Insect that attacks crops

Different Pests Cause Different Damage

Insects can become pests in the garden when they cause damage to garden plants. The signs of damage vary, typically depending on the way that the insect feeds on the plant.

Damage from insects with chewing mouthparts typically appears on leaves or stems as ragged edges, holes, or other missing tissue. Insects that often cause chewing damage include caterpillars and Eastern lubber grasshoppers.

Insects with piercing-sucking mouthparts have strong mandibles that they move laterally to often cause yellowing or browning on plants, and possible wilting. Examples include aphids, scales, spider mites, and whiteflies.

Scale damage on leaf

Pest insects can also be classified by the types of damage they cause. For example, defoliators tend to feed voraciously and strip a plant nearly bare. Many caterpillars fall into this category. Other insects include leafminers, which burrow into the leaves of plants leaving tell-tale tunnels in the leaves. One well-known leafminer is the citrus leafminer, which is actually a larval stage of a moth.

Gall makers insert all or part of their bodies into plant tissue—typically into leaves, stems, or twigs—and cause the tissue to swell. Examples include blueberry gall midge larvae that burrow into leaves to feed, and gall wasps that deposit their eggs into plant tissue.

Galls on leaf

Wood/phloem borers include twig girdlers and powderpost beetles that cause damage by feeding on living wood and wooden structures.

There are a number of bugs that can infest your plants, either indoors or outdoors. If you notice your plant is not growing the same as it once did, is a different color, or has visible bugs on it, you need to take action in order to save your potted plant.

Plants are known to bring around bugs, after all many bugs sustain life by using plants as their food and home. Carefully inspecting your plants on a regular basis will help prevent an outbreak from getting too bad. Here we detail the most common types of bugs found on plants, as well as ways you can help prevent an infestation from taking your favorite potted plants hostage.

6 Of The Most Common House Plant Bugs:

If you are dealing with a bug infestation on your potted plants, you might be unsure what sort of bug you are dealing with. This list of the most common plant pests will help you determine the type of critter ‘bugging’ your plants.

1. Aphids

Aphids are commonly found on houseplants, and can deter plant growth by removing sap from the plant. Eventually, this robs the plant of vital nutrients, while the aphids colony continues to grow. Plants that have a serious aphids infestation become sticky with the honeydew this bug secretes.

This bug is usually visible on the underside of leaves huddled together in a cluster, and can be the same green color as your plant. The most natural way to get rid of aphids is to introduce ladybugs into the picture. (Read more about Aphids)

2. Spider Mites

You may need to bust out the magnifying glass in order to spot signs of spider mites, as these bugs are incredibly tiny. Plants that have spider mites typically lose their bright green coloring in exchange for a dull brown or washed out appearance.

Severe infestations will come with webbing all over the undersides of the leaves, and at this point it becomes difficult to eradicate the mites. Insecticides will not work to get rid of spider mites because they are not insects.

Steps to take to solve a spider mite infestation:

  • Isolate your plant
  • Use soap and water to spray the plant on a regular basis, remember spider mites reproduce at a rapid rate every 3-7 days.
  • If possible, relocate the infested plant to a humid space, spider mites like dry air for breeding.

(Learn more about Spider Mites)

3. Mealybugs

We have discussed mealybugs in a previous blog; these very determined bugs tend to return time and time again. A white cotton-like ‘fluff’ growing over your plant can identify mealybugs. The white is partially the mealy bugs but also it is the waxy substance the bug secretes, which also works to help protect them from being sprayed off.

A Q-Tip with alcohol on it can be spread over the plant to kill off the mealybugs. You want to continually dose the plant with a stream of water to loosen all of the mealybugs. Next, apply a generous coat of neem oil over the plant so that the bugs are unable to return. (Read more about Mealy Bugs)

4. Whitefly

The whitefly is able to leave the plant the moment you start spraying it, but as soon as you stop spraying the whitefly will return, this is why attacking mature whiteflies is useless. Instead it’s the baby whiteflies you want to go after because they do not move. Dipping leaves in insecticidal soap or spraying the plant regularly can help get rid of the larva so that you don’t continue to have an issue with whiteflies. (More on Whiteflies)

