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78 ESPECIALLY FOR COLLECTORS Vol.14: no.l
lectors' labels are a model of neatness but some, alas, are untidy and illegible and written with ink which fades; they are but little credit to the owner.
Mounting for Life History Cases
A life history display, showing not only the full series of stages but also a sample of the food plant with the larva mounted thereon in a feeding or resting attitude, is a great improvement in the usual cabinet series. Either natural or artificial twigs, leaves, or grasses may be used.
Acknowledgements
I am greatly indebted to Donald Allen, F.R.P.S., F.R.E.S., F.R.S.A., who contributed the photographs for the plates; the photograph of a living larva in Plate 6B, upon which Mr. Allen's photograph of a preserved skin has been superimposed, is by the late Alfred E. Tonge. Sincere thanks are due to Mrs. K. G. V. Smith who typed the manuscript and to Mr. K. G. V. Smith for his excellent line-drawings for the figures.
My special thanks are due to the Amateur Entomologists' Society (London) who have permitted me to use the photographs and extracts from my original paper "Preserving Caterpillars — How to "Blow" and "Pickle" Larvae Successfully." This paper is still available as Leaflet No.20 from the A.E.S., 1 West Ham Lane, London, E. 15, at the modest price of Is.2d. post free (U.S. 15 cents).
16, Elton Grove, Birmingham, 27, ENGLAND
MAINE BUTTERFLY SEASONS — GOOD OR BAD? by A. E. Brower
The request for information on the poor collecting seasons for Lepidop-tera concerns directly a subject in which I have been interested and in which I have been keeping some records for the past tweny-nine seasons in Maine. Any statements comparing seasons need to b~ based upon comparative knowledge over a considerable period of time. When Henry David Thoreau travelled through Maine over one hundred years ago, making detailed observations on the life he saw, he remarked on the great dearth of wild flowers and animals in the climax forest which dominated the greater part of Maine. He also noted the rapidity with which Aster, Solidago, Fireweed >and some other genera came in on land cleared of the forest, and that insects were common with the flowers. Much of the cleared land became farm and pasture land, but great areas were heavily cut, often devastated by fire, and left to nature. The timber cut reached a maximum in 1909. The mantle of soil recently spread by the last ice sheet was probably already becoming low in lime and some other elements when the land was cleared. These elements and the
1960
Journal of the Lepidopterists' Society
79
scanty accumulation of humus by the forest rapidly decreased in the cleared land. Soon many plants found their environment unfavorable, and abandonment of farm lands began and still continues. The forest began to reclaim the fields and pastures. I know of more than one cellar hole in which large trees are growing, and of former settlements without an inhabitant. Thousands of acres are reverting annually to the category of forest land. The amount of land supporting roads, buildings, cities and manicured lawns has increased steadily. Along with these changes has been an inevitable decrease of some of the more commonly seen and widely distributed butterflies.
One species of butterfly, Pieris rapce. (L.), has, like the introduced weeds on which it feeds, increased until it swarms in areas, and the Alfalfa Butterfly (Colias eurytheme Bdv.) has recently colonized this region. In 1949 we had a notable flight of the Thistle Butterfly {Vanessa cardui L.) and in 1957 a great flight of Red Admirals (Vanessa atalanta L.) across Maine, but in both instances the butterflies came from far south of our border. Native species which increased with the clearing of the forest have, in turn, decreased as their environment became less favorable. The native species presumably always occurred in far less numbers than have been repeatedly reported in the middle West or far West. The writer has actually caught in the Ozark Mountains of south Missouri more butterflies in one day, and day after day, when collecting for jewelry workers, than he has seen some seasons in Maine, especially if Pieris rapce is excluded. Apparently even larger numbers occur in the West. Some of the local butterflies or species occurring in very restricted areas of Maine do occur in good numbers some seasons. The last few seasons have had long periods of cold cloudy weather with comparatively few butterflies to be seen. In 1959 I was afield on some of the better days for Theclas, and I made some trips to the special habitats they frequent, but without seeing a specimen all season. Tf one is out at the right time and in favorable local habitats and not a specimen is seen, one or more poor seasons can be expected to follow. Collectors agree that collecting for diurnals in general has been extremely poor in Maine.
In casting about for an explanation of the poor collecting seasons, spraying has been advanced as an explanation or as the explanation. As Boden-heimer has pointed out in his book on Insects as Human Food, the Americans and west Europeans are the only peoples on earth who do not regularly use one or more insects as human food, and insects are a most important portion of the diet of many peoples. Insects were staple items in the diet of some American Indian tribes and were used by many tribes. But now in America the grower is being faced with a mounting demand for fewer and fewer larvae of the Blueberry Fruit-fly per ton of blueberries, and for ever more nearly perfect apples. Control the pests; produce more nearly perfect produce. This demand has forced the grower to apply one to many applications of powerful sprays year after year in an attempt to eliminate crop pests. Possible effects on the other life of the blueberry barrens, apple orchards or potato fields has not mattered. The same attitude has dominated attempts to control mosquitoes
80
ESPECIALLY FOR COLLECTORS
Vol.14: no.l
and pests of man's shade trees. Despite these multiple applications to such crops, often of heavy dosages of spray materials, many insects, weeds, birds and animals are maintaining a high population in close contact with these heavily sprayed agricultural areas, possibly other more susceptible species are being eliminated without being noticed. The economic entomologist who is forced to study the biology of the particular pest species to determine the most effective time for spraying; who struggles to secure an application which will give 95% or higher kill, to reduce loss, and to hold down the number of necessary spray applications, can be expected to demand proof that other wild life is generally decimated, especially outside the area covered by the spray. This will not apply to aquatic life where the effect of a spray may show for a considerable distance beyond the area actually covered by spray. But few governmental agencies have initiated comprehensive studies on the complex and often long-time effects their spray operations might have on the web of life. To determine these over-all effects of a spray program requires a large outlay of time and money.
Spraying of nonagricultural or forest lands is often singled out for adverse criticism. In the case of habitats of limited extent, such as salt marshes, an attempt to spray the whole habitat could have disastrous effects on some species, other than the ones the spray was aimed at. On forest lands in Maine the dosages have been low and only one application has been made in a year. In 1958 when the only large forest acreage was sprayed (against the Spruce Budworm), less than 1.8% of the forested area was sprayed; and but a small part of an area sprayed has been resprayed or is included for respray in 1960 spray plans. Studies on spray effects have not shown any important effect on other groups of life in the spray area. One of twenty-five light traps has been operated during thirty days for years in an area sprayed in 1954 and 1958, but no obvious change in the yearly catch of many thousands of moths has been noticed. Close study might be expected to showT a change in some species vulnerable at the time of spraying. No change in the numbers of Spruce Budworm (Choristoneura fumiferana Clem.) would be evident because a resident population of this species is poorly attracted to light and the value of the traps depends upon their attractiveness during a flight or migration. Due to the far larger number of species of moths, nocturnal flight, and adverse effect of cold nights on collecting in Maine, changes in moth population are far harder to determine and evaluate than for butterflies. If sprayed areas are added together the total average acreage sprayed per year is not much over one per cent of the area of Maine. The numbers of Lepidoptera on favored local habitats where I have collected repeatedly in the past have not been decimated by sprays applied many miles away. There must be some other explanation for the poor butterfly collecting.
8 Hospital St., Augusta, Maine, U. S. A.