Category Archives: Target Pests

Cutworm

Common Name: Cutworm
Latin Name: Agrotis, Prodenia, and other species
Order: Lepidoptera
Family: Noctuidae
Main Host(s): Field and row crops, e.g. corn and other grain crops, vegetables, ornamentals and deciduous fruit trees.

Life Cycle

Cutworm
Source: Clemson University – USDA Cooperative Extension Slide Series, Bugwood.org

Cutworms are found mostly in the southern U.S., especially the Southeast, but have been seen north as far as Canada. They are not selective in regards to feeding preference, feeding on various row crops such as corn, or vegetable crops, ornamentals and deciduous fruits and vines.

Cutworms are grouped in three categories, i.e. the surface Cutworms that are eating holes in vegetable fruiting structures (tomatoes, beans, etc) or cutting plant seedlings, the climbing Cutworm (for example on grape), and the subterranean Cutworms feeding on plant roots. Cutworms feed mostly at night and larger larvae make shelters in the soil where they hide during the day.

Depending on the species, cutworms overwinter as egg, larvae or pupae, in the latter case there usually is more than one generation per year. Variegated and black cutworms are examples. Still other species have one generation per year. For species that overwinter as pupae, in the spring — the farther south the earlier — the moth emerges from the soil to mate and lay eggs. Those species overwintering as larvae start feeding on young plants in the spring, cutting them off right at the soil line and giving this pest its name.

Impact & Damage

Damage caused by Cutworm species can be severe, such as damage to plant seedlings when a crop is being established. Feeding on vegetable fruiting structures will impact the harvestable crop, while the climbing Cutworm feeding on woody plants such as grapes cause economic damage during spring flush.

Recommended Control

Growers should begin scouting for Cutworms when plants are still quite small. Larvae are susceptible to both DiPel^® and XenTari^®, and both products are extremely effective on Cutworms. These products should be applied as a complete coverage starting when plants are small. While many growers prefer to wait until scouting shows damage, it is best to treat before damage occurs by monitoring the adult population.

References & Sources:

www.biorationalapproach.com
entoplp.okstate.edu/ddd/insects/cutworms.htm
www.nysipm.cornell.edu/factsheets/grapes/pests/cc/cc.asp
www.uri.edu/ce/factsheets/sheets/cutworms.html
ipm.ncsu.edu/ag295/html/cutworm.htm
entnemdept.ufl.edu/creatures/veg/black_cutworm.htm
ipm.illinois.edu/vegetables/insects/black_cutworm/index.html

Tuta Absoluta

Common Name: Tomato Leafminer
Latin Name: Tuta absoluta
Order: Lepidoptera
Family: Gelechiidae

Main Host(s): Tomato

Life Cycle

Tuta absoluta has received a lot of attention in recent years. Also known as the Tomato Leafminer, the pest is originally from South America, where it remains a problem. It has spread to Mediterranean and Middle Eastern countries, moving up into greenhouse areas of Hungary and Southern Germany. Recently, USDA officials have become concerned that the pest may spread to Florida.

The pest is best known for attacking tomato but has also been found feeding on potato, eggplant and green bean. Tuta is an open field pest in warm climates but especially in greenhouses it can proliferate quickly and produce 10-12 generations each year.

A Tuta female can lay several hundred eggs, singly on plant terminals. The eggs hatch in 4-6 days, and with 4 larval stages and a short pupal duration, a new generation appears in 30-35 days under optimal conditions. Larvae will appear many times at the plant surface for molting into the next stage. They can move to other plants, making new galleries. When populations increase tomato stems and green fruits are attacked. Tuta can overwinter as egg, pupa or adult.

Impact & Damage

The larvae feed voraciously on tomato plants, with damage resulting from the larvae boring into leaves, stems and fruits. Within a few months, various life stages overlap and a multitude of control options need to be employed to keep the pest under control to prevent yield losses which can amount to total crop loss.

Recommended Control

An effective T. absoluta control program treats the pest as soon as it appears. Growers can use pheromone traps to determine when to begin, and should begin applications when the adult moth population is low and egg laying has just started. Superficially and at low populations leaf damage from Tuta larvae looks similar to the damage of Liriomyza Leafminer Fly larva. Insecticides against Liriomyza may not work against Tuta. Effective IPM programs using beneficial insects and biorational products such as DiPel^® and XenTari^® have been developed especially for greenhouses (Spain, Italy, Morocco).

