Biological notes on Sparasion latreille (Hymenoptera: Scelionidae), an egg parasitoid of Atlanticus gibbosus scudder (Orthoptera: Tettigoniidae)

4 Pages·1997·1.9 MB·

by  E E Grissell

PROC. ENTOMOL. SOC. WASH.
99(4), 1997, pp. 693-696
BIOLOGICAL NOTES ON SPARASION LATREILLE (HYMENOPTERA:
SCELIONIDAE), AN EGG PARASITOID OF ATLANTICUS GIBBOSUS
SCUDDER (ORTHOPTERA: TETTIGONIIDAE)
E. E. Grissell
Systematic Entomology Laboratory, PSI, Agricultural Research Service, U.S. Depart-
ment of Agriculture, c/o National Museum of Natural History, MRC 168, Washington,
DC 20560 U.S.A.
—
Abstract. The first behavioral observations for any species of Sparasion and the first
report of the genus Atlanticus (Orthoptera: Tettigoniidae) as a host of Sparasion are pre-
sented. In Florida, a number of female wasps were observed burrowing headfirst into
sandy areas. In every instance where a female burrowed into sand and the area subse-
quently was excavated, an egg of Atlanticus, oriented vertically, was found at 12 to 15
mm
beneath the surface. Females emerged headfirst from the sand if they remained un-
derground for more than a few minutes. A single female was excavated from the ground
while in the process of ovipositing into an egg; she was at its uppermost end with her
head oriented toward the surface.
Key Words: Hymenoptera, Scelionidae, Sparasion, Tettigoniidae, Atlanticus gibbosus,
egg, parasitoid
The genus Sparasion Latreille is repre- except the host record itself (Cowan 1929)
sented by over 100 species throughout the and subsequent citations of this record
Holarctic and Oriental regions (Johnson (Mills 1941, Hitchcock 1942, Wakeland
1992), eight of which occur in America 1959, Muesebeck 1979). Although a few
north of Mexico (Muesebeck 1979). Essen- additional papers refer to Sparasion in re-
tially nothing is known about the biology lation to a potential host, these were merely
or behavior ofthese wasps. Kozlov and Ko- specimens of Sparasion collected in a hab-
nonova (1990) recently described over 50 itat relative to the potential host. For ex-
new species of Sparasion, and not a single ample, Spencer (1958) reported Sparasion
one had been reared. The paucity of bio- sp. "probably parasitic upon eggs ofthe tet-
logical or behavioral data for species in this tigoniid Anabrus longipes Caudell," and
genus is doubly remarkable because it has Thorens (1991) collected Sparasion sp. in
been recognized for nearly 200 years (de- a locality containing an acridid grasshopper
scribed in 1802), and its single known host (Chorthippus sp.).
in the Americas is the Mormon cricket, An- In this paper I present anecdotal obser-
abrus simplex Haldeman, an insect of leg- vations made on the behavior of an unde-
endary stature in the United States. Sur- scribed species ofSparasion in Florida that
prisingly, even for this common, well- attacks eggs ofAtlanticus gibbosus Scudder
known host, no truly biological or behav- (Orthoptera: Tettigoniidae). This is the first
ioral observations have been published for report ofAtlanticus as a host for Sparasion.
its parasite, Sparasion pilosum Ashmead, These observations were made in 1974 and
694 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
1975 and were to form the basis of more Field recognition of this species requires
detailed studies to follow. Other obligations experience based upon preserved speci-
mm
prevented further investigation, however, mens. The wasps are ca. 5 in length,
and as no one has published biological in- appear black in color, and are most easily
formation for the genus in the intervening seen as they fly or walk back and forth over
twenty years, my notes provide enough data a small area of soil. Females are distin-
to highlight significant aspects of the here- guished from males by the orange legs
tofore unknown behavior of a species of (black in males) and short, hidden antennae
Sparasion. (elongate and easily seen in males).
Determination of Atlanticus gibbosus
Methods
was made by D. A. Nickle, who compared
I made observations in two areas about dried eggs excavated from the Alachua site
16 km apart in Alachua County, Florida. In (21 July 1975) with eggs dissected from
both areas the soil consisted of sand, which dried adult female Atlanticus in the collec-
in the absence of rain, was loose and pow- tion of the National Museum of Natural
dery dry for the top 1 or 2 cm. History. Atlanticus gibbosus is the only
Alachua (0.5 km southeast). This site common shield-backed grasshopper found
was a large, sandy, disturbed area formed in Florida and is particularly abundant dur-
by the intersection of a railroad track and ing the summer months when my obser-
several dirt roads. The entire area had been vations were made.
