EDITORIAL. 
The loss caused by the jointworm flies of the genus Harmolita 
(Isosoma) in the United States runs into millions of dollars per 
annum, the wheat jointworm (/. tritici) being the greatest devastator. 
W. J. Phillips (Bulletin 808, Professional Paper U.S.A. Department 
of Agriculture) has gathered together the available information and 
classified the species into groups that attack grain crops, cultivated: 
grasses, and wild grasses. The two first groups cause considerable loss 
' by the injury they entail to the crops. The members of the last 
group, however, may possibly be beneficial in an economic sense, as 
they provide intermediate hosts for the parasitic insects which prey upon 
the genus, the more important parasites being common to the majority 
of species of Harmolita. The life-histories of several species are 
described, together with the. way in which injury is caused to the ~ 
plants attacked. H. tritici causes the most serious losses, reducing the 
yield of wheat by as much as 50 per cent., the grains being somewhat 
small and shrivelled. H. grandis is also confined to wheat, and pro- 
duces two generations in the year, but as it is easily controlled its 
powers of destruction can be kept in check. Breeding experiments 
indicate that each species is probably confined to a single host, as it 
has proved impossible to induce the more important forms to attack 
other crops than that with which they are normally associated. The 
jointworms are much subject to parasitic attacks, and for this reason 
do not often get quite out of hand and’ destroy an entire crop; but, 
even so, they exact a toll of from 1 to 5 bushels per acre unless control 
measures are adopted. _ Experiments seem to show that ploughing 
under the stubble is the most effective remedy, as wholesale destruction 
of the insects is thus brought about. It would be necessary to arrange 
the crop rotation so as to allow the wheat-stubble to be ploughed up, 
but if this could be done it is estimated that millions of dollars could 
be saved yearly. 
Parasites such as lice and mites cause considerable loss in the 
poultry industry by reducing egg-production and injuring the quantity 
and quality of the flesh of the birds. <A cheap but effective remedy 
is therefore much to be desired, and it is now claimed by F. C. Bishop 
and H. P. Wood (Farmers’ Bulletin 801, U.S.A, Dept. Agric.) that 
sodium fluoride fulfils these conditions, and that, if properly used, one 
application will completely destroy all the lice present on any bird. 
The treatment can be carried out by dusting or by dipping. In the 
former case, pinches of the fluoride are placed among the feathers close 
to the skin on the parts most frequently attacked; dusting with a 
shaker is less effective, and also caused more Jrritation to the nose 
and throat of the operator. In the latter case, 4-1 of commercial 
sodium fluoride is dissolved in a gallon of tepid water, and the birds 
are then dipped for a few seconds. The lice die more rapidly in this 
case than when the dry powder is used. It is estimated that the cost 
of treatment works out to about one farthing per bird, 1 Ib. of sodium 
fluoride sufficing for about 100 hens.—( Nature, 22nd July, 1920.) 
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