How to control pineapple mealybug? Detailed control methods
The pineapple mealybug, scientific name Dysmicoccus brevipes (Cockerell), belongs to the order Homoptera, family Pseudococcidae. Dysmicoccus brevipes is the most commonly seen species. Damage symptoms: adults and nymphs damage pineapple rhizomes, leaves, fruits and seedlings by sucking their sap. On affected leaves, symptoms first appear on the lower leaves, gradually fading upward to yellow and finally...
The pineapple mealybug, scientific name Dysmicoccus brevipes (Cockerell), belongs to the order Homoptera, family Pseudococcidae. Dysmicoccus brevipes is the most commonly seen species.
Damage symptoms: adults and nymphs damage pineapple rhizomes, leaves, fruits and seedlings by sucking their sap. On affected leaves, symptoms first appear on the lower leaves, which gradually fade upward to yellow and finally turn red-purple; in severe cases all leaves soften, droop and wither, ultimately causing the death of the whole plant. Affected roots first turn dark brown, then gradually rot, causing the plant to decline in vigor. On affected fruits, the rind loses its luster, and the "honeydew" they secrete can lead to sooty mold, with severe cases showing shrinkage. Affected seedlings develop poorly and may even wither.
Morphological characteristics
Adult: the female adult is about 2.5-3 mm long, flat and oval, covered with white waxy powder, with waxy projections along the margin, 7-8 antennal segments, 17 pairs of pore clusters, and wax-secreting setae; the anal lobes bear 2 medium-sized conical setae. Tubular ducts are distributed on abdominal segments 6-8, clustered along the margin; the hind tibia is about twice as long as the tarsus; females are mostly pink in body color. At sexual maturity, a white waxy cotton-like ovisac is attached to the end of the abdomen. The male adult is very small, yellowish-brown, with transparent wings held flat over the back of the body, and a pair of slender waxy structures at the end of the abdomen. It has a pair of transparent forewings.
Egg: body length 0.35-0.38 mm, oval, initially yellow, gradually turning yellowish-brown, in irregular cotton-like masses, attached to the host plant.
Nymph: 3 instars in total. Resembles the female adult but smaller, with antennae and legs. Female nymphs become adults after 3 molts; male nymphs become pupae after 2 molts.
Pupa: located in a cocoon sac formed of silky waxy material; the cocoon is irregular in shape, mostly elongated, attached to the plant.
Life cycle: one generation takes 45-59 days. The female adult can mature its ovaries and reproduce only after sucking the sap of the host plant; reproduction is parthenogenetic, mainly viviparous. In winter, especially in January-February, oviparity often occurs, or oviparity and viviparity alternate. Viviparous nymphs tend to cluster under the mother's body, and once they find a suitable site they begin to feed and cause damage; some remain motionless near the mother or crawl repeatedly over her. The nymph stage generally lasts 30 days in summer and up to 2 months in winter. Female adults lay eggs in cotton-like ovisacs. After emergence, male adults generally remain motionless in plant crevices, do not feed, and have a short lifespan of only a few days. The male nymph stage lasts about 14 days in summer, and the pupal stage generally 12-15 days. Heavy rain or continuous rain has a washing-off effect on mealybugs. Ants carry mealybug bodies, which helps the mealybugs spread. Ants prefer to feed on mealybug excrement, and when this excrement is consumed, it is beneficial to the growth and reproduction of the mealybugs.
Control methods
Strengthen orchard management to enhance tree vigor, fertilize and irrigate rationally, and improve tree resistance. Prune scientifically, cut out diseased and weak branches, and regulate ventilation and light penetration. Combined with pruning, clean up the orchard to reduce insect sources.
Use insect-free seedlings when planting; if necessary, treat the heads by soaking in a 40% dimethoate 500-800 times dilution.
Fumigation for insect control: seedlings carrying the pest can be fumigated. In an enclosed space, use a mixture of 10-16 g sodium cyanide, 15-24 mL sulfuric acid and 40 mL water to generate hydrocyanic acid gas and fumigate for 1-2 hours to kill the insects, after which they can be planted out.
Chemical control: in severe outbreaks, spray rosin mixture
Commonly used agent: rosin.