Article 65 – ‘Unseen enemies’ Part 4

Hi, welcome to Taiga Bonzai in this post the final one in this series we look at the points of view of others whom have various opinions on how to tackle the ever increasing problem of pests and disease; a major threat to our very existence. But whatever course of action deemed necessary taken either by individuals, communities and/or sovereign nations, there will always be stiff opposition and the threat of sanctions of one description or another due to bureaucracy and petty mindedness.

Introduction – thus far we have highlighted the many factors responsible for the present situation that we as humans now face all of which are of our own making. The financial cost of it all to date has been phenomenal and will continue to ensue rising exponentially where sustainability, (meeting our own needs without compromising the ability of future generations to meet their own needs) will not be possible; bringing us to the point of no return. We now view some of the directives of nations whom are attempting to arrest the situation from their own perspective.

United Nations FAO -at a conference in Rome 3rd April 2019 Bukar Tijani assistant director general for the Food and Agriculture Organisation of the United Nations (FAO) Consumer Protection Department stated that. “With increased trade and travel, the risks of plant pests spreading into new areas across borders is now higher than ever before. Each day we witness a shocking number of threats to the well-being of our plants and by extension to our health, environment and economy.”

FAO estimates that annually between 20 to 40 percent of global crop production is lost to pests. Each year plant diseases cost the global economy around $220 billion and invasive insects around $70 billion. “Many farmers and governments grapple with warding off highly destructive pests and diseases that are – on top of everything else – also new to them. The International Plant Protection Convention IPPC provides them with the tools and knowledge to keep their plants healthy and prevent pests from jumping borders.” added Tijani.

New IPPC standards adopted – 1. fumigation methods, this is in response to growing concerns over fumigants that can be harmful to human health and the environment. The standard sets requirements for temperature, duration, fumigants and quantity to make fumigation effective and puts forward solutions to lessen fumigations environmental impact by using recapture technology to reduce gas emissions. 2. Diagnostics protocols that describe procedures and methods for the official diagnosis of six pests, including the oriental fruit fly Bactrocera dorsalis and Xylella fastidiosa ensuring a correct diagnosis is essential to catalyze rapid actions to manage the pests.

B. dorsalis has affected trees such as avocado, banana, guava and mango in at least 65 countries. In Africa, import trade bans due to oriental fruit fly infestations cause annual losses of around $2 billion. Xylella fastidiosa is a deadly bacteria that attacks economically important crops such as olive, citrus, plum trees and grapevines. Since 2015, it’s been rapidly spreading from the Americas to Europe and Asia. Once the disease infiltrates a plant, it is there to stay, it starves the plant of water until the plant dies or becomes too weak to grow fruit. X. fastidiosa costs $104 million per year in wine losses in California and in Italy the bacteria has led to the decline of 180,000 hectares of olive groves destroying many centuries-old trees; a loss of €390 million over three years. X. fastidiosa constitutes a threat not only to Italy but to all the Mediterranean region’s economy.

X. fastidiosa is not known to be in the UK however, there have been outbreaks of the disease in mainland Europe in France, Italy and Spain. Portugal confirmed its first case in 2019 on lavender hence, the UK Government is concerned about how to prevent the disease being accidentally brought into the country on imported plants. In 2020 Lord Framlingham a Conservative peer asked the Government what the UK’s regulations are regarding X. fastidiosa.

UK regulations – were to introduce measures to strengthen the protection of plants from certain pests and diseases, including Xylella. They were made under article 52 of the EU Plant Health Regulation allowing the UK to take additional temporary national measures if they inform the European Commission and put forward a technical case to request EU measures against a specific pest, but those measures have not or will not be introduced in time to mitigate the risk concerned.

Moreover, the UK Government has argued that current EU emergency measures on Xylella do not address risks highlighted in the UK’s pest risk analysis on the disease. In particular, it is not clear if or when the EU emergency measures will be reviewed to address these risks and ensure a greater degree of assurance of disease freedom, in relation to plants of those species being moved in the EU and introduced from third countries. As such, there remains an unacceptable level of pest risk and this instrument introduces national measures under article 52, in the absence of EU requirements.

