Ants from northern Arizona and southern Utah

In June 1971, ecological studies were Environ-mental Studies atBrighamYoung University envi-ronmental impact ofthe Navajo Generating Station near Page, Arizona,andtheproposed Kaiparowit

Great Basin Naturalist

3-31-1979

Ants from northern Arizona and southern Utah

Dorald M Allred

Brigham Young University

Arthur C Cole

Department of Zoology and Entomology, University of Tennessee, Knoxville, Tennessee

Recommended Citation

Allred, Dorald M and Cole, Arthur C (1979) "Ants from northern Arizona and southern Utah," Great Basin Naturalist: Vol 39 : No 1 , Article 9

This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive For more information, please contact scholarsarchive@byu.edu, ellen_amatangelo@byu.edu

ANTS FROM NORTHERN ARIZONA AND SOUTHERN UTAH

DoraldM.Allred'and Arthur C.

Cole-Abstract.—Antsof22specieswerecollected incanpit-trapsfrom16 different vegetative associations to

deter-minedistribution, seasonaland annualoccurrence,and populationas bases formonitoring environmentalimpact.

Thirteen speciesweresufficientlyabundantanddistributed to qualify as indicator species.Mymiecocystus

mexi-canuswasthemost widespreadecologically.Pogonomymiexoccidentaliswasthemostabundantspecies,butsecond

in ecological distribution.Thegreatestnumberof specieswasfound in the juniper-£p/jgdra-grass association,and

the fewest species inEphredra-Coleogyne-Grayia

In June 1971, ecological studies were

Environ-mental Studies atBrighamYoung University

envi-ronmental impact ofthe Navajo Generating

Station near Page, Arizona,andtheproposed

Kaiparowits Generating Station in Kane

Countyinsouthern Utah.' Fieldstudiesof

ar-thropods were conducted from July to

Sep-tember in 1971, and from May toAugust in

1972 and 1973 Of the 12 sitesoperated in

1971, the 16 in 1972, and the 12 in 1973,

some werestudiedonlyoneyear,otherstwo,

andsomeallthreeyears

Thetrappingmethod,studysites,and

pre-dominant vegetation on each site are

de-scribed by Allred and Tanner (1971, Great

Basin Nat 39:89-96) The antswere

identi-fiedbyArthurC.Cole

SpeciesCommonly Collected

Camponotusviciniis Mayriscommon and

widespreadinthe aridandsemiaridwestern

United States Nesting generally beneath

stonesandlogs, it isa strongandhighly

One specimen wastaken atsite 1, 106 at

site 2,27atsite 6,54atsite 19,41atsite27,

and5atsite28.Largest numbersweretaken

atsite19,aColeogyne community Ants were

takenfrom Julyto Septemberin 1971, most

abundantly during the latter two months;

ApriltoSeptemberin1972,most abundantly

in August; and May toAugust in 1973, also

most abundantly in August Comparison of July and August collections for the three yearsshowedtwiceasmuchactivity in 1972 and 1973 than in 1971 For the period of

May to August, only slightly more activity

wasnotedin1972thanin1973

Conomymia insana (Buckley), known pre-viously as Dorymynnex pyramiciis (Roger),

andsemidesertregions,andtheagileworkers nin rapidly over the soil in great numbers duringtheirdiurnal foraging

One of the most common species of ants

ofthe 19sites. Largest numbers were found

were foundinJulyand Augustof 1971,most abundantly in July; from May to September

of 1972, most abundantly in August; and

fromMaytoAugustof 1973,alsomost abun-dantly in August Comparison of July and

August for the three years showed about equal numbersof antsin 1971and1972,but

peri-odofMaytoAugust, four timesasmanyants weretakenin1972thanin1973

CrematogasterdepilisWheeler formslarge

coloniesbeneathstones orin nestsmarked by

irregular cratersofsoil.

sites,thelargestnumbers were found onsites

1 and 2, Ephedra-Vanclevea-grass and

juni-'Department of Zoology and Life Science Museum, Brigham Young University, Provo, Utah 84602.

'Department of Zoology and Entomology, University of Tennessee, Knoxville, Tennessee 37916.

'These studies were funded cooperatively by Salt River Project, Arizona Resources Corporation, and Southern California Edison.

