Palm weevil its symptoms and methods of prevention
Palm trees are distinguished by their tolerance to different environmental conditions and their resistance to drought, which led to their spread and expansion of their cultivation and increasing their numbers in many countries of the world and the Arab countries in particular, as their cultivation extends from Mauritania to Iraq and the Arab Gulf states. This tree is exposed to many different insect and pathological injuries that affect its cultivation and production. In the past two decades, injuries have appeared on palm trees with a new insect known as ((Red Palm Weevil or Indian palm weevil or Asian palm weevil)) and this insect published the first information about it in India in 1891, and was described as a pest Dangerous coconut palms in 1906, and a serious pest appeared on the date palms in Punjab in 1917.
This insect is spread in Iran, India, Pakistan, Ceylon, the Philippines, Malaysia, Taiwan and Indonesia on the oil palm trees, coconut, sugar palm and date palm and in the Arab Gulf region was registered for the first time in the United Arab Emirates in 1985, in the Emirate of Ras Al Khaimah and then in the Kingdom of Saudi Arabia in Qatif in 1987, and in Egypt in the eastern and Ismaili governorates in 1992. In Syria, at the end of 2005 in the Lattakia governorate. The Indian red palm weevil (Rynchophorus ferrugineus Fabr) follows the rank of insect sheaths (Coleoptera) of the licorice family (Curculiondae) and the following table shows the types of red palm weevil and its plant family of palms and their areas of spread:
Type of host insect from the palm spread area
Rynchophorus ferrugineus Date Palm Date Palm Countries Middle East, Arabian Gulf, Southeast Asia, Tropical Africa, New Guinea, Florida, Central and South America, Iran, China, Kuwait, Palestine, Jordan, Malaysia.
Rynchophorus bilinactus, Coconut palm
Rynchophorus phoenicis, sugar palm
Rynchophorus palmarum, Sago palm
Rynchophorus papuanus, Palmyra palm
And the infection of this insect leads to the death of the affected trees, as it causes the palm tree to be emptied of its hardness and the plant sap dries up. These insects are characterized by the ability to fly to far regions up to 1500 m and with high fertility, and the insects cause injury to all palm trees in the orchard, thus turning the orchards into an infested area, which eliminates seedlings and fruitful palms during a period between one to two years. The incidence rate on date palm varies according to environmental conditions. Varieties and age of the palm tree, where the ratio ranged between 2% in Pakistan and 60% in the Qatif oasis in the Kingdom of Saudi Arabia. Studies have confirmed that 5% of young date palm trees, up to 10 years old, die due to infection with this insect.
Symptoms of infection:
It is difficult to know the first stages of an infection because the larvae are inside the trunk of the palm tree and cannot be seen outside the trunk, but the damage can be seen and the later stages of the infection are known by mucilage and an unpleasant smell. Symptoms of the infection are:
Palm yield decreases, fronds begin to wither and yellow, then the leaves dry completely and are easy to remove.
The continued feeding of the larvae on the stem tissue converts the stem of the palm tree into a tube filled with decomposing tissue and the larval waste and smells bad.
Because the larvae devour the soft, living tissues and make tunnels in the heart of the palm, the palm head tends to curve.
The leg becomes prone to fracture if exposed to strong winds or any external influence.
The presence of regular or semi-regular holes on the stem as an indication of the larvae entering after hatching the eggs on the stem.
The presence of sawdust on the stem due to the processing of fully developed larvae for the process of converting them into a virgin, directly behind the leaf bases (distress).
It can be seen that the infection on the stem is severe in the area extending from the surface of the soil to a height of 2 m above it.
Insect prevention methods:
Attention to the agricultural operations of serving palm trees, in particular (removal of seedlings), brothels and pruning (removal of dry fronds and the remains of old tastes) and agitation with interest in fertilization and irrigation on a regular basis.
Combating palm stalk excavators and rodents that cause tunnels in the trunks of palm trees.
Dip the seedlings to be planted before the transplant process with one of the appropriate pesticides as a precaution.
Spraying healthy trees in areas affected by a pesticide as a precaution.
Organizing guiding seminars to educate farmers and farmers and clarify everything related to this harmful insect by issuing guidelines and preparing posters and explanatory posters on everything related to this insect.
Use traps to attract complete insects, including poisonous traps that attract insects through the smell of fermented materials, as well as food pheromone traps to attract this insect through the use of Aggregation pheromone with pieces of palm stem or sugar cane immersed in the appropriate pesticide and found that the combined pheromone taste Ferrugitom 200) The user with pieces of palm trunks and pesticides was successful in catching large numbers of insects and uses one taste for every 15 palm trees in the case of irregular cultivation and one taste for every 50 palm trees in the case of regular plantings and the taste should be renewed every (4 – 6 weeks). This method is one of the indicators of the presence of the insect as it leads to the disposal of large numbers of it.
Spraying the affected trees completely with one of the pesticides, then removing the infected palm completely, and the process of fogging is done to the place of the removed trees and it is well rubbed and cut the infected stems into small pieces and transfer these pieces with all their residues to the site