The brown marmorated stink bug (Halyomorpha halys) is an Asian species that was introduced into Allentown, Pennsylvania around 1996 from China or Japan. In 2015 it was found in 42 states including Missouri. Its range is increasing in Missouri and is projected to be a major pest of vegetable and fruit crops including apples, peaches and blackberries, as well as, a nuisance in homes where it can overwinter. However, it will not reproduce inside homes or cause structural damage. It can be confused with other stink bugs, notably the brown stink bug, which is smaller and less destructive.[图片]Symptoms and Diagnosis Brown marmorated stink bugs (BMSB), like other stink bugs, feed by inserting their mouth parts into the leaves, flowers, buds, fruits, and seeds of host plants and sucking plant sap. Large infestations of stink bugs may cause plants, especially small plants and young tender growth, to wilt, become stunted and misshapen, or die. Other damage includes yellow or white blotches on leaves; misshapen or aborted fruits, seeds, and buds; calluses, blemishes or depressions; and black pits on nuts. Tomatoes exhibit a condition called cloudy spot (pale yellow spots and a white pithy area just under the skin at the puncture site). Peaches and other fruits may develop scarring and dimpling resulting in cat-facing or a pitted appearance. The seeds in soybean pods may be deformed, small, discolored, or shriveled.[图片]Life Cycle Adult brown marmorated stink bugs are about ½ inch long and have the characteristic “shield” shape of stink bugs. They are mottled brownish grey in color with a white or pale gray underside. The antennae and legs have light bands. The edges of the abdomen that extend beyond the sides of the wings have brown and white bands. The native brown stink bug is smaller and has a light green underside. It lacks the bands on the antennae and legs. Adults overwinter outdoors and in buildings and emerge in late March through April when they mate and lay eggs on the underside of leaves May through August. The eggs (about 1/16 inch in size) are light yellow, yellow-red or green and are laid up against each other in clusters of 20 to 30 eggs. The eggs hatch in 1-3 weeks into brightly colored red and black nymphs with banded legs and antennae. They have a “tick-like” appearance. The nymphs begin feeding and progress through 5 instars to adulthood. By the second instar the banded abdominal extension has clearly begun to develop. In northern areas there may be only one generation a year but in warmer, southern states there may be up to three generations a year. In Missouri, there may be two generations a year.[图片]In late September into mid-October adults seek protected areas for overwintering. They can gain access into homes through cracks and opening around windows, doors, siding, fascia boards, chimneys, attics or window air conditioners where they overwinter in walls and other locations. In spring, they can be found in interior spaces as they look for ways to reach the outdoor. Integrated Pest Management Strategies There are no easy controls for the brown marmorated stink bug, but here are some suggestions for management. Outdoors 1. Sanitation. Control weeds in susceptible crops and in areas adjacent to gardens to decrease breeding and overwintering habitat. It is important to remove weeds early in the growing season before stink bug populations increase or the loss of habitat may force pests to move into the garden. 2. Collect insects. Hand pick and destroy eggs and bugs. When hand picking, use gloves as dermatitis at the point of contact can occur. Some individuals are also allergic to the smell of stink bugs. Indoors, use a shop vacuum to vacuum up the overwintered adults.[图片]3. Use natural controls. Although there are currently no known natural predators, it is always wise to encourage other natural predators such as parasitic wasps and flies by growing small-flowered plants. The unpleasant odor produced by stink bugs deters many predators but several bird species do consume these pests. 4. Use insecticides. Control with pesticides is short-lived and difficult. Also, resistance to some pesticides has already been observed. If damage is severe and there is a need to save a crop, you can try sabadilla, pyrethrin or permethrin (Eight). Check label directions for suitability with your crop before using.

