also 
all females. All the descend- 
ants of the original aphid or 
“stem-mother” as she is called, ordinarily remain in the same 
cluster of leaves, which become much distorted in consequence 
and crowded with the numerous family. As each individual 
casts its skin several times in the process of its growth, and as the 
discharge of honeydew is abundant, the rosette after a time con- 
tains considerable waste matter which causes it to look untidy 
within. Conditions are kept remarkably sanitary, however, by 
the aid of the waxy secretions of the aphids, particles of which 
cover the honeydew so that the liquid rolls about in white coated 
pellets without drenching the insect. A further protection is 
afforded also by the waxy powder which remains upon their 
bodies rendering them impervious to moisture. 
The earlier members of the family, including the stem-mother, 
are all wingless. In June, however, comes a generation that 
with maturity develops wings! These late individuals, or 
“spring migrants” as they are called, resemble the apterous 
generations previously mentioned in being all females, but they 
are smaller bodied and differ in various structures as well as in 
having wings. And instead of remainingdn the leaf cluster with 
their relatives, they take flight, seeking fresh vegetation for the 
establishment of the summer colonies. They are strong on the 
wing and probably fly to distances of at least a mile if they do 
not find a suitable location nearer at hand. And when they 
desert the Elm leaf which has furnished sap for their develop- 
ment, they are “instinctively” led to an entirely different habi- 
tat, namely the Apple tree, the Hawthorn, or the Mountain 
Ash (all Pyrus species). 
Finding one of these trees, the migrant alights on a leaf, 
crawls to the underside and remains there quietly while giving 
birth to young which seek some tender place on the branch or, 
by preference, a “water sprout” before settling to feed. And 
these summer colonies of our aphid of Elm and Apple, like their 
spring antecedents, are composed only of females; and the im- 
mediate progeny of the mi- 
grants are wingless and have 
their bodies whitened by the 
secretions of the wax glands. 
These fine waxy filaments 
now fluff out in a white mass 
about the insects, however, 
whence they are commonly 
known at this period as the 
“woolly aphids of the apple,” 
— in many parts of the world 
the worst pest with which the 
orchardist has to contend. It 
is not, however, the economic 
significance of this insect with 
which the present discussion 
is concerned, but its life his- 
tory with reference to the 
remarkable migration from 
Elm to Apple and return. 
For late in the season a 
generation of winged females 
is developed on the Apple. 
These are the “ fall mi- 
grants,” in appearance very 
much like the spring mi- 
grants; and they in turn 
SUMMER AND WINTER RESIDENCES OF SOME OF OUR BEST KNOWN AND 
MOST UNPOPULAR PLANT LICE 
PRIMARY HOST PLANT 
SECONDARY HOST PLANT 
NAME OF APHID 
Elm (Ulmus americana) 
Elm (LUmus americana) 
Elm (Ulmus campestris) 
Elm (Ulmus americana) 
Elm (Ulmus montana) 
Maple (Acer saccbarum) 
Ash (Fraxinus pennsylvani- 
ca) 
Cottonwood (Populus sp.) 
Poplar (Populus deltoides) 
Poplar (Populus occidenta- 
ls) 
Skunk-bush (Rhus triloba- 
ta) 
Currant (Ribes aureum) 
Russian Olive (Elaeagnus) 
Plum (Prunus) 
Russian Olive (Elaeagnus) 
Peach, Plum. Cherry 
Willow (Salix) 
Apple (Pyrus) 
Apple (Pyrus) 
Choke Cherry (Prunus) 
Apple (Pyrus) 
Hawthorn (Crataegus) 
Plum (Prunus) 
Plum (Prunus) 
Spindle Tree (Evonymus) 
Plum (Prunus) 
Plum (Prunus) 
Rose (Rosa) 
Rose (Rosa) 
Rose (Rosa) 
Black Haw (Viburnum) 
Currant (Ribes) 
Apple, Hawthorn, Mountain 
Ash 
Juneberry (Amelanchier) 
Currant, Gooseberry (Ribes) 
Grass (Aira and Agrostis) 
Grass (Echinochloa) 
Alder (Alnus incana) 
Fir (Abies balsamea) 
Beets (Beta vulgaris) 
Lettuce (Lactuca) 
Buttercup (Ranunculus) 
Wheat, Oats, Barley, etc. 
Lettuce. Sow Thistle (Sonchus) 
Persicaria 
Arrow-head (Sagittaria) 
Canada Thistle (Cirsium ar- 
vense) 
Potato, Cabbage, and others 
Parsnip 
Rib Grass (Plantago) 
Oats, Wheat, etc. 
Oats, Barley, etc. 
Clover (Trifolium) 
Clover (Trifolium) 
Grass (Panicum, Setaria) 
Thistle (Cirsium lanceolatum) 
Bean, other plants 
Hop (Humufus) 
Grass 
Potato and others. 
Oats, Wheat 
Grain 
Grape (Vitis) 
Lettuce, Endive, etc. 
Schizoneura lanigera 
Schizoneura americana 
Schizoneura ulmi 
Tetraneura graminis 
Tetraneura ulmi 
Prociphilus tessellata 
Prociphilus venafuscus 
Pemphigus betae 
Pemphigus bursarius 
Thecabius populicondup- 
lifolius 
Rhopalosiphum rhois 
Rhopalosiphum lactucae 
Rhopalosiphum hippophae 
Rhopalosiphum nymphaeae 
Myzus braggii 
Myzus persicae 
Aphis saliceti 
Aphis malifoliae 
Aphis avenae 
Aphis pseudoavenae 
Aphis bakeri 
Aphis crataegifoliae 
Aphis setariae 
Aphis cardui 
Aphis rumicis 
Phorodon humuli 
Hyalopterus arundinis 
Macrosiphum solanifolii 
Macrosiphum granaria 
Macrosiphum dirhodum 
Macrosiphum illinoiensis 
Macrosiphum lactucae 
IOO 