97

per-Ephedra-grsLSScommunities, respectively

In 1971, antswere foundinJulyandAugust,

more abundantly in August; in April and

from June to August in 1972, most

abun-dantlyin July;andinMay,June,and August

of1973,most abundantlyinMay.In Julyand

Augustof the threeyears,twiceasmanyants

were taken in 1971 than in 1972, and 18

timesasmanyas in1973

Formica ohtusopilosa Emery nests in dry,

sunny areas of rather coarse soil. The large

entranceis surroundedby anirregular array

ofpebbles Workers forage rapidly over the

insolatedsoilsurface

Forty-one specimenswere takenat site 3,

an Ep/iedra-grass community, and 18 at site

28, an Artemisia-grass community The

ap-parentabsence ofthisspeciesinother areas

isunusual Ants were taken in 1971 in July

andAugust, predominantly in July; in 1972

from Juneto Septemberinaboutequal

num-berseach month; andinaboutequalnumbers

from May to August in 1973 Activity for

Julyand August in 1971 was about equal to

the same months of 1972, but about five

times greater thanin 1973.Forthe period of

May toAugust, four timesasmanyantswere

takenin1972thanin1973

Formica rufibarbis gnava Buckley forms

rather large coloniesinearthennests

general-lymarked byanirregularcrater ormound.

Seventy-one specimens were takenat site

2, a ixmiper-Ephedra-grsiSScommunity, and7

specimensatsite 3,anEphedra-grasshabitat

All but oneofthe specimens were taken in

1971, mostly duringJuly.Only one specimen

wastakenin1973,inMay

Iridomymiex pruinosum (E Andre) is a

desertandsemidesertbiota.Althoughitoften

constructs small circular or irregular craters

be-neath stonesanddebris.Workersforage

high temperature

Ants were taken from eight sites. More

weretakenfromsite 6,anArtemisia

foundonlyinAugustof1971,and from June

toAugustin1972

Monomorium minimum(Buckley)isa

min-or in open soil with or without a crater It

forms populouscolonies

Thirty-five specimens were taken from

seven sites. Largest numbers were found at

site 28, an Artemisia-grass community Ants weretakeninAugust1971,fromMayto Sep-tember in 1972, and only in May of 1973 Mostof thespecimensin1972 weretakenin

during 1972

Myrmecocystus mexicanus Wesmaelbuilds

surmounted by a mound bearing a single,

large circular entrance of firmly packed

coarse sand The workersare nocturnal for-agers

Antsofthisspecieswere someofthemost

abundant and the most widespreadof all

those found A total of652 was taken from

all 19sites, thenumbersnotdifferent

signifi-cantly from one site to another They were found during each of the summer months that studies were made. Largest numbers

were found in August of 1971, in July and

August of 1972, and in May andJune of

1973 Comparison of July and August for

each ofthe three years showedabout equal

numbers in 1971 and 1972, but only

to August, half again as many ants were

takenin1972as in1973

Myrmecocystus melliger Forel constructs

cir-cular or semicircular crater These ants run rapidlyover the groundduring theirdiurnal foraging,andare aconspicuousthough famil-iarelementof desertandsemidesertareas

Seventy-onespecimensweretakenfrom 12

sites. Nosignificant differencewasnoted be-tween the numbers of ants at each of the

sites. They weretaken inJulyand Augustof

1971 in about equal numbers; from June to

August of 1972, predominantly in July; and

insmallnumbersinMay,July,and Augustof

1973.Comparisonof Julyand Augustamong

thethreeyears showedaboutequal numbers

in1971and1972,butonlyone-fifth asmany

in 1973 For the period of May to August, four timesas many antswere taken in 1972

