NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
AGGLUTINATION REACTION DUE TO MALLEIN INJECTIONS
IN HORSES*
BY
R. N. NAIK, G.B.V.C.,
Assistant Veterinary Research Officer, Imperial Institute of Veterinary Research,
Muktesar.
(Received for publication on 1st February 1932.)
Miessner [ 1902 ] and Pfeiler and Weber [ 1912 ] have shown that agglutinins
appear in the blood in from 5 to 7 days following the subcutaneous injection of
mallein. According to Sustmann [ 1908 ] the presence of these agglutinins remains
for more than three months. Serum samples of healthy horses subjected to the
mallein test as well as those of glandered horses give therefore identical agglutina-
tion titres and the results of the agglutination test in animals of the first category
can only be relied upon when they have not been subjected to the mallein test
during the preceding three months.
It is not uncommon to obtain a suspicious reaction with the mallein test in a
few horses and in such instances, particularly when early confirmation is neces-
sary, one may wish to resort to some form of serological test, such as the comple-
ment fixation or agglutination test. But, in view of what has been stated above,
the agglutination test in such horses recently tested with mallein may lead to
anomalous results. The necessity therefore arose to find out whether there was any
sharp demarcation in the titres of serum from horses infected with glanders and
from those injected with mallein and also to ascertain the maximum period during
which the serum of a horse tested with mallein gave a positive agglutination reaction.
An antigen was prepared by using a B. mallei strain, stock culture No. 124 of
this Institute. It was grown on glycerine broth medium, pH 7.3 at 37 °C. After
incubating for 10 days the culture was killed by autoclaving and was centrifuged at
6,500 revolutions per minute for one hour. The supernatant fluid was thrown off
and the sediment was emulsified in physiological salt solution containing 0.5 per
cent. carbolic acid and was re-centrifuged at the same speed and for the same period.
The sediment was then emulsified and standardised to barium sulphate standard
opacity No. 32 in carbolised physiological salt solution.
There were available at the moment a certain number of healthy horses that
had been recently subjected to the mallein test in this Institute. The sera of these
animals were submitted to agglutination tests periodically. The results of these,
* Paper read at the 19th Session of the Indian Science Congress, Bangalore, 1932.
( 265 )
266 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [II, III
which are summarised in Table I, show that out of nine ponies variously subjected
to the mallein test about a month previously
(i) three ponies gave a positive agglutination reaction indistinguishable
from that usually obtainable in the case of glandered horses ;
(ii) two ponies gave a suspicious reaction; and
(iii) the remaining four ponies gave a negative reaction.
It will be further observed that after about 8 weeks from the date of last injec-
tion of mallein all the animals gave a completely negative reaction to the second
agglutination test.
The problem which now seemed to merit attention was whether repeated injec-
tions of mallein were followed by a steady increase in the amount of agglutinins
until they reached what might be regarded as the maximum titre, and if the
findings in this respect were positive, it seemed desirable further to follow up the
question and endeavour to ascertain the exact period during which the agglutinins
persisted in the circulation.
In order to obtain information on these points, a horse which had shown the
minimum amount of normal agglutinins in its blood serum was selected and
injected every week subcutaneously with mallein, the serum being drawn during
the period intervening between every two injections. The results of these weekly
agglutination tests are summarised in Table II. An examination of this Table
shows :
(i) that a positive agglutination reaction was obtained a week after the
injection of mallein;
(ii) that the intensity of the reaction, instead of showing an increase due
to repeated weekly injections of mallein actually fell slightly in the fifth
week ; and
(iii) that a negative reaction was exhibited at the end of the third week after
the last injection.
SUMMARY.
1. No sharp demarcation can be made out between the agglutination titres of
serum from horses recently injected with mallein and of serum from horses infected
with glanders.
2. The presence of agglutinins induced by an injection of mallein may be
found only up to about two months following the date of injection.
MALLEIN
INJECTIONS
IN
HORSES.
267
3. If a healthy horse is subjected to repeated injections of mallein the aggluti-
nation reaction simulating that of a positive case of glanders is noticeable a week
after the first injection.
4. Repeated injections of mallein do not increase the titre above that which is
obtained a week after the first injection.
5. The presence of specific agglutinins in the blood serum of horses repeatedly
injected with mallein does not persist longer than three weeks after the last
injection.
