Armyworms, Pest insects and other invertebrates, Pests, diseases and weeds, Agriculture, Agriculture Victoria



Armyworms are caterpillar pests of grass pastures and cereal crops. They are the only caterpillars that growers are likely to encounter in cereal crops, although occasionally native budworm will also attack grain when underlying weed hosts dry out. Armyworms mostly feed on leaves, but under certain circumstances will feed on the seed stem, resulting in head loss. The change in feeding habit is caused by depletion of green leaf material or crowding. In the unusual event of extreme food depletion and crowding, they will «march» out of crops and pastures in search of food, which gives them the name «armyworm».


There are three common species of armyworm found in southern Australia:

  • Common armyworm (Mythimna convecta)
  • Southern armyworm (Persectania ewingii)
  • Inland armyworm (Persectania dyscrita)


Caterpillars of the three species are similar in appearance. They grow from about 2 to 40 mm in length. They have three prominent white or cream stripes running down the back and sides of their bodies. These are most obvious where they start on the thoracic segment («collar») immediately behind the head. These become particularly apparent in larvae that are >10mm. They have no obvious hairs, are smooth to touch and curl-up when disturbed. Armyworms have four abdominal prolegs (Figure 1).

Mature caterpillars are 30-40 mm long. For an accurate identification, they must be reared through to the adult (moth) stage.

Armyworms can be distinguished from other caterpillar pests that may be found in the same place by three pale stripes running the length of the body; these stay constant no matter what variation in the colour of the body. Other species of caterpillar which may be confused with armyworms include:

  • loopers (tobacco looper or brown pasture looper) which walk with a distinct looping action and have 1 or 2 pairs of abdominal prolegs; armyworms have 4 pairs, and when >10 mm do not walk with a looping action.
  • budworm larvae which have prominent but sparse hairs and bumps on their skin, or anthelid larvae which are covered in hairs; armyworms are smooth bodied with no obvious hairs.
  • cabbage moth larvae which wriggle vigorously when disturbed; armyworms curl up into a tight «C».
  • cutworm (brown or common cutworm) larvae which have no obvious stripes or markings and are uniformly brown, pink or black.


Moths are often seen flying on warm, humid nights. They are medium-sized, with a wingspan of 30-40 mm. Each species has a characteristic colour and wing markings.

  • Southern armyworm: grey-brown to red-brown forewings with white zig-zag markings on the outer tips and a pointed white «dagger» in the middle of the forewing. The hind wings are dark grey (Figure 2).
  • Inland armyworm: similar to the southern armyworm except the white «dagger» in the centre of the forewing is divided into two discrete light ellipses which almost touch. The hind wings are pale grey.
  • Common armyworm: the forewings are dull yellow to red-brown, speckled with tiny black dots, and a small white dot near the centre.

Pupae of all three species are about 20 mm long, shiny brown and are found under clods or within cracks in the soil.


Moths are most active on warm humid evenings during

spring and autumn. Armyworm eggs are laid in batches of about 5-30, glued together in the hidden, twisted crevices of dried grasses, straw and stubble or sometimes in seed heads. The eggs may take 6-20 days to hatch, depending on local temperatures. The young larvae, which are about 2-3 mm in length, may disperse away from the egg laying sites on fine silken threads. These are used to allow wind dispersal within a few metres of the egg-laying site.

There are usually six stages (instars) of caterpillar growth, and the skin is shed after each. Older caterpillars crawl around at night and may move up and down plants regularly. They spend the day curled up at the base of the plant under clods of soil or in the plant crown. It is the older and larger larvae that cause all the damage to crops.

The larvae do not remain at this voracious stage for many weeks; they soon commence tunnelling into the soil to pupate. The mature caterpillars pupate in the surface of the soil at the base of the plant. The adult moth finally emerges at least 4 to 6 weeks (possibly many more) after pupation, and migrates away from the region.

NB: It is most unusual for crops to be reinvaded twice in succession; a heavy infestation in one year rarely results in a further problem in the following season.

Seasonal activity

Common armyworm

The common armyworm is the more usual pest in spring and early summer. This species appears to spend its winter in the warmer regions of northern Australia, and the subsequent generation of moths migrate south in early spring. As crops and pastures commence drying, the larvae are usually large enough to lop off tillers and stems bearing the seed heads: this accountsfor most economic loss incurred by armyworms. The moths that emerge from the spring generation migrate to other areas where green pastures or crops permit a new generation of egg-laying.

