"d 
964 The American Naturalist. [November, 
trichum which causes a fatal malady of chinch bugs. More than three 
thousand experiments are reported, more than half of which were be- 
lieved to be successful. The great difficulty in the practical use of the 
fungus was the dry weather, during which no progress could be made. 
Greenland Insects.—In reporting on a small collection of Micro- 
lepidoptera from McCormick Bay, Professor C. H. Fernald remarks ê 
* One of the most interesting features of this small collection is the very 
dark color of the insects. The specimens of Laodama fusca and also 
of Pyrausta torvallis are much darker than any I have ever seen before, 
either of those taken in New England or Labrador, but when we recall 
that Mr. Mengel states that they rest on the lichen-colored rocks, we 
have not far to seek for the cause of this dark color." These lichens 
are dark brown or black, and the laws of natural selection would lead 
to the establishment of a dark race through the elimination of the 
light-colored individuals. Professor Fernald describes one new species 
—BSericoris mengelana. 
Habits of Larval Coleoptera.—F. M. Webster reports’ that 
larvee of Leptotrachelus dorsalis Fab. feed on larve of Isosoma tritici 
Riley, and pupate in wheat stubble, after plugging up open end. The 
larva of Phalacrus politus Mels. develops in smut of rye and Indian 
corn. A female Neoclytus erythrocephalus was seen ovipositing in trunk 
of dead apple tree, and Bruchus mimus Say was reared from seeds of 
Cercis canadensis. The larva of Disonycha caroliniana Fab. feeds on 
foliage of Portulaca oleracea, and Apion segnipes Say develops in pods 
of Tephrosia virginiana. 
Biology of the Horse Bot.—From observations on the eggs of 
the common horse bot fly, Professor H. Osborn reaches the following 
conclusions ? “(1) That the eggs do not hatch, except by the assist- 
ance of the horse's tongue. (2) That hatching does not ordinarily 
occur within ten or twelve days, and possibly longer, or, if during this 
period, only on very continuous and active licking of the horse. (3) 
That the hatching of the larve takes place most readily during the 
third to fifth week after deposition. (4) That the majority of the 
larvee lose their vitality after thirty-five to forty days. (5) That the 
larve may retain their vitality and show great activity upon hatching 
5 Ent. News, V, 132. 
7 Ent. News, V, 140. 
*U. S. Dept. Ag., Div. Ent., Bull. 32, p. 48. 