5. Scale Insects

Scale insects are hard to notice at first and often grow into quite a colony before being detected. At only 3mm in length on average, scale insects have a brown shell that offers them protection against things like pesticides. Scale insects derive life from sucking the juices from your plant, as a colony grows they will start to cause obvious damage to your plant. You can kill them by using a cotton swab or Q-tip soaked with alcohol. (More information on Scale insects)

6. Thrips

These small, dark bugs are hard to see, plus they have wings and so when you spray the plant, you may notice they take off for flight and move to an adjacent plant. For this reason, a plant infested with thrips should be isolated. Thrips burrow into the leaves suck up the plant juices and leave behind noticeable scarring in the leaves. (Learn more about Thrips here)

Preventing Bugs From Infesting Your Plants

Sometimes, no matter how hard you try a bug will find its way into your plant and create an entire colony. But for the most part, with careful watch and precautious plant care you can help keep the bugs from populating your greenery.

Ways to help keep bugs from infesting your plants include:

  • Keep new plants isolated for at least one month before exposing the other plants to a possible bug. Check your isolated plant frequently for any signs of distress or infestation.
  • Thoroughly clean the planter whenever repotting a plant
  • Always keep your planters clear of old, dead leaves and foliage
  • Use sterile potting soil. If you use garden soil for your planters you can encounter a world of issues, only partially related to bugs.
  • Give your plants a good cleaning here and there using a soft cloth and lukewarm, non-toxic soap.
  • Inspect plants regularly; a magnifying glass can be helpful to identify the start of mites, or other bugs, before they balloon out of control.

Should You Use Pesticides And Insecticidal Soaps On Your Plants?

Some pesticides might advertise for use on plants, but many are too strong and high in toxicity, causing damage to a plant faster than a bug colony. Also, most pesticides are not for use on indoor plants and require a well-ventilated area. Pesticides come with side effects to the environment, as well as your health. If at all possible, it’s best to find alternative, more natural solutions to getting rid of pests on your plants. If you must use a pesticide, you should always read the directions carefully and only use as directed.

Insecticidal soap is made of a potassium fatty acid that works against 40-50% of infestations related to soft-bodied bugs. Larger bugs or bugs with hard shells are much more difficult to get rid of using an insecticidal soap. Although more gentle than some pesticides, insecticides are still toxic and can cause irritation to human skin, as well as damage to your plants. Try spot treating first to make sure there are no negative implications to your plant before applying any substance over the entire surface (Read Here).

A-Z list of horticultural insect pests

  • Avocado leaf roller

    Read about the Avocado leaf roller pest and the damage it does to avocados, custard apples, coffee, tea and other crops in North Queensland and learn how to control it.

  • Banana aphid

    Information on the Banana aphid insect pest which can spread banana bunchy top virus (BBTV) including description, distribution, hosts, damage and controls.

  • Banana flower thrips

    Information on the Banana flower thrip insect pest, which is found throughout the banana-growing districts.

  • Banana fruit caterpillar

    Banana fruit caterpillar (Tiracola plagiata), insect pest of banana and citrus, description of adult, life cycle, hosts, damage, control options, distribution.

  • Banana rust thrips

    Information on the Banana rust thrip. Bananas are the main host, although the Banana rust thrip has been found in citrus and in some native plants.

  • Banana scab moth

    Banana scab moth (Nacoleia octasema) insect pest of bananas.Description, life cycle, host range, damage and control options.

  • Banana spider mite

    Banana spider mite (Tetranychus lambi) the most important and widespread mite pest of bananas. Description, life cycle, host range, damage and control options.

  • Banana weevil borer

    Banana weevil borer (Cosmopolites sordidus), insect pest of genus Musa inclu. banana (M. sapientum) and abaca (M. textilis).Description, damage,control methods.

  • Banana-silvering thrips

    Information on the Banana-silvering thrip insect pest, which affects bananas, chokos, passionfruit and a number of weed species.

  • Banana-spotting bug

    Banana-spotting bug (Amblypelta lutescens lutescens) insect pest of wide range horticultural crops. Decription, life cycle, damage and control options.

  • Bean blossom thrips

    Information on Bean blossom thrips, which affect French beans.