Southern and inland armyworm

Southern and inland armyworm caterpillars can be found in autumn and winter, often in relatively high densities, throughout the grasslands and crops of south eastern Australia. There are two generations per year. Most eggs are either laid in autumn, often immediately after rain, or in late winter.The hatch of the autumn generation is synchronised with the emergence of autumn pastures and crops. The young caterpillars cause little damage while feeding on leaf surfaces. The older larvae can defoliate the plant.

Moths of the southern and inland armyworm appear not to lay eggs after a spring emergence. There has been little research on the biology of these two species, but field observations suggest they have a winter habit, and that larvae do not usually survive the warmer temperatures of the late spring and summer periods. The moths re-appear in the autumn, particularly at about the time of the first autumn rains. It is at this stage that they start laying eggs in the dry grass and stubble from the previous pasture or cereal crop.


The young larvae feed initially from the leaf surface of pasture grasses and cereals. As the winter and spring progress and the larvae grow, they chew ‘scallop’ marks from the leaf edges. This becomes increasingly evident by mid to late winter. By the end of winter or early spring, the larvae are reaching full growth and maximum food consumption. It is this stage that farmers most frequently notice as complete leaves and tillers may be consumed or removed from the plant.

Damaging infestations or outbreaks occur in 3 situations:

In winter when young tillering cereals are attacked and can be completely defoliated. The caterpillars may come from:

  • the standing stubble from the previous year’s cereal crop, in which the eggs are laid;
  • neighbouring pastures which dry out, resulting in the resident armyworms being forced to march into the crop.

In spring / early summer when crops commence ripening and seed heads may be lopped;
In early summer when grass pastures are cut for hay, particularly in Gippsland.

Leaves of cereal plants or grasses appear chewed («leaf scalloping») along the edges. The most damage, however, is caused in ripening crops when the foliage dries off. The armyworms then begin to eat any green areas remaining. In cereals, the last section of the stem to dry out is usually just below the seed head. Armyworms, particularly the older ones, that chew at this vulnerable spot cause lopping of the heads and can devastate a crop nearing maturity in one or two nights. Generally, the larger the armyworm, the greater the damage. In wheat and barley whole heads are severed, while in oats individual grains are bitten off below the glumes.

The crops affected include all Gramineae crops including cereals, grassy pastures, corn and maize.


Major outbreaks occasionally occur across Victoria, particularly after periods of drought. There are many factors which may lead to an outbreak. They may arise from large invasions of moths which have bred in arid regions of New South Wales, South Australia or western Queensland. Alternatively, they may arise because of significantly less mortality of eggs and young caterpillars. Droughts appear to trigger outbreaks because of the adverse effects they have on the natural enemies of armyworms; these predators and parasites are much slower in recovering from a drought than are armyworms.

The role of stubble retention

Winter outbreaks are most common in crops under conditions of stubble retention and minimum cultivation. Most eggs would not be laid in a crop in the absence of stubble. It should be emphasised that stubble and undisturbed soil also provides a continuous habitat for a range of natural enemies which help to control many pest problems. Further, the direct and indirect benefits of these conservation tillage practices far outweigh their costs, including the occasional outbreak of armyworm.

Sampling and detection

Signs of the presence of armyworms include:

  • Chewing/leaf scalloping along the leaf margins.
  • Caterpillar excreta or «frass» which collects on leaves or at the base of the plant. These appear as green or yellow cylindrical pellets 1-2 mm long.
  • Cereal heads or oat grains on the ground. Oat grains may be attached to a small piece of stalk (1-2 mm), whereas wind removed grains are not. Barley heads may be severed completely, or hang from the plant by a small piece of stalk.

Early detection is essential, particularly when cereals and pasture seed or hay crops are at the late ripening stage. Although accurate estimates of caterpillar densities require considerable effort, the cost saving is worthwhile.

Sampling can be achieved by using a sweep-net/bucket, or visually ground or crop searching for either caterpillars or damage symptoms.

The sweep-net/bucket method provides a rapid and approximate estimate of infestation size. The net or bucket should be swept across the crop in 180 o arcs several times, preferably 100 times, at different sites within the crop to give an indication of density and spread. Armyworms are most active at night, so sweeping will be most effective at dusk. Average catches of more than 5-10 per 100 sweeps suggest that further searches on the ground are warranted to determine approximate densities.

When ground sampling, it is necessary to do at least ten «spot checks» in the crop, counting the number of caterpillars within a square metre.

Most farmers fail to detect armyworms until the larvae are almost fully grown and 10-20% damage may result. The earlier the detection, the less the damage. The young larvae (up to 8 mm) cause very little damage, and are more difficult to find. The critical time to look for armyworms is the last 3 — 4 weeks before harvest.