bulldozed through a low hillock in recent
times, probably as a barrow pit. A number Observations
of annual and perennial plants, most nota- Alachua, 21 to 27 July 1974.—On 21
bly Cassia sp. (Fabaceae), were returning July I arrived at the site at 10:45 am and
to the site. saw several female Sparasion flying slowly
Gainesville (grounds of the Florida State over a small sandy area at about 2 to 5 cm
Collection of Arthropods, Division ofPlant above the surface. Two to 5 wasps were
Industry building). This site was an un- seen walking or flying in any given area
paved road that had been cut through the (approximately 30 cm- to 1 m-). Once a fe-
woods around the back side of the DPI male landed on the ground she walked
building. The site has been paved in the in- about erratically over the surface with her
tervening years since observations were abdomen bobbing slightly up and down,
first made. wings folded and held horizontally over the
Determination of the status of this Spa- abdomen. The antennae were extended
rasion as undescribed was made first by the downward in an inverted V-shaped pattern
late C. F W. Muesebeck and subsequently just above the surface. When a female
was confirmed by Lubomir Masner, Agri- found an area of interest, she touched her
culture Canada. Additionally, I have com- antennae on the sand and vibrated them;
pared the species with types and other spec- then she would plunge headfirst into the
imens in the National Museum of Natural sand. As she entered, she rotated her body
History, Smithsonian Institution, and it ap- from side to side, and her antennae ap-
pears to differ from all available material. peared to play some role in excavation, but
Currently no systematist in authority is this could not be confirmed. In most cases
willing to describe the taxon. All voucher her body would quickly disappear beneath
specimens collected in this study are the surface, and just as quickly she would
housed in the Florida State Collection of back out completely and begin the probing
Arthropods, Gainesville, Florida, along activity in nearby areas. Females did not
with large series of material representing come out headfirst unless they had been un-
the same taxon. derground at least several minutes.
VOLUME 99, NUMBER 4 695
In one instance I saw a female emerging on Cassia. The area was extremely wet, and
headfirst from the sand. I excavated at the no females were seen. It rained heavily for
point of emergence and found a tettigoniid the next few days as well, and I abandoned
mm mm
egg ca. 6 in length at 13 below the site. —
the surface (top of egg at 13 mm). A few Gainesville, 2 July 1975. At 10:45 am,
minutes later I saw a female wasp burrow along the edge of a sandy road, I observed
headfirst into the sand. It took 40 to 50 sec- a female burrow headfirst into nearly level,
onds for her to completely disappear from loose, dry sand. In 10 minutes a female
sight. Five minutes later she emerged head- (presumed to be the same, but perhaps in-
first from the soil. Then almost immediately correctly, see below) emerged headfirst
mm
another female burrowed headfirst into the from the sand about 3 from where she
sand in the same area. After 8 minutes I entered. Her body was covered with dust,
excavated the soil and found the female and she spent several minutes cleaning her
near an egg. The top of this egg was 10 abdomen and then her head. Then she
mm mm
beneath the surface. The egg was 6 walked away. I immediately excavated the
in length. Shortly thereafter I saw another sand beginning about 10 cm away from the
female burrow headfirst into the ground and emergence site. I excavated to a depth of
mm mm
completely disappear in ca. 45 seconds. Af- 20 (the first 15 were dry, then be-
mm
ter waiting 17 minutes for her to emerge, I came damp). At 15 in depth and near
excavated the sand and found an egg. The where the female emerged, I found two
female wasp was oriented head upwards, eggs of a tettigoniid a few cm apart. These
mm
above the tip ofthe egg, with her ovipositor were about 5 in length and placed ver-
embedded into it. When I removed the egg, tically in the moist sand with the tops at the
mm
the wasp was still attached to it, but she 15 level. I also found three female
broke free and flew away. This egg was 12 Sparasion, heads upright, near these two
mm below the surface and was 6 mm long. eggs but not in contact with them. These
I placed the above eggs in gelatin capsules, females either walked or flew away quickly
but nothing emerged from them. as the sand fell away from their bodies dur-
On 23 July I visited the same site from ing my excavation. I brought the eggs into
9:30 to 11:30 am and saw numerous males the lab and placed them in gelatin capsules,
flying above the sand; some alighted on the but nothing emerged.
ground, others alighted on Cassia. I did not
Discussion
see any females until 10:15 and observed
no digging or mating attempts. During eight days of observations (over
On 25 July I visited the site at 10:30 am. a two year period), the numberofboth male
The sand was slightly damp on the surface. and female wasps seen flying and landing
I saw males and females cruising the area. on the sand varied, with up to seven fe-
In one case I saw 7 females on the ground males in a 30 cm- area. The absence ofob-
within a 30 cm- area. Some began to bur- served matings was unusual for such an
row into the sand but then stopped. No fe- abundance of individuals, but matings may
males entered the ground. Some of the fe- have taken place earlier or later than the
males approached each other, and occasion- period during which my observations were
ally one would "hop" at the other (a short made (in late morning, ca. 9:30 to 11:30
jump of 1 to 2 cm). Several times I saw am).