  • Black scale

    Black scale (Saissetia oleae) insect pest of olives, citrus and gardenia, distributed throughout Queensland. Description, life cycle, damage and control options.

  • Cicada

    Cicada (Macrotristria dorsalis) insect pest, including description, life cycle, distribution, damage, host range, and control measures.

  • Citrus mealybug

    Citrus mealybug (Planococcus citri) is a major and frequent pest of many fruit and ornamentals throughout Australia. Description, life cycle, damage and control.

  • Clearwing borer

    independently. Description Clearwing borer (Carmenta chrysophanes) insect pest in all lychee and longan growing areas in Queensland. Description, life cycle, host range, damage, control.

  • Cluster caterpillar

    Cluster caterpillar background information and control options.

  • Corn earworm and native budworm

    Information and control options for the corn earworm and native budworm insect pests.

  • Cryptic mealybug

    Cryptic mealybugs pose a significant threat to a range of Australian horticultural industries. Description, life cycle, damage and control.

  • Diamondback moth

    Diamondback moth insect pest information and control options.

  • Eggfruit caterpillar

    Information on the Eggfruit caterpillar. Eggplant is the main commercial host but it also occasionally attacks tomato, capsicum and pepino.

  • Elephant beetle

    Elephant beetle (Xylotrupes gideon) is a pest of pineapple, longan and lychee. Exclude beetles with net or remove manually. There is no chemical control.

  • False spider mite

    False spider mite (Brevipalpus sp.) is minor pest of a variety of fruit crops.Predatory mites control numbers but if fruit loss is high, consider treatment.

  • Flower eating caterpillar

    Flower eating caterpillar information and control options.

  • Fruit piercing moth

    Fruit piercing moth information and control options.

  • Fruit-spotting bug

    Fruit-spotting bug information and control options.

  • Giant grasshopper

    Giant grasshopper (Valanga irregularis) damages a variety of plants inclu. coffee and citrus. Chemical control may be used to spot spray heavily infested areas.

  • Green vegetable bug

    Species fact sheet – Green vegetable bug, Nezara viridula.

  • Helopeltis

    Information on the Helopeltis pest in Queensland, including impacts, distribution and control methods.

  • Loopers

    Loopers insect pest information, including description distribution, damage, and control options.

  • Lychee erinose mite

    Lychee erinose mite (Aceria litchii) is a serious pest of lychee foliage, flowers and fruit.Control can be achieved with a strict program of suitable miticides.

  • Macadamia nutborer

    Macadamia nutborer (Cryptophlebia ombrodelta) damages lychee, logan, macadamia and many ornamentals. Control many be manages by biological and chemical methods.

  • Mango seed weevil

    Mango seed weevil (Sternochetus mangiferae), a minor pest with no serious economic damage to fruit. Control programes use quarantine, hygiene and chemical spray.

  • Mango shoot caterpillar

    Mango shoot caterpillar (Penicillaria jocosatrix) is a minor and frequent pest of mango and cashew in late summer. Control should coincide with growth flushes.

  • Mound forming termites

    Mound forming termites (Nasutitermies spp) can affect cashew, mango and citrus grown in drier areas but are usually not a problem in well-managed crops.

  • Orange fruit borer

    Orange fruit borer (Isotenes miserana) is a minor and sporadic pest of a variety of fruit crops in coastal Queensland.Use chemical sprays when numbers indicate.

  • Oriental scale

    Oriental scale (Aonidiella orientalis) is a minor pest of a wide range of crops and ornamentals. Infestations are best treated with biological control agents.

  • Passionvine bug

    Passionvine bug (Leptoglossus australis) is a minor but frequent pest of many fruit crops crops and some cucurbits. No chemcial control is currently available.

  • Pink wax scale

    Pink wax scale (Ceroplastes rubens) is a minor and frequent pest of many tropical fruit crops but is well managed with a range of biological controls.

  • Potato moth

    Potato moth (Phthorimaea operculella) is a serious pest of tomatoes and is usually supressed by parasitoids. Avoid planting adjacent to susceptible crops.

  • Queensland fruit fly

    Queensland fruit fly (Bactrocera tryoni) is a major pest of many fruits in eastern Australia. Chemcial sprays, parasitoids and orchard hygiene may be used.