There are a number of chemicals registered for control of armyworms. For winter outbreaks (during tillering), economic thresholds of 8 to 10 larvae per m 2 provide a guide for spray decisions. For spring outbreaks (during crop ripening) spraying is recommended when the density of larvae exceeds 1 to 3 larvae per m 2 although this figure must be interpreted in the light of:

  • timing of harvest,
  • green matter available in the crop,
  • expected return on the crop, and
  • larval development stage (if most are greater than 35-40 mm or pupating, it may not be worth spraying).

If spraying is necessary, it is highly recommended that this be carried out in late afternoon or early evening for maximum effect, as armyworms are nocturnal feeders.

What is a Trojan or Trojan Horse?

A Trojan is also known as Trojan horse. It is a type of malicious software developed by hackers to disguise as legitimate software to gain access to target users’ systems. Users are typically tricked by some attractive social media adds who then directed to malicious website thereby loading and executing Trojans on their systems.

Cyber-criminals use Trojans to spy on the victim user, gain illegal access to the system to extract sensitive data.

These actions can include:

Types of Trojan Virus (Updated Aug 2019)

  1. Trojan-Downloader: is a type of virus that downloads and installs other malware.
  2. Trojan-Droppers are complex programs used by cyber criminals to install malware. Most antivirus programs do not detect droppers as malicious, and hence it is used to install viruses.
  3. Ransomware — It is a type of Trojan (Trojan — ransom) that can encrypt the data on your computer/device. The cyber criminals who control this ransomware would demand a ransom for providing the decryption key. It is very difficult to recover the data without the decryption key. The WannaCry and Petya were recent ransomware attacks. Cyber security experts recommend users to follow a robust and systematic backup and recovery policy
  4. Trojan-Banker malware programs steal account-related information related to card payments and online banking.
  5. Trojan-Rootkits prevent detection of malware and malicious activities on the computer. These are sophisticated malware that provides control of the victim’s device. Rootkits are also used to enroll the victim’s device as part of a botnet.
  6. Trojan-Backdoor is a popular type of Trojan. It creates a backdoor to allow cyber criminals to access the computer later on from remote using a remote access tool (RAT). As this Trojan provides complete control over the computer, it is a dangerous but commonly used Trojan.

There are many more types of trojans — some can send premium SMS, steal your instant messaging credentials, spy on system activities to capture keystroke data, steal email addresses and gaming credentials.

How Do Trojans Horse Virus infect the system?

A backdoor Trojan gives the hackers malicious access to take remote control over the infected computer. They entitle the malicious hacker to work on the infected computer as per the malicious intentions. They can send, receive, delete and launch files, display data and reboot the computer. Backdoor Trojans are mostly used by hackers to exploit a group of infected computers to form a zombie network or malicious botnet that can be used for criminal purposes.

Exploit is a type of Trojan that contains a malicious code or data to attack a vulnerable software or application that runs on an infected computer.

Rootkits are developed by malware authors to gain access to the victim’s system, while they conceal their presence or their malicious activities from being detected to extend their presence to run and execute on the infected computer.

This is a type of trojan developed to extract user’s account data, debit or credit card data through online banking systems, e-payment gateway.

These programs are developed to perform Denial of Service (DOS) attacks so as to infect the victim’s web address. the malware program sends multiple from the victim’s infected computer and forms a network with several other infected computers –to strongly enforce an attack against the target address causing a denial of service.

Trojan-Downloaders as the name suggests, it is developed by hackers to download and install new versions of malicious programs onto the target victim’s computer.

These programs are developed by malware authors to install Trojans/viruses and escape the detection of malicious programs. Most of the traditional antivirus programs are inefficient to scan all the components this Trojan.

Trojan-FakeAV programs pretend to operate like an antivirus software. They are developed by cyber thieves to obtain money from the target user – in return, in order to detect and remove threats, despite the threats that they report are non-existent in real-time.

The main targets for Trojan-Game Thief are online gamers and their prime motive is to steal the user account information.

Trojan-IM programs primarily extract users’ logins and passwords of Skype, Facebook Messenger, ICQ, MSN Messenger, Yahoo Pager, AOL, and many more.

Trojan-Ransom is developed to alter data on the victim’s computer – so that the system doesn’t perform its function correctly and also it does not let the user, use certain data. The criminal would demand a ransom to be paid by the victim to unblock the restricted access to the data and restore the computer’s performance.

Trojan-SMS programs send text messages from the victim’s mobile device to other phone numbers.

