Economic importance:
The date stone beetle is considered one of the insects that infects the fruits of dates on the palm or fallen ones. It may move with the dates to the store. The insect spreads in the governorates of the Delta (Kafr al-Sheikh, Buhaira, Damietta, Dakahlia, Sharkia and Ismailia), the New Valley, the Bahariya Oasis and the northern coast. This pest has 4 generations per year. The infestation rate in Egypt is 4-25%, depending on the cultivar, and the infestation rate in Israel is 30-40%.
Morphological description:
The adult: a small insect (2-3 mm) long, brown in color. There are pits in longitudinal rows on the two sheaths, and the larva is semi-curved inside the kernel. It is a primary pest of the immature green dates.
Symptoms of infestation:
The infestation is characterized by the presence of circular holes, often near or in the cup, and there may be one or two holes on the fruits of dates, as the hole leads to a tunnel of wall forces that always reaches the stone.
The presence of tunnels facilitates infestation with the dry date beetle and the Dosophila fly, which leads to rotting of the fruits and their falling off.
Many of the fruits dry on the stalk, and most of the fruits fall off in July and August.
The infestation on date stone is characterized by the presence of numerous tunnels and entry and exit holes.
Life cycle
The beetle females make a regular round hole on the fruit and in the stone because the males are not able to make the holes and the numbers of females are very many compared to the males which may reach 98% in the field or laboratory breeding. Then the adults remain in the main tunnel for a period of 1-2 days, where mating occurs, and the females begin to make tunnels and eggs are laid (only females are able to dig and make tunnels) and the eggs are laid individually, the mated female lays about 20-50 eggs, while the unmated female It can lay only 7 eggs (unfertilized eggs produce only males), and the eggs hatch after about 5-9 days into larvae, the larval period is 11-23 days, and the larva has 3 larval instars, and larvae of both the first and second ages cannot feed themselves, the mother feeds them The larvae of the third age can feed on the exudates of the holes made by the mother, but they cannot dig themselves, and the pupal period is 4-13 days, and the new females and males remain for a period of 2-3 days inside the tunnels and mating occurs, and the females spend the winter period in the form of beetles inside the tunnels that were made it in the fallen cores on the ground or between the bases of the date palm leaves.Mated females give eggs that result in males and females, while unmated females give eggs that result in males only.In a study on the effect of the presence of the capsule in the dates of the tympanic variety on the rate of infestation with this insect, it was observed that the incidence of infestation with dates containing the capsule was delayed from the dates without the capsule, and the infestation rate was 4-5% in dates devoid of the capsule, compared to 13-3% in dates containing the capsule.
Protection and control methods:
- Mechanical control by pruning and removing the remnants of the previous date crop, including old bunches, old floral stalks, old dates falling in the axils of leaves and on the ground, and unknown dates (scattered), and the safe disposal of all these residues, including larvae and pupae, after harvesting the crop during October, November and December.
- Then the heart of the palm tree and around the place of exit of bunches and the bases of the leaves are dusting with agricultural sulfur.
- One of the recommended pesticides can be used to wash the heart of the palm and the bases of the leaf after date fruits collection and pruning.
- Attention to good agricultural practices service such as balanced fertilization, irrigation, good hoeing and weed disposal.
- • Make a belt around the palm tree with a piece of gauze or polyethylene with a width of 15 cm with an adhesive substance in order to prevent the insect from moving from the trunk of the palm tree to the fruit area.
- • Making traps from date stones, by placing the pits at the bottom of the palm tree or in the form of a knot on the trunk of the palm tree at a height of 1.5 m from the surface of the earth, or on the stalk, so that it hangs between the trees with a length of 40 cm.
- Use of some plant extracts, such as cumin extract, black pepper, and zin zalakht, which lead to a reduction in the infestation rate.
- Use of biological control using insect pathogens such as Beauvreria bassiana.
- In case of severe infestation and the failure of the previous methods to control the infection, one of the insecticides can be sprayed on the trunk in the months of June and July, taking into account the calculation of the PHI period of the pesticide.