  • Red scale

    Red scale (Aonidiella aurantii) infests a range of hosts including citrus, passionfruit. Biological control is crucial so spray only if infestation is high.

  • Red-shouldered leaf beetle

    Information on the Red-shouldered leaf beetle insect pest.

  • Root-knot nematode

    Root-knot nematode, Meloidogyne spp, is a problem in many crops especially tomatoes. Plant resistant varieties and use crop rotation, nematicides for control.

  • Silverleaf whitefly

    Information on the Silverleaf whitefly insect pest.

  • Soft brown scale

    Information on the Silverleaf whitefly insect pest.

  • Stem girdlers

    Stem girdlers are ring-barking weevils involving at least three weevil species causing sporadic damage in all lychee/longan districts. There is no control.

  • Sugarcane bud moth

    Sugarcane bud moth (Opogona glycyphaga) affects bananas with crops planted close to sugarcane suffering more. Dust with chemical when applying bunch cover.

  • Swarming leaf beetles

    Information on the Swarming leaf beetle insect pest.

  • Tomato russet mite

    Tomato russet mite (Aculops lycopersici) affect tomato, chilli and capsicum. Maintain good farm hygiene and destroy old crops and weeds, spray when appropriate.

  • Two-spotted mite

    Two-spotted mite (Tetranychus urticae) has a wide host range and can be a sign of excessive insecticide use. Manage with predatory mites and limited spraying.

  • Wireworm-true and false

    Information on the Wireworm (true and false) insect pests.

One of America’s most popular food staples is at war against an insect smaller than an apple seed that is spreading an incurable disease. And they are losing.

Over the last few years, the nation’s orange industry has taken a more than $4 billion hit as dead trees and useless crops recently sent orange harvests to their lowest in two decades.

“It’s like a patient that keeps getting sicker and sicker and sicker, until it dies,” says Michael Rogers, interim director of the Citrus Research and Education Center at the University of Florida.

The disease is called huanglongbing, also known as citrus greening. Producing oranges too bitter for juice and too misshapen and discolored for fresh fruit, the bacteria leaves farmers little choice but to destroy every one of their sick trees.

The crawling culprit facilitating its spread is the Asian citrus psyllid, a plant juice-sucking bug that with a gust of wind can easily become airborne and carry the fatal bacteria that destroys oranges, limes, lemons and grapefruits.

“If we don’t protect our citrus,” warns the USDA’s Save Our Citrus campaign, “that cup of juice you drink with your breakfast, the beautiful lemon tree in your yard and the curry you use to add zest to your cooking might not be there in the future.”

In Florida, disease-carrying bugs have ravaged citrus crops, triggering dire predictions about the coming extinction of orange juice. Indeed, “the majority of the citrus trees have the disease,” according to Rogers.

The state’s orange production has been steadily declining since the bacteria was first identified there in 2004, according to USDA data, along with the number of acres bearing the fruit.

Rather than invest time and money in grove regrowth, some citrus farmers are deciding to sell out to real estate developers, Rogers explains. Yet for those who try and stand their ground against the expanding threat, they are arming themselves with a variety of tools to try and control the psyllid population, including spraying, tenting and steam treatments, the USDA says.

Another possible solution being explored, but one that has been met with some controversy: genetically modifying oranges to make them more resilient to pests and diseases. While GMOs could be more of a long-term solution, says Rogers, a more short-term one is naturally cross-breeding oranges to create “new varieties” that can “better tolerate the disease.”

However, it would be at least four years before their effectiveness could be measured, when the new citrus trees finally yield, he acknowledged.

Insect pests of vegetables

Insects

Aphids

Aphids are 1–3mm, soft-bodied insects that can be green, grey, or black. Most commonly seen in spring and autumn, aphids can be winged or wingless and are usually slow-moving. Aphids cluster on the tips of the shoots, sucking the sap from the plant, which reduces plant vigour. Aphids can also spread viruses which can severely reduce yields and quality.

Aphids on broccoli.

A number of natural enemies such as lacewings and ladybugs will give some biological control. If required, control with sprays such as garlic extract or horticultural oils and horticultural soaps. Sprays containing pyrethrum and piperonyl butoxide can also be used but crops can not be picked for one day after its use.

