Monday 23 October 2023

Green Garden Looper: All You Need to Know About This Common Pest

The Green Garden Looper (Chrysodeixis eriosoma) is a moth species that belongs to the Noctuidae family.

This species is not just a subject of entomological interest but holds significant importance in agriculture and horticulture.

Found in various regions, including Japan, China, India, Sri Lanka, the Malay Peninsula, Australasia, and Hawaii, the Green Garden Looper has been identified as a serious pest.

Its ability to feed on a wide range of plants—over sixty species, to be precise—makes it a notable concern for farmers and gardeners alike.

Adult moths of this species primarily feed on flower nectar.

In this article, we will look at this insect in detail, including its lifecycle, diet, habitat, what damage it can cause, and the control methods that agriculturalists can adopt against it.

Green Garden Looper
Chrysodeixis eriosoma. Source: LiCheng Shih, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons

Taxonomy and Identification

Scientific Classification

The Green Garden Looper falls under the following taxonomic classification:

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Insecta
  • Order: Lepidoptera
  • Family: Noctuidae
  • Genus: Chrysodeixis
  • Species: C. Eriosoma

Physical Identification

In terms of physical characteristics, the adult moth exhibits a dark gray-brown coloration.  

A notable feature on its head is a set of bunched hairs that resemble a short pair of horns.

The wingspan of the moth measures approximately 3 cm (~1.2 inches). On each forewing, there’s a silvery figure that appears like the number eight, with the two halves separated.

This is a distinguishing feature when compared to related species like C. subsidens where the halves are fused.

Source: LiCheng Shih, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons

Another related species, C. argentifera, has a tiny silver “s” on its forewings, which is absent in the Green Garden Looper, providing another point of differentiation.

The caterpillar is the one that is usually referred to as the green looper, based on its green color.

The caterpillar is the one that causes the primary damage to plants. 

It feeds on the underside of leaves, creating visible patterns of damage that can be used for identification.

Distribution and Habitat

The Green Garden Looper (Chrysodeixis eriosoma) has a widespread distribution, making its presence felt in various parts of the world.

Regions of Prevalence

The moth is predominantly found in the tropical and subtropical regions. Countries and regions where the Green Garden Looper is notably prevalent include:

  • Asia: Japan, China, India, Sri Lanka, and the Malay Peninsula.
  • Oceania: Australasia, which encompasses Australia and New Zealand. In New Zealand, it’s particularly common in horticultural areas from Blenheim northwards.
  • Pacific Islands: Hawaii is one such region where the Green Garden Looper is present.
  • Other Regions: The species has also been recorded in places like Wadelai, Aden, Russia, and the USA.

Specific Areas of Infestation

While the Green Garden Looper is found in the aforementioned regions, it’s essential to note that its presence can vary in density.

For instance, in New Zealand, its occurrence is sporadic south of Christchurch but becomes common in horticultural areas north of Blenheim.

In regions like Japan, China, India, and Sri Lanka, the Green Garden Looper is recognized as a significant pest, affecting various crops and plants.

Looper Caterpillar. Source: John Tann from Sydney, AustraliaCC BY 2.0, via Wikimedia Commons

Preferred Habitats

The Green Garden Looper is versatile in its habitat preference. It’s commonly found in gardens, agricultural fields, and horticultural areas.

The moth and its larvae have a particular affinity for regions with a diverse range of plant species, given their polyphagous nature.

They are attracted to areas with an abundance of their preferred food sources, which include over sixty species of plants.

This includes field and vegetable crops, ornamentals, and weeds.

Some specific plants they target include chickpeas, maize, potato, sunflower, soybean, tobacco, beans, cabbages, cucurbits, peas, and tomatoes.

Life Cycle of the Green Garden Looper

The life cycle of the Green Garden Looper is intricate, transitioning from egg to adult, with each stage showcasing unique characteristics and behaviors.

Eggs

The eggs typically hatch within a few days to a week, influenced by environmental conditions.

Laid on the underside of leaves, these eggs are generally small and blend seamlessly with the leaf’s texture.

The female moth strategically selects host plants for laying eggs, ensuring that the emerging larvae have immediate access to food.

