Know-how for growers
Vio-trap is an mean of control of the olive fruit fly (Bactrocera oleae) which should be applied in a timely manner according to the instructions, given that even in years of small population it causes damage to the olive fruit.
It must be noted that each female gives birth to 180-350 eggs 50% (half) of which in the next generation are once again females giving a potential of infection capable in two generation to cause huge damages if the climate conditions are also helpful.
3-5 generations per year have been observed in Greece. Thus a single female who will find optimal conditions and its descendents are not controlled in some way, will give populations more than a billion (1.000.000.000) insects.
Also it should be noted that the olive fruit fly, although a monophagus insect of olive, uses alternative food sources as an adult that helps it be more active and aggressive and also survive in adverse conditions.
Time of implementation: The correct time of implementation varies depending on the year’s climate conditions and for Greece it begins on the 1st of June until the 20th of July and the method of determining the exact date can and should be done with ‘McPhail’ traps.
A very early fructification is expected for 2010 in the southern parts of the country and the hanging of traps must take place in May. The correct time of trap suspension is when the olive fruit flies begin flights and before the females become fertile.
Operation of trap: The trap exterminates the populations of the olive fruit fly from the first 3-4 days of its action with possibility of extermination of many thousands insects per day.
One thing it cannot do is to kill the eggs that have already been born and the emigrational females that are ready to give birth and come from nearby olive groves.
A good measure that has been applied is the limited fertilization of nitrogen and watering, avoiding the good nourishment of the olive tree, the part that attracts all population of the olive fruit flies from the surrounding area.