Caterpillars

Caterpillars are usually the larval stages of moths or butterflies. They are normally hairless, with a long cylindrical body from 10–50mm long and range in colour. Caterpillars may attack leaves, stems, flowers, fruits and roots.

Green caterpillars of the large cabbage white butterfly and the small diamond-back (cabbage) moth can severely damage the leaves of the Brassica family which includes broccoli, cabbage, kale and cauliflower.

Cluster caterpillars, woolly bear caterpillars and looper caterpillars will attack the leaves of most vegetables.

The woolly bear caterpillar will eat just about anything that is green.

The eggfruit caterpillar bores into aubergine and the native budworm will bore into the fruit of many vegetables, especially, capsicums, tomatoes and sweet corn. These fruit pests are hard to kill and early spraying is required to kill the caterpillars before they enter the fruits.

Other caterpillars attack the roots and stems. Potato moth caterpillars will ‘mine’ potato leaves and bore into potato tubers.

Cutworms

Cutworms hide in the soil by day and attack plants at night. They damage the stem of young seedlings at the base, causing the plant to collapse.

Cutworm caterpillar.

Control with Bacillus thuringiensis, a biological insecticide which targets only caterpillars but needs to be sprayed every five days or after rain or overhead watering.

Spinosad is a chemical of low toxicity which has a translaminar movement, which means the chemical moves into the leaf, making the active ingredient resistant to rain and sunlight once the spray has dried. Sprays containing pyrethrum and piperonyl butoxide can also be used but crops can not be picked for one day after spraying.

Top 5 Pests That Attack Garden Plants

So you’ve worked hard keeping your garden looking its best, but what’s this you see on the leaves of your beautiful plants – bugs! No matter how well you groom the garden, pests are inevitable. Here are the top 5 pests that are known to attack plants in the garden.

1. Aphids – Aphids, tiny, pear-shaped bugs with long, slender mouthparts, aren’t picky. They bother members of nearly every plant family in North America, including shade trees, flowers, vegetables, fruits and ornamentals. A healthy plant can withstand a few aphids, but a severe infestation can cause distorted foliage and dropped leaves as the pests siphon out the sweet juices. Aphids also excrete a sweet substance known as honeydew, which supports the growth of black sooty mold. According to Utah State University Extension, there are more than 1,300 aphid species in North America. Aphids are most often green, but depending on the species and the type of plants they eat, they may be brown, yellow, black or red.

2. Scale insects – There are at least 200 species of scale insects. The miniscule, delicate-looking, flying male adults are rarely seen, but the tiny, crawling nymphs and the adult females manage to weaken plants as they suck out the juices. Most species of adult female scale insects are protected by hard or soft “shells,” and are commonly found on plant stems. Hard-shelled, or armored scale, are more difficult deal with because the pests are so well protected.

3. Whitefly – These annoying pests aren’t actually flies. Unsurprisingly, they are related to other sap-sucking pests, including scale and aphids. Whiteflies lay tiny eggs on the underside of leaves. After hatching, the microscopic, crawling nymphs begin feeding in a few hours, increasing in size until they emerge as winged adults. The adults do little harm, but the nymphs suck plant juices at all stages of development. Like aphids, whiteflies leave sweet honeydew, which attracts black sooty mold. The honeydew also attracts ants, which may kill beneficial insects that help control whiteflies and other harmful pests.

4. Spider mites – Difficult to see with the naked eye, speck-sized spider mites are usually easy to spot by the fine webbing they leave on plants. If you suspect spider mites, use a magnifying glass to look for mites and eggs on the underside of leaves. Mites often appear after pesticides are used to kill other insects, as the toxic chemicals destroy the mites’ natural enemies. Mites are often more problematic in dry, dusty conditions or when plants are water stressed.

5. Thrips – Yet another pest that damages plants by sucking out juices, thrips are tiny, flying insects with fringed wings. They tend to feed in large groups and are easy to spot because they fly away en masse when disturbed. There are at least 6,000 types of thrips, and some are actually beneficial. This is yet another good reason to avoid pesticides, as chemicals kill the good and the bad indiscriminately.