...显示更多

分布与危害 #卡特兰蓟马 蓟马主要寄生于卡特兰的花瓣重叠处，也可能寄生于心叶中，以开花期为害最严重。花朵被侵害后，可能产生畸形并提前凋谢。 发生规律 蓟马在高温干燥的季节，虫口密度易增高，以设施内有遮蔽的环境中，繁殖更快。卵大多产在植物较幼嫩的部份，如新芽、幼叶、花瓣等组织内或表面，幼虫大多活泼好动，不时在叶面、花瓣上爬行，成虫与幼虫之外形与习性相若，都是锉吸式器，锉吸花部。 防治方法 预防方法 1、采用营养土育苗，清除残株病叶减少虫源，选合适时间栽植。 2、还有勤浇水可消灭地下的若虫和蛹，勤除草可减轻为害。 治疗方法 幼虫期喷施国光乙刻（20%氰戊菊酯乳油）2000倍+国光乐克（5.7%甲维盐）3000倍，或国光必治（40%啶虫.毒）1500-2000倍；或国光依它（45%丙溴辛硫磷）1000-1500倍，根据害虫危害情况适当用药2-3次，间隔7-10天。喷药时应注意喷及花内蓟马隐藏处。

相关图片 [图片]#杜鹃红蜘蛛 分布与危害 危害杜鹃 形态特征 红蜘蛛的雌成虫体长0.3毫米左右，暗红色，近椭圆形，体背隆起，足4对，暗红色。雄成虫体长0.25毫米，楔形，扁平，鲜红色。 发生规律 一年发生多代，成虫在植株根部越冬，主要在叶背面近叶柄部的主脉附近危害。每年的6至7月高温、少雨、干旱天气繁殖快，发生数量较多。危害严重时，被害叶片焦枯脱落。 防治方法 1、人工防治：4月份以后应经常检查，发现个别叶片上有红蜘蛛时，应及时摘除虫叶并烧掉。有条件的可人工释放天敌，如瓢虫、草青蛉、蓟马等，进行生物防治。 2、药剂防治：若发现较多叶片有红蜘蛛时，可进行药剂防治，使用10%苯丁哒螨灵乳油(如国光红杀)1000倍液或10%苯丁哒螨灵乳油(如国光红杀)1000倍液+5.7%甲维盐乳油（如国光乐克）3000倍液混合后喷雾防治，建议连用2次，间隔7-10天。

相关图片 [图片][图片]#白粉蝶 分布与危害 白粉蝶学名Pieris rapae L.别名菜白蝶、菜青虫。我国各地发生普遍，寄主除有一串红外，还有羽衣甘蓝、醉蝶花、大丽花、旱莲、十字花科等。 以幼虫食害嫩芽、嫩叶、花蕾和花冠为害，导致叶片呈残缺现象，花瓣脱落。 形态特征 成虫体长12-20毫米，翅展45—50毫米。雌粉蝶淡黄白色。前翅基部灰黑色，顶角有1个三角形黑斑，下方有2个黑色圆斑；后翅前缘也有1个黑斑。雄粉蝶乳白色，翅面黑色部分较小，前翅有2个黑斑，仅前1个较明显。 卵长约1毫米，底径0．4毫米，为瓶形，表面有脊纹，长方格形。初产时淡黄色，后变橙黄色。 幼虫体青绿色，末龄幼虫长28-35毫米。体背密布细小毛瘤，上生细毛。体各环节有横皱纹。背线淡黄色，气门沿线有1列黄色斑点。 蛹纺锤形，长15-21毫米，绿色多变。体中间膨大，有棱角状突起。尾部和中间用丝连结在寄主上。 发生规律 在上海1年发生8代，世代重叠。以蛹在向阳的篱笆、屋檐、墙脚、枯枝落叶下越冬。翌年3—4月羽化。卵多散产于叶背面。幼虫孵化后，在叶背取食，稍大后咬叶片成孔洞，严重时仅留叶脉。3-6月发生最多，为害最重。成虫寿命14—30天。每雌虫产卵100-200粒。卵期4-8天，幼虫历期11-22天，蛹期5—16天。最适温度20-25º相对湿度76％。 防治方法 （1）加强栽培管理，合理施肥灌水，增强植株抵抗力。合理密植，调节通风透光，保持适当温湿度，及时清园，减少虫源。 　　 （2）必要时进行人工捕杀幼虫和蛹。 （3）保护利用天敌，主要有白粉蝶绒茧蜂、风蝶金小蜂、舞毒蛾疣姬蜂。 （4）化学防治：尽量选择在低龄幼虫期防治。此时虫口密度小，危害小，且虫的抗药性相对较弱。防治时用45%丙溴辛硫磷（国光依它）1000倍液，或国光乙刻（20%氰戊菊酯）1500倍液+乐克（5.7%甲维盐）2000倍混合液,40%啶虫.毒（必治）1500-2000倍液喷杀幼虫，可连用1-2次，间隔7-10天。可轮换用药，以延缓抗性的产生。

