The date palm Dubas insect is considered one of the dangerous pests of date palms in Iraq, Oman and Iran. The insect was recorded in Egypt and infests date palms and Canary palms. The infestation also entered Yemen in 2000 AD on cuttings imported from Oman and moved to several governorates inside Yemen in 2006 AD. One of the factors that helped spread the insect is its ability to move by wind for a distance of 50-70 km during the year.
Life cycle and symptoms of infestation:
Harmful stage: adult insect and nymph
Whereas, the date palm Dubas insect belongs to the order Homoptera. This insect was named by this name because it secretes a sugary substance (molasses) during its feeding, in addition to what the affected parts of the palm tree secrete of this substance.
Adult: light green or yellowish green, with brown spots on its body, 5 mm long.
Nymph: light yellow, with brown spots on her back. There are long whiskers at the back of her body. Its length when fully grown is about 2 mm.
symptoms of infestation:
Adult insects and nymphs feed by sucking plant sap in the places of infestation, from palm fronds (fiber), stalks and fruits, from spring to autumn. Infested trees appear brightly when the sun shines, and dirt accumulates on the affected parts, as fungi grow on them. The continuation of the infestation for several years may lead to the death of the tree, and the presence of molasses on the fruit reduces its quality. Plantations loaded between palm trees are also affected by the fall of molasses. On it, as this substance reduces the vitality of these plants (cultivations), and it appears on their leaves in the form of black discoloration, due to the growth of fungi on this substance.
There is no doubt that the recurrence of severe infection causes weakness and death of some palm trees.
Insect generations:
The insect has two generations a year, one in the spring and the other in the fall.
Where the infestation begins in May (the spring generation), so the nymphs begin to feed on the wicker and secrete the honeydew that accumulates on the wicker, causing it to dry out and change its color. While in the second generation in the fall, the accumulation of the honeydew falling on the fruits leads to their shrinkage in the case of severe infestation, as thousands of bugs feed on young leaves and black dots formed as a result of fungal growth on the honeydew. With the presence of Insect moulting skin abundance.
life cycle :
The eggs of the first spring generation are laid in November, and their incubation period lasts about 141 days, after which they hatch in April into small nymphs that moult in several moults. The nymph takes about 47 days, after which it turns into a full insect in the month of June, where it lives 15 days, and thus the spring generation takes 203 days. As for the autumn generation, the female lays her eggs during the second week of August, and this continues until the third week of September, and the eggs hatch from nymphs, which then turn into full insects. This generation takes about 113 days.
Protection and control methods:
- Taking care of the distances between palm trees when planting them.
- Mechanical control by good pruning during the months of December and January, and the removal of the remnants of the previous date crop from old bracts, old floral stalks, old dates falling in the u nderarms of leaves and on the ground, and unknown (scattered) dates, and the safe disposal of all these remnants of larvae and pupae dormant after harvesting the crop during the month of 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 collection and pruning.
- Attention to good service operations such as balanced and balanced fertilization, good hoeing and weed disposal.
- The use of biological control using the following predators and parasites:
First the predators:
Abu al-Eid eleven-pointed Coccinella undecimpunctata.
Abu al-Eid seven-pointed Coccinella septempunctata.
Abu Al-Eid Al-Aswad Chilocorus bipostulatus.
lion aphid.Chrysoperla carnea
Praying mantis Sphodromantis viridis
Secondly, parasites:
The parasite Pseudoligostia babylonica on Dubas eggs
• Chemical control In the event of severe infection and failure of the previous methods to control the infection, this insect can be controlled by spraying trees with insecticides recommended for each country, for example Malathion 57% at a rate of 1 g / liter of water. Control takes place in the spring when the hatching rate reaches about 75%. And this is in April and May, and the autumn generation struggles in September and October, and the trees are sprayed several times every 7-10 days.