Larvae (Caterpillar)

Lasting between 2 to 4 weeks, the duration of this stage is influenced by food availability and environmental conditions.

Predominantly green, the larvae use their color as a form of camouflage against potential predators.

Their back is usually the palest part, with some larvae showcasing black dots along their sides. 

The absence of some ventral prolegs gives them a distinctive “looper” movement, reminiscent of Geometridae caterpillars.

Source: John Tann from Sydney, AustraliaCC BY 2.0, via Wikimedia Commons

As the primary feeding stage, larvae are responsible for the most damage to plants.

They feed on the underside of leaves, initially creating “windows” between the veins and later, more pronounced holes. In certain plants, they can even penetrate green fruits.

Pupa

This transformational stage spans 1 to 2 weeks.

Upon reaching its growth zenith, the caterpillar crafts a silken cocoon, typically attaching it to the leaf’s underside.

Within this protective layer, metamorphosis occurs, leading to the formation of a brown pupa.

During this dormant stage, the pupa remains stationary, undergoing the transformation into an adult moth, shielded from predators.

Adult Moth

The lifespan of the adult moth generally spans a few weeks; the exact lifespan can vary.

Exhibiting a dark grey-brown hue, adult moths have a wingspan of about 3 cm.

A silvery figure adorns each forewing, while males boast long orange hair-like scales on their abdomen’s sides.

Nocturnal in nature, adult moths prioritize reproduction. They sustain themselves on flower nectar and are often attracted to nocturnal light sources.

Throughout its life cycle, the Green Garden Looper contends with threats from various predators, including birds, spiders, and parasitic wasps.

Environmental elements, such as temperature and humidity, also play a pivotal role in determining the duration and success rate of each life stage.

Diet and Feeding Habits

One of the most striking features of the Green Garden Looper’s diet is its polyphagous nature.

It can feed on a wide variety of plants, with the species known to target over sixty different plant types.

This adaptability not only allows the Green Looper to thrive in various regions but also poses a significant challenge for farmers and gardeners due to its broad palate.

Source: John Tann from Sydney, AustraliaCC BY 2.0, via Wikimedia Commons

Specific Plants Targeted: While the Green Garden Looper can feed on a plethora of plants, certain species are particularly favored. Some of these include:

  • Field Crops: Such as chickpeas, maize, sunflower, and soybean.
  • Vegetables: Including potatoes, beans, cabbages, cucurbits, peas, and tomatoes. The larvae, in particular, are known to cause significant damage to these plants. They feed on the underside of leaves, initially creating translucent “windows” and, as they grow, more pronounced holes. In plants like tomatoes, they can even penetrate and damage green fruits.
  • Ornamentals and Weeds: These provide additional feeding grounds, especially when preferred vegetables and field crops are not readily available.

The impact on these plants can be substantial.

The feeding habits of the Green Garden Looper can lead to reduced crop yields, compromised plant health, and increased vulnerability to diseases.

Adult Moth’s Diet

While the larvae are responsible for most of the plant damage, adult moths have a different dietary preference. They primarily feed on flower nectar.

This sugary substance provides them with the necessary energy to sustain their activities, including reproduction.

The nocturnal nature of the adult moths means they are often seen feeding on flowers that bloom at night or during the early morning and late evening hours.

In conclusion, understanding the diet and feeding habits of the Green Garden Looper is crucial for effective pest management.

By identifying their preferred plants and feeding patterns, farmers and gardeners can implement targeted strategies to mitigate their impact.

Damage and Impact

The Green Garden Looper (Chrysodeixis eriosoma) can lead to significant damage and economic implications, particularly for those in the agricultural sector.