Many ornamental trees and shrubs are susceptible to Phytophthora root rot and can develop root and crown rot, particularly if the soil around the base of the plant remains wet for long periods of time. Typical symptoms of a root disease are apparent on infected plants. The leaves will appear droughtstressed and may die quickly as the weather warms in late spring or early summer. Trees that are especially susceptible include oak and dogwood.[图片]Symptoms and Diagnosis Leaves will appear drought stressed, sometimes turning dull green, yellow, red, or purple as they wilt. Infected trees may survive a few years before the disease kills the whole plant. The bark around the soil-line may appear darkened. Cutting away some bark should reveal red-brown discoloration in the wood underneath it. Disease symptoms are distinguishable from Armillaria root rot because mycelial mats do not develop in tissues infected with Phytophthora root rot.[图片]Life Cycle Root rot-causing Phytophthora species can survive in the soil for years, as long as moist conditions persist. It can spread through splashing rain, irrigation water, and runoff water. Disease fungi can spread through contaminated soil and garden equipment as well. Rot is more likely to spread in early spring and late fall during cool, rainy weather. But symptoms are more likely during stress periods of low rainfall. Flooded and saturated soil conditions for 6–8 hours are especially conducive to the spread of root rots. Wounds are not required for infection.[图片]Integrated Pest Management Strategies 1. Improve water drainage. Prior to planting, make amendments to the soil composition to help manage drainage away from tree roots. Don’t allow water to pool around the collar or root system. Core aerate to improve drainage and lessen compaction. 2. Raise the planting site to avoid poor drainage and prevent pools of standing water from forming around valuable ornamentals. Plant on mounds of soil. Never plant trees deeper than they were planted at the nursery. 3. Separate plants, shrubs, and trees according to their irrigation needs, and avoid overwatering.[图片]4. Remove soil. If soil has been piled up over the crown, remove it carefully to expose root flare. This is where fungal infection is likely to occur. 5. Plant resistant or less susceptible varieties. Consider replanting with tolerant plants after Phytophthora root rot has been diagnosed. Trees that are tolerant to Phytophthora root rot include white cedar and American arborvitae.

