Poinar, G.O. Jr.

Stockwell, S.A.

Horizon / Pleins textes

Notes brèves 
Discussion 
Reports of microsporidian infections of nematodes 
are  rare but their  occurrence in  nature is undoubtedly 
more  widespread than realized.  Previous  natural  occur- 
rences  include Thebhunia ren$mmkin rhe gut epithelial 
cells of the house mouse parasite, Protospirura wzuhis 
(Kudo & Hetherington, 1922) and Microsporidium 
rhabdophilium from  the microtrophic  nematode, Rhab- 
ditis  myriophila (Poinar & Hess, 1986). Other possible 
natural infections are cited by Poinar & Hess (1988). 
Veremtchuk & Issi (1970) were able to experimentally 
infect Neoaplectana carpacapsae with the microspori- 
dians Nosema  mesnili and Plistophora schubergi respecti- 
vely after  passing the nematodes through insects which 
contained  these  infections. The  authors did not menrion 
whether the infection  could  be  continued  indefinitely in 
the nematodes  when the latter were transferred to 
healthy  hosts. This raises the  question of whether in  the 
present case with N. glaseri, the infection was initially 
obtained f r o p  an infected  insect.  Since  microsporidian 
infections  are  normally  obtained per os and  the  feeding 
stages of neoaplectanids  occur in  the hemocoel of dying 
and  dead insects, it is highly probable that  the infection 
was originally obtained from  an infected  insect.  How- 
ever it is clear that &parasite s a s  hig?dy vident  for the 
nematode and that it is now being carried within the 
nematode  population. It is unlikely that the  microspo- 
ridian  could  complete  its  development in  the  insect  host 
since with the relatively short period between being 
released in  the  host  and  death of the insect,  its  develop- 
ment  could  not be completed. 
Aside from  seriously  reducing  a  particular  nematode 
population in nature, the microsporidian could have 
serious  consequences if it was inadvertently  introduced 
into  a  mass  culture facility. Thus, care  should  be xcerci- 
sed  before  introducing  nematodes from  nature  into  an 
ifz ve'tm development system. 
REFERENCES 
KUDO, R. & HETHEKINGTON, D. C. (1922).  Notes  on  a 
microsporidian  parasite  of anematode. J.  Parasitol., 
PIZANO, M. A., AGUILLERA, M. M., MONTEIRO, A. R. & 
FERROZ, L. C. C. B. (1985). Incidencia de Neoaplectana 
glaseri Steiner, 1929 (Nematoda : Steinemematidae) para- 
sitando ovo de Migdolus  Jjyanus (Westwood, 1863) (Col : 
Cerambycidae). Soc.  brasil.  Nematol.,  9th Rem,  Piracicaba, 
1 P. 
POINAR, Jr., G. O. (1986). Entomophagous nematodes. Fort. 
Zool., 32 : 95-121. 
POINAR,  Jr., G. O. & Hess,  R.  (1986). Microspon'diuna  rhabdo- 
philum sp. n. (Microsporida : Pansporoblastina), a parasite 
of the nematode, Rlzabditis myriophila (Rhabditina : 
Rhabditidae) Revue Nématol., 9 : 369-375. 
POZNAR, Jr., G. O. & JANSSON, H. B. (1 986). Infecrion of Neoa- 
plectana and Heterorhabditis (Rhabditida : Nematoda)  with 
the predatory fungi, Monacrosporiunz  ellipsosporum and 
Arthrobotrys oligospora (Moniliales : Deuteromycetes) Re- 
vue Nématol., 9 : 241-244. 
POINAR, Jr., G.O. & Hess, R. (1988). Protozoan diseases of 
nematodes. In : Poinar, G. O., Jr. & Janqson H. B. (Eds). 
Diseuses of Newatodes. 
VEREMTCHUIC, G. V. & ISSI, 1. V. (1970). [Development of 
insect  microsporidians  in  the  entomopathogenic  nematode, 
Neoaplectana agriotos (Nematodea : Steinernematidae)]. Pa- 
rasitologiya, 4 : 3-7. 
8 : 129-132. 
Accepté pour publication le 21 septembre  1987. 
A NEW  RECORD OF A  NEMATODE PARASITE (MERMITHIDAE) OF A  SCORPION 
George O. POINAR, Jr.  and  Scott A. STOCKWELL 
Division of Entomology  and Parasitology, University of California, Berkeley, CA 94720, USA. 
Scorpions  represent  one of the oldest groups of 
extant terrestrial arthropods and are among the most 
primitive of al1 land  arachnids. The now extinct Paleo- 
zoic scorpions (suborder Branchioscorpionina K.-W., 
1985) lived in water together with representatives of 
their supposed ancestors, the eurypterids. The oldest 
known Neoscorpionina Thorell and Lindstrom, 1885 
(pulmonate  scorpions)  are Paleopisthacanthus and 
Conzpsoscorpus from  the Carboniferous (Kjellesvig- 
Waering, 1986). 
In  contras  to relatively numerous  reporp of mermi- 
thid nematodes from spiders  (Poinar, 1985) few  nema- 
