1909] JOHNSON — LOCAL ECOLOGICAL STUDIES 9 
scarcely reached Connecticut; the Leopard Moth (Zeuzera pyrina), which has 
spread from the vicinity of New York city to Danvers, Mass.; the Harlequin Cabbage- 
bug (Murgantia histrionica), which has migrated from Mexico to Long Island, N. Y.; 
the two asparagus beetles, Crioceris 12-punctata, which is now found in Milton, Mass.; 
C. asparagi, which has reached New Hampshire; and many other species. ‘These 
advances northward, however, by many species of the ‘Transition and Austral ZONES 
may in part be only temporary, an unusually cold winter destfoying the invaders. 
It has been shown by Prof. E. Dwight Sanderson, in a paper on “The influence of 
minimum temperatures in limiting the northern distribution of insects”’ (Jour. of Eco- 
nomic Entom. I, 245, 1908) that a temperature of — 24° F. will practically check the 
northern spread of the Brown-tail Moth. ‘The northern limit of the asparagus and 
elm beetles “agrees quite closely with the average annual minimum isotherm of about 
—10° F.” Prof. Sanderson also points out that the present Upper Austral zone of 
Doctor Merriam does not extend far enough northeast. 
I now wish to consider some of the minor or local features bearing on distribu- 
tion. In the maritime area, in which is included the fauna of the immediate coast 
line, and on which the limitation of the Upper Austral is partly based, we have a num- 
ber of species even north of Cape Cod which are not only common in the Upper 
Austral, but in the Lower Austral as well. Among the Diptera might be mentioned 
Chrysops flavidus and C. plangens from Maine to Florida, Tabanus nigrovittatus, 
the common “greenhead”’ from Nova Scotia to Florida, Odontomyia microstoma, 
from New Hampshire to Maryland, Culex sollicitans (the “Salt Marsh Mosquito”’) 
from Maine to Florida and even in Jamaica; Stichopogon argentea among the sand 
dunes from Maryland to Massachusetts; Hypocharassus pruinosus from St. Augus- 
tine, Fla., to Cohasset, Mass.; Triodonta curvipes from Cape May, New Jersey, to 
Nova Scotia; Phyllogaster cordyluroides, Florida to Massachusetts; Chaetopsis 
apicalis, Ormond, Fla., to Cohasset, Mass., and Caenia spinosa, Florida to Massa- 
chusetts. In the other orders I can only mention a few of the more conspicuous: 
Els quadrinotata, E. plumipes and Microbembex monodonta in the Hymenoptera; 
Cicindula dorsalis, Strategus antaeus, Saprinus pennsylvanicus, S. patruelis and 
Phalerva testacea in the Coleoptera; Junonia coenia, Callidryas ebule, Terias nicippe, 
T. lisa and Ecpantheria scribonia in the Lepidoptera, and the salt marsh dragon-fly, 
Micrathyria berenice, all common insects in Florida which are also found in Massa- 
chusetts. 
The distribution of one insect often governs the distribution of another, thus 
we find even at the most northern limit of distribution in New England of the Car- 
penter bee (Xylocopa virginica), its parasite, Spogostylum simson. 