Pheidole bicarinatapaiuteGreggisasmall ant with dimorphic workers that generally

majors and minors forage largely for seeds

during the coolerdaytimehours

12sites.Numberswerehighestatsites6and

28, which were Artemisia communities In

1971, ants weretaken fromJuly to

Septem-ber, mostlyinAugust; from Mayto

Septem-ber in 1972, predominantly in September;

and only in June and July of 1973,

pre-dominantlyinJune Comparisonof July and

August for the three years showed twiceas

many in 1971 as in 1972, and 25 times as

Augusttwiceasmanyweretakenin 1972as

in1973

PheidolesitarchessoritisWheeleris

anoth-erdimorphicharvester that constructssmall,

be-neath stonesinunshadedareas

10 sites. Largest numbers were foundatsite

3,anEphedra-grsLSScommunity.In1971 they

were found inJulyandAugust, mostly July;

from June toAugust in 1972, predominantly

inAugust,and from June toAugust in1973,

predominantly in June Comparison of July

and August for the three years showedonly

two-thirds asmany in 1972 as in 1971, and

only one-fourthasmanyin 1973.Forthe

pe-riod of May to August,numbers were about

equalin1972 and1973

Pogonomyrmex occidentalis (Cresson) is a

common harvester whose numerous, large,

conical or subconical mounds, each

sur-rounded by an area cleared of plants, are

someofthemost conspicuousfeatures of the

desert The nests are usually in coarse,

gravellysoil,and boththeunderground

por-tionandthesuperstructurecontainchambers

seedsarestored

Ants ofthis species were the most

abun-dant but not the most widespread of all

taken A total of 800 specimens was taken

from 15 ofthe 19 sites. Ants ofthe species

Myrmecocystusmexicaniis were more

wide-spreadthan P. occidentalis, butnotas

23,althoughsites 8,13,and14alsohad

duringeachofthe summermonthsthat field

numbers were foundin August,and in 1973

in June Comparison of July and August

showed four times as many in 1972 as in

1971, and 13 timesas many as in 1973.For the periodofMay to August, eight timesas

manyweretakenin1972as in1973

Pogonomyrmex rugosus Emery, another

sur-mountedbyalow gravelmoundordiscwith

work-ers vigorously defend their nests and sting readily

Thirty-three specimens were taken from

fivesites.Largestnumberswere foundatsite

equal numbers from July to September in

1972

SpeciesRarely Collected Camponotussemitestacea Emery: one

speci-men 6 June 1972,3 on6 July 1972, 3

on 5 August 1972, one on 30 April

1973, site 2—juniper-Ep^edra-grass; 3

on4 July 1973,site6—Artemisia

Conomyrma bicolor (Wheeler): 5 specimens

15August1972,site19—Coleogyne Crematogaster mormonum Emery: 7

speci-menson18, 19August1971,site

Liometopum luctuoswn Wheeler: 2

speci-mens 19 June 1972, site 28—Artemisia

1973,site27—juniper-pinyon Myrmecocystus mimicus Wheeler: 7

speci-mens on 14, 16 August 1971, site 2—

]uniper-£p/iedra-grass; one on 6 June

1972, site S—Ephedra-grass; one on 14 August1972,site22-Coleogyne

Pogonomyrmex imberbiculus Wheeler: 3 specimens on 18,20 August 1971, 2on

11 August 1972, site

9-Atriplex-Arte-misia

Pogonomyrmex suhnitidus Emery: 4

speci-mens 18-20 August 1971, one on 10 April 1972, 2on12 July 1972, 3on 10,

12August 1972, one on 11 September

1972,site10—£p/iedra-grass

Veromessorlobognathus (Andrews): one spec-imen 19 August 1971, 2on 10, 11 Au-gust 1972, 2 on 11 September 1972, 6

on 6, 7 June 1973, site

Co-leogyne; 3 on 12 July 1972, site

8-Graj/ia-grass.

These studies were established in major

vegetative types withina48-kmperimeterof

the proposed sitesoftheelectric generating

first year was based on vegetative type,

di-rection from the potential source of

abundanceoforganismspresent thatcouldbe

usedas indicator speciestomonitor

environ-mental changes Some sites were

dis-continued after one season because of

in-accessibility, discontinuous vegetative

data

In order to compare populationsand

sea-sonal changes, the numbersofants collected

were adjustedto the numberoftrapping

at-tempts The normal variability in seasonal

and annual populations, slightly different

trapping periods within thesamemonth,and

theinfluence of periodicand abruptclimatic

changeson the activityof the ants duringa

given trapping periodwereignored

Pit traps are effective primarily for

ground-dwellingarthropods thatmoveonthe

ground more frequently than they fly. The

be used effectively for those species which

maybesotrapped,andadequatelydetermine

logis-tics. The number of trapping attempts is

showninTable1.