The writer desires to express his deep gratitude to Mr. F. Ware, the Director
and Mr. H. Cooper, the Veterinary Research Officer of this Institute, for their
guidance and encouragement.
REFERENCES.
Miessner (1902). Centralb für Bakter, Parasitenund Infekt. Originate, 53, 482.
(1902). Ibid, 54,121.
Pfeiler and Weber (1912). Berliner tierarztliche Wochenschrift, 785.
Sustmann (1908). Diss. Zürich. (Lit. on Aggl.)
268 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [II, III
TABLE I.
Agglutination reaction due to mallein injection.
Serial
No.
1
2
3
4
5
6
7
8
9
Serum from
Pony 78 . .
Pony 282 . .
Pony 79 . .
Pony 200 . .
Pony 1/305 .
Pony 268 . .
Pony 270 . .
Pony 275 . .
Mare 3/281 .
Control.
1
2
Pony 18 . .
Donkey 33 .
Details of Mallein test
Date
12-3-30
8-4-30
21-5-30
8-4-30
19-5-30
19-5-30
21-5-30
19-5-30
23-5-30
24-2-30
19-5-30
19-5-30
12-5-30
8-5-30
24-4-30
21-5-30
How applied
I. D. P.
I. D. P.
Subcut.
I. D. P.
I. D. P.
I. D. P.
Subcut.
Subcut.
I. D. P.
Subcut.
Subcut.
I. D. P.
Subcut.
Subcut.
Double Intrader-
mal.
Subcut.
1st Agglutination test—Reactions given
Date
tested
..
.. 18-6-30
18-6-30
18-6-30
18-6-30
7-6-30
18-6-30
18-6-30
18-6-30
..
..
..
18-6-30
24 hours
1/25
..
.. W. C.
W. C.
V. N. W. C.
..
V. N. W. C.
..
V. N. W. C.
W. C.
W. C.
N. W. C.
..
..
..
W. C.
1/50
..
.. W. C.
W. C.
V. N. W. C.
. .
V. N. W. C.
..
N. W. C.
W. C.
W. C.
Dist.
..
..
..
W. C.
1/100
..
.. W. C.
V. N. W. C.
N. W. C.
..
V. N. W. C.
..
N. W. C.
Adv.
V. N. W. C.
App.
..
..
..
V. N. W. C.
1/200
..
..
V. N. W. C.
N. W. C.
V. adv.
N. W. C.
. .
N. W. C.
Dist.
N. W. C.
..
..
..
..
V. adv.
1/500
..
..
N. W.
C.
Dist.
Dist.
..
Adv.
..
Adv.
?App.
App.
Dist.
..
..
..
..
?App.
1/1000
..
.. App.
Dist.
?App.
..
App.
Dist.
..
Dist.
..
..
..
..
..
..
..
1/2000
..
..
..
..
..
..
?App.
..
..
..
..
..
..
..
..
Positive case.
Healthy.
18-6-30
18-6-30
W. C.
V. N. W. C.
W. C.
V. N. W. C.
W. C.
Dist.
W. C.
App.
N. W.
C.
..
Dist.
..
?App.
..
MALLEIN INJECTIONS IN HORSES
269
TABLE I—contd.
Agglutination reaction due to mallein injection—contd.
Serial
No.
1
2
3
4
5
6
7
8
9
1
2
Serum from
Pony 78 . .
Pony 282 .
Pony 79
.
Pony 200 .
Pony 1/305
Pony 268 .
Pony 270 .
Pony 275 .
Mare 3/281
Control.
Pony 18 .
Donkey 33
Details of Mallein test
Date
12-3-30
8-4-30
21-5-30
8-4-30
19-5-30
19-5-30
21-5-30
19-5-30
23-5-30
24-2-30
19-5-30
19-5-30
12-5-30
8-5-30
24-4-30
21-5-30
How applied
I. D. P.
I. D. P.
Subcut.
I. D. P.
I. D. P.
I. D. P.
Subcut.
Subcut.
I. D. P.
Subcut.
Subcut.
I. D. P.
Subcut.
Subcut.
Double Intrader-
mal.
Subcut.
Positive case.
Healthy.
1/25
..
..
W. C.
W. C.
W. C.
..