The European Commission’s response – in a decision on 4 June 2020, the European Commission said that it informed the UK the new national measures “that go beyond the existing requirements, are not supported by most recent scientific justification and are disproportionate.” It stated that the UK “should amend the UK Official Controls Regulations of 2019, by removing the amendments concerning Xylella fastidiosa and Ceratocystis platani which were made to those regulations by the UK Official Controls Regulations of 2020.”

On 19 June 2020, Department for Environment, Food and Rural Affairs (Defra) stated that the UK disagreed with the European Commission’s conclusions and that it was disappointed that “the opportunity has not been taken to extend the UK measures across the EU, providing enhanced protections for the EU’s member states.” Defra argued “that the biosecurity threat regarding the pests had not changed and the rationale for introducing stronger requirements remained.”

The department said it continued to encourage stakeholders and industry to “employ risk management practices which maintain the robust protection and assurance that the Defra regulations provide.” Defra also stated that The Animal and Plant Health Agency and the devolved administrations will continue to carry out intensive inspections of imported plants, taking account of risk factors such as origin, presence of insect vectors and suspect symptoms. “We will keep the need for any further actions under review in light of the ongoing risk situation, including developments in the EU and the results of our own surveillance.”

The Royal Horticulture Society (RHS) is also in agreement, plant health is increasingly under threat. Climate change and human activities have altered ecosystems, reducing biodiversity and creating new niches where pests and diseases can thrive. At the same time, international travel and trade has tripled in volume in the last decade and can quickly spread pests and diseases around the world causing great damage to horticulture, crops and the environment. New statutory controls on importing plants and plant products into the UK to safeguard plant health. “Meaning that plant material entering the UK will require a phytosanitary certificate (PC); the EU plant passport is no longer valid in the UK.” 

The U.S. DEPARTMENT OF AGRICULTURE – (USDA) state that world trade has significantly increased over the years to meet the growing demand and at this moment in time (December 2021) America is the only country to import more than it exports. USDA researchers Michael Livingston, Craig Osteen and Donna Roberts argue “That this increase in agricultural imports raise the risk of inadvertently introducing foreign pests and diseases.” which has been proven to be the case. For example, the emerald ash borer and Asian longhorned beetle introduced in the 1990’s are creating serious damage to trees in the Northeast and Great Lakes States.

More recently Ralstonia solanacearum, a bacterial pathogen that damages potatoes, eggplant, tomatoes and other horticultural products was detected on greenhouse geraniums imported from Kenya and Guatemala. “The cost of foreign pests and diseases can also include the temporary loss of export markets, such as when Japan, Korea and other countries suspended imports of U.S. beef when bovine spongiform encephalopathy (BSE) was detected in an imported cow in December 2003.” Studies by the National Plant Board, the Government Accountability Office, the Office of Technology Assessment and others report that foreign pests and diseases cause billions of dollars of economic losses to U.S. agriculture each year, while also adversely affecting ecosystem values and services.

These cost estimates include sizable public expenditures, including emergency funding to address new pest or disease threats and outbreaks. Today, 21 Federal agencies are responsible for some aspect of managing foreign pests and diseases in the United States. USDA’s Animal and Plant Health Inspection Service (APHIS) has by far, the leading role accounting for about $9 out of every $10 that the Federal Government spends annually on prevention and control of foreign pests and diseases. Annual expenditures for APHIS programs ranged from $1.1 to $1.5 billion between 2003 and 2007 including, emergency expenditures for programs such as increased BSE surveillance in 2004-06 and the introduction of import bans.