Thirteen of the 22 species found in this

study are sufficiently abundant and

dis-tributed that they maybe used as indicator

species to determine environmental changes

(Table2).

In this study relative numbers of

individ-ualsare referredto as "activity,"inasmuchas

populations were measured only by

above-groundactivityandnotnumbersofcolonies

or individuals within those colonies An

as-sumption ismade thatabove-groundactivity

and abundanceisdirectlyproportionaltothe

numberofcoloniesandindividuals

Greatest activity of the ants occurred in

July and August of 1971 and 1972, and in

Juneof1973(Table3).

Some study sites showed significant

numberofspecieswasnotedin 1973.Where

sites, onesite increasedinnumberofspecies

in 1972 over 1971, 3 decreasedin 1973over

1972,and onewas equal for1972 and 1973 Nine of12sitesshoweda speciesdecreasein

1973 over one or both the two previous

years

Table5 shows the variety ofpredominant ants for each of the study sites.

Myrmeco-Table1. Numberof trap-days' for pit trapson16major studysites,1971-1973

Site

Table3 Totalnumberof ants of all species collected in pit traps at 16major studysites,1971-1973.

cystus mexicanus was on all 16 of the sites

evaluated, but not significantly abundant on

2sites.Pogononiyrmexoccidentaliswason 14

of thesites,but ofsignificantcompositionon

only 9. Only 2 sites had the same species

composition(sites8and30),but therelative

percentages ofeachspecies differedbetween

them

Comparisonofsiteswhich were mostalike

in predominant plant species showed some

and 22 had only one species ofant in

com-mon.Site4hadthreeuniquespecies,andsite

22 had two unique species Comparison of

sites 14and23,whichalsocontained

signifi-cantamountsofColeogyne,showedbothsites

withonespeciescommontoeachandtothe

other Coleogyne sites, both sites with two

species common to each and to site 4, and

site14withonespeciescommontosite22

Comparison of £p/iedra-grassland sites 3,

10,and 30showedonlyonespeciescommon

3and30,onespeciesto 10and30,three

spe-ciesunique tosite 3, two tosite 10,and one

to site 30 Comparison of sites 1 and 20,

which also had significant amounts of

to each and to sites 10 and30, one species

commonto each andto site 3, one common

to each and site 30, site 1 with one species

commontosites3and30,and with eachsite

withone uniquespecies

Artemisiasites 6and 28 hadonly one

spe-cies in common. Three specieswere unique

tosite 6,andfour speciestosite28

Grai/ia-grasssites 8 and 13 hadthree

spe-cies in common, and each had one unique

species

Juniperwoodlandsites2and 27 hadthree

species in common, site 2 had two unique

Annual differences in species composition variedbetween the threeyears.Twospecies

thatwere activein 1972 and 1973 werenot taken in 1971 One species active in 1973

was not taken in the other years, and one species present in 1972 wasnottakeninthe other years Three species present in 1971 werenot takenin 1972or1973 Onespecies taken in 1971 and 1973 was not found in

1972, and five species taken in 1971 and

1972werenottakenin1973

Relativeactivity(measuredbythenumber

of specimens caught in traps) of individual species differed between years One species wasmoreactivein 1971 than inotheryears,

10were mostactivein 1972, 2 in 1973,and one more active in 1972 and 1973 than in

1971 In years when comparisons could be

much more active in 1972 than in 1973

Camponotus vicinus was only slightly more

timesas active; Crematogasterdepilis3times

Myrmecocystus mexicanus half again as

ac-tive; Pogononiyrmex occidentalis 8 times as

as activein 1972 as in 1973 Pheidolesoritis

was about equally active in 1972 and 1973, and Veromessor lohognathus was 2 times as

activein 1973as in1972

ComparisonofthemonthsJulyandAugust

for the threeyears showedthat

so-ritis were most active in 1971; Iridomyrmex pruinosum, Monomorium minimum, Pogono-niyrmex occidentalis, P. rugosus, and Vero-messor lohognathus in 1972; Conomyrma

in-sana, Formica obtusopilosa, Myrmecocystus mexicanus,M.placodops, and Pogononiyrmex subnitidus in 1971 and 1972; and

Camp-onotusvicinusin1972and1973