मोगर्‍याच्या झाडावरील रोग/कीड/बुरशी, हे नक्की काय आहे?

माझ्या गुलाबाच्या झाडाच्या पानांवर मध्यंतरी कीड लागली होती.
कडुलिंबाचा थोडा पाला मी २ दिवस भिजत ठेवला. त्या पाल्यामुळे किंचित पिवळसर झालेले पाणी मी झाडांवार स्प्रे केले. असे दोन रविवारचे व्रत केले. कीड निघून गेली.

वावडिंगाचा काढा करून स्प्रे करायला सांगतात. पण ती फारच उस्तवारी होईल!

झाडाची पानं पिवळी पडत आहेत?
हे वाच!

रूनी,
हा स्केल्सचा प्रकार आहे. कुंडी बाथटब मधे नेऊन त्या रोपाला अक्षरशः अंघोळ घाल. किंवा रोप पाण्याच्या बादलीत उलटं (पानं खाली) बुचकळून काढ.
असं आठवड्यातून दोनदा तरी कर. त्यानंही कमी झालं नाही तर नीम ऑईल, साधं डिश वॉशिंग लिक्वीड, (किंवा insecticidal soap हे मिश्रण फवार. हे उपाय लवकरात लवकर केलेस तर उत्तम.

इथे एकदम व्यवस्थित माहिती दिली आहे.

LIFE CYCLE

Females of many scale species reproduce without mating (there are no males). At maturity, adult females produce eggs that are usually hidden under her body or cover. Eggs hatch into tiny crawlers (mobile first-instar nymphs), which are yellow to orangish in most species. Crawlers walk over the plant surface, are blown by wind to other plants, or can be inadvertently moved by people or birds. They settle down and begin feeding within a day or two after emergence.

Settled nymphs may spend their entire life in the same spot without moving as they mature into adults. Nymphs of other species can move slowly but rarely do, such as when species that feed on deciduous hosts move from foliage to bark in the fall before leaves drop. For species with multiple generations, all scale life stages may be present throughout the year in areas with mild winters.

Armored Scales. Most armored scales have several generations a year. Armored scales overwinter primarily as first-instar nymphs and adult females. Except for crawlers and adult males, armored scales spend their entire life feeding at the same spot. Settled armored scales lose their legs, molt, and form their characteristic covers, which they gradually enlarge as they grow.

Soft Scales. Most soft scales have one generation each year and overwinter as second-instar nymphs. The multi-generational brown soft scale is an important exception Brown soft scale females and nymphs of various size can be present throughout the year. Most immature soft scales retain their barely visible legs and antennae after settling and are able to move, although slowly. At maturity, females of certain soft scales, the woolly sac scales (Margarodidae), and some other species produce distinct external cottony or wax-covered egg masses.

DAMAGE

When plants are heavily infested with scales, leaves may look wilted, turn yellow, and drop prematurely. Scales sometimes curl leaves or cause deformed blemishes or discolored halos in fruit, leaves, or twigs. Bark infested with armored scales may crack and exude gum. Certain armored scales also feed on fruit, but this damage is often just aesthetic. Soft scales infest leaves and twigs but rarely feed on fruit. A major concern with soft scales is their excretion of abundant honeydew, which contaminates fruit, leaves, and surfaces beneath plants. Honeydew encourages the growth of black sooty mold and attracts ants, which in turn protect scales from natural enemies.

When numerous, some scale species weaken plants and cause them to grow slowly. Branches or other plant parts may die if they remain heavily infested with scales. If plant parts die quickly, dead brownish leaves may remain on branches, giving them a scorched appearance. Several years of severe infestations may kill young plants. Certain armored scales may be more likely to kill plants. Soft scales reduce plant vigor, but seldom kill trees or shrubs.

MANAGEMENT

Scales are often well controlled by beneficial predators and parasites, except when these natural enemies are disrupted by ants, dust, or application of persistent broad-spectrum insecticides. Preserving (conserving) the populations of parasites and predators (such as by controlling pest-tending ants) may be enough to bring about gradual control of scales as natural enemies become more abundant. If scales become too numerous, a well-timed and thorough spray using horticultural (narrow-range) oil applied either during the dormant season or soon after scale crawlers are active in late winter to early summer should provide good control. Complete spray coverage of infested plants (such as the underside of leaves) is needed to obtain good control. Thorough spray coverage is especially critical when treating armored scales and oak pit scales, as these scales are generally less susceptible to pesticides than soft scales.
Monitoring

Inspect plants to determine whether female scales, nymphs, honeydew, or sooty mold are present. When assessing whether scales or their damage are abundant enough to prompt you to manage them, distinguish live scales from dead or parasitized ones by flipping over the female scale body or cover using a sharp tool. The dead scales from previous generations can remain on plants, and sometimes a large proportion of scales are dead or parasitized by natural enemies. During the growing season, inspect trunks for ants. If the descending ants have swollen, almost translucent abdomens, they are probably feeding on honeydew produced by scales or other insects that suck plant juices. Tracing back trail-making ants can lead you to colonies of the honeydew-producing insects.

