11. Aphid: Toxoptera citricidus, T. aurantii (Aphididae: Hemiptera)

Distribution and status: Found in all citrus growing regions.Minor pest

Host range: Rutaceae and Rosaceae families.

Damage symptoms

Nymphs and adults suck sap from plant parts causing the curling up, deformation, yellowing and crinkling of tender shoots resulting in stunted growth. Blossoms and newly set fruits also affected. Honey dew secreted by the aphids acts as substrate for sooty mould growth.

Bionomics

Adult  are wingless and shiny black, nymphs dark reddish brown. Nymphs of brown aphid give out yellow haemolymph and black aphid red haemolymph on squashing.

Management

• Release of coccinellid predator, Menochilus sexmaculatus @ 50 per tree.
• Spray 3.0 L dimethoate 30 EC or 1.5  L monocrotophos 36 SL or 2.5 L oxydemeton methyl 25 EC in 1500-2000 L water per ha during March and again in September.