Trojan-Spy programs, as the name suggests, can spy on how the victim is using the computer – for example, tracking data, taking screen shots or extracting a list of running applications.

These programs are developed by hackers to extract email addresses from the victim’s computer.

Easy Steps for How to protect against Trojan Horse Attacks?

Cyber criminals send emails with malicious links or attachments. Users get tricked by attractive advertisements and offers and when they open the attachment or click on the links, get their device infected with a Trojan Virus.

Installing the right endpoint protection software is critical and it would help users to stay ahead of trojan attacks. Comodo Endpoint protection integrates unparalleled antivirus, robust firewall, anti-spyware, application control featuring host intrusion prevention techniques — all in one single console to deliver comprehensive protection. The Endpoint protection platform from Comodo also features a future proof technology called the containment technology that creates an isolated virtual environment, hard drive, registry, and virtual COM interface. If any unknown files try to enter the system, it will continue its malicious activity, however, the malicious activity is restricted only in the virtual environment. This ensures that your systems’ original document and files are not infected. With all Comodo’s Containment technology, all kinds of infection are at bay.

The computer worm that changed the world

The premiere episode of Kernel Panic takes viewers back to the very beginning: the world’s first major Internet attack. This groundbreaking malware was known as the Morris Worm, and in 1988 the virus spread across global networks, leaving significant outages and panic in its wake. The Morris Worm opened the world’s eyes to unforeseen vulnerabilities, planting the seeds of public mistrust that have steadily grown for decades and, today, are flourishing.

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How To Use Eggshells In The Garden | Cost-Cutting Gardening Hacks

Want ideas on how to use eggshells in the garden other than just for composting? Help yourself to these practical and cost-cutting ways to maximize your eggshells.

How to Use Eggshells in the Garden in 15 Smart Ways

Amazing Ways to Use Eggshells in the Garden

Can you keep track of the eggs consumed in your household? From cooking the family’s favorite egg omelets and pancakes to baking your delicious deviled eggs, cakes, and pastries, eggs are never absent at home.

It’s no secret eggs are healthy for us, but did you know they’re healthy for the garden too? The eggshells, at least, of which I am in no short supply.

If you happen to be curious as to how to make use of these eggshells that you think don’t serve much purpose once cracked, then lucky you! I’ve been practicing some of these gardening ideas myself.

Find out how to use eggshells in the garden and cut back on gardening costs with this infographic:

1. How to Use Eggshells in the Garden Compost

Eggshells are organic compost material valued in the garden for its hefty calcium content beneficial to the soil and plants. They are green compost materials that comprise only a third in a healthy and balanced compost.

But don’t throw the rest of the eggshells away because I still have several more great ways to use eggshells in the garden.

To use eggshells for composting:

  1. They’re better crushed for a faster breaking down process. Put them in a bag and crush them with anything hard.
  2. You can also step on them, in your shoes of course, as eggshells can be sharp.
  3. Then spread them over or mix them with the rest of the organic compost materials.

2. Eggshell Pest Deterrent

Slugs and snails are among the most notable pests in any garden. They like to munch on tender leaves of vegetables and fruits.

To prevent these critters from invading the plants, spread crushed eggshells around them.

The slugs and snails will find the sharp edges of the eggshells such an impenetrable barrier they’ll abandon their quest.

Be careful, though, as the scent of rotten eggs could potentially attract scavengers like rodents instead.

3. Eggshells Seed Starting Pots

The idea of biodegradable seed-starting planters is truly ingenious. Eggshells are biodegradable, meaning they rot in the soil leaving their nutrients behind.

Instead of plastic seed-starting pots, why not use eggshells where they can just be planted along with the seedling. No more worries over having to disturb the roots of the plants or even destroying them.

If you find this a great plan for your own seed-starting projects, you’ll have to sanitize them first by pouring hot water over the shells. They can also be allowed to dry under the sun to save on utility costs.

Puncture tiny holes at the bottom of the shells for seed-starting. Then you can place them back up in the tray to let them stand.

4. Pretty And Dainty Eggshell Planter Ideas

Not only do eggshells make great seed-starting pots, but they also make nice planters for ornamental plants. Our favorite mini plants like cacti and succulents will feel at home in these equally cute planters.

Face Emoji Eggshell Planters

For the extra artsy gardeners, eggshells will make a great medium for crafts such as these silly emoji faces. Your imagination is your only limit to making great designs for these tiny planters.

