For years, our regions have witnessed an unprecedented and intense spread of various insects that have caused losses in the revenues of the various agricultural sectors.
Among these insects are:
- Tomato worm Tuta absoluta
- The sewing worm fly liriomyza on cucurbits and other vegetables
- The whitefly, Bemisia Tabaci
- The citrus whitefly Dialeurodes Citri, the woolly citrus fly Aleurothrixus Floccosus, and the Paraleyrodes fly that touched citrus orchards
- The mealybug Dactylopius opuntiae, which infected cactus trees, inflicted heavy losses, and caused its withering and drying up.
The reasons behind these sudden waves
Over the years, humans played a major role in changing the environment in which insects live, whether through land reclamation and replacement of forests with new types of crops, or the myriad of modern agricultural practices aiming at mass production. This has led to a major imbalance in the ecological equilibrium, disrupting a system that has existed for thousands of years and threatening the existence of various species. The latter has led to the sudden waves of changes observed over the past years, noting that the life of insects is closely linked to complex external and internal factors (soil, temperature, humidity).
As for the density of insect strains, it is also related to the ecosystem, as any defect, even the slightest, may affect the balance between an organism’s ability to reproduce or survive. This means that a small number of new insects can remain alive to ensure the continuity of their species, despite the death of their precedence, according to the following equation:
n = number of members of the insect family
i = sex index of the insect f/f+m
F = female , m = male
Environmental and climatic factors are not the only responsible for the proliferation of insects. In fact, many physiological factors can explain how insects reproduce at once and over large areas, despite the varying climatic factors.
Methods of Control
Pest control can either be preventive or curative.
Preventive control is the set of measures taken to prevent the spread of the pest, which reduces the incurring expenses of Curative control. Among these measures, we cite:
A- Monitoring the prevailing conditions.
b- Completing all mechanical and chemical agricultural operations in a timely manner.
C- Performing detailed diagnosis of the phenomena and pests observed in order to select the best effective methods.
As for Curative control, its goal is to reduce the number of insects present and ensure the safety of agricultural productions. However, its effectiveness remains linked to many factors like the method of control, the conditions of its application…
In light of the latter, human activity is of great impact as it may disturb the prevailing ecological balance and negatively or positively affect the density of insects in a specific area. Therefore, it is necessary to follow the appropriate agricultural guidelines, within the framework of the Integrated Crop Management – ICM in order to preserve both the environment and agricultural productions.
by Ibrahim Youness