...显示更多

Peach leaf curl is a springtime disease caused by the fungus, Taphrina deformans. It infects the leaves and shoots of peaches and nectarines. Apricots are immune. It is one of the most common diseases of these fruits. It causes the leaves to curl and turn reddish in color. A severe infection can cause reduced yields. [图片]Symptoms and Diagnosis Symptoms first appear in spring. New leaves become curled and develop reddish areas. The reddish areas become thickened and puckered resulting in severely distorted leaves. As the disease progresses, the thickened areas turn yellowish gray and become covered with velvety spores. Affected leaves turn yellow or brown and fall prematurely. Affected shoots usually send out new leaves which often are unaffected by the disease unless rainy weather ensues. In more severe infections, shoots may become thickened and die. [图片]Aphids can also cause leaves to curl. If present, the insects or cast skins will be evident to the naked eye. Life Cycle The fungus overwinters on bud scales, on twigs, and on fallen infected leaves. In spring the fungal spores are splashed onto newly developing leaves. During cool, wet weather the spores germinate on the young leaves and initiate infection. Development of the disease slows as temperatures increase. Older leaves are resistant to infection. Consequently, the disease is most prevalent in the spring. [图片]Integrated Pest Management Strategies 1. Keep plant healthy — avoid excess fertilization. A healthy plant can better withstand the loss of leaves, but excess fertilization can cause succulent tissue that is very susceptible to infection. 2. Clean up diseased leaves. Raking up and disposing of diseased leaves can't hurt, but its value in controlling the disease is slight. 3. Don't panic.Once infection has occurred fungicidal sprays are not effective. A healthy plant should refoliate. Because refoliation normally occurs during warmer, dryer weather, re-infection is usually not a problem. Thinning the fruit crop in years of severe infection can also help maintain plant vigor. To limit damage the year after a moderate to severe infection, follow the protective spray program below. [图片]4. Use properly timed protective fungicidal sprays. If leaf curl was a problem in the spring, apply a protective fungicidal spray after leaf fall in October or November or before bud break in late winter, January through February. After buds have begun to swell fungicidal sprays are not satisfactory. Do not apply to foliage. Chemicals effective in controlling leaf curl include copper-based fungicides like Bordeaux mixture, Bravo, lime-sulfur spray, or other brands that list the control of peach leaf curl on their label. [图片]5. Replace the tree with a more disease tolerant variety. If you want to avoid using fungicidal sprays, consider replacing the tree with a more tolerant variety. ‘Redhaven’ and cultivars derived from ‘Redhaven’ have greater tolerance to peach leaf curl disease.

...显示更多

Gummosis is the oozing of sap from wounds or cankers on fruit trees. Gummosis can result from environmental stress, mechanical injury, or disease and insect infestation. Cytospora canker or Valsa canker, the fungal cause of gummosis, affects stone fruit trees like apricot, cherry, peach, and plum. Cytospora infection is distinguishable from insect damage and mechanical injuries because sawdust or pieces of bark are not mixed in the sap, as it would be with insect or mechanical damage. Cytospora canker is also known as perennial canker.[图片]Symptoms and Diagnosis On trees infected with Cytospora canker, new shoots or leaves may turn yellow or wilt. Sunken lesions develop on the bark. These lesions enlarge, and gummy, amber-colored sap oozes from the bark. Curly orange threads (fungal chains) may grow out of the bark as the disease progresses. Leaves may brown and drop. The disease kills the wood underneath the cankers, often causing whole branches to die. Infected wood and the defoliation that may occur weakens the tree, but if the disease infects the trunk, the whole tree may die.[图片]Life Cycle Cytospora canker is caused by one of two different fungi. The fungus overwinters on dead wood or in sunken lesions. Curly orange fungal chains will release spores in the spring which are distributed by winds and rain splash. Once the spores land on a host tree, they enter through wounds made from insect boring, mechanical injuries, or winter injury. Symptoms are more prevalent during warm (70–85 degrees F), wet spring weather as the moisture facilitates entry into wounds. Trees just coming out of dormancy are most susceptible to the pathogen.[图片]Integrated Pest Management Strategies 1. Be careful not to damage trunks with lawn mowers or other yard and garden equipment. Fungal spores enter the tree through injured tissue where they germinate and penetrate the tissue. This is the primary mode of infection. 2. Take steps to prevent winter injuries. Plant in well-drained soils or amend soils to improve drainage as needed. Avoid planting in open or windy areas to reduce desiccation. Select winterhardy cultivars matched to your hardiness zone. Paint the lower branches and trunks of 1–3 year old trees with white latex paint to reduce cold damage.[图片]3. Proper care and maintenance. Prevent insect boring damage by maintaining the health of the tree. Prune and dispose of diseased branches in late winter. Burn infected wood, if possible. 4. Plant more resistant varieties. None of these are immune, but fungal development is slower if the disease becomes established.

