One of the problems of repeated applications of pesticide is the emergence of resistant populations and the removal of beneficial species, often the predators of the pests. Generally predators take longer to have their numbers recover after the application of pesticide compared to the pests. This window of time allows the pest to increase its numbers unchecked. As a result the farmer is required to apply more pesticide, making it harder for predators to recover. This cycle is perpetuated and is called the pesticide treadmill.
.jpg)
By trying alternative methods, there are many benefits:
1. Only the pest species are targeted.
2. No chemical residues
3. Often more cost effective (particularly in the long term)
4. May lead to the eradication of the pest all together.
Some examples of this are:
1. Pheromone traps, these are effective when females use a chemical scent to signal to males they are ready to mate. By using the hormone, males can be lured to traps.
2. Introduction of diseases - disease tends to be pest specific. However it may require regular reapplication and disease resistance may emerge.
3. Introduction of predators - Again this can be considered if the predator does not target non pest species. A case where this went horribly wrong was the cane toad.
4. Sterile male release. By releasing sterile males, the females lay eggs that wont hatch. However, sterile males need to be released repeatedly.
No comments:
Post a Comment