Action thresholds before spraying have not been established for scales in most situations. Monitor and record scale densities and use the density that caused damage (dieback or unacceptable honeydew) as your preliminary control action threshold. Refine this threshold over time for your local situation as you gain experience.

Tape traps for crawlers discussed in the Foliage Sprays section and honeydew monitoring are useful in certain situations. Honeydew dropping from plants can be efficiently monitored using water-sensitive paper, which is commonly used for monitoring insecticide droplets and calibrating sprayers. Products include bright yellow cards that produce distinct blue dots upon contact with honeydew or water. Regularly monitoring honeydew beneath plants (such as the number of drops during four hours, once a week) can help to develop thresholds and evaluate effectiveness of the treatment. Honeydew monitoring is useful where there is a low tolerance for dripping honeydew, when managing many trees (such as along city streets or in parks), and on tall trees where the honeydew-producing insects may be located too high to easily observe. For more information on monitoring honeydew, see the Aphids section in Pests of Landscape Trees and Shrubs listed in References.
Cultural Control

Provide plants with good growing conditions and proper cultural care; especially appropriate irrigation, so they are more resistant to scale damage. Prune off heavily infested twigs and branches to eliminate scales when infestations are on limited parts of the plant. Pruning to open up tree canopies helps to control black scale, citricola scale, and possibly other species in areas with hot summers, such as the Central Valley of California. This pruning increases scale mortality as a result of heat exposure.

When landscaping, choose plants that are relatively pest-free and well adapted to local conditions. Consider replacing problem prone plants. Most pests are highly host specific. Scales that can feed on many different plants usually damage only certain of these plant species and though present, do not damage other species or cultivars in the same plant genus. Notable exceptions include California red scale (which can severely infest and damage all Citrus species) and San Jose scale (which damages many different fruit and nut trees).

Biological Control

Scales are often controlled by small parasitic wasps and predators including beetles, bugs, lacewings, and mites. Predatory Chilocorus, Hyperaspis, and Rhyzobius species lady beetles (ladybugs) can easily be overlooked because many are tiny, colored and shaped like scales, or feed beneath scales. Hyperaspis species are tiny, shiny, black lady beetles with several red, orange, or yellow spots on the back. Rhyzobius lophanthae has a reddish head and underside, and a grayish back densely covered with tiny hairs. The twicestabbed lady beetle, Chilocorus orbus, is shiny black with two red spots on its back, and reddish underneath. The multicolored Asian lady beetle, Harmonia axyridis, is a relatively large, variably colored species. It is mostly orange, red, or yellow with 19 large dark spots, or fewer, smaller, or no spots on its wing covers. The alligatorlike larvae of lady beetles often occur openly on plants. In certain species, small larvae are hidden under the female scale body or cover where they feed on scale eggs and crawlers.

Parasitic wasps are often the most important natural enemies of scales. Parasites include many species of Aphytis, Coccophagus, Encarsia, and Metaphycus. The female wasp lays one or several eggs in or on each scale, where the tiny maggotlike wasp larvae feed. When parasitized, some scales are darker-colored than normal. Estimate parasite activity before making a treatment decision. Check for discolored (parasitized) scales and scale covers with round exit holes made by emerging adult parasites. Lift the covers of armored scales and examine beneath them for immature parasites.

Natural enemies, or beneficial insects, are commercially available for release against California red scale and perhaps certain other scales. However, conserving resident natural enemies is a more efficient and longer lasting strategy than buying and releasing beneficials in gardens and landscapes.

Ant control, habitat manipulation, and pesticide management are the key conservation strategies. Grow flowering plants near scale-infested trees and shrubs to help attract and support natural enemies. Adults of predatory bugs, lacewings, lady beetles, and parasitic wasps live longer, lay more eggs, and kill more scales when they have plant nectar or pollen and insect honeydew to feed on. Minimize dust, which interferes with natural enemies. For example, wash plant surfaces midseason, or when the foliage is covered with dust.

Depending on the scale species and the extent to which biological control has been disrupted, it will take several months of conservation efforts (such as controlling ants and dust and avoiding application of persistent insecticides), or until the next season or longer, before scale populations are reduced by biological control. If current levels of scales are intolerable, use a short residual insecticide such as oil or soap to reduce scale populations while conserving natural enemies.

रूनी, ह्या दुव्याचा उपयोग हईल का ते पहा!