...显示更多

Gray mold of strawberries is caused by a fungus, Botrytis cinerea, which infects both the flowers and fruits. Because of this, Botrytis can greatly reduce fruit yields and is considered one of the most damaging diseases of strawberry. Botrytis is most prevalent during prolonged cool, wet weather during bloom and near harvest.[图片]Symptoms and Diagnosis Blossoms commonly turn brown and die. A soft, light brown rot may appear on any part of the berry, but generally occurs first in the area of the cap, destroying the berry within 48 hours. The infected fruit spot is at first a light brown color and somewhat soft in texture. As the entire berry becomes infected, the rotted area becomes firm and turns a darker brown color. Fruits soon "mummify" and, like the blossoms, become covered with a gray, dusty powder which are the spores of the Botrytis fungus. Berries resting on damp soil or touching infected plant parts are most commonly infected.[图片]Life Cycle Botrytis fungi overwinter as dark-colored, resting bodies (sclerotia) on dead tissue. In the spring during cool humid weather, spores form and spread by wind or water to wounded or extremely soft plant tissues. Infection can also occur from growth of fungal mycelium from previously infected plant parts. The fungus can survive on decaying vegetation so it can infect healthy plants throughout the growing season. Integrated Pest Management Strategies 1. Remove infected plant parts. Collecting and removing infected plant parts can slow the spread of the disease. This should be done frequently especially during fruit bearing time.[图片]2. Improve air circulation around the plants. Space plants widely and prune leaves so that adequate air flow may speed drying of the vegetation. Work with plants when they are dry. 3. Avoid spring applications of nitrogen fertilizer. High nitrogen levels promote excessive leaf growth and available surfaces for infection. 4. Harvest regularly. Remove and dispose of rotten or severely damaged fruit throughout the season.[图片]5. Move plants to a better location.Select sites for planting that have good air circulation, are not shaded, and not subject to frost injury. 6. Use fungicide sprays, if necessary. Apply a fungicide at 5–10% bloom and at full bloom. Fungicides may be reapplied every 7–10 days during wet seasons. Pesticides registered for use include captan, chlorothalonil (Daconil), copper, iprodione (Chipco), mancozeb, sulfur, thiram, and ziram.

...显示更多

Downy mildew is an extremely serious fungal disease of grapes that can result in severe crop loss. It is caused by the fungus Plasmopara viticola.[图片]Symptoms and Diagnosis The pathogen attacks all green parts of the vine, especially the leaves. Lesions on leaves are angular, yellowish, sometimes oily, and located between the veins. As the disease progresses, a white cottony growth can be observed on the lower leaf surface. Severely infected leaves will drop. If enough defoliation occurs, the overwintering buds will be more susceptible to winter injury. Infected shoot tips become thick, curl, and eventually turn brown and die. Young berries are highly susceptible, appearing grayish when infected. Berries become less susceptible when mature. Eventually, infected berries will drop.[图片]Life Cycle The fungus overwinters in diseased leaves on the ground. Spores are released in the spring and spread to the leaves and berries by splashing rain and wind. The fungus has two types of spores, both germinating into swimming spores. These spores swim to the stomates (breathing pores) of plants and initiate infection. Water is necessary for the spores to swim and infect, so outbreaks of the disease coincide with periods of wet weather. Downy mildew is favored by all factors that increase the moisture content of soil, air, and the plant, with rainfall being the principal factor for infection during the growing season. Downy mildew infection can become a severe problem when a wet winter is followed by a wet spring and a warm summer with frequent rainfall.[图片]Integrated Pest Management Strategies 1. Maintain plant vigor. Make sure soils are welldrained. Fertilize according to soil test information obtained at least every other year. 2. Sanitation. Remove fallen leaves which are the source of overwintering inoculum. 3. Pruning. Prune out the ends of infected shoots.[图片]4. Fungicides. Fungicides are an important control measure, especially on susceptible cultivars. They should be applied just before bloom, 7 to 10 days later (usually at the end of bloom), 10 to 14 days after that, and finally, 3 weeks after the third application. For cultivars very susceptible to downy mildew or where the disease was severe the previous season, an additional application is suggested about 2 weeks before the first blossom opens. Pesticides registered for use include captan, copper, fosetyl-Al, mancozeb, maneb, and ziram. 5. Cultivars. Select and plant resistant cultivars.