Tips on Controlling Sap-Sucking Insects

Chemicals should always be a last resort when plants are affected by sap-sucking insects, as pesticides are non-selective, killing beneficial insects that feed on harmful pests. As a result, unwanted pests come back stronger and more difficult to control.

Always encourage the presence of natural enemies such as:

  • ladybugs
  • big-eyed bugs
  • lacewings
  • minute pirate bugs
  • parasitic wasps

Insecticidal soap spray and horticultural oil sprays are often effective for severe infestations, and are less harmful to beneficial insects.

Insects affecting solanaceous crops

Authors: Dr. Alton “Stormy” Sparks, Jr. and Dr. David G. Riley – University of Georgia

Introduction

The term “Solanaceous crops” generally refers to plants in the nightshade family, Solanaceae, within the Genera Capsicum (peppers), Lycopersicon (Tomato), and Solanum (Eggplant and Potato). When referring to fruiting vegetables, all of the above except potato, a root/tuber crop, are included. However, many of the insects that attack tomato also attack potato. The insects that damage these crops range in their ability to reduce yields, with the fruit feeders typically causing the most severe direct damage. However, insects that transmit disease agents, such as whitefly or thrips vectored plant viruses, can also have similar devastating effects on yield. Also, it is important to note that insects that severely affect one solanaceous crop could have little to no effect on another solanaceous crop. For example, Broad mite can produce severe symptoms in Pepper, but have been rarely reported in commercial Tomato fields in the southeastern USA.

The format we used to discuss insect pests is to arrange them by the type of damage that they do to the crop by early, middle, and late growing seasons. Pest descriptions are included in the following sections and the levels of injury expected from an insect species are noted by crop species. For specific commercial control options, please refer to the tomato, pepper, and eggplant sections of the UGA Pest Management Handbook. Additional outside information can be obtained from the University of California’s “UC IPM Guidelines for Tomato” and John Capinera’s “Handbook of Vegetable Pests” from Academic Press.

Insects Attacking Solanaceous Crop Seedlings (Early Season)

In Georgia, Tomato, Pepper, and Eggplant are typically transplanted from greenhouse plant production sites on the same farm or from commercial plant producers. Since all of these crops are susceptible to Frost damage, early planting in greenhouses followed by transplanting into the field avoids freeze damage. This is particularly important for tomato in the spring when early planting takes advantage of early favorable market windows. It also can avoid early season pests. Additionally, greenhouse or shade house transplant production concentrates expensive chemical treatments into a much smaller area and guarantees more uniform plant stands in the field. Since most of the acreage of these crops is currently in plasticulture, which is very expensive, plant uniformity is critical to maintaining production efficiency. However, these types of high input, uniform production practices also can lead to specific insect problems that can be exacerbated in these controlled environments. For example, insecticide treatment in greenhouses can concentrate selection for Pesticide resistance to that insecticide if resistant insects survive the greenhouse production and are carried with transplants to the field. Some of the more easily controlled pests of solanaceous crop seedlings are flea beetles that cause small shot-holes in leaves, Wireworms , or Whitegrubs, that attack the stem and roots causing the plant to wilt, and Cutworms that clip the plant off at the soil line. The treatment timing for soil insects, such as wireworms, is usually at bed formation using soil fumigants. For later invading cutworms, it is at the time that damage is first detected, and for defoliators, it is at 10% defoliation. Currently, the most difficult early season pest to control is Thrips that transmit Tomato spotted wilt virus (TSWV) which causes a severe wilt disease in most solanaceous crops. Tobacco thrips usually settles on tomato very early in the season beginning at transplant. Control options for this include host plant cultivars resistant to the virus, metallic reflective mulch (shown to be effective in tomato), early season insecticides targeting thrips and reducing thrips feeding at transplant, and plant activators that chemically induce resistance. Pre-season weed monitoring for thrips and TSWV can help to predict risk at a given location.