Types of Damage Caused to Gardens and Crops:

  • Leaf Damage: The larvae are the primary culprits when it comes to plant damage. They feed on the underside of leaves, creating translucent “windows” in their early stages. As they mature, these windows become larger, ragged holes, compromising the plant’s ability to photosynthesize effectively.
  • Fruit and Vegetable Damage: In addition to leaves, the Green Garden Looper larvae can also target fruits and vegetables. Plants like tomatoes can have their green fruits penetrated and damaged, leading to reduced yield and quality.
  • Stem Damage: In some cases, the larvae might also feed on the stems, causing them to weaken and, in severe cases, break.
  • Overall Plant Health: Continuous feeding can stress plants, making them more susceptible to diseases and other pests.
Leaf with window paneing. Source: Forest & Kim StarrCC BY 3.0 US, via Wikimedia Commons

Economic Implications for Farmers and Gardeners:

  • Reduced Yield: The direct damage to leaves, stems, and fruits can lead to a significant reduction in crop yield. For commercial farmers, this translates to decreased income.
  • Increased Costs: Farmers might need to invest in pest control measures, be it natural predators, chemical insecticides, or other interventions. These measures represent an added cost.
  • Market Value: Damaged crops, especially visible damage to fruits and vegetables, can reduce their market value. Consumers are less likely to purchase produce with visible pest damage.
  • Resource Allocation: Time and resources that could be used for other farming activities might be redirected to manage and control the Green Garden Looper infestation.

Identifying Damage Caused

Identifying the damage caused by the Green Garden Looper early can help in implementing timely control measures. Some visual cues include:

  • Translucent “Windows” on Leaves: These are the initial signs of larval feeding and appear as thin, see-through patches on leaves.
  • Ragged Holes on Leaves: As the larvae grow, their feeding leads to larger, irregular holes on the leaves.
  • Damaged Fruits: Punctures or holes on green fruits, especially on plants like tomatoes, are indicative of Green Garden Looper damage.
  • Weakened or Broken Stems: If the stems of plants appear weakened or have visible bite marks, it might be due to the larvae’s feeding habits.

Farmers and gardeners should regularly inspect their plants, especially the underside of leaves, to catch any early signs of infestation and mitigate the potential damage.

Control and Management

Managing the Green Garden Looper is crucial for maintaining the health of gardens and crops.

A combination of preventive and reactive measures can be employed to effectively control and manage this pest.

Inspection and Daily Care of Plants

Routine inspection is the first line of defense against the Green Garden Looper.

By regularly checking plants, especially the undersides of leaves, gardeners and farmers can identify early signs of infestation.

Removing affected leaves or handpicking caterpillars can help reduce the population

Daily care, including proper watering and ensuring good soil health, can also make plants less susceptible to damage.

Eggs of an Omnivorous Looper

Natural Methods of Control

Several natural predators can help control the Green Garden Looper population. These include:

  • Birds: Many bird species feed such as robins and chickadees on caterpillars, making them natural allies in controlling the Green Garden Looper.
  • Parasitic Wasps: Certain wasp species lay their eggs inside Green Garden Looper larvae. When the eggs hatch, the emerging wasp larvae consume the caterpillar from the inside.
  • Spiders: These arachnids can capture and feed on both the larvae and adult moths. 

Cultural Control Methods

  • Trap Crops: Planting crops that are particularly attractive to the Green Garden Looper can divert them from more valuable crops. Once the pests congregate on the trap crops, they can be easily removed or treated.
  • Handpicking: While labor-intensive, handpicking caterpillars during routine inspections can be an effective way to reduce their numbers.
  • Tilling: Regularly tilling the soil can destroy pupae, preventing them from maturing into adult moths.

Chemical Control

When natural and cultural methods are insufficient, chemical control might be necessary.

However, it’s essential to choose insecticides that are both safe and effective. Some options include:

  • Bacillus thuringiensis (Bt): This is a naturally occurring bacterium that is toxic to certain pests, including the Green Garden Looper. It’s safe for humans, pets, and beneficial insects.
  • Neem Oil: Derived from the neem tree, this oil can deter Green Garden Loopers from feeding.
  • Synthetic Insecticides: While effective, they should be used judiciously to prevent harm to beneficial insects and avoid potential health risks to humans. 

A multi-faceted approach can effectively control and manage the Green Garden Looper.

Difference between Tomato Looper and Cabbage Looper

Both the Tomato Looper and the Cabbage Looper are pests that can cause significant damage to crops.

