R.
SENIOR-WHITE
123
TABLE VI—contd.
—
10 Adjusted Intermediate Index
(lb)
11 Standard error of Interme
diate Index (lb).
12 Standard error × t 10 per
cent (lb.)
Sindhi
Bull
No. 33
4259
294.7
529
Sindhi
Bull
No. 8
3985
422.2
722
Sindhi
Bull
No. 56
4092
16793
2873
The table brings out very clearly the import
ance of calculating the sampling error of the
index. It will be seen that although the three
sires are of about the same value as judged by
the calculated values of the Intermediate Index,
the degree of reliance that can be placed on
their breeding values is very different, e.g., it
would be wrong to recommend the use of bull
No. 56 for increased production without addi
tional proof of his ability, since on his present
showing his actual worth may be as low as
1280 lb. On the other hand, it is almost cer
tain that bulls Nos. 8 and 36 are worth more
than 3281 and 3729 lb. of milk and can, there
fore, be used with confidence on dams of those
levels for increasing production.
ACKNOWLEDGEMENT
I am grateful to Mr N. R. Joshi with whom
practically every view point expressed in this
note was discussed and to Mr A. N. Sankaran
for his help in the computations.
SOME NOTES ON THE LIFE-HISTORY OF MUSCA PLANICEPS WEID
By R. SENIOR-WHITE, F.R.S.E., Major, A.I.R.O. (Med.), Malariologist, B. N. Railway
(Received for publication on 6 January 1944)
THE observations forming this note were
made in the Ceylon foot-hills, 1,300 ft., 22
years ago. As the writer sees no chance of
ever continuing them, they are now put on
record, in the hope that they may be continued
by another hand, as they show that the biono
mics of this fly contain many interesting
points.
The genus Musca is biologically divided into
three groups, the saprophages, the haemeto-
phages, and the haematophiles.
The latter
obtain their supply of blood at punctures made
by other biting flies, principally Stomoxys
and the haematophages in the same genus. M.
planiceps belongs to the haematophages.
M. cingalaisina Big. and M. indica Awati
are synonyms of the species.
For eight months fresh cow-dung was ex
posed fortnightly for 24 hours and then removed
to the laboratory for breeding out.
The emergences were:
1. Hippelates sp. . .
2. Sepsis sp. . .
3. Sepsis rufa Meig .
4. Brachyophyra sp. .
5. Spilogaster sp. . .
6. Morellia hortensia Wd.
7. Musca pattoni Aust. .
8. Musca bezzii P. & C.
9. Musca conducens
2524
Wlk.
1 ♂
79
1$
3 ♂ ♀
9 ♂ 7 ♀
34 ♂ 86 ♀
4 ♂ 11 ♀
2 ♂ 2♀
6* 2851 9
July
September
July
July
Every
month
except October
and December
June and July
July,
August,
September, and
November
September and
January
In every month
10. Musca planiceps Wd.
11. Musca inferior Stein
12. Musca crassirostris
Stein
13. Orthelia lauta Wd.
14. Orthellia sp. . .
57 ♂ 61 ♀
1 ♀
34 ♂ 58 ♀
8 ♂ 4 ♀
5 ♂ 5 ♀
In every month.
July
August, Septem
ber, November,
December
July
January
Thus M. planiceps is a constant, though
numerically not numerous, breeder in fresh
cow-dung, which is, in the locality studied,
pre-eminently the pabulum of M. conducens,
forming nearly 92 per cent of all emergences.
M. planiceps, with second place, forms 32 per
cent of the remaining species.
The genus
Musca has—in the Indian Sub-Region,—ad
vanced into viviparity once in the haemato-
phagous and once in the haematophilous group,
but not with the most successful biter, crassi-
rostris, whilst bezzii, in the haematophiles, is
a species of rather restricted distribution. The
larva of bezzii is born in stage II, but that of
planiceps is born in stage III, in this respect
resembling the species of Glossina. But where
as the larvae of Glossina are full fed and ready
to pupate when born, those of planiceps are in
early stage III and change their pabulum after
birth from the maternal secretion to cow-dung
and complete their development in this material.
This must involve profound changes in meta
bolism, completely unstudied.
Larval development.
The newly emerged
female contains only immature eggs. The
mature egg passes into the common oviduct,
enlarged to form a uterus. A mature egg,