Succulent Eggshell Planters

Succulents are enjoying some kind of popularity in home and garden design with their diversity. Take this succulent design for your indoor garden, with tiny succulents that could fit perfectly in tiny eggshell planters.

5. Eggshells for Your Stock Pot or Bone Broth

Did you know that adding eggshells to your vegetable stock or bone broth is highly beneficial for your health? Crushed eggshells are known for its calcium content but it also contains other minerals as well:

Worried it will affect the taste of your bone broth? Don’t be. You get all this nutrition and the flavor stays the same.

6. Eggshells On Bird Feeders

Birds are more useful to your garden more than you think. They provide protection to your plants since they are natural prey to some of the most common garden pests.

Some bird species are also pollinators helping fertilize plants and bear fruits. Besides, the sight of them in the garden brings cheer and amusement.

We give back to them by putting up birdbaths and bird feeders.

Go extra further by providing them calcium supplements which they will appreciate. Sterilize and crush the eggs, then mix them with the seeds in the bird feeder.

7. Eggshells Garden Decor

I’ve seen this garden decor idea before in a Christmas garden decoration with Christmas balls in place of eggshells through the tips of Yucca leaves.

For a more organic approach to this simple design, it’s great to have eggshells in place of plastic balls. But the eggshells could also use a bit of design or painting.

8. Eggshells for Healthy Tomatoes

To promote healthy growing tomatoes, best to place a handful of coarsely crumbled eggshells under your tomato plants. The amount of extra calcium, minerals, and elements will be extremely beneficial to your tomatoes as they steadily grow throughout the season.

9. Eggshells for pH Balance

Scatter finely ground eggshells all over your garden to balance out the acidity of your garden soil. The calcium carbonate found in eggshells can neutralize the pH balance of the garden soil if it is too acidic for your crops to grow.

It is important to note that hand crushed eggshells are not sufficient enough to change the pH and add calcium to the soil. Studies prove that the eggshells must be thoroughly ground in order to balance the pH and increase the soil calcium level.

10. Eggshells for Chicken Feed

Toss a handful of eggshells to your chickens if you want them to lay healthy eggs. The calcium from eggshells is beneficial for a vitamin boost, especially when laying eggs.

All you need to do is:

  1. Collect enough eggshells and dry them out at room temperature.
  2. Lay them out then crush the eggshells smoothly with a mortar and pestle.
  3. Place them on a baking sheet.
  4. Bake for ten minutes at 375°F.

11. Eggshells for a Great Coffee Experience

Did you know that ground eggshells make a fine addition to your coffee? The high heat when making campfire coffee runs the risk of boiling over the coffee grounds.

The eggshells will prevent this from happening. Also, when coffee is brewed long enough to make it very bitter, eggshells help make your coffee less acidic.

One egg’s worth of finely crushed shell is good for four cups of great coffee!

12. Eggshells for the Worm Bin

Eggshells are also useful in worm composting aside from the regular compost pile. If you’re into vermiculture, the worms will consume the crushed eggshells and convert this nourishment into worm castings.

These castings are highly nutritious and will help increase the pH of your worm bin.

13. Eggshells as Deer Repellent

Does deer frequently visit your precious garden in the dead of night? If so, scatter crushed eggshells around your garden perimeter to keep those deer from munching on your veggies.

Deer hate the smell of albumen or egg white, which will drive them away from your greens.

14. Extra Calcium for Your Dog

Crushed eggshells provide an extra source of protein and calcium for dogs. Here’s how:

  1. Place clean eggshells on a baking pan and bake for 30 minutes at 250°F.
  2. Put the baked eggshells inside a zipper bag then crush until its powder-like.
  3. Mix the crushed fine powder eggshells with the dog food for extra calcium that aid in fortifying your pet’s bones and teeth.

15. Eggshells as Garden Mulch

After using eggs for meals and food preparations, bring the eggshells out and spread them all over your garden. The slowly decomposing eggshells will help supply air to the soil and provide calcium as well.

Note: The finer the eggshells are crushed, the faster they will decompose.

Check this video for more ideas on why and how to use eggshells in the garden:

There you have it smart green thumbs! Practical ideas on how to use eggshells in the garden.

I hope I’ve also enlightened you on why you should use eggshells in the garden and how to cut back on your gardening expense. Isn’t it surprising that what we need for the garden are accessible at home?

How do you use your eggshells in the garden? I’d be delighted to find out about your own ideas in the comments section below.

Planning a vegetable garden for a fresh and free food source? Check these 3 common gardening mistakes first to avoid them and avoid wasting time, effort, and money.


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Editor’s Note: This post has been updated for quality and relevancy.

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