Mealy bugs are the commonest pest on euphorbias. They are up to 3 mm long, oval, similar to wood-lice but whitish, easily distinguished by the white, cotton-like substance they produce. The adults prefer inaccessible areas and so may be difficult to find unless plants are very carefully examined. In an infestation of E. flanaganii at the shoot tips, the plant reacts by the whole branch drying back and being shed. Infected plants should be isolated to prevent spread of the pest. As First Aid, the cocoons containing oval, yellow, shiny eggs, the small yellowish larvae, and the whitish adults, can be removed from individual plants with a pin. However, since the mealy bugs prefer inaccessible areas, even in the soil around the plant’s neck, generally this only achieves a reduction in numbers.

Treatment is with regular spraying with pyrethrum, nicotine solution or mineral-oil based insecticides. Also regular applications or sprays with soft soap and spirit helps against the drought loving mealies.

Mealy bugs
Normal form on Frailea spec. (cactus)	Long haired form on Euphorbia susannae