W. C.
..
V. N. W. C.
W. C.
W. C.
N. W. C.
..
W. C.
W. C.
W. C.
1st Agglutination test—Reactions given
1/50
..
..
W. C.
W. C.
W. C.
..
W. C.
..
V. N. W. C.
W. C.
W. C.
Dist.
..
W. C.
W. C.
V. N. W. C.
1/100
..
..
W. C.
W. C.
W. C.
..
W. C.
..
V. N. W. C.
N. W. C.
W. C.
App.
V. N. W. C.
W. C.
Dist.
48 hours
1/200
..
..
W. C.
N. W. C.
N. W. C.
..
V. N. W. C.
..
V. N. W. C.
Adv.
N. W. C.
..
..
V. adv.
W. C.
App.
1/500
..
..
N. W.
C.
Dist.
Dist.
..
Adv.
..
N. W.
C.
App.
Dist.
..
..
App.
N. W.
C.
..
1/1000
..
..
Dist.
?App.
?App.
..
App.
Dist.
..
Dist.
adv.
..
..
..
..
..
Dist.
adv.
..
1/2000
..
?App.
..
..
? App.
..
?App.
..
..
..
..
..
App.
..
Result.
..
+++
++
++
+++
+++
—
—
—
..
—
+++
—
270 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [II, III
TABLE I—contd.
Agglutination reaction due to mallein injection—contd.
Serial
No.
1
2
3
4
5
6
7
8
9
1
2
Serum from
Pony 78 .
Pony 282 .
Pony 79 .
Pony 200 .
Pony 1/305
Pony 268 .
Pony 270 .
Pony 275 .
Mare 3/281
Control.
Pony 18 .
Donkey 33
Details of Mallein test
Date
12-3-30
8-4-30
21-5-30
8-4-30
19-5-30
19-5-30
21-5-30
19-5-30
23-5-30
24-2-30
19-5-30
19-5-30
12-5-30
8-5-30
24-4-30
21-5-30
How applied
I. D. P.
I. D. P.
Subcut.
I. D. P.
I. D. P.
I. D. P.
Subcut.
Subcut.
I. D. P.
Subcut.
Subcut.
I. D. P.
Subcut.
Subcut.
Double Intrader-
mal.
Subcut.
Positive case.
Healthy.
II.—Agglutination test—Reactions given
Date
tested
..
..
17-7-30
17-7-30
17-7-30
..
17-7-30
2-7-30
..
..
..
..
..
..
..
17-7-30
17-7-30
1/25
..
..
W.C.
W.C.
W.C.
. .
W.C.
W.C.
..
. .
. .
. .
..
..
..
W.C.
V. N. W. C.
1/50
..
..
W.C.
V. N. W. C.
W.C.
..
W.C.
..
W.C.
..
..
..
..
..
W.C.
V. N. W. C.
24 hours
1/100
..
..
V. N. W. C.
Dist.
V. N. W. C.
..
N. W. C.
..
N. W. C.
..
..
..
..
..
..
..
W.C.
Dist.
1/200
..
..
Dist.
?App.
App.
..
Dist.
..
Dist.
..
..
..
..
..
..
..
W.C.
App.
1/500
..
..
?App.
..
..
..
?App.
..
App.
..
..
..
..
..
..
..
Adv.
..
1/1000
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
App.
Dist.
..
1/2000
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
?App.
..
MALLEIN INJECTIONS IN HORSES
271
TABLE I—concld.
Agglutination reaction due to mallein injection—concld.
Serial
No.
1
2
3
4
5
6
7
8
9
1
2
Serum from
Pony 78
Pony 282 .
Pony 79 .
Pony 200 .
Pony 1/305
Pony 268 .
Pony 270 .
Pony 275 .
Mare 3/281
Control.
Pony 18 . .
Donkey 33.
Details of Mallein test
Date
12-3-30
8-3-30
21-5-30
8-4-30
19-5-30
19-5-30
21-5-30
19-5-30
23-5-30
24-2-30
19-5-30
19-5-30
12-5-30
8-5-30
24-4-30
21-5-30
How applied
I. D. P.
I. D. P.
Subcut.
I. D. P.
I. D. P.
I. D. P.
Subcut.
Subcut.