References & Sources:

www.biorationalapproach.com
www.tutaabsoluta.com/
North American Plant Protection Organization
archives.eppo.int/MEETINGS/2011_conferences/tuta_absoluta.htm

Tomato Fruitworm

Tomato fruitworm

Source: University of Arkansas

Common Names: Tomato Fruitworm, Cotton Bollworm, Corn Earworm

Latin Name: Helicoverpa zea

Order: Lepidoptera

Family: Noctuidae

Main Host(s): Corn, cotton, leafy and fruiting vegetables, ornamentals, tobacco, alfalfa.

Life Cycle

In corn, the pest is known as the Corn Earworm, and in cotton it is called the Cotton Bollworm. On some crops H. zea occurs together with Heliothis virescens, together they are known as the heliothines. But H. zea is not limited to just these few host plants, as it infests many crops in the U.S. It has been found on many leafy and fruiting vegetables as well as ornamentals and field crops such as alfalfa, vetch, sorghum and tobacco.

Tomato Fruitworm adults are strong flyers and disperse northward in the summer where they can have 1-2 generations. Up to seven generations are possible in the Southern States.

A single female will lay on average 35 eggs per day and has a life span of 5-15 days. Eggs are laid singly, are pearly white or cream color, and measure about 0.6 mm in diameter. They are easily visible when first laid and can be found anywhere on the plant from the leaf stems to the calyx of the tomato, usually on terminal growth. Tomato Fruitworm larvae show burrowing behavior and after a short while on the foliage after egg hatch they will go into flower buds or fruiting structures. The 6-7 larval stages cover a 3-4 week period.

Impact & Damage

Tomato Fruitworm can do considerable damage to high value crops such as tomato, bell pepper, eggplant, snap beans, sweet corn and others. Since larvae bore into the harvestable crop, the tolerance for damage is low.

Recommended Control

Pheromone traps are available for early warning of emerging and migrating moths. Scouting is absolutely necessary to assess the egg laying peak of the incoming population. In order to preserve beneficial insect populations, biorational control methods such as DiPel^® and XenTari^®, are often recommended early in the season. In addition, Tomato Fruitworm has developed resistance to many insecticides (most recently pyrethroids), so rotating DiPel and XenTari with conventional chemical insecticides provides a cornerstone to effective insect resistance management programs.

References & Sources:

www.biorationalapproach.com
entnemdept.ufl.edu/creatures/veg/corn_earworm.htm
ipm.illinois.edu/fieldcrops/insects/corn_earworm.pdf
www.ipm.ucdavis.edu/PMG/r783300111.html
www.ncbi.nlm.nih.gov/pubmed/20069859

Spodoptera Littoralis

Source: Biologische Bundesanstalt für Land- und Forstwirtschaft Archive, Bugwood.org

Common Names: African Cotton Leafworm, Egyptian Cotton Leafworm, Mediterranean Brocade

Latin Name: Spodoptera littoralis

Order: Lepidoptera

Family: Noctuidae

Main Host(s): Extensive host plant range including ornamentals, vegetables, fruits and row crops.

Life Cycle

Spodoptera littoralis is native to Africa, the Middle East and the Mediterranean countries of Europe. In Spain, Italy and Greece the insect can be found in numerous greenhouse crops including tomato, pepper and melon. S. littoralis is not established in the northern parts of Europe and the UK due to cooler temperatures and its quarantined pest status. However, in the northern EU countries, it can be introduced in greenhouses and nurseries with shipments of transplants and nursery stock.

The pest has a wide host range, feeding on the leaves and fruiting structures of more than 44 plant families. Popular hosts include cotton, corn, tomato, okra, onion, cabbage and cucurbits. The moths are good flyers and can disperse over a long distance in search of new/suitable host plants. In warm climates, up to 8-9 generations are possible. The pest overwinters as pupa in the soil.

