Presentation on theme: "Pests of Orchards California red scale Grape vine moth Citrus leaf miner White louse scale Queensland fruit fly Phylloxera Anthracnose Lemon scab Melanose."— Presentation transcript:
Pests of Orchards California red scale Grape vine moth Citrus leaf miner White louse scale Queensland fruit fly Phylloxera Anthracnose Lemon scab Melanose Spined citrus bug Other problems deficiencies latkins2003
California red scale Order- Hemiptera ( hard) Appearance – The adult female cover circular, conical orange/red. The winged adult male cover is oval & grey. Crawlers & adults inject a toxic poison in saliva latkins2003
California red scale latkins2003 California red scale crawlers Adult male California red scale.
California red scale latkins2003 Damage- All of the above ground may be infested= Fruit blemishing, leaf yellowing, fall, twig & branch die back
California red scale latkins2003 Plants affected- Citrus,Acacias,Willows, Olives. Most widespread pest of citrus in NSW. Conditions- Prefers dry inland or coastal, dust covering plants Very troublesome pest
California scale Control Biological-Red & blue ladybird beetle larvae ( Chilocorus spp). The adult beetle lays her eggs under scale cover= larvae feed Aphytis melinus wasp lays her eggs under the scale cover of a second instar unmated female scale= hatched larvae feed, adult wasp also feed Cultural- Keep trees healthy, do not over fertilise / over- water, Control ants. They severely disrupt red scale parasites while tending red scale Avoid excessive dust build up on leaves and fruit, (eg from manure mulches, kaolin clays) latkins2003
Californian scale - Control latkins2003 Cultural - Fine, talc-sized particles of ash from bush fires can also disrupt biological control. Washing trees to remove dust or ash particles can help solve this problem. Heavy fogs, drizzle, or rain can also help by either removing dust and ash particles or causing them to adhere to the leaf surface. Chemical- White/pest oil ( not on blossom )
Citrus leaf miner Order- Lepidoptera Appearance –usually observed when leaves are damaged by larvae tunnels and pupal stage Damage-The larvae tunnel down new shoots near tips or junctions = wilting, distortion and obvious tunnelling Plants affected Citrus Common on coast and has a major impact inland on citrus orchard industry latkins2003
Life cycle Damage occurs in later summer and autumn Larvae tunnel in surface layer of new leaves Pupal chamber is formed at the end of the larval stage where the larva wraps itself in a silk casing at the edge of the leaf. Adult lays eggs along leaf margin 0.3 mm in size 14 – 17 days complete lifecycle latkins2003
Control Winter fertilising to promote new growth in spring Prune off affected leaves and destroy Natural predators can control from 20 – 90% of all infestations White oil is the only recommended chemical control for home nurseries latkins2003
Spread- Rain, wind Control- Occurs during damp weather & only on immature fruit, coastal areas. When symptoms seen it is too late to save infected fruit. Need for preventative spraying before next crop. Chemical- Apply Bordeaux (+ white oil) in spring ant half petal fall and again in late Jan/early Feb at blossoming of second crop latkins2003
Melanose FUNGUS Appearance/ Damage-Small Reddish to dark brown spots on leaves & fruit. Streaky if spores are washed by rain, skin of fruit may become cracked and have a ‘mud- cake’ appearance Young leaves & fruit are susceptible & usually occurs on older trees in wet warm conditions latkins2003
Melanose Mudcake or sandpaper symptoms of melanose on grapefruit. latkins2003 Tearstaining caused by melanose spores washed down the fruit by dew or rain.
Melanose latkins2003 Plants affected-Citrus-Washington navels,Emperor mandarins & lemons Spread- Water – dripping & splashing Control- remove & destroy infected parts,Copper oxychloride + white oil at petal fall
Bronze Orange Bug Piercing and sucking mouthparts True bug Gregarious Damage the tips of new growth and cause leaf distorton Toxic urine from adults and older nymphs (eyes and hands, sensitive skin) latkins2003
Summer fruit drop latkins2003 Citrus normally shed large numbers of fruitlets shortly after blossoming in the spring and at early fruit set (pea size). when warmer weather places stress on the tree. related to lack of water at, or soon after, fruit set. Root diseases and lack of nitrogen or trace elements may also be responsible..