I. D. P.
Subcut.
Subcut.
I. D. P.
Subcut.
Subcut.
Double Intrader-
mal.
Subcut.
Positive case.
Healthy.
II.—Agglutination test—Reactions given
1/25
..
..
W. C.
W. C.
W. C.
..
W.C.
. .
W.C.
..
..
..
..
..
..
W.C.
W.C.
1/50
..
..
W.C.
W.C.
W.C.
..
W.C.
. .
W.C.
..
..
..
..
..
..
. .
W.C.
W.C.
48 hours
1/100
..
..
W.C.
V. adv.
V. N. W. C.
..
V. N. W. C.
. .
V. N. W. C.
..
..
..
..
..
..
W.C.
Adv.
1/200
..
..
N. W. C.
App.
Dist.
..
Dist.
.,
Adv.
..
..
..
..
..
..
W.C.
App.
1/500
..
..
App.
..
?App.
..
App.
App.
..
..
..
..
..
..
N. W.
C.
..
1/1000
..
..
..
.. ..
.. ..
... ..
..
..
..
..
..
..
..
..
..
Dist.
..
1/2000
..
..
..
.. ..
.. ..
.. ..
..
..
..
..
..
..
..
..
..
App.
..
Result
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
+++
..
EXPLANATION OF THE ABBREVIATIONS USED ABOVE :—
W.C. =
V. N. W. C. =
N. W. C. =
V. adv. =
Water clear.
Very nearly water clear.
Nearly water clear.
Very advance.
Adv. = Advance.
Dist. =
Distinct.
App. = Appreciable.
? App. = Doubtful appreciable.
+++ = Positive reaction.
++ = Suspicious reaction.
— = Negative reaction.
272 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [II, III
TABLE II.
Agglutination reaction due to repeated mallein injections.
Animal
Pony No. 307 .
Date of
Mallein
injection
26-7-30 {
4-8-30
11-8-30
18-8-30
25-8-30
Date on
which the
pony was
bled for
agglutina-
tion test
22-7-30
2-8-30
11-8-30
18-8-30
25-8-30
1-9-30
8-9-30
15-9-30
22-9-30
29-9-30
6-10-30
13-10-30
Agglutination Reaction
1/25
W. C.
W. C.
W. C.
W. C.
V. N. W. C.
W. C.
W. C.
W. C.
W. C.
W.C.
V. N. W. C.
V. N. W. C.
1/50
N. W. C.
V. N. W. C.
W.C.
W. C.
W.C.
W.C.
W.C.
V. N. W. C.
V. N. W. C.
V. N. W. C.
N. W. C.
V. adv.
1/100
Dist.
V. N. W. C.
W. C.
W. C.
W.C.
N. W. C.
V. N. W. C.
N. W. C.
Adv.
V. adv.
Dist.
Adv.
24 hours
1/200
? App.
N. W. C.
V. N. W. C.
N. W. C.
N. W. C.
V. adv.
V. adv.
App.
App.
App.
App.
Dist.
1/500
Dist.
Adv.
Adv.
V. adv.
Dist.
App.
?App.
? App.
?App.
?App.
..
..
1/1000
App.
Dist.
App.
App.
App.
..
..
..
..
..
..
..
1/2000
? App.
?App.
? App.
..
..
..
..
..
..
..
..
MALLEIN INJECTIONS IN HORSES
273
TABLE II—contd.
Agglutination reaction due to repeated mallein injections.
Animal
Pony No. 307 .
Date of
mallein
injection
26-7-30 {
4-8-30
11-8-30
18-8-30
25-8-30
Date on
which the
pony was
bled for
agglutina-
tion test
22-7-30
2-8-30
11-8-30
18-8-30
25-8-30
1-9-30
8-9-30
15-9-30
22-9-30
29-9-30
6-10-30
13-10-30
1/25
W.C.
W. C.
W.C.
W.C.
W.C.
W.C.
W.C.
W.C.
W.C.
W.C.
W.C.
V. N. W. C.
1/50
V. N. W. C.
W.C.
W.C.
W.C.
W.C.
W.C.
W.C.
V. N. W. C.
W.C.
W.C.
V. N. W. C.
N. W. C.
Agglutination Reaction
48 hours
1/100
Adv.
W.C.
W.C.