The female lays from 100-300 whitish-yellow eggs in clusters covered with moth scales on the under surfaces of leaves. The eggs hatch in four days (depending on temperature) and initial larval feeding causes leaf skeletonization – an early indication of infestation. Six larval instars of Spodoptera littoralis over a three week time period occur in warm climates, with an additional larval stage and longer development times in cooler regions.

Impact & Damage

Early larval damage appears as skeletonization of leaves. Larger larvae will do extensive damage, stripping foliage and infesting plant fruiting structures. In Africa and the Middle East, field research has documented instances of chemical insecticide resistance, such as to chlorpyrifos in Turkey.

Recommended Control

XenTari^®is particularly effective against S. littoralis larvae and is widely used in Spodoptera control. This proprietary strain of Bacillus thuringiensis aizawai (ABTS-1857) contains two additional toxin proteins with very good, highly-specific activity against Spodoptera species. As with most caterpillar larvae, the earlier the treatment is made the more effective it will be since the youngest larval stages are the most susceptible. In field or greenhouse setting, an IPM/IRM program rotating or tank mixing chemical insecticides with biorational pest control products such as XenTari will give the best result.

References & Sources:

www.biorationalapproach.com
www.eppo.int/QUARANTINE/insects/Spodoptera_litura/PRODLI_ds.pdf
www.europe-aliens.org/pdf/Spodoptera_littoralis.pdf
www.rothamsted-international.org/files/posters/Posters/OktayGurkan.pdf
www.fera.defra.gov.uk/plants/publications/documents/factsheets/spodoptera.pdf
1.agrifish.dk/spodoptera_littoralis.aspx?ID=13428

Soya Pests

Soybean Looper

Source: Clemson University – USDA Co-op Ext Slide Series

Common Names: Includes Soybean Looper, Velvet Bean Caterpillar, Green Clover Worm, Webworm, Armyworms
Latin Names: Pseudoplusia includens, Anticarsia gemmatalis, Plathypena scabra
Order: Lepidoptera
Family: Noctuidae; Plathypena: Erebidae (formerly Noctuidae)

Main Host(s): Soybean and other legume crops, but for some species also large variety of other host plants including cotton, tobacco and vegetables.

Life Cycle

Velvet Bean Caterpillar

Source: Clemson University – USDA Co-op Ext Slide Series

The Velvet Bean Caterpillar is tropical and subtropical with wide distribution, occurring from the southern U.S. to Argentina. It is considered an important pest in the U.S., Brazil, Mexico, Colombia, Venezuela and Argentina. Soybean Looper occurs from the U.S. to southern South America. In the northern U.S., growers can find Alfalfa Caterpillars. The pest mix can include not only the Soybean Looper and Velvet Bean Caterpillar, but also the Green Clover Worm, Webworm and Armyworm species.

Many of these pests migrate, and in a variety of combinations they impact most soybean regions in North and South America. The adults move into soybean fields in mid- to late summer, and some species (Loopers) will lay eggs singly with many hundreds of eggs per female. Egg hatch is between 3-7 days depending on temperature. The number of larval stages may vary per species and field conditions but is usually around six. The Velvet Bean Caterpillar has green and dark colored forms. Many of the soybean pest caterpillars are defoliators and especially the older larvae in large numbers can defoliate plants. Some species such as the Soybean Looper start feeding on the lower half of the crop and move upward.

Impact & Damage

At the early stages of crop growth, beneficial insects and fungal diseases can bring down some caterpillar populations before insecticide treatments are warranted. At the vegetative growth stage of soybeans, the amount of leaf damage tolerated is a bit higher than at more mature crop stages. Late in the season, however, the impact from these pests, if left unchecked, can be severe, decreasing yield.

Recommended Control

DiPel^® is highly effective on both of the important soybean pests, Soybean Looper and Velvet Bean Caterpillar. For greatest efficiency, DiPel should be applied at preflowering with low pest pressure to control the first to third larval stages. It can be applied both by ground application or by airplane. DiPel can be mixed with a knockdown chemical insecticide, such as a pyrethroid, organophosphate or carbamate. Use of DiPel in combination with these other insecticides can maximize control.