mm
females digging within 5 ofeach other. Females seemed most attracted to areas
It began to rain heavily, and the wasps dis- of dry, friable sand; wet sand appeared to
appeared. pose a deterrent to initial surface penetra-
On 27 July I arrived at 11:00 am. A few tion. All observed females entered the sand
males were flying overthe sand and landing headfirst. After a female entered the sand
696 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
her presence was undetectable from the sur- of voucher specimens of Sparasion, which
face until she either backed out (usually are housed in the FSCA collection. Finally,
only a few seconds after penetration) or I thank Richard Dysart, European Biologi-
emerged headfirst. It appeared that once a cal Control Laboratory, USDA, for access
female found a spot beneath the surface that to his bibliography of scelionid references,
was of interest, presumably because a tet- and Ray Gagne, Systematic Entomology
tigoniid egg was present, she managed to Laboratory, USDA, for the translation of
reverse direction under the sand. Females some French text.
apparently could detect host eggs from the
Literature Cited
surface, but they eithercould not detectoth-
er wasp females or these females were not Cowatnh,e MF.oTnn1o9n29C.riLcikfeet.hiUsntiotrey,dhSatbaittess,Daenpdarcotnmternotl ooff
a deterrent. Agriculture, Technical Bulletin No. 161. 28 pp.
Although I could not demonstrate by ev- Hitchcock, O. B. 1942. Mormon Cricket Control,
idence of successful rearing that Atlanticus 1941-42, pp. 11-13. In Mills, H. B.,ed..Montana
gibbosus is, in fact, a true host of this Spa- insect pests, 1941 and 1942. Twenty-ninth report
of the state entomologist. Montana State College
rasion, I believe that the observations point Agricultural Experiment Station Bulletin 408, 36
to this conclusion. The constant association pp.
of female wasps with Atlanticus eggs and Johnson,N. F. 1992. CatalogofworldspeciesofProc-
the presence of a female wasp ovipositing totrupoidea, exclusive of Platygastridae (Hyme-
noptera). Memoirs of the American Entomologi-
into an egg both suggest that this tettigoniid
cal Institute 51, 825 pp.
is likely to be a host. Additionally, Atlan- Kozlov, M. A. and S. V. Kononova. 1990. [Scelioni-
ticus is a member ofthe Tettigoniinae, as is nae ofthe faunaofthe USSR: Hymenoptera, Sce-
the only proven host of Sparasion in the lionidae, Scelioninae]. Opredeliteli Fauna SSSR
Nearctic, the Mormon cricket. 161, 344 pp. [In Russian.]
Mills, H. B. 1941. Montana insect pests 1939 and
1940. Twenty-eighth report of the state entomol-
Acknowledgments
ogist. Montana State College Agricultural Exper-
iment Station Bulletin 384, 27 pp.
I thank David Nickle, Systematic Ento- Muesebeck, C. F. W. 1979. Proctotrupoidea, pp.
mology Laboratory, USDA, Washington, 1121-1186. In Krombein, K. V., R D. Hurd, Jr.,
DC, for identification ofthe tettigoniid eggs D. R. Smith, B. D. Burks, eds. Catalog of Hy-
and for information on tettigoniine tettigo- menoptera in America North of Mexico. Vol. 1.
niids. For reading and commenting upon Symphyta and Apocrita (Parasitica). Smithsonian
the manuscript I thank Lubomir Masner, SpencIenrs,titGu.tiJo.n P1r9e5s8s., WTahsehinnagtutroanl,cDonCt.rol11c9o8mpppl.ex af-
Agriculture Canada (Ottawa), Andy Austin, fecting grasshoppers in the dry belt ofBritish Co-
The University ofAdelaide (Adelaide, Aus- lumbia. Proceedings of the 10th International
tralia), John Brown and David Smith (Sys- Congress ofEntomology (Montreal 1956)4: 497-
502.
tematic Entomology Laboratory, USDA,
Thorens. P. 1991. Predateurs et parasitesde Chorthip-
Washington, DC), and an anonymous re- pns mollis (Orthoptera, Acrididae) dans deux sta-
viewer. I am indebted to C. F. W. Muese- tions du pied sud du jura. Bulletin de la Societe
beck (deceased) and L. Masner for infor- Neuchateloise des Sciences Naturelles 114: 43-
57.
mation and help with the identification of Wakeland, C. 1959. Mormon crickets in North Amer-
this species. I thank Jim Wylie, Florida ica. United States Department of Agriculture
State Collection ofArthropods, for the loan Technical Bulletin 1202, 77 pp.