It is the month of February, and there is a bite in the evening air. Goa is gearing up for Carnival even if Ash Wednesday is like a wet blanket on Valentine’s Day, as if the ‘Leap Year’ superstition wasn’t bad enough for young romantics.
Self-perpetuation is the strongest urge of any living creature. Sigmund Freud broke up the animal response into two major desires or compelling forces – food and sex.
Food sustains life in the current generation, and mating makes the next generation possible.
To ensure that one gets a mate of the same species, our DNA is wired to produce very specific mating smells known as ‘pheromones’. These smells are produced by the females of the species.
If dogs produce it most during the month of August, the mango fruit fly, Bactrocera dorsalis is the target from Valentine’s Day to May Day.
Apart from sunny skies and sandy beaches, if there’s one thing that’s associated with Goa, it’s mangoes – and Goa has plenty of delicious varieties to relish.
And, it’s that time of the year when the local population wait for mango season, waiting and watching patiently as flowers turn to fruits on mango trees. Quite often, this joy is short lived due to pests, known as fruit flies.
DEALING WITH FRUIT FLIES
Entomologists – scientists who study insects – found male fruit flies hovering around flowers of basil plants (related to the tulsi plant).
This was no religious ritual. The chemicals present in basil flowers were analysed, and the pheromone-like substance was identified as methyl eugenol, a volatile compound.
Ever since, fruit flies have been honey-trapped and poisoned or simply allowed to starve to death believing they could survive on love and fresh air. The pheromone itself was fake.
The mango fruit fly is related to the melon fruit fly, but the pheromone itself is different. These traps and specific pheromone lures are available at the Zonal Agriculture Offices (ZAO) and with Pest Control India (PCI) as also some garden input stores and nurseries.
Attracted by the pheromone, the male fruit flies gather in the trap. They will not leave the trap as long as the smell persists. The pheromone lasts for three to six months, while the male flies die of starvation within a week!
The female fruit flies of mangoes, melons and gourds face a similar problem as some villages in which the young and able-bodied men migrate in search of work in distant lands or on the high seas.
It is aggravated by the fact that the fruit flies have a life span of days, not years. The females die eventually. There are no fertilized eggs and, hence, no worms in the fruits. One can call it the ‘Ex’ effect.
The author is a former Chairman of the GCCI Agriculture Committee, CEO of Planter's Choice Pvt Ltd, Additional Director of OFAI and Garden Superintendent of Goa University, and has edited 18 books for Goa & Konkan