In late summer and autumn many specimens of a small fruit fly, known as the "vinegar fly," make their appearance, attracted by the odor of overripe fruit.
One mixture which we use is a mixture which is normally used against the fruit flies which are oftentimes injurious to fruit, particularly in the east and in tropical countries.
Professor Morgan, for example, has found a strain of fruit flies whose offspring in cold weather are usually born with supernumerary legs.
Thus, some proportion of a fruit fly population may not visit orchids if other plant species are available.
The sterile insect technique has demonstrated its ability to reduce fruit fly populations, and consequently reduce damage to fruit.
The issue of concern is how accurately this reflects fruit fly visitation to orchids?