Table Of ContentPROC. ENTOMOL. SOC. WASH.
93(2), 1991, pp. 480-488
INQUILINES IN EGG NESTS OF PERIODICAL CICADAS
(HOMOPTERA: CICADIDAE)
Louise M. Russell and Manya B. Stoetzel
SystematicEntomologyLaboratory, PSI, AgriculturalResearchService, USDA, BARC-
West, Beltsville, Maryland 20705.
Abstract.—Egg nests of brood X of 17-year periodical cicadas (Magicicada spp.) of
1987 were occupied by four orders ofInsecta. Species ofPseudococcidae and Eriococ-
cidae (Homoptera) developed from eggs to adults, larvae oftwo species ofCleridae and
onespeciesofCoccinellidae(Coleoptera)were found, larvaeofTorymidaeandimmature
and adult Scelionidae (Hymenoptera) were present, and two species ofGryllidae (Or-
thoptera) deposited eggs in the cicada egg nests. Specimens were identified to family,
genus or species. Mealybugs entered nests where unhatched cicada eggs and dead cicada
nymphs were present; all other species occupied nests containing only cicada egg shells.
Previously none of these insects were known to deposit eggs or to molt in periodical
cicada egg nests.
Key Words: Cicada egg nests, coccoids, beetles, wasps, crickets
This article records the insects and eggs, that dropped from beech and oak trees as-
other than cicadas themselves and their cending 22-28 m.
eggs, that we found in egg nests of brood Our examination of egg nests began in
X of 17-year periodical cicadas (Magici- mid-May 1987 andcontinued through Oc-
cadaseptendecim (L.), M. cassinii(Fisher), tober 1990, except for December to March
andM. septendeculaAlexanderand Moore) ofeachyear. Inquilinesincicadanestswere
of 1987. These observations complete the first found in mid-June 1987 and addi-
study of brood X made by Stoetzel and tionalspecieswereobservedin 1988-1989;
Russell (1991). living examples of only Planococcus ja-
ponicus Cox were found in 1990. New in-
Materials and Methods formation was obtained on the diversity of
the inhabitants ofcicada egg nests and on
Weexaminedover3500eggnests,aterm the biology and habits ofsome ofthem.
used by Marlatt (1907), Snodgrass (1921) Non-cicadan insects in cicada egg nests
and Lloyd and White (1976), for pockets were recorded by Andrews (1937) who
ofeggs in the bottom ofpunctures or slits mentioned beetles and aphids; by Hopkins
madeby femaleperiodicalcicadasintwigs. (1900)whoreportedwoollyaphidsandwho
The egg nests, with one exception, were was cited by Smith and Linderman (1974);
from trees and shrubs in a wooded sub- and by Simon (1988) who listed scale in-
urban area of 0.25 ha in Silver Spring, sects, woolly aphids and unspecified pests.
Montgomery County, Maryland; some In our study we identified to family, genus
nestswere in twigs pruned from shrubs less or species specimens of the Homoptera,
m
than 5 high, while others were in twigs Coleoptera, HymenopteraandOrthoptera.
VOLUME 93, NUMBER 2 481
Fig. 1. Filamentous coveringofPlanococcusjaponicus on an azalea leaf.
Fig. 2. Planococcusjaponicus in egg nest ofperiodical cicada.
The accessibility of cicada egg nests to and Eriococcidae (eriococcids) were pres-
other insects changed considerably during ent on Ericaceae and Fagaceae, and one
42 months. In the springandeariy summer eriococcid was abundant on Ulmaceae.
of 1987, many egg nests were sufficiently PlanococcusjaponicusCox(1989), a spe-
open to permit entrance by small insects; cies misidentified by Ezzat and McConnell
thereafter, access depended on the extent 1956)asPlanococcusazaleae(Tinsley)and
(
and nature of plant growth around nests. easily confused with Crisicoccus azaleae
Some punctures became wider, and nests (Tinsley) of Ferris (1953) and McKenzie
remained exposed while others varied in (1967), was abundant in twig crotches and
size and shape, and some were completely
ontheundersideofleavesofazalea(=Rho-
closed, with or without a brush of wood
dodendron sp.) in the spring of 1987.
fibersremaininginthecenterofthewound.