tode  parasites have ever been  reported  from  represen- 
tatives of the order Scorpionida. Millot and Vachon 
(1949) reported  finding two juvenile nematodes in  the 
body cavity and alimentary  tract of a  male Parubuthus 
granimanus from  East Africa. Vachon (1952) also obser- 
ved juvenile nematodes inside East African scorpions 
but  further details on  the above associations  are  lacking 
and neither of the reports  provides  any  taxonomic  in- 
formation on the supposed parasites. Thus it was of 
great  interest  when  a  specimen of Paruroctonus  utahensis 
srges O. Poil lar, 3, & Scott A. Stockwell 
Fig. 
shon 
tube 
362 
1. a : Ventra 
ing head of 
(arrow)  and 
11 portion of abdominal  cavity of the  scorpion, Paruroctonus utahensis, opened to expose the nematode;  b : 
nematode  emerging  from the digestive  gland of the scorpion;  c : Anterior  portion of nematode  showing 1 
I nerve  ring (N); d : Posterior  end  showing  bifurcated  hypodermal  tissue  and  plug in the tail  cuticle (am 
Revue Nématol. I I  (3) : 361-364 
Detail 
mouth 
IW). 
' (1988) 
Notes brèves 
~~ ~ ~~~~~~~ 
(Williams, 1968) was discovered with  a  fully  developed 
parasitic  juvenile  mermithid in  its  body  caviq. An 
account of this event and tentative  description of the 
parasite  is  presented  here. 
Materials  and  methods 
A parasitized male of Paruroctonus utahensis was 
collected from Monahan's  Sans  Hills  State  Park in  Ward 
County,  Texas on  June 15,1984 (S.A. Stockwell). It was 
preserved in 70 O/O alcohol and  subsequently  opened for 
investigation of the development of the reproductive 
organs.  At that time,  a long, brownish  worm was seen 
coiled up  in  the body cavity (Fig. 1 a). It was intimately 
associated  with the digestive glands (Fig. 1 b), The worm 
was subsequently removed, processed to glycerin and 
examined microscopically. 
Results 
The parasitic  worm was identified  as  a  fully  developed 
parasitic juvenile mermithid  (Mermithidae) which was 
just at  the  point of emergence. This could  be  surmised 
from  the relative  thickness of the tail  cuticle  which is 
generally much  thinner  on developing  parasitic juven- 
iles. Unfortunately  the  reproductive  structures  and  the 
head papillae had not yet fully formed so it was not 
possible to assign the species to an existing genus or 
determine if it represented  a new genus,  although the 
structure of the tail appeared unique for mermithid 
nematodes. 
The mermithid was an immature female that pos- 
sessed six faint head papillae and a pair of  small  projections 
on either  side of the  mouth  tube which could  be  inter- 
preted  as  lip papillae. The total  length was  13.2 cm, the 
body width at the head was 63 pm and at midbody, 
238 pm. The distance from  the  head  to nerve  ring was 
231 pm, from  the head  to  anterior tip of the trophosome, 
349 pm  and  from  the tail to the posterior tip of tro- 
phosome, 95 Pm. The body cavity of the  nematode was 
filled  with  spherical Iipid droplets  ranging  from 2-18 pm 
in diameter. 
At the head end could  be  seen  a mouth opening  with 
a  cuticularized mouth  tube extending back 35  pm  and 
then  changing  into a  non-cuticularized  canal  that  could 
not be followed to its terminus (Fig. 1 c). The body 
cuticle  ranged from 3-5 pm  in thickness  and the cuticle 
surrounding  the tail  ranged from 19-25 pm  in thickness. 
The tail tip was unique. The hypodermal  mass  presen- 
ted  a  bifurcate  aspect which is unusual  in mermithids. 
The  tip of the cuticle  surrounding  the  tail  contained  a 
plug or  scar  roughly  16 pm long  by  16 pm wide which 
was composed of modified  fibrous  material  (Fig. 1 d). 
Such  a  scar  type of terminus as found  here is unique  for 
mermithids although similar structures occur on the 
Revue Nématol. 11 (3) : 361-364  (1988) 
mermithid  grasshopper  parasite, Agamermis  decaudata 
Cobb, Steiner & Christie  (Christie, 1936). 
There were patches of roughened  cuticle dong the 
body of the parasite. These could be areas of cuticular 
infection by some microorganism, evidence of a host 
reaction or indication of a gradua1 decline in vitality 
(Fig. 1 c). 
Discussion 
With this report representing the first documented 
case of a  mermithid  parasite of scorpions, it is obvious 
that this phenomenon is of rare occurrence. It is not 
