DIPTERA (TWO-WINGED FLIES) . 
65 
Lieut. -Colonel J. W. Yerbury, who has had great experience in 
collecting Diptera both in this country and abroad : — 
" Diptera are to be found everywhere. Still, the followiDg points 
should always be considered : — 
" Locality. — In temperate climates virgin soil is best, with a south 
or west aspect for choice. 
"In the tropics shelter from the prevailing wind is the most 
important point. 
" Shelter, however, is an important factor everywhere, and the 
line taken should be selected with due regard for the direction of 
the wind. 
" Habits. — The habits of the various families differ greatly, and, as 
a natural consequence, their favourite localities vary also. Before 
discussing these in detail, it may be advisable to enumerate some of 
the general attractions for the order. 
" Flowers. — Some flowers are particularly attractive to Diptera, 
and these are as a rule white or yellow in colour. 
" In England the flowers of the following may be enumerated as 
specially attractive : common and Portugal laurel, holly, black- 
thorn, hawthorn, bramble, plane, barberry, and at times rhododendron 
and dog-rose ; but the attraction of the two latter does not as a rule 
last long. Probably all these are equally attractive in Europe, and 
to them may be added dane-wort (Sambucus ebulus). 
" In the tropics Diptera should be looked for on the flowers of 
several palms and various species of Bher-trees (Zizyphus), etc. 
" Sugar, as applied by Lepidopterists, has not as a rule much 
attraction. Still, occasionally it is attractive to Calypterate Muscidce, 
and in a lesser degree to Stratiomyidce ; while at night many Daddy- 
long-legs (particularly Limnobia) come to sugar. 
" Ordure. — Many Diptera are attracted by this — not only Scato- 
phagidce and Muscidce, but Diptera of families which one would not 
expect to see, the moisture being the probable attraction. 
" Living Animals. — Many species of Tabanidce and other families 
are to be seen round living animals, but as a rule are not to be 
caught, the exception being the Hippoboscidce, which can often be 
taken with ease. It is seldom possible to catch flies round animals. 
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