Mealybugsmovedfromtheselocationsinto
The healing ofperiodical cicada punctures
cicada egg nests in mid-June and settled
was discussed by Lloyd and White (1976),
White and Lloyd (1979), and Stoetzel and amongthecicadaeggsandeggshells. Adult
males and females developed by mid-July
Russell (1991).
when the females produced a quantity of
Results and Discussion loose, white filaments and deposited eggs.
Homoptera.—Homopterawerethe most Mealybugs remained in cicada egg nests
numerous inquilines that we found in ci- during the summer and some moved away
cadaeggnests. Coccoidea(scaleinsects)be- as the punctures closed. The insects and
longingto the Pseudococcidae (mealybugs) their white, filamentous coverings (Fig. 1)
PROCEEDINGSOFTHEENTOMOLOGICALSOCIETY OFWASHINGTON
482
Fig. 3. Eriococcussp. in egg nest ofperiodical cicada.
Fig. 4. Ovisac oiEriococcus sp. in egg nest ofperiodical cicada.
Fig. 5. Cocoons ofEriococcussp. in egg nest ofperiodical cicada.
were present on leaves and twigs ofazalea plant. On 5 June 1989, however, we de-
through October 1990. tected P. japonicus (Fig. 2) in cicada egg
Planococcusjaponicus was not found on nests in fallen twigs ofbeech {Fagus gran-
other azaleas growing near the infested difolia J. F. Ehrh.) and white and pin oaks
VOLUME 93, NUMBER 2 483
Fig. 6. Gossypariaspuria in eggpuncture ofperiodical cicada.
(QuercusalbaL. andQ.palustrisMuenchh.) above egg nests and were found most often
m
thatwere 10-20 fromtheinfestedazalea. in oaks.
By 15 June 1989 and into early July, fe- In June and July, specimens had scant,
maleshadproducedathincoveringofwhite white, silklike filaments over them and a
filaments in which they deposited eggs. On little white powdery wax beneath them,
beech, livingadultswerenotobservedafter materialsthatincreased and eventually be-
8 August 1989, but dead ones were found came female ovisacs and male cocoons.
in the fall of 1990 in cicada punctures that Ovisacs and cocoons were formed 23-30
were not well healed. In November 1989, September 1988 in the laboratory in egg
dead mealybugs with white filaments and nests that were collected in August; none
eggswerepresenton oaksineggnests, shal- were found out-of-doors at that time, but
lowpuncturesorrarelyinthebrushofwood both were discovered out-of-doors on 31
fibers. Mealybugs were scarce on dropped June and in October and November 1989.
twigs ofbeech and oaks. Afewovisacsfoundin 1989doubtlesswere
An Eriococcus was observed in cicada formed in a previous year; some were torn,
egg nests in beech 19 July 1988, 15 July crushed, orholeyandotherscontainedpar-
1989 and in nests in white and pin oaks 30 tially destroyed adult females, a few eggs
June 1989. Adult females, immatures, and egg shells. Some cocoons were crushed
hatched and unhatched eggs were present but none had holes that might have been
through August ofeach year. made by predators or parasitoids. Some
Newly-molted adult females were pale ovisacs and cocoons had an openingat one
cream colored; young adults were pale yel- end that suggested an exit for the insect.
low, becoming brownish as they aged. One Judging by the gradual accumulation offil-
to three females (Fig. 3) occupied a nest in aments by adult females, it appeared that
1988, usually at the bottom beneath cicada they produced the ovisacs, while cocoons
egg shells or in deep punctures. In 1989, of the males were made by an immature
after greater plant growth had occurred, stage.
they were in deep or shallow punctures Ovisacs (Fig. 4) were white, oval, 2.50-
PROCEEDINGS OFTHE ENTOMOLOGICALSOCIETY OFWASHINGTON
484
#
8
Figs. 7, 8. Larvae oftwo species ofCleridae from egg nests ofperiodical cicadas.
Fig. 9. Larva ofCoccinellidae and egg from which it was removed, from egg nest ofperiodical cicada.