known whether the  mermithid is an opportunistic para- 
site that chanced to come into contact with the host 
or  a  specific  scorpion  parasite.  Dissections of additional 
specimens of P. utahensis revealed no  further incidence 
of parasitism  and tend  to  support  the  former conclusion. 
Given the rather unique morphological  characters of the 
nematode, however, it is also possible to consider the 
parasite as a highly specialized form  that has become 
adapted to scorpions but occurs very infrequently. It 
could have a very long  developmental  period  inside the 
scorpion, only emerging during brief periods of rain. 
Contact with new hosts  might  occur  when  the  scorpions 
burrow  into loose Sand to escape the heat. It is even more 
likely,  however, that  the infection was acquired  when the 
scorpion  ingested  prey that already  contained  infective 
stages of the  parasite.  Such  a cycle (indirect)  has  been 
shown  to  occur in mermithid  parasites of spiders, 
however, in  such cases the spiders always return  to wslter 
when the parasite  emerges  and an aquatic  habitat  ap- 
pears to  be necessary for  further  nematode development 
and  the location of paratenic  hosts  (Poinar & Benton, 
1986). In the present case, the infected scorpion was 
collected in shifting Sand dunes and probably never 
came  into  contact  with  permanent  or  temporary  surface 
water. This might  imply that  the  nematode was adapted 
to  another  medium of survival in  the free-living stages 
after leaving the body of the scorpion, or that the 
nematode  chanced to  infect  a  scorpion  that  never  had 
an  opportunity  to  return  to  a  water  source  for  liberation 
of the parasite. The roughened  areas on  the cuticle of 
the  nematode  might  be  signs of a  reduction in parasite 
vitality, which supports  the  hypothesis  that  the  scorpion 
was a  developmental  dead-end for  the parasite. 
REEERENCES 
CHRISTIE, J. R. (1936). Life history of Agamemis decaudata, 
a  nematode  parasite of grasshoppers  and  other  insects. J. 
agric. Res., 52 : 161-178. 
KJELLESVIG-WAERING, E. N. (1986). A restudy of the fossil 
Scorpionida of the world. Paleontogr. am., 55 : 1-287. 
MILLOT, J. & VACHON, M. (1949).  Ordre  des  Scorpions. In : 
363 
Alun F. Bird 
B 
Grassé, P.-P. (Ed.) Truitéde Zoologie. Anatomie,  Systémati- PQINAR, Jr, G. O. & BENTON,  Jr., C.L.B. (1986). Aranimemis 
que, Biologie. Tome M : 386-436. aptispeczllu n.  g., n.  sp.  (Mermithidae : Nematoda),  a 
POINAR, Jr., G. O. (1985).  Nematode  parasitism of spiders  and parasite of spiders  (Arachnida : Araneida). Syst. Parasitol., 
harvestmen. J. Aruchnol., 13 : 121-128.  8 : 33-38. 
Accepté pour publication le 26 octobre 1987. 
VACHON, M. (1952). Études sur les scorpions. Inst. Pasteur 
Algérie,  Alger,  482 p. 
A TECHNIQUE  FOR STAINING T H E  ENDOSPORES  OF 
PASTEURIA PENETRANS 
Alan F. BIRD 
Division of Soils, CSIRO, PMB No. 2, PO Glen  Osmond, S. A. 5064, Australia. 
The following  simple  staining  technique  increases the by a range of histochemical Stains. The most  satisfactory 
ease of detection  and  counting of endospores of Pus- of these was Brilliant Blue G (BBG), obtained from 
teuria penetrans (Sayre & Starr, 1985) adhering  to  the Sigma  (Catalogue  No. B-1131). This  stain  has a molecu- 
second  stage  larvae (L,) of species of Meloidogyne. lar weight of 854.04 and  should  not  be  confused  with  the 
Adhering endospores were stained to varying degrees closely related Brilliant Blue R (BBR) (Sigma B-0630) 
Fig. 1. A : Part of a  living  unstained  infective  second  stage  larva (LJ of Meloidogyne haplu with  attached  spores of Pasteuria  penetrans 
(see  arrows)  viewed  under  normal  (bright  field)  illumination; B : Similar  to A but rhe spores  on  this  specimen  were  stained  with 
Brilliant  Blue G (BBG) and show up much  more  clearly  (see  arrows) than those  in A; C : Anterior  part of A at  higher  magnification 
under  oil  immersion  showing  unstained  spores  (arrows); D : Anterior  part of B at  higher  magnification  under  oil  immersion  showing 
spores  stained  with  BBG  (arrows)  (Bars  represent, A, B : 25  Pm; C, D : 10 Pm). 
364 Revue Némutol. 11 (3) (1 988) 


A new record of a nematode parasite (Mermithidae) of a scorpion

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