A NEW SPECIES OF AESHNA— ITS N^T^IPH AND ITS HABITS

578 PROCEEDINGS? OF THE NATIONAL MUSEUM

16. A NEW SPECIES OF AESHNA— ITS N^T^IPH AND ITS HABITS

586 PROCEEDINGS OF THE NATIONAL MUSEUM.

vol. 52.

with greenish blue abdominal spots and the stripes on the thorax blueaboveand creamyyellowishbelow.

The abdomen

of thelatter is

brown

shading darker caudad, the thorax brown, and the eyes grayish,neverasblue as in the male.

The

females,whetheryellow or blue, invariably had the blue dash in the eye. (See figs. 354, 366-375,and 380-381.)

Abdomen

(withoutappendages), 45-47

mm.;

appendages,6; hind wing, 45-46.

Nymph. —

^Ihavenotbeenable to distinguishthe

nymph

fromthat figured

by

Walker^{^} for interrupta interrupta.

Some show

the

same

colorpattern as figured in his monograph,while others

show

each middorsal dark spot inclosing a pale spot as in my.figure of neva- densis

nymph.

(Seefigs.376-379.)

Lengthofbody, 34

mm.; men

turn, 6.5long, 5.5broad; hind wing, 9-10; hind femur, 6.5; inferiorappendages, 4-4.5; genital valves, 2;

widthofhead,8; abdomen, 8.

NO.2192,

DBAGONFLIES, CALIFORNIA AND NEVADA— KENNEDY.

₅₈₇

of the Coast Mountains, while palmata lives mostly on the colder streamsof theSierras.

The

rangesof thetwospecies toucharound SanFranciscoBay. Ihave two female palmatafromStockton.

A

single female,wliich is probablypalmata,was collected on Stevens Creek,SantaClaraCounty,California,wliichisonlyafewmilesfrom Stanford.

On

tliis

same

creekI collected severalexuviaeof waTkeri.

Theserecords from theneighborhood ofStanford are the northern- most records for walkeri and the farthest southwest records for palmata.

Since writing

my

firstdescription of thisspecies (notpublished) I

foundit veryabundant on Santa Cruz Island, August, 1915. This mountainousisland, 23 miles oft' the coast of California, contained no waterexcept thatfoundinthesmall, clearspring streams flowing

down

thenarrowmountaingorgeswliichopenedtothesea atvarious pointsinthelineof chffs wliichsurroundit.

Aeslmawalkeri

was

most abundant on thestreamflowing

down

at Fry's Harbor. Thisstream

was

about2mileslongandinthat length

fellover athousandfeet. Itflowed

down

from

Mount

Diablo, arocky crag risingto aheightof about3,000feet.

The

canyoncontaining thestream

was

aV-shapedgorge athousandfeetdeepwithitssides covered with a thin growth of grass and scattering clumps of live oaks,wheretheywerenot tooprecipitous for vegetation.

Exceptinoneortwoplaces, eitheroneorboth banksofthestream werenearlyvertical walls of rockand the course was broken every fewhundredfeet

by

a waterfall offrom 10 to40feet. Inplacesthe streamwas shaded

by

Uveoaksandalders,andhereandtheregreat clumpsof green sword ferns, 7 feet high, gave a pleasing rehef to the gray and

brown

of the naked rock. In several quarter-mile stretchesthecourseofthestream

was

sodeep thatitsbed wasafairly smooth troughofrock, being too steepto retaintherocks and sand washed

down

from above. Such stretches frequently contained pools,mererock bowls,6 to 10 feet indiameter, fllledwithwater,in whichgreen cloudsoffilamentous algaefloated over the blackleaves andvegetable trashinthebottom. Suchpoolswere ahvewithtad- poles,Aeslmawalkerinymphs, and ArcJiilestesnymphs.

The

upper half-mile of the stream

was

very stagnant, and here Argia vivida flourished.

At

noplace in thestream did aquatic vegetation occur and in onlyafewplacesdid roots hangin the water. Because of thislackofvegetationinwhich Aeslmausuallyoviposits,the habits of thisspecieswereunusual.

Duringthesunnypartofthedaythemales arefoundcoursingup and

down

thecreek.

As

thereisusuallyamorningfogontheisland, whichdoesnotclear

away

until 9 o'clock,it isfrequently 11 o'clock beforetheAeslma malesareonthecreek.

They

thenpersist inflying up and

down

uirtilthemiddleofthe afternoon,

when

they leave the

588 PROCEEDINGS OF THE NATIONAL MUSEUM.

vol.52.

water one

by

one tohuntinsectsin the simshine aboveonthehill- tops. Inthe patroUingofthecreektheycombinefeedingandhunt- ingforfemales.

A

malewill flyslowly along the rocky wall over- hangingthe water, inspecting everynook andcranny,andonly give a hurried inspectiontotheopenside ofeachpool. Afterbeingsatis- fiedthathehasnot overlooked afemalehewillriseover the water- fall at the head of the pool and proceed to inspect, in the

same

manner, thestreamabove.

