They are particularly on the watch for the Mediterranean fruit fly and for the mongoose.
In the fruit fly, Drosophila ampelophila, we have found about 125 characters that are inherited in a perfectly definite way.
A fourth case is shown in the fruit fly, where an ebony fly with long wings is mated to a grey fly with vestigial wings (fig. 24).
The most extensive and conclusive experiments along this line are those by Morgan on the fruit fly Drosophila.
Again, a mutant stock in the fruit fly (Drosophila) has as its most marked characteristic very short wings.
The earlier ripening fruit usually escapes damage from fruit fly, but the late fruit often suffers considerably.
Many kinds of pears do well, but, unfortunately, this fine fruit is very liable to be attacked by fruit fly.