98 Papaya
practices. Use of sticky bands or alkathene sheet or a band of insecticide paste on
branches or on main stem to prevent movement of crawlers from ground to trees is
an effective practice.
9.1.2.2 Biological
Natural enemies of the papaya mealy bug include the commercially available mealy
bug destroyer Cryptolaemus montrouzieri, ladybird beetles, lacewings, Scymnus
sp. and certain hymenopteran and dipteran parasitoids. Conservation of these natu-
ral enemies in nature plays important role in reducing the mealy bug population.
In the nature, lepidopteran predator, Spalgiepius sp. (Lycaenidae) is a well-known
representative of carnivorous butterfly feeding on ovisacs, nymphs and adult stages
(Muniappan et al. 2006).
9.1.2.3 Chemical
Locate ant colonies and destroy them by drenching with chlorpyriphos 20 EC at
2.0 mL/L of water. Apply chemical insecticides as the last resort such as dimethoate
30 EC (2.0 mL/L), or imidacloprid 17.8 SL (0.6 mL/L) two times at 15 days interval.
Spot application of insecticide immediately after noticing mealy bug is again very
effective. If the activities of natural enemies are not observed, use of botanical insec-
ticides such as neem oil (1.0%–2.0%), NSKE (5.0%) or fish oil Rosin soap (25.0 g/L of
water) should be the first choice. Drenching soil with chlorpyriphos around the collar
region of the plant to prevent movement of crawlers of mealy bug and the ant activity
FIGURE 9.1 (See colour insert.) Mealy bug infestation on papaya plants.