Insects Attacking Solanaceous Crops During Vegetative Growth and Flowering (Mid-Season)

Probably the most severe insect problem in early spring in the coastal plain of Georgia is thrips that transmit TSWV. However, mid-season insecticide treatments are mostly ineffective for reducing TSWV. Early season, preventative treatments are much more effective. In the early spring, usually no Lepidoptera pests attack Tomato and Pepper, but can occur at the end of the spring season. Where it occurs, Pepper weevil can be the most severe pest in peppers (it does not damage tomato), but the distribution in Georgia is mostly limited to farm sites where weevils were introduced and populations were not systematically eradicated. Pepper weevil must be controlled by flowering to prevent establishment of damaging levels in the field. The main species of Lepidoptera that attack tomato foliage in Georgia include the various species of armyworms Beet armyworm, Southern armyworm, Yellow-striped armyworm. Other Lepidoptera pests include Cabbage looper, Tobacco hornworm, and Tomato fruitworm. Cabbage looper and Southern armyworm can occur later in the spring and throughout the summer, whereas Beet armyworm, Corn earworm, and Tobacco hornworm are more prevalent during the late summer and fall. Other important chewing insects that can occasionally occur on Tomato and Eggplant are Colorado potato beetle and vegetable weevil.

Another group of insects that can reduce the quality of foliage during mid-season in the spring is Aphids which secrete honeydew thus promoting the presence of Sooty mold on leaves. During early to mid-season in the late summer and fall, Sweetpotato whitefly can transmit geminiviruses that severely stunt plant growth and affect fruit quality. Whiteflies also can produce a honeydew that results in sooty mold when adult and nymph numbers are high. Two other foliage feeders that have been reported in Georgia in recent years are mites Spider mites in Tomato and Eggplant and Broad mite in Pepper and Eggplant] and less frequently, Leafminers. Broad mite occur more frequently in the fall production season, but Spider mites can occur in the spring and fall growing seasons. Insects that should be controlled mid season to avoid bloom drop and damage to fruit buds include Stink bugs , Leaffooted bugs, and other plant bugs. Thresholds for initiating control actions against insect pests in Georgia closely follow those recommended by University of Florida IFAS and include the one Lepidoptera larva or bug per six plants threshold prior to fruit formation. Thrips populations greater than 5 per blossom can cause direct damage, but again, most of the damage occurs at much lower levels when thrips vector TSWV, and this must be prevented at an earlier plant growth stage. Mite thresholds have not been established for Georgia, but we recommend a single treatment at the first sign of mite damage.

Insects Attacking Mature Solanaceous Crops (Late Season fruit feeders)

Insect control becomes critical once developing fruit are present. Most of the Lepidoptera pests previously mentioned can damage the fruit either by surface feeding or boring directly into fruit. In Georgia, Tomato fruitworm and Beet armyworm are both typical summer pests that bore into tomato fruit. Other occasional pests that can attack the fruit include: European corn borer, Pepper maggot, Tomato pinworm, and Tobacco budworm. Worms that feed on fruit surfaces after extensive foliar damage late in the season include Tobacco hornworm and various Armyworms. The treatment threshold for worms that attack the fruit is very low. Depending on the amount of scouting done, the presence of worms in the field usually signals the need for treatment. Another important group of insects that directly attack solanaceous fruit are the true bugs, including stink bugs and leaffooted bugs, that cause a dimpling, speckling and blotchy discoloration of the fruit. This type of damage often does not become apparent until the fruit begins to ripen (for example, the pink and red stages of tomato ripening). Other insects that cause dimpling of tomato are Thrips. Insects that cause irregular ripening of tomato include Whiteflies. This can be directly from whitefly feeding or indirectly through the transmission of geminiviruses. Thrips vectored tomato spotted wilt virus also causes distinctive irregular ripening with circular patterns on the fruit. In pepper, dimpling of the fruit can be a sign of Pepper weevil oviposition into the fruit. This can occur on fruit that appear marketable to the untrained eye, thus allowing infested fruit to be processed and shipped. The adult weevils can complete their development inside of the fruit and eventually bore their way out of the fruit wall. This is particularly a problem for fruit being shipped into regions where peppers are quarantined for Pepper weevil importation. Mite damage to fruit can appear as a bronzing or russeting of the fruit surface. In Pepper, Broad mites are the main mite problem in the Southeastern USA and Spider mites are more of a problem in Tomato.

  • Sparks, A. and Riley, D. Insects Associated With Vegetable Crops in Georgia

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