4 mm long and 1.25-2 mm wide. The out- er than newly formed ones. Cocoons (Fig.
mm
side was composed of silklike filaments, 5) were white, oval, 1.25-1.50 long
mm
with a little white, fluffy material beneath and 0.50-0.75 wide, and were similar
the filaments and powdery wax at the bot- instructuretoovisacsexceptthattherewas
tom. Old ovisacs were harderand smooth- no fluffy material under the outside fila-
VOLUME 93, NUMBER 2 485
Fig. 10. Adult ofProbaryconus heidemanni from egg nest ofperiodical cicada.
ments and old ones did not differ from larvae were not feeding on eggs or insects
newly-formed ones. when discovered.
—
Most ovisacs and cocoons were incon- Hymenoptera. Inquilines found in egg
spicuous; in 1988 they were found among nests of periodical cicadas in beech be-
cicada egg shells; but later they were in, or longed to two groups. Two larvae ofa To-
along, the edge ofpunctures, in the brush rymus (Torymidae, Chalcidoidea) were
of wood fibers or beneath pieces of bark. collected in September 1988 and 23 May
The only plainly visible ovisac was in a 1989. Adults ofProbaryconus heidemanni
node in oak. Eriococcids were scarce on (Ashmead) (Scelionidae, Proctotrupoidea)
dropped twigs of oak and very scarce on (Fig. 10) emerged from elongate eggs 31
beech. July 1989. Larvaeorpupaewereintheeggs
Another eriococcid, Gossyparia spuria which resembled, and may have been,
(Modeer), the European elm scale (Fig. 6), cricket eggs.
was abundant along margins of healed Orthoptera.—Two species of crickets
punctures, clustered increvicesbetween the (Gryllidae) used egg nests ofperiodical ci-
bark and scar tissue; and a few were under cadas as egg hatcheries. Hatched eggs, un-
the brush ofwood fibers. The species was recognized at the time, were first discov-
collected from Ulmussp., Bethesda, Mont- ered 14 September 1987; similar eggs
gomery County, Maryland, August 1988, proved to be those ofcrickets when juve-
by T. J. Spilman. niles emerged in 1988.
Coleoptera.—Beetles were the least nu- One cricket egg (Fig. 1 1) virtually filled
merous ofthe secondary occupants ofpe- a cicada eggnest but occasionally two were
riodical cicada egg nests. Two larvae (Figs. present with one on top ofthe other; single
7, 8), representing two species ofCleridae, eggs usually were enveloped in cicada egg
were collected in June 1988; and a larva shellswhich sloughedoffifdisturbed. After
(Fig. 9), collected in July 1988 and prob- newgrowth developed around nests, crick-
ably belonging to the Coccinellidae, was et eggs were partially incased in wood; it is
removedfromanelongate, smoothegg. The difficult to understand howjuvenilescould
PROCEEDINGSOFTHE ENTOMOLOGICALSOCIETY OFWASHINGTON
486
w
^.
13
Fig. 11. Cricket egg in egg nest ofperiodical cicada.
Figs. 12, 13. Immature crickets from egg nests ofperiodical cicada.
escape undertheseconditions. Cricketeggs The eggs of both cricket species were
weremostnumerousinfallentwigsofbeech cloudy white and very fragile. The eggs of
mm mm
and white and pin oak, but some were in one species were 4-4.5 longand 2
pruned twigs of dogwood (Cornus flohda indiameter; when mountedonaglass slide
L.) and Rhododendron sp. and examined under a compound micro-
VOLUME 93, NUMBER 2 487
scope, the head end appeared honey- Acknowledgments
combed and the remainder minutely stri- We dedicate this article to the memory
amtemd. The smaller crimckmet eggs were 4-4.5 of the life and research accomplishments
long and 1-1.5 in diameter; the of our friend and colleague, Donald R.
head end also was honey-combed but the Whitehead.
remainderwas smooth. Eggs ofboth types, We express our deep gratitude to col-
somewith redeye spotsandembryos, were leaguesofthe Systematic Entomology Lab-
present 1 May to 21 June 1988 and in oratory, PSI, ARS, USDA: P. W. Iglehart
March 1989. Eggs hatched 6-20 June 1988 for typing the manuscript; M. J. Mello for
but nojuvenilesemergedcompletely in the preparing slides; T. J. Spilman for collect-
laboratoryin 1989. Inbothyearssomeeggs ing specimens on elm; R. A. Gagne, E. E.