In a single afternoon's collecting I caught 14 males, which

was

probablyahalf ofaUlivingonthestreamatthetime, for inthenext two days males weresoscarcethatItook onlytwomore.

The

femalesdonotspendas

much

timeonthecreekasthemales.

Few

were found on the creek before3 o'clock, but

when

ithadbe-

come

almosttwihght inthedepthsof thegorgetheywerenervously hurrying

up

and

down

the creek ovipositing.

The method

of this

was

sounusualthatIdidnot recognizeatfirst

what

theyweredoing.

A

female would ahght on one of the rockwallsoverhanging a pool and wouldtry to inserther ovipositorintherock. After an attempt ortwoshewouldflyafewinches orfeetand

make

another attempt.

As

the rocks over the poolsin the shadier spotswere

seamed

with Unesofgreen moss, shewould soonlocatesucha

seam

anddriveher ovipositorintotheveinofmoss.

The

eggsthuswerelaidinthetliin

seam

ofmoist earthwhich supportedthe moss. Usuallylessthan a halfdozenstabswould be

made

in one

seam when

shewouldflyto anotherandrepeat thelaying. In twoplaceswheretreeroots

hung

into the water, femaleswereflushed thatwere probablyovipositing in these. Oviposition

was

goingon as late as 5 o'clock

when

it

was

almosttwilight inthe shadier portionsofthegorge.

Incopulation a maleusuallyfounda female while she

was

seated onavertical

waU

ofrock,andpickingheroffthetwo wouldfly

away

in copulation. This usuallylasted

some

time while the pair

hung

to

some

hve oak bush onthehillside. Pairsdidnotflyincoupleas doesAnax.

The nymphs

were abundantinthe shallowalgae-fiUed pools,where they crawled slowlyunderandover themassesofgreen algae.

One was

observed eating a small tadpoleofwhichtherewere

many

of at leasttwospecies inthe stream.

Thisremarkable Aeshna,which is probably one of thelast tobe describedfromnorth of Mexico, I take pleasure in

naming

forDr.

E.

M.

Walker,

who

in his beautiful

monogTaph

oftheNorth Ameri- canspecies oftliisgrouphasopenedthe

way

forfuture students.

AESHNAWALKERI, newspecies.

Lengthof abdomen,including appendages: Male (Palo Alto, Cali- fornia),51-57

mm.;

female (SantaCruzIsland,Cahfornia),56. Fe- maleappendages,6

mm. Hind

wing: Male,43-47

mm.;

female,48.

%

NO.2192.

DRAGONFLIES, CALIFORNIA AND NEVADA— KENNEDY. 589

Type.—

Csit.No.20817,U.S.N.M.

A

male from San Francisquito Creek, SantaClara County, California.

No

allotype hasbeen

named

as Ihave nofemalesfromthe

same

regionasthemale.

Structm-ally the malesof this variety differ from palmafa in the broader superior appendages with shorter preapical spines, and in the shorter anteriorlaminaand shorteranterior hamuli. (See figs.

385-386and 395-396; alsofig.404,constricta.)

As

to the

number

of cellsbetween A2and A3at their origin,fouroftheStanford maleshave onecellineach hindwingandthreehaveonecellinonehindwhig and two cells in the other. This venational character is not reUable becauseitalsovaries inpahnata,ofwhichIhavetwomalesfromthe Sierras in each ofwhich there are two cells between Ag and A3at their origin.

The

Uvecolors oftheSanta CruzIslandmalesare as follows

:

Labrum

grayish white, face bluish gray, horizontal surface of fronscreamy.

Stem

of "

T" mark

wideatbase. Frontalvesicleand occiput creamy. Eyes gray above, pale graybelow with anarrow blue dash backed

by

a narrowblack hne. Postocular areas black.

(Seefigs.383 and391.)

Prothorax brown, with the anterior and posterior lobes paler.

Mesothorax and metathorax dark brown. Anteriorstripes paleblue andatantealarsinustwo-thirdsaswideasthelateralstripes,tapering regularly to the mesostigmal ridge. Lateral stripes whitish, blue- gray, very slightly bluer above.

Both

lateral stripes with nearly straight parallel edges, 1-1.2

mm.

wide. This character varies, as four of the sixteen Santa Ciuz males have the upper end of the antero-lateral stripesUghtly sinuous. Legs very dark

brown

except tibiaeandtarsiwliich are black.

Wings

hyaline_; pterostigmasblack.

Abdomen

black, exceptsegments 1 and 2,whicharedark brown.

AU

markingspureblue.

The

colorpatternissimilar tothaton male palmata(figs.393 and398) except that

ML

^ispresentonlyto 6andis

veryminute.

AL

decreasesrapidlyinsizefrom3-8,being very small on7and8.

PL

^ispresentonlyto 5 or 6and

when

presentisbroadly joinedto

PD. On

alltheSanta CruzIslandmales therightandleft

PD

on segment9 arebroadlyjoined. Intheseven Stanford malesaUcon- ditions offusionwerepresent (see figs.387-390).