...显示更多

Cedar-apple rust (Gymnosporangium juniperivirginianae), cedar-hawthorn rust (G. globosum), and cedar-quince rust (G. clavipes) are closely related rust diseases that require two hosts to complete their life cycle. All three rusts can infect most varieties of eastern red cedar (Juniperus virginiana) as well as many other junipers and an alternate host. Cedar-quince rust has the broadest host range and can affect many genera in the rose family including apple, crabapple, pears, quince, hawthorn, serviceberry, mountain-ash, flowering quince, cotoneaster, chokeberry, and photinia.[图片]Symptoms and Diagnosis Symptoms on juniper: Perennial, elongated swellings on the tips of twigs and branches, which may crack and form cankers, are symptoms of cedar quince rust on red cedars and junipers. In damp spring weather, cushion-shaped, orange, gelatinous blisters burst through the bark where the branches are swollen. Cedar-quince rust disease damages the ornamental value of susceptible cedars and junipers, killing young branches and weakening plants when cankers occur on the main trunk.[图片]Symptoms on apple and other hosts: Young branches and fruit (not leaves) are usually infected and symptoms vary widely among the various hosts. On hawthorn, the pinkish aecia (tubes) occur mainly on branches, thorns, and fruit. Hawthorn and serviceberry fruit often becomes heavily covered with aecia. Branch and thorn infections result in spindle-shaped, perennial cankers that expand each growing season. However, most infected branches are girdled by the canker during the second season, causing dieback to a bud or side-shoot.[图片]Life Cycle Basidiospores that are released from the juniper gall telial swellings infect stems and fruit of quince and the other deciduous hosts. Seven to ten days after infection, spots or swellings develop, followed a few days later by the formation of tiny black dots within the spots. Four to seven weeks later, aecia are formed. Aeciospores, released from the aecia during rain or as morning humidity lowers, become airborne and infect susceptible junipers during late summer and fall. The following spring (or one year later), swellings (consisting of both fungal and host plant tissues) develop on the juniper host. When the swellings are mature, a few hours of wet, cool (74 to 78 degrees F) spring weather are sufficient for repeated telial swelling and the release of basidiospores that infect quince and other deciduous hosts. The cedar-quince rust galls may remain infectious for 4–6 years or more (up to 20), whereas the cedar-apple gall is only infectious for one year.[图片]Integrated Pest Management Strategies 1. Prune. Prune out cankers associated with cedarquince rusts from landscape junipers and deciduous host plants. The spread of cedar-quince rust can be limited by reducing the infested plant parts. This is practical if a few plants are infected and the number of galls per plant is limited. 2. Co-exist. Live with the disease. It may disfigure plants when twigs are infected.[图片]3. preventive fungicide. Use preventive fungicides labeled for use on quince and other hosts. Fungicide sprays are aimed at protecting developing twigs and branches from infection during the time the galls on the junipers are orange and gelatinous. This usually lasts for several weeks and fungicide applications are not necessary once the galls become dry and inactive. Always read and follow label directions. Pesticides registered for use include captan, chlorothalonil (Daconil), mancozeb, sulfur, thiram, and ziram.[图片]4. Avoid planting susceptible plants together. Do not plant junipers close to susceptible varieties of apples, crabapples, or quince. 5. Resistant varieties. Remove and replace diseased plants with resistant varieties.

...显示更多