DESCRIPTION OF A NEW SPECIES OF GOLDEN BEETLE FROM 
COSTA RICA. 
By Martin L. Linell, 
Aid, Department of Insects. 
Among a small lot of Costa Rican Coleoptera, recently presented to the U. 
S. National Museum by Mr. John Keith of San Jose, Costa Rica, through 
Capt. G. P. Scriven, U. S. A., there were three specimens of the magnificent 
golden and silvery beetles from that locality. One of these I have identified 
as Plusiotis resplendens of Boucard, a true Plusiotis; the second one as P. 
chrysargyrea of Salle, a species intermediate between Plusiotis and Pelidnota 
as regards the mandibles, the only structural character separating these two 
genera. The third specimen, which is described below, strictly belongs to 
Pelidnota, since it has the mandibles as distinctly bidentate as in the majority 
of species of this genus, but it would evidently be wrong to separate it from 
association with the species of Plusiotis, inhabiting the same region, which it 
resembles so much in form and Coloration. Its nearest ally seems to be the 
above-mentioned Plusiotis chrysargyrea, which it approaches in form, although 
having a still broader thorax. The species is readily distinguished from any 
form of the group hitherto described both in coloration and elytral sculpture. 
PLUSIOTIS KEITHI, new species. 
Oblong, parallel, somewhat convex, above splendidly golden colored. 
Clypeus, front and a broad side-margin of thorax pinkish brown. A large 
purple spot at inner margin of eyes and a line of same color on the thorax, 
separating the golden color of the disk from that of the side-margin. Head 
rather coarsely punctured with finer punctures intermixed. Clypeus rugose, 
almost semicircular, with strongly reflexed margin. Mandibles distinctly bi- 
dentate. Thorax at base nearly as broad as the elytra, sparsely and finely 
punctured at the middle, more densely at the sides. Elytra without striae, 
sparsely covered with large, shallow, somewhat rugose punctures. Apical callus 
prominent. Sutural striae impressed towards the apex. The finely rugose 
Proceedings of the U. S. National Museum, Vol. XVIII, No. 1040. 
Advance sheet, January 12, 1895. 2 
A NEW BEETLE FROM COSTA RICA-LINELL. 
VOL. XVIII. 
pygidium, the whole under surface and the legs of a pinkish brown with silvery 
reflections ; all sutures shining cupreous. A line on inner margin of tibiae and all 
the tarsi rich purplish blue. Mesosternal process very long, conical. 
Size.-Length, 30 mm.; width, 16 mm. 
Type.-Accession number 26,734, U.S.N.M. 
Boucard who has monographed the genus Plusiotis, has also studied these in- 
sects in nature during his travels in Central America. In regard to the habits 
of the golden and silvery species, he states that they feed in concealment during 
the day on the leaves of trees, especially young oaks. Just before sunset they 
take wing for a short time. Their period of life is very brief and their habitat 
is extremely restricted. How difficult it is for collectors to obtain them may be 
better understood by citing his own words, narrating one of his visits to these 
regions. He says : " I was in Costa Rica in the proper season and at the exact 
locality where these insects are found, but was not able to get more than three 
specimens, although I offered a high price for them to the natives and did my- 
self all that possibly could be done. Every one in the country knew what I 
meant, when I asked for golden and silvery beetles, but they did not procure 
any."