References & Sources:

www.biorationalapproach.com
www.ksre.ksu.edu/library/entml2/s116.pdf
cropwatch.unl.edu/web/cropwatch/archive?articleID=4236335
www.mdcrops.umd.edu/UMDextension/AgronomyNews20100902.pdf
pubs.ext.vt.edu/444/444-770/444-770.html
msucares.com/insects/soybeans/pubs/insect_mana gement.pd f

Pineapple Pests

Common Name: Thecla moth, Elaphria moth
Latin Name: Thecla basilides, Elaphria nucicolora
Order: Lepidoptera
Family: Thecla: Lycaenidae; Elaphria: NoctuidaeMain Host(s): Pineapple; for Elaphria also sugarcane

Life Cycle

T. basilides and E. nucicolora are major pests of pineapples in the tropical regions of the Western Hemisphere, including Mexico, Central and South America. Thecla also occurs on wild hosts (Bromeliacea), as well as corn and cacao. Elaphria is found in the more (sub)-tropical regions of the Americas, including South-Eastern US, Caribbean and tropical South America. It counts as host plants sugarcane, watermelon and wild herbs. E. nucicolora is also called the sugarcane midget moth.

Thecla females lay single eggs on upper and middle fruitlet bracts. The eggs hatch in five days and the young larvae bore into the pineapple inflorescence. Thecla larvae generally damage the developing fruit in weeks 7-12, prior to flowering and well thereafter. No eggs are laid on mature fruit. Elaphria becomes a problem in weeks 10-15 of pineapple fruit development.

Impact & Damage

Elaphria nucicolora

Thecla Damage

Thecla larvae bore into the fruit making galleries, causing fruit deformities. These galleries allow Fusarium subglutinans disease to enter the fruit, leading to more damage. The damage done by Elaphria larvae consist of scraping the surface of the developing fruit causing so called gummosis.

Recommended Control

For control of Thecla, growers should start with a spray of DiPel^® in the pineapple pest control program generally begun in the seventh week after induction of flowering, followed up with a traditional insecticide and then rotate back to DiPel seven to 10 days later. This rotation continues throughout the time when the two pests are a threat, with the DiPel applications continuing up until harvest when a no-residue product is needed. For Elaphria control, XenTari^® is recommended and a similar rotational program is used.

References & Sources:

www.biorationalapproach.com
www.fao.org/fileadmin/user_upload/inpho/docs/Post_Harvest_Compendium_-_Pineapple.pdf
cep.unep.org/repcar/proyectos-demostrativos/costa-rica-1/publicaciones-proagroin/Guia%20manejo%20integrado%20en%20pina%20ENG.pdf
www.gmanetwork.com/news/story/129751/economy/pineapple-growers-end-endosulfan-use
www.globalissues.org/article/789/pineapples

Peach Twig Borer

Common Name: Peach Twig Borer
Latin Name: Anarsia lineatella
Order: Lepidoptera
Family: Gelechiidae

Main Host(s): Fruit and nut trees such as peaches, nectarines, prunes, plums, apricots, almonds

Life Cycle

Peach Twig Borer (PTB) is a pest common to the Mediterranean area but also to many fruit and nut growing areas around the world, from North America to Europe and Asia, with the exception of Australia and Japan. Its primary hosts are stone fruits such as peaches, nectarines and prunes, but nut trees such as almonds are susceptible as well.

Source: Eugene E. Nelson, Bugwood.org

PTB “strikes” appear as visible blemishes on twigs, which become weakened and can later snap.

DiPel provides excellent control of this pest, reducing the stunting that results from this type of

injury. Between one to four generations of PTB occur depending on the climate of the region.

Young PTB larvae overwinter as young first or second stage larvae in shelters called hibernacula.

On second- and third-year wood, they will generally emerge in early spring as daytime

temperatures begin to hit about 15C (60F). Degree-day models have been developed by scientists

to predict PTB emergence. Pupae can be found beneath bark or in crevices. Females lay egg

masses of about 80-90 eggs on shoots, fruit and underside of leaves. The eggs hatch in 5-8 days,

or longer in cooler areas. The overwintering larvae of this species feed on buds and leaves and

enter the young shoots, causing “flagging”. The summer larval generations feed on immature fruits

and shoots.

Impact & Damage

Summer generations of peach twig borer infest the fruit and can cause considerable economic damage. The “flagging”, i.e. snapping of young shoots by the overwintering larvae boring into the terminals can cause stunting and reduce the vigor of young trees.