However, they are distinct species with unique characteristics and behaviors. Here’s a detailed comparison based on the provided sources:

Taxonomy

  • Tomato Looper: Known scientifically as Chrysodeixis chalcites, this moth belongs to the Noctuidae family. It is also referred to as the golden twin-spot moth.
  • Cabbage Looper: Scientifically known as Trichoplusia ni, it is another member of the Noctuidae family.

Physical Characteristics

  • Tomato Looper: The adult form of the tomato looper is predominantly brown-gold with two conspicuous droplet-shaped white marks on the forewing. The body is brown and hairy. The larvae are yellowish-green with a clear yellow longitudinal stripe on either side.
  • Cabbage Looper: The adult and larval forms of the cabbage looper are quite similar in appearance to the tomato looper, making them difficult to distinguish.

Distribution and Origin

  • Tomato Looper: This is a tropical and subtropical species originating in the Mediterranean and northern Africa. It has become a frequent pest in greenhouses.
  • Cabbage Looper: Commonly found in North America and other parts of the world.

Feeding Habits

  • Tomato Looper: Highly polyphagous, it feeds on plants from over 20 families, including crops like cauliflower, corn, soybean, potato, strawberry, banana, sweet pepper, tomato, chrysanthemum, and geranium.
  • Cabbage Looper: Known to attack certain vegetable crops and may be present at low levels in others.

Damage

  • Tomato Looper: Primarily a foliage feeder, it can also attack fruits like tomatoes and sweet peppers. The damage includes eating through leaves, making them appear skeletonized.
  • Cabbage Looper: Causes damage to leafy greens, especially cabbage and related crops.
Cabbage looper moth. Source: Andy Reago & Chrissy McClarrenCC BY 2.0, via Wikimedia Commons

Identification Challenges

The main challenge in distinguishing between the two loopers is their striking similarity in appearance.

The only accurate method to differentiate the species is by dissecting the adult moth genitalia

Larvae of both species are also extremely similar, with DNA sequencing being the only accurate method for differentiation.

Control Measures

For both loopers, various chemical insecticides are registered for control. It’s crucial to rotate among chemical families to prevent resistance.

Biological controls, such as Bacillus thuringiensis, can also be effective if the infestation is detected early.

Conclusion

The Green Garden Looper, scientifically known as Chrysodeixis eriosoma, is a moth species of significant concern in the agricultural and horticultural sectors.

This pest has showcased its adaptability by thriving in various regions worldwide, from Asia to Oceania.

Its polyphagous nature, allowing it to feed on over sixty plant species, poses a considerable challenge for those trying to manage and control its population.

The damage caused by the Green Garden Looper, both in terms of physical harm to plants and the economic implications for farmers and gardeners, cannot be understated.

Effective control and management strategies, ranging from natural predators to chemical interventions are important towards effective management of this pest.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about green garden loopers. Scroll down to have a look at some of them.

Letter 1 – Green Looper, probably

Subject: Unidentified Bug
Location: Swan View, Western Australia
December 26, 2012 7:38 am
Hello. Can you help me with the identity of this strange looking insect.It was about 2cm long. I photographed it in late October in Swan View, Western Australia.
Cheers
Andrew T-P
Signature: Bug ID

Green Garden Looper
Green Looper or Tobacco Looper???

Dear Andrew,
Your Owlet Moth really looks to us like the Tobacco Looper,
Chrysodeixis argentifera, pictured on the Brisbane Insect Website as well as on the Butterfly House website where this description is given:  “The adult moth is predominently brown in colour, with bunched hairs on its head which look like a short pair of horns. On each fore wing is a silvery figure of eight and a tiny silver ‘S’. This silver ‘S’ distinguishes it from the related species: Chrysodeixis eriosoma, which is otherwise very similar. They both have a wingspan of about 3 cms. Some adults had grey patches adorning their fore wings. The hind wings are fawn in colour with a dark brown terminal area.”  That description causes us to believe this might actually be the Green Looper, Chrysodeixis eriosoma, because of the lack of the tiny silver “S”.  Butterfly House also has a page on the Green Looper.

The post Green Garden Looper: All You Need to Know About This Common Pest appeared first on What's That Bug?.



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