The

femalediffersbutslightlyfromthatofpalmata. In

my

south- westernpahnatafemales (fromAuburn,Stockton,andStevens Creek, SantaClaraCounty)theanterioredgeoftheposthumeral pale stripe isdistinctlysinuateas also inafemalefromSunnyside,Washington.

In waTkeri females, ofwhich I have eight from Santa

Cmz

Island, this anterioredgeiseither straightorshghtyconvex.

The

pterostig-

mas

areblack whileinthewesternpalmatafemalesthese arebrown.

The

appendages aremorespatulatethaninpalmata andthe occiput

isonlyhalfas large. (Seefigs. 392and397.)

590 PROCEEDINGS OF THE NATIONAL MUSEUM.

vol. 52.

7

400

Figs.383-392.-Aeshna walkeei. 383-384.Colorpattern. 385.Male, appendages. 386.Hamules.

387-390.Color, segments9and10of male. 391.Feons. 392.Female, segments 9AND10.

Figs.393-398.—Aeshnapalmata.

Figs.399-402.-Aeshna walkeei, nymph. 400.Mentum. 401.Vulva. 402.Female, appendages.

Fig.403.—Aeshnapalmata, nymph, female appendages.

Fig.404.—Aeshnaconstricta,male appendages.

NO.2192.

DRAG0NFLIE8, CALIFORNIA AND NEVADA— KENNEDY. 591 The

live ctriorsoftheSanta CruzIslandfemalesarc as follows

:

Labrum

grayish white, face pale brown, dorsal surface of frons creamy, stem of the

"T" mark

wide at the base. Frontal ^vesicle and occiput creamy. Eyes dark brown, paler and more grayish below,with a blueandblack dash. Postocular areaentirely black.

(Seefig.384.)

Prothorax dark brown, the anterior and posterior lobes paler.

Mesothoraxand metathorax dark

brown

(not asdarkas inthe male).

The

anterior stripesmereblue hues. Lateralstripes as inthe male, buttheanteriornot sinuousonitsanterior edge, colorapale blue-gi-ay, veryslightlybluerabove;bothstripesborderedon eachside

by

very dark brown.

Both

stripes ran

up

onto the wing sclerites.

The

posterioredgeof the dorsalend ofthe anterior lateral stripe is ex- tended caudad more or less distinctly for the width of the stripe along the alar ridge.

But

little variation in thoracic color occurs

among

the eight females caught.

Wings

with stigma very dark brown,black except on averyclose inspection; costalhalf ofwing

membrane

flavescent as far as stigma,posterior to whichitis more intense thanelsewhere. Legs with coxae,trochanters, and femora darkbrowTi, tibiaeandtarsiblack.

Abdomen

dark brown,becomingdarker caudadso thatsegments 8-10 are nearly black; appendages black.

One

female

was

taken inwhich the abdominal markings wereblue;inthe otherstheywere yellowish ohve green.

None

with pure yellowmarkings wereseen.

The

abdominal markings are similar to thoseof the male.

From

thoseofthefemalepalmata(fig.394)theydifferinhavingaminute

AD

present on segments 3-7, in having

PL

^{present on segment} 7, and inhaving

PL

and

PD

connateon^allsegmentson which bothoccur.

Therearenobluemarkingsontheventral surfaceoftheabdomen.

Nymphs.

— Two

females. Length of body, 34-37.5

mm.,

labium, 6.5-7, hind femur, 6.5-7; hind wing, 7.5-8; head, 8-9.

Width

of abdomen,7-8

mm.

(Seefigs.399-402.)

The nymphs show

acombinationofumbrosaand palmata

nymphal

characters.

The

shapeofthelabrumisintermediatebetweenthatof umbrosa andpalmata,itsapicalbreadth betweentwo-thirdsandthi'ee- fourths ofitslength; butthe lateral lobes have no internal distal tooth, thus resembling palmata.

The

dorsalpaired appendages are almostas longasor,inonespecimen, shghtly longerthanthemiddle appendage. Inthespecimenhavingthe shortest dorsal appendages these were four-fifths as long as the middle appendage. In this character it differs from both umbrosa and palmata^(fig.403), as in bothofthesethe dorsalappendagesareonly two-thirdsaslongasthe middleappendage. Inthefemale

nymphs

thegenitahaextendunder the anteriorfourthor third ofsegment 10.

The

colorationinallthe exuviaeis verydark,the legs especiallybeingvery vividlybanded, bothonthefemur and^tibia.

592 PROCEEDINGS OF THE NATIONAL MUSEUM.

vol.52.

These

nymphal

sldnswerecollectedJanuary6, 1915, onthe roots and trunks of alder trees overhanging Los Trancos Creek where theyhad been probablysincethe preceding August,

17.

SOME

LISTS

OF ODONATA COLLECTED

IN

NEVADA AND CENTRAL