Recommended Control

Scouting for larvae in their hibernacula will help establish pest control timing for individual orchard plots. A spray program is initiated when 20% emergence is observed. DiPel^® is an excellent control for PTB and unlike some chemicals used against this pest, DiPel is completely harmless to bees. A second DiPel application should be made at 80% to 100% emergence, about a week later under normal conditions. Using biorational products, like DiPel, in early season can prevent flare up of secondary pests during the summer. Pheromone traps are used to monitor the adult moth population and predict egg laying of the summer generation(s).

References & Sources:

www.biorationalapproach.com
extension.usu.edu/files/publications/factsheet/peach-twig-borers07.pdf
jenny.tfrec.wsu.edu/opm/displaySpecies.php?pn=90
Pesticides and Beneficial Organisms; IOBC/wprs Bulletin Vol. 35, 2008; pp. 44-50
www.ipm.ucdavis.edu/PHENOLOGY/ma-peach_twig_borer.html
www.ipm.ucdavis.edu/PMG/r5300311.html

Obliquebanded Leafroller

Obliquebanded Leafroller
Source: USDA/FS – Region 8 – Southern Archive, Bugwood.org

Common Name: Obliquebanded Leafroller
Latin Name: Choristoneura rosaceana
Order: Lepidoptera
Family: Tortricidae
Main Host(s): Fruit trees and bushes such as peaches, pears, apples and blueberry, as well as woody ornamentals, hawthorn, alder, roses, etc.

Life Cycle

Obliquebanded Leafroller (OBLR) is native to and fairly widely distributed in North America. It is of greatest concern on the East Coast of the U.S. and Canada. OBLR larvae feed on a wide range of plants and trees, but preferred hosts are members of the rose family, which include peaches, pears, and apples. The pest also invades fruiting bushes such as blueberry and woody ornamentals, hawthorn, alder, and of course, roses.

There are typically two adult generations of OBLR per year. The spring flight of OBLR adults begins about three to four weeks after petal fall on apples, and continues for three to four weeks. Egg masses, containing a few hundred eggs, are laid on the upper surface of leaves. Eggs hatch after 10-12 days. The larvae feed on floral parts, developing fruits and young leaves, folding leaves for shelter. There are 6 larval stages. At pupation the larva spins a cocoon attached to the leaf.

OBLR overwinters in the third larval stage and they start feeding on floral parts and developing fruit in Spring. The first summer generation of larvae feeds on more mature fruits causing significant damage.

Impact & Damage

Injury from overwintering OBLR larvae occurs just prior to and shortly after petal fall, when the developing fruit is damaged. This Spring time feeding will lead to fruit drop or deeply scarred fruit. The summer larval generations feeds on more mature fruit with shallow surface feeding. Such feeding can have a severe economic impact on fruit quality.

Recommended Control

To avoid problems with OBLR frequently the emphasis is on controlling the overwintering larvae, which become active with increasing temperatures. Applications of DiPel^® in Spring during the bloom stages – from “tight cluster” to “petal fall” – can provide an excellent early start reducing the population. The flight of the summer adults can be monitored with pheromone traps to ensure a grower will be prepared for egg hatch of the second generation and a timely schedule of DiPel in rotation with other insecticides following IPM and insecticide resistance management.

References & Resources:

www.biorationalapproach.com

agsci.psu.edu/tfpg/part2/insects-mites-web/obliquebanded-leafroller
www.virginiafruit.ento.vt.edu/oblr.html
www.ipm.ucdavis.edu/PMG/r4301011.html
whatcom.wsu.edu/ag/comhort/nooksack/ipmweb/blue/leafroller.html
jenny.tfrec.wsu.edu/opm/displaySpecies.php?pn=48
www.agf.gov.bc.ca/cropprot/tfipm/leafrollers.htm

