NO. I FIREFLIES OF THE GENUS PHOTURIS — BARBER 53

54 SMITHSONIAN

MISCELT.ANEOUS

COLLECTIONS

VOL. II7 Elytra: 11.8X2.6 mm., ^appear darkbrown except for rather narrow (0.35-mm.) lateral margin and (0.25-mm.) sutural margin; mar- gins yellow,andnot continuousaroundthetips. Thereisanobscure lighter-brown oblique stripe from the humerus.

Head: Width acrosseyes 2.85 mm.; eye length 1.25

mm.

Frons yellow, 1.2

mm.

wide above antennal sockets, 1.5

mm.

above eyes, rather wider and less divergent than usual; inner edges of antennal sockets 0.2

mm.

apart.

Maxillary palpi dark brown, labial lightbrown.

Labrum dark brown; a dull median tooth or protuberance, and a sharperoneon eachside.

Antennae: 7.65

mm.

long,mainly almost black,proximal ends of joints lighter; ninth toeleventh joints shorterthan fourthto eighth.

Tergites: Brown.

Sternites: 2 to 5 dark brown, 5 lighter on posterior edge; 6 and ₇ luminous, yellow^; 8 triangular, yellow.

Legs: Coxae of first two pair light brown, of third pair very dark brown^; femora mostly dark brown, lighter proximally; tibiae and

tarsidarkbrown;lobes offourthtarsaljointrather long. Posterior legs 10.6

mm.

long, 0.73 oftotal length.

Inthewriter'ssemipopular

"Common

Firefliesof

Delaware"

he ex- pressed the ideathatthe species giving threeto fiverapid coruscations per flash

and

flashing at 5- to lo-second intervals is the one

which was

sent to

DeGeer by

Acrelius

from

Wilinington

and

described

by

the former in 1774 ^as (Photiiris) pensylvanica.

The

reason for this opinion

was

that this is

by

^{far the}

commonest

type of PJioturis flash

now

seen in thevicinity of

Wilmington,

although both the sharp

and

crescendo flashes of hicicrescens

and some

of the other types de- scribedby Barberarealsopresent. Thisis a dry-landspecies

and

has been taken incopula

by

the writer in a nearby wheatfield

where

hun- dreds of the insects

were

flying over the wheat,

around

the border growth,

and among

the trees across an adjacent road. Barber,

how-

ever, calls this species Photuris versicolor Fabricius, 1798,

and

re- strictsthespecific

name

pensylvanica to a

marsh

speciesgiving atwo-

component

flash, the first

component

of

which

is short

and

sharp

and

the second long, basing his opinion on the probable character of the land surface

around Wilmington

about 1750.

He

is doubtless correct in hisconjecture as tothe marshes atthis locality at that time; there

is stillplenty of

marsh

landalongthe

Delaware

River

and

theestuary of Christiana Creek, though

most

of that along the

Brandywine

has been filled in.

Mr.

Barber did not, so far as I

remember,

ever,tell

me

that he

had

arrived at this conclusion, although he did write to

me

about DeGeer's use ofthe

word

"prairies" in connection with his descriptionof the locale of the specimens sent

by

Acrelius.

From

the

NO. I FIREFLIES

OF THE GENUS PHOTURIS — BARBER

₅₅ translation of Hesselius' Journal

(Delaware

History, vol. 2, No. i, p. 83, 1947), ^flying over

meadows

might be interpreted as "fields,"

and

the"sparkling" might be

more

likethe three- to five-flasher than the double coruscation of Barber's pensylvanica. I have been unable to find out

what Swedish word

in Acrelius' letters to

DeGeer was

translated as "prairie"

by

the latter. Observations in both northern

Delaware and

on the opposite

New

Jersey shore of the

Delaware

River haveso far failed to revealthepresence of a species giving the double flash of Barber's Photiiris pensylvanica DeGeer, but condi- tions here have undoubtedlychanged materially in the last

200

years,

and

it is not impossible that industrial wastes have exterminated a once-plentiful species.

Free translations of the descriptions given

by DeGeer and by

Fabricius aregiven

below

:

DeGeer, Hist. Ins., vol. _4, pp. 52-53, I774:

Lampyrid elongated, eb'tra of a pale yellowish-gray, andthorax black in the middle withtworedspots.

Lampyris pensylvanica oblong, elytrapale grayishbrick-colored, thorax black between the margins with two red spots.

The lampyrids ofthis species are found in Pennsylvania. Mr. Acrelius, who

sent

me

them from this country, says that they are found particularly on the prairiesduringthewholesummer, wheretheyglitterandappeartotheeyesofthe observers as a multitude of sparks; but they sparkle even more whenthey fly.

Onecandistinguishthem easilyfromthe otherspecies.

Insize and shape they resemble the three preceding species (of lampyrids), but the head is larger and less hidden in the thorax, which is smaller than in the other species; there is also a greater distance between the two large black eyes, and the antennae, which almost equal the length of the abdomen, are slenderandalittlehairy.

On

thethorax andelytra there aremany small hairs.

The disc of the thorax is pale yellow, with a large oval black spot in the middle, beside which there are two ^small round red spots near the edges; the elytra are yellowish gray, with brown shading near the anterior ends. The abdomen is brown below, but the last three segments are sulfur yellow. The wings are dark brown, the antennae lighter brown, and the legs ochre yellow with some smallbrown spots.

Fabricius, Suppl. Entomol. Syst., p. 125, Hafnia, 1798:

L{ampyns) black, thoraxspotted, elytral marginsand medianvittayellowish, apexofabdomen very light. Habitat inNorth America. Dom. Hirschell.

Body large; antennae black, bases of joints yellowish. Head yellowish or black. Thorax rotund, black spot in the middle, large red spots on both sides,

and broad yellowish margin. Elytra smooth, margined with black becoming yellowish, with abbreviated vitta. Abdomen broad, white. Legs black, knees yellowish.

DeGeer's description of the pronotalpigmentation sounds

more

like a Photinits than a Photuris, but hismention of the partially exposed

56

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. II7