appeared to be sterile and some collapsed. Grissell, J. M. Kingsolver, P. M. Marsh,
Whenjuveniles left the eggs, the head end A. S. Menke, D. R. Miller, S. Nakahara
of the shells was deflected but remained and D. A. Nickle for identifications, com-
partially attached. Numerous cricket egg ments and/or reviews. We are grateful to
shells were found in egg nests through No- V. L. Blackburn and R. D. Riley, APHIS,
vember 1989 and several were present PPQ, USDA, for mountingand examining
through October 1990. specimensand fortheirinterestinthe proj-
Upon hatching, the juveniles (Figs. 12, ect. We thank J. C. Cox, Natural History
13) were soft bodied and easily injured. Museum, London, for information on a
Theywere active immediately andjumped mealybug. For their reviews ofthe manu-
about vigorously. — script, we are indebted to L. L. Deitz, De-
Unidentified eggs. Several unidentified partment of Entomology, North Carolina
eggs were present in periodical cicada egg State University, Raleigh, NC 27650; and
nests. Some resembled cricket eggs and the B. D. Kondratiefl", Department of Ento-
coccinellid egg in shape, while others were mology, Colorado State University, Fort
more slender and still others were percep- Collins, CO 80523.
tibly shorter. Many appeared to be viable
and exuded fluid when punctured but red Literature Cited
eye spots and embryos did not develop.
Andrews, E. A. 1937. The seventeen-year cicada,
They were observed in egg nests in various alias locust. Quarterly Review Biology 12: 271-
trees and shrubs from May to August 1988 293.
and from April through October 1989 and Cox, J. M. 1989. The mealybuggenus Planococcus
1990. Eggs found in the fall of 1990 were (Homoptera: Pseudococcidae). Bulletin British
embedded in wood. Larvae hatching from Museum (Natural History) (Entomology) 58: 1-
78.
theeggsapparentlywould havetobechew- Ezzat, Y. M. and H. S. McConnell. 1956. A clas-
ers in order to survive and eventually es- sification of the mealybug tribe Planococcini
cape from the wood. (Pseudococcidae, Homoptera). University of
Maryland Agricultural Experiment Station Bul-
Conclusion letin A-84: 1-108.
Thepresence ofextraneous insects in egg FerriAs,meGr.iEc.a.1V9L53.i-viAit,la2s79o-f5t0h6e.scSatlaenifnosredctUsniovfeNrosritthy
nests of periodical cicadas demonstrated Press, Palo Alto, California.
the usefulness ofcicada egg nests for pur- Hopkins, A. D. 1990. Theperiodicalcicadaorsev-
poses other than the original one. Because enteen-year locust in West Virginia. West Vir-
some egg nests, or punctures, remain par- giniaAgriculturalExperimentStationBulletin68:
[255]-327.
tially open for three or more years, it is Lloyd, M. and J. White. 1976. Sympatry ofperi-
possible that they will provide convenient odical cicada broods and the hypothetical four-
shelters for insects indefinitely. yearacceleration. Evolution 30: 786-801.
488 PROCEEDINGSOFTHEENTOMOLOGICALSOCIETY OFWASHINGTON
Marlatt, C. L. 1907. The periodical cicada. U.S. ovipositionbyperiodicalcicada. Environmental
Department Agriculture Bureau Entomology, Entomology 3: 725-732.
Bulletin 71: 1-181. Snodgrass, R. E. 1921. The seventeen-year locust.
McKenzie, H. L. 1967. Mealybugs of California. SmithsonianReport 1919,Publication2607:381-
University California Press, Berkeley and Los 409.
Angeles. 526 pp. Stoetzel, M. B. and L. M. Russell. 1991. Observa-
Simon, C. 1988. Evolution of 13- and 17-year pe- tions on Brood X of periodical cicadas: 1987-
riodical cicadas (Homoptera: Cicadidae: Magi- 1990 (Homoptera: Cicadidae). Proceedings En-
cicada). BulletinEntomologicalSocietyAmerica tomological Society Washington 93: 470-478.
34: 163-176. White, J. and M. Lloyd. 1979. 17-year cicadas
Smith, F. F. and R. C. Linderman. 1974. Damage emergingafter 18years:Anewbrood?Evolution
to ornamental trees and shrubs resulting from 33: 1193-1199.