Plant Parasitic Nematodes

Common Names: Various, including Root-knot nematode, Cyst nematode, Ring nematode, Lesion nematode, Reniform nematode, Citrus nematode, Dagger nematode, Burrowing nematode
Latin Names: Meloidogyne spp., Heterodera spp., Criconemoides spp., Pratylenchus spp., Rotylenchulus spp., Tylenchulus spp., Xiphinema spp., Radopholus spp.
Orders: Tylenchida, Dorylaimida
Families: Meloidogynidae, Heterodiridae, Criconematidae, Pratylenchidae, Hoplolaimidae, Tylenchulidae, Longidoridae

Main Host(s): Fruit, nuts, vegetables and ornamentals

Life Cycle, Impact & Damage

Nematodes are a highly diverse group of organisms, commonly called roundworms. Ubiquitous and widespread, these pests can be found in large numbers in many different habitats. Plant parasitic nematodes feed on plants, especially roots.

A common feature of plant parasitic nematodes is their stylet or spear. The stylet is a sharp, pointed tube the nematode uses to puncture cells and suck out the plant’s nutrients. Symptoms of crop infection may include wilting, chlorosis, dead or devitalized buds, root galls, rot, necrosis, lesions and injured root tips. Nematodes feed through a feeding tube, or stylet. DiTera causes stylet paralysis, limiting the pest’s ability to feed.

Recommended Control

DiTera^®, Valent BioSciences’ biological and organic nematicide, controls a wide variety of nematode species. It kills both juvenile nematodes (infective stage) and nematode eggs. It also increases plant vigor by promoting new root growth and creating a root “barrier” to nematodes that is formed as DiTera encourages natural endophytes in the soil to colonize on roots.

DiTera DF controls nematodes by several modes of action. It paralyzes the nervous system, immobilizes the stylet and kills eggs. It also acts as a repellant and as a confusing agent, causing pests to have trouble finding hosts and mates. Repeated use of DiTera DF actually enriches the soil and creates an antagonistic environment for nematodes.

References & Sources:

www.biorationalapproach.com

Light Brown Apple Moth

Source: Department of Primary Industries and Water, Tasmania Archive, Bugwood.org

Common Name: Light Brown Apple Moth
Latin Name: Epiphyas postvittana
Order: Lepidoptera
Family: Tortricidae

Main Host(s): Peaches, cherries, apples, pears, but also berries and many vegetables, ornamental, nursery and greenhouse plants.

Life Cycle

The light brown apple moth (LBAM) is quite common in its native Australia and New Zealand. LBAM is known to have a large number and variety of plant hosts. These include fruit trees such as peaches, cherries, apples, pears, but also berries and many vegetables, ornamental, nursery and greenhouse plants. It was discovered in California, mostly in coastal areas, in 2007. Since the first observations of the pest in California, many states are on the alert for LBAM.

In both appearance and behavior, the LBAM is similar to other Leafroller species in the Tortricidae family. Adult moths emerge after one to three weeks of pupation and mate soon after emergence. Females begin to lay eggs two to three days after emerging, depositing masses of 50 eggs or more at night on the upper side of leaves.

Larvae seem to survive moderate winters in weedy host plants or old fruit and will pupate in spring, producing the first adult summer generation. Several generations occur during the year with up to four possible generations in warmer climates.

Impact & Damage

The large number of hosts that caterpillars of LBAM can feed and survive on is a big problem for efficient control. Monitoring for this pest is absolutely critical not only because larvae can do a great deal of damage, but also because the pest penetrates plant and fruiting structures such as a grape bunch and create an entry point for Botrytis or other diseases.

Recommended Control

Good sanitation practices in orchards and vineyards during the dormant season is the first line of defense to prevent a buildup of larvae. Pheromone traps have been used to monitor its spread and delineate quarantined areas. As with other leafrollers, this species is very susceptible to DiPel^®, the world’s leading brand of Bacillus thuringiensis (Bt). Early application of DiPel is important to control the young larvae. Spray calibration should be carefully checked to be sure an adequate amount of the product is applied.

References & Sources:

http://www.biorationalapproach.com/
www.cdfa.ca.gov/plant/lbam/
www.aphis.usda.gov/plant_health/plant_pest_info/lba_moth/maps.shtml
www.ncagr.gov/plantindustry/plant/entomology/LBAM.htm
cms.oregon.gov/ODA/PLANT/IPPM/Pages/profile_lbam.aspx
www.ipm.ucdavis.edu/PMG/r302303011.html