W.C.
W. C.
W.C.
W.C.
N. W. C.
N. W. C.
N. W. C.
V. adv.
Adv.
1/200
App.
V. N. W. C.
W.C.
V. N. W. C.
V. N. W. C.
N. W. C.
N. W. C.
Dist.
Dist.
App.
App.
Dist.
Dist.
1/500
..
N. W. C.
V. adv.
V. adv.
V. adv.
Dist.
Dist.
App.
App.
?App.
?App.
..
1/1000
..
Dist.
App.
App.
App.
App.
App.
..
..
..
..
..
1/2000
..
?App.
? App.
?App.
? App.
..
..
..
..
..
..
..
Result
..
+ + +
+ + ±
+ + ±
+ + ±
+ + ±
+ +
—
—
—
—
—
W.C.
V. N. W. C.
N. W. C.
V. adv.
EXPLANATION OF THE ABBREVIATIONS USED ABOVE:—
= Water clear.
= Very nearly water clear.
= Nearly water clear.
=Very advance.
Adv. = Advance.
Dist. = Distinct.
App. = Appreciable.
? App = Doubtful appreciable.
+ + + = Positive reaction.
+ + ± = Positive but reactions less marked.
+ + = Suspicious reaction.
— = Negative reaction.
G
AGGLUTINABILITY OF DIFFERENT STRAINS OF BACILLUS
MALLEI*
BY
R. N. NAIK, G.B.V.C.,
Assistant Veterinary Research Officer, Imperial Institute of Veterinary Research,
Muktesar.
[ Received for publication on 1st February 1932.]
Hutyra and Marek [ 1926 ] quote Ladany's statement that different strains of
B. mallei show differences in their agglutinability and that strains which show
distinct stringy cultures and cause a bluish red discoloration on potato medium are
the best for the preparation of antigen.
As the agglutination test has been brought into practice at this Institute and
is resorted to mostly when the mallein test fails to give a conclusive evidence of
glanders infection in horses, it was considered desirable to make a study of the
agglutinability of different stock strains of B. mallei in order to choose the best
strains for use as antigen.
Three strains of B. mallei, viz., stock strains No. 72, No. 124 and No. 169
were taken for study. These strains had been isolated in this Institute in 1908,
1926 and 1930 respectively from different localities in India. Strain No. 169
produces a slight bluish red discoloration on potato medium and a distinct stringy
culture (of. Ladany's statement as cited above) but the other two do not possess
this cultural characteristic. Antigen of these strains was prepared by growing the
organisms on glycerine broth medium, pH 7.3 at 37°C. After incubating for 10
days the culture was killed by autoclaving and was centrifuged at 6,500 revolutions
per minute for one hour. The supernatant fluid was thrown off and the sediment
was emulsified in physiological salt solution containing 0.5 per cent. carbolic acid
and re-centrifuged at the same speed and for the same period. The sediment was
then emulsified and standardised to barium sulphate standard opacity No. 32 in
carbolised physiological salt solution.
Serum samples were selected from three clinical cases and two healthy animals
as follows :—
Pony No. 18.—This animal was artificially infected by feeding balls of living
culture of strains No. 72 and No. 124 regularly at three months interval for about
* Paper read at the 19th Session of the Indian Science Congress, Bangalore, 1932.
( 274 )
BACILLUS MALLEI
275
23 months and re-infected with 1 c.c. of broth culture of strain No. 169 intravenous-
ly 5 days after the last administration of the living culture ball. Three months
later the animal was found to have developed symptoms almost approaching those
of clinical glanders.
Donkey No. 38.—This was also artificially infected with B. mallei and died of
glanders.
Mule No. 9460.—This animal was in contact with a clinical case of glanders
from which strain No. 169 used in this experiment had been recovered. It repre-
sented a typical case of clinical glanders.
Pony No. 292 and Donkey No. 33.—Both of these were perfectly healthy
animals.
Serum samples from all these five animals were submitted to the agglutination
test against the three strains of antigen mentioned above, and the titres obtained
are given in the following table. These titres show that all the three antigens were
more or less uniformly acted upon by the positive serum samples.
SUMMARY.
A study was made of the agglutinability of three strains of Bacillus mallei
and they showed no difference in this property.
ACKNOWLEDGMENT.
