Greater date moth (Arenipses Sabella) Or Aphomia sabella (New name)
Pyralidae – Lepidoptera
Life cycle and symptoms of infestation:
The greater date worm is considered one of the early pests in the fruiting seasons, as it is found dormant in the form of larvae and pupae after harvesting the dates crop in the axils of the leaves and inside the fiber and on the remnants of the previous crop from old flowering plants, old dates falling on the ground, and unknown (scattered) dates that are worthless and have not been harvested and fell to the ground. Where the insect females lay eggs on the covers of the male flower that come out first, then on the covers of the female flower in the month of March and early April (the first according to the temperatures and where the date of the emergence of the flower changes with the change of the prevailing climate in this region) and the eggs hatch to larvae that feed on these covers and penetrate them Inside, as it feeds on the juicy, unopened saplings and attacks the bracts and saplings of fruits, where it is noticed that the pollen inside the flower beds turns black as a result of the larvae feeding on them and on the bases of the flower beds, and thus leads to the incomplete flowering and knotting process. And leave its residue on flowering stalks. The highest rate of infestation with the greater date worm was recorded at the end of April, where the larvae attack the stems of the branches at the point of contact with the palm tree and dig into the bases of the bunches or bunches, which causes the bunches to break later and affects the quality of the fruits.
This effect can be seen in the month of July when the weight of the bunches increases and the infested bunch stem cannot bear the fruits of dates, so it breaks and remains connected to the palm tree with a small part that does not allow the passage of sufficient juice necessary to feed the fruits of the bunches, so the fruits become small in size and contain less sugar compared to the non-infested bunch fruits. The larvae infest the fruits in the khelal stage, where the larvae are in the middle of bunches, and there is a quantity of dry fruits that were damaged by the larvae in the middle of the bunches, as well as the presence of dry fruits connected to stalks that the larvae cut and remained in the bunch. At the end of the season, moths lay eggs on the remaining dates in the field, whether on the palm trees or on the offshoots or on the waste after collection. The eggs hatch into larvae that enter the dates and bore into the hard stone. The larvae’s feces is also observed with the silky tissues inside the dates. The larvae turn into a pupae inside a cocoon of silk on the fibers between the bases of the leaves.so that the moths emerge again to re-infest in the following season.The larvae can infest the leaves of the juicy heart of the offshoots, which may be contaminated after with fungus and bacteria and lead to the death of the palm tree. In 2021, it was observed that there were many infestations of the new offshoots with the greater date worm, which led to its death.The insect has 2-3 generations annually.
Protection and control methods:
• Mechanical control by pruning and removing the remnants of the previous date crop, including old bracts, 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 the branches and the bases of the leaves are fumigated 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 crop collection and pruning.
• Attention to good service operations such as balanced fertilization, irrigation, good hoeing and weed disposal.
• Using behavioral control using light traps to monitor the emergence of adult insects since the beginning of the season in winter, as well as to eliminate them. Their use is also taken into account in sawmills drying dates, in warehouses and factories.
• Covering date pods with perforated bags after discoloration of the fruits to prevent butterflies from laying eggs on the fruits of dates.
• The use of biological control using the parasite Trichogramma for eggs and the parasite Bracon for larvae at the beginning of the appearance of eggs and larvae of the insect and throughout the season and in the sawmill, warehouse and factory.
• The use of biological control using insect pathogens such as Beauveria fungus and B.T. bacteria compounds and viruses.
Pictures showing the larva and the moth of the greater date worm.
Pictures showing the infestation symptoms of the greater date worm.
