THE LIFE HISTORY OF THE BIRCH TINGITID, CORYTHUCHA PALLIPES PARSHLEY The yellow birch tingitid made its appearance under three differ ent names— viz., pallipes Parshley, cyrta Parshley and betuiac Drake— in the same paper by Gibson (1918, pp. 69-105) on the study of the Genus Corythucha Stal. According to pagination pallipes has page-priority and is the valid name for the species. Parshley (1920, pp. 28 and 29) has recently pointed out the fact that cyrta and betulae are identical. Dr. Parshley has kindly loaned me the type series of pallipes and oirta and we are fully convinced that. cyrta and betulae are not only specifically the same, but also synonymous with pallipes. Although cyrta and betulae can be connected up in the type series, Gibson (1. c., p. 86) failed to observe this identity. Lack of food-plant data and a series showing variability accounts for the original failure to note the kinship of pallipes and cyrta.
The yellow birch tingid is undoubtedly the most common species of Heteroptera living in the vicinity of Cranberry Lake. Tt seems to show a decided preference for yellow birch. Betula lutea Michx. f., but it is also very common on white birch, Betula alba L., beech, Fa.mcs grandifo/ia Ehrh. and ironwood or hop hornbeam, Ostrya virgiviava Mill. K. Koch. Dr. Osborn noted a young mountain ash, Pyrus americana (Marsh) DC. badly infested by pallipes at Barber Point in July. The writer also found the insect breeding on mountain maple, Aver spieatunt Lam., soft maple, Acer saccharinum L., hard maple, Acer saccharum 'Marsh, and striped maple or moosewood, Arer pennsylvauirum L., but the species seems to breed only occasionally and never in large num bers on maples. The type series of pallipes (1918, Parshley in Gibson, p. 86) were collected on an introduced willow; Sa-lix siebol diana., at Stanford, Connecticut, by Mr. W. E. Britton. I have seen several other specimens, bearing the same date, locality and food-plant, that must have been collected with the types by Mr. Britton. The number of specimens would seem to indicate that the insect mast have been at least feeding and perhaps breeding on the introduced willow. The insect has not been observed to
feed or breed on the willows (growing near badly infested birch trees) in the Cranberry Lake region. Parshley (in Gibson, 1918, p. 85) also states that this insect (under cyrta) has been taken on sphagnum, but does not list this as a food plant. Two or three published records report. Corythucha f-uylamlis Fitch upon birch, but these probably refer to pallipes. Tn fact I have seen pallipes, bearing food-plant label "birch", in a few collections wrongly determined as C. ittgiandis Fitch. Corythucha pergandel TTeide mann and Co•ythucha 1?cideman»i Drake occasionally feed and breed on birch, but alder is by far the most common and the pre ferred food-plant of these species.
Distribution: C. pallipes is a transcontinental species and probably occurs throughout the northern part of the United States and southern Canada. Specimens are at hand from New York, Massachusetts, Maine, New Hampshire, Connecticut, Michigan, Wis consin, Oregon, Washington and Canada (Ottawa and Manitoba).
Variation: Like a number of its congeners, pallipcs shows con siderable variation in size, shape of the hood, and also in the relative proportion of the height of the crest of the hood with the height of the median carina. There is also a moderate degree of variation in size and general color of the entire insect. This variation accounts largely for the synonomy of the species. The adult insect ranges from 3.5 mni. to 4.32 mm. long. In relation to the median carina, the height of the crest of the hood varies from about twice to approximately three times that of the median carina. The posterior portion of the hood also varies considerably in width. On the same food plant one can find the extremes of variations as well as gradual gradations leading to all intermediate forms. There seems to be no distinct varieties, but the most com mon form generally has the hood a little larger than the type (pallipes). There is also a little variation in the height of the lateral carina.