The writer desires to express his deep gratitude to Mr. F. "Ware, the Director
and Mr. H. Cooper, the Veterinary Research Officer of this Institute, for their guid-
ance and encouragement.
REFERENCE.
Hutyra, F. and Marek, J. (1926). Special Pathology and Thorapoutics of the Diseases of Domestic
Animals, III, 859.
G 2
276 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [II, III
TABLE
Results of the agglutination test against the
—
Pony No. 18
Donkey No. 38 .
Mule No. 9460 .
Control.
Pony No. 292
Donkey No. 38 .
Pony No. 18
Donkey No. 38 .
Mule No. 9460 .
Control.
Pony No. 292 .
Donkey No. 33 .
Pony No. 18
Donkey No. 38 .
Male No. 9460 .
Control.
Pony No. 29
Donkey No. 23 .
1/25
V. N. W. C.
N. W. C. .
V. N. W. C.
V. N. W. C.
V. N. W. C.
V. N. W. C.
V. N. W. C.
W.C.
V. N. W. C.
V. N. W. C.
V. N. W. C.
N. W. C.
W.C.
W. C.
V. N. W. C.
1/50
V. N. W. C.
V. N. W. C.
V. N. W. C.
N. W. C.
N. W. C.
V. N. W. C.
W.C.
W.C.
V. N. W. C.
N. W. C.
V. N. W. C.
V. N. W. C.
W. C.
W.C.
Adv.
24 hours
1/100
V. N. W. C.
W. C.
V. N. W.C.
V. adv.
Adv.
V. N. W.C.
W.C.
W.C.
V. N. W.C.
V. adv.
V. N. W. C.
W. C.
V. N. W. C.
N. W. C.
Dist.
ANTI
1/200
V. N. W. C.
W.C.
V. N. W. C.
Adv.
Dist.
1/500
AGAINST STOCK
N. W. C.
W.C.
V. adv.
?App.
?App.
AGAINST STOCK
V. N. W. C.
W.C.
W.C.
Dist.
Dist.
Adv.
V. N. W. C.
Dist.
..
?App.
AGAINST STOCK
N. W. C.
W.C.
N. W. C.
Dist.
?App.
Adv.
Adv.
Dist.
?App.
..
EXPLANATION OF THE
W.C.=
V. N. W. C.=
N. W. C.=
V. adv.=
Adv.=
Dist.=
App.=
? App.=
—
=
BACILLUS MALLEI
277
antigens of different strains of B. Mallei.
GEN
1/1000 1/2000
STRAIN NO. 169.
Dist.
V. adv.
Dist.
..
..
App.
Dist.
? App.
..
..
STRAIN NO. 124
Dist. .
Adv. .
App. .
..
App.
App.
App.
..
STRAIN NO. 72.
App.
Dist.
App.
..
..
? App.
App.
? App.
..
..
1/25
W.C.
W.C.
W.C.
W.C.
W.C.
1/50
W.C.
W.C.
W.C.
W.C.
W.C.
1/100
W.C.
W.C.
W.C.
W.C.
N. W. C.
48 hours
1/200
W.C.
W.C.
W.C.
N. W. C. .
Dist.
1/500
V. N. W. C.
W.C.
N. W. C.
? App.
? App.
1/1000
Dist.
V. N. W. C.
Dist.
..
1/2000
App.
Dist.
?App.
..
W.C.
W.C.
W.C.
W.C.
W.C.
W.C.
W.C.
W.C.
W.C.
V. N. W. C.
W.C.
W.C.
W.C.
W.C.
V. adv.
W.C.
W.C.
W.C.
N. W. C.
Dist.
V. adv.
V. N. W. C.
Adv.
App.
App.
Adv.
Adv.
Dist.
..
..
Dist.
Dist.
App.
..
..
W.C.
W.C.
W.C.
W.C.
W.C.
W.C.
w. c.
W.C.
W.C.
V. N. W. C.
W.C.
W. C.
W.C.
W.C.
Adv.
V. N. W. C.
W.C.
W.C.
N. W. C.
App. ..
Adv.
N. W. C.
Adv.
App.
..
Dist,
Dist.
App.
..
..
App.
App.
? App.
..
..
ABBREVIATIONS USED.
Water clear.