Rind splitting Rind splitting of fruit, particularly in navels, also occurs before or near maturity as a result of climatic factors, specifically a drop in average temperatures and an increase in relative humidity at a time when the rate of fruit growth is decreasing. There is no control for the disorder.
Preharvest drop Preharvest drop in the autumn before fruit is fully mature is a common problem with navels and grapefruit. Some of this drop is natural, but in coastal areas fruit stung by Queensland fruit fly during the late autumn colour-change period is also very prone to drop. Some mandarin and lemon varieties will also shed fruit when damaged by the spined citrus bug. Brown spot infection in mandarins will result in fruit drop.spined citrus bug Brown spot
Alternate cropping (biennial bearing) Alternate cropping (biennial bearing) is a common problem with many citrus varieties, such as Valencia orange, Wheeny grapefruit, and mandarins. Pruning or thinning of the heavy crop and early harvesting will assist in reducing the problem.
Second crop fruit Sometimes orange trees will produce blossoms in the autumn after a stress period, and set a second crop. This fruit is often of poor quality (thick skins and low juice content) and is susceptible to fruit fly attack. With lemon trees, however, these intermediate crops are desirable
Grape vine moth latkins2003 Order- Lepidoptera Appearance – Adult- black moth with yellow markings & tuffs of orange hair at the tip of the abdomen. Larva – blend of green, yellow, black with red markings at sides and a red band over body at hind end. Scattered white hairs over body.
Grapevine moth control Biological- Dipel, birds, wasps predatory shield bug Oechalia schellenbergii. Natural predators are usually effective Physical- hand pick off from leaf dersides Chemical-Only spray in severe infestation latkins2003 Oechalia schellenbergii.
Grapevine moth control latkins2003 Larva being eaten by mating shieldbug
Phylloxera Order- Hemiptera Appearance –This aphid can live below or above ground & when swelling or galls are cut open aphids =green - yellow Damage- Roots- have fleshy yellow galls on the fine roots ( may be curved in a S shape).Leaves have fleshy yellowish irregular swellings. Infected plants are weak & do not produce good crops Plants affected- stressed grape vines (which are less able to repel their attack), in heavy soils & humid environments and warm temperatures. AN EXTREMELY SERIOUS PEST OF GRAPEVINES latkins2003
Phylloxera -Damage latkins2003 Root-feeding stages are the most damaging, causing a loss in plant vigour, wilting and leaf yellowing. Vines may eventually die within 3-10 years. The aphids live on the surface of root galls and inside the leaf galls.
Phylloxera -Damage latkins2003 Galls on infected leaves
Phylloxera -Damage The effect of phylloxera aphids feeding on the roots is to cause the vines to get progressively weaker, and they produce fewer leaves and grapes. latkins2003
Phylloxera control There is no chemical control & no economic means of removing it from the soil once it is established Cultural- QUARANTINE regulations, grow on resistant root stocks latkins2003
Anthracnose VARIOUS FUNGUS Appearance/ Damage- Small to large, dark circular spots or sunken lesions with raised rim on leaves, stems & fruit Can occur at any stage of growth, twig die back, corky spots on fruit, fruit drop & rot latkins2003
Anthracnose latkins2003 Stem and pods have black fruiting bodies, “acervuli,” with black hairs, “setae. Anthracnose leaf spot on watermelon leaf
Anthracnose characterised by discrete lesions that are usually found along leaf veins. In severe cases these lesions may run together and kill the entire leaf. Young leaves may become distorted as healthy tissue continues to grow around dead areas. latkins2003