Insect Pests of Date Palm in Arid Region

Date palm scale (Parlatoria blanchardi)

Host Range : Date palm

Nature of Damage

• Date palm scale is very serious on young palms between two to eight years of age, but even under severe attacks, the palm and its offshoots do not die.
• Nymphs and adults suck the sap from the leaflet, midribs and the dates. Under each scale insect, a discoloured area appears on the leaflet.
• Heavy infestation causes leaflets to turn yellow and contributes to the premature death of the fronds.

• Population of this pest is mild during May and June. On the onset of monsoon its population builds up and reaches to severe form during December and January months.
• The scale insect was observed as major pests in all the orchards in mild to severe form ranging from 1.10 cm² at Dantore to 18.77 cm² at Bikaner.

Description

• Anterior and posterior ends without minute "teeth"; rear abdominal segments formed into pygidium (diaspidid or armored scales)
• The egg is oblong with whitish yellow color.
• After hatching, the 1st instar, crawler that gets out from beneath the scale is also oblong yellowish white in color.

• The female passes through two nymphal instars, while the male passes through four.
• The female becomes semicircular, elongated, and apterous, while the male is elongated and winged.
• The scale is protecting itself with an armoured scale composed of exuviae and other secreted materials.
• After the last nymphal moult, the male usually emerges from beneath the scale, while the female remains motionless.

Lesser Date Moth (Batrachedra amydraula)

Lesser date moth is an important insect pest of date palm infesting fruits. This is one of the most important pests of the date palm in UAE that may cause more than 50% loss of the crop if not properly managed. In Rajasthan, the incidence of this pest was around 16 to 20%.

Host Range : Date palm

Nature of damage

• It starts its activity in date palm plantations, is then transmitted into storage with infested dates and can go through multiple generations within stored dates.

• The highest fruit damage was recorded in the variety Medjool (16.01%) followed by Khalas (14.54%) and Nagal (13.78%), whereas, lowest fruit damage was recorded in the varieties Zagloul, Medini and Zahidi as 1.43, 1.51 and 2.30 per cent.

Description

• Hind wing long, narrow; marginal fringe longer than hind wing width (case-bearing moths).

• The first larvae appear in April to start the damage on the newly formed fruits.
• The larva has a period of dormancy August till March of the next year between the bases of the terminal fronds.
• Pupation takes place in March and adults of the new cycle emerge in April, giving more larvae in 3 overlapping generations to damage different growth stages of dates.

Source: Insects Pest of Arid Fruit Crops

Related resources

1. Date Palm Pests and Diseases: Integrated Management Guide