Very nearly water clear.
Nearly water clear.
Very advance.
Advance.
Distinct.
Appreciable.
Doubtful appreciable.
Negative.
PAPERS ON INDIAN TABANIDAE
* IX. THE LIFE-HISTORY OF HAEMATOPOTA RORALIS, FB.
BY
P. V. ISAAC, B.A., M.Sc. (LOND.), D.I.C.,
Offg. Imperial Entomologist, Imperial Institute of Agricultural Research, Pusa.
(Received for publication on the 14th May 1932.)
(With Plate XXIII.)
Introduction.
The life-history of no fly of the genus Haematopota has been studied completely
in any country. H. pluvialis L. is well-known all over Europe as a blood-sucker
of cattle, but its eggs are unknown in nature and the larval habits have not been
studied to any satisfactory extent. Patton and Evans [1929] remark that the
common cleg—H. pluvialis L. during the warm sunny days of June and July, will
attack men and animals in large numbers, in the British Isles. Cameron [1930]
succeeded in making the adult of this species lay eggs in cages in a laboratory in
Edinburgh. In Canada, Cameron [1926] reared the adults of the common species,
H. americana O. S. from larvae collected from the banks of sloughs. The eggs of
this species too are unknown. On the plains of India the two common species are
H. javana Wied. and H. roralis Fb. Patton and Cragg [1913] have observed
two undetermined species of Haematopota, around Madras, laying their eggs on
foliage at the edge of shallow streams or small ponds. At Pusa, Fletcher [1921]
reared a male H. javana from a larva found in the soil at the root of an indigo
plant.
Economic importance.
This species has a very wide distribution over the plains of India and also
occurs in Ceylon and the Malayan Archipelago. The female sucks blood from
cattle. About this fly, it has been reported from Ahmedabad District in Bombay,
that its bite is so harmful and annoying to cattle that, during certain seasons, the
cultivators cannot take their animals out for grazing and fieldwork before noon
and so do their field operations at night.
* Eight previous papers by the author, in the series, " Papers on Indian Tabanidae ", appeared
in the Memoirs of the Department of Agriculture in India, Entomological series.
( 278 )
PAPERS ON INDIAN TABANIADE
279
The adults.
The adult female is easily caught when it preys on animals. The males are
rarely seen. The bright eye-colours of the male and female disappear after death,
In the accompanying plate the eye-colours were recorded from living specimens.
Pre-imaginal stages.
The eggs are laid in long, narrow, flat, single-tiered clusters of about 40 to 100.
The individual eggs only slightly overlap one-another, and each egg mass forms
an elongated patch on the leaf of paddy or other foliage. Each egg is cigar-shaped,
1.5 mm. long, shining and black in colour. The colour of the new laid egg is
black.
The just hatched larva is 1.5 mm. long. It has no mandibles but has at the
cephalic extremity a minute process used by the embryo for cutting open the
egg-shell.
The full-grown larva is 18 mm. long. It has a retractile head, three thoracic
segments and eight abdominal segments. It has a close resemblance to larvae of
Tabanus. The terminal segment carries a very short siphon tube at the tip of
which is the opening for the tracheal trunks. The two lateral tracheal trunks are
narrow and the larva is unable to float in water.
The pupa is 13 mm. long, brown and slightly curved in the abdominal region.
Life-cycle.
H. roralis Fb. is usually found breeding in paddy fields or other low watery
tracts in association with narrow channels of running water. The adults are often
seen in such places on the foliage in cool shady parts.
The egg-masses are found in the open, usually on blades of paddy or wild
grasses, on the edges of streams. The eggs hatch in the early morning and the
larvae drop into the water below, sink to the bottom, undergo the first moult and
then burrow into the soil. The egg stage lasts for four days only.
The larvae live in damp soil. After the first instar the larvae possess strong
retractile mandibles as in the larvae of Tabanus. The food in nature is apparently
any soft-bodied animal they can prey on, tear open and suck. The larvae are not
cannibalistic. In the laboratory the larvae were kept in clean damp sand and fed
on fly-maggots taken from cow-dung in the fields.
The second moult takes place after six days or more from the date of hatching.
The larvae that do not encounter winter and hibernate pass through six instars and
then pupate. Seven moults were observed in a larva that hibernated.