In evaluating such bans, economists try to measure the benefits of imports against the management production market and/or resource costs that might be associated with an outbreak of a disease or pest. Studies show that this varies on a case-by-case basis. Import bans have reduced total welfare in some cases, because the cost of disease establishment was out weighed by the consumer benefits from imports. For example, APHIS estimated that the annual net benefits of replacing a long standing ban on imports of Mexican avocados with more targeted phytosanitary measures totaled about $70 million, providing analysis support for USDA’s decision to grant Mexico full access to the U.S. market in 2007.

A recent study by an ERS economist, which examined options for policies to reduce the risk of entry of the Mediterranean fruit fly (medfly), illustrates how economic analysis can inform public decision making. The medfly is a serious pest for many fruit and vegetable crops and is known to exist in 65 foreign countries. (hereafter referred to as quarantine countries) APHIS allows imports of fresh produce from these countries only if they have been treated to eliminate medfly larvae. Currently, eight treatments are approved for the medfly. One of the most widely used is cold treatment, under which produce imported for fresh consumption must be refrigerated according to specific schedules (temperature-duration combinations) before allowed entry into U.S. markets.

Australian viewpoint – pests and diseases are a significant social, economic and environmental burden for Australia. They can affect primary production productivity; access to export markets, public health and
amenity; conservation of biodiversity and the natural and built environments to our individual and collective detriment. These effects can reveal themselves through increased costs of production, loss of or restrictions to export trade, reduced tourism, loss of biodiversity, greater public health costs and reduced public amenity.

Some introduced pests and diseases such as pest animals (rabbits, foxes, carp), weeds (blackberry, mimosa), animal diseases (Johne’s disease) and plant pests (potato cyst nematode) have become established over time in Australia with no prospect of eradication. Some of these pests and diseases may have economic, environmental or social impacts of national significance. Consequently, a nationally coordinated approach may be required. Given the shared responsibilities for their management among stakeholder groups, the effective management of nationally significant threats requires clarity of policy direction, priority, roles and responsibilities.

Governments at the national, state and territory levels; industry and individual landholders have invested jointly and individually in pest and disease management over many decades. These investments have been made across the biosecurity continuum onshore, at the border and offshore. Managing biosecurity is critical to a sustainable and productive agricultural sector and healthy environment. It protects our farmers and our environment from the impacts of serious pests and diseases that can significantly increase the costs of production and market access, domestically and internationally and affect our native flora and fauna. Effective management of established pests and diseases also assists Australia to meet its obligations with respect to international trade.

Under the Coalition of Australian Governments Intergovernmental Agreement on Biosecurity signed in 2012, Australian governments are progressing reforms to strengthen the national biosecurity system. The objective is to deliver more effective and more sustainable biosecurity outcomes for governments, industry and the broader community. One focus of this agreement is to establish a national framework for managing established pests and diseases of national significance. Consistent with emerging policy across numerous portfolio areas, there are opportunities to:

  • move away from government enforcement as a primary means of managing the impacts of established pests and diseases
  • adopt approaches in which the nature and magnitude of investment is determined by the extent and balance of public and private benefits
  • focus public investments on strategic functions including addressing market failure
  • promote more collaborative working arrangements between government and those stakeholders directly affected by established pests and diseases rather than have stakeholder groups acting in isolation.”

World Trade Organisation (WTO) – Kamal Saggi and Mark Wu in their World Trade Review Volume 16 Issue 2nd April 2017, pp. 279 – 302, state “Global exports of agricultural goods exceeded $1.7 trillion in 2014, with food accounting for over 80% of the total value.” “Such cross-border movement of food and agricultural goods helps ensure the sustenance and economic well-being of billions around the world. Yet, trade rules for agriculture remain an extremely sensitive issue. This is particularly the case when agricultural imports carry the threat of disease.”

Not surprisingly then, under the rules of the World Trade Organization member countries are allowed to restrict the importation of agricultural products from diseased regions. However, if governments could do so without limitation then this freedom could quickly devolve into a protectionist excuse that has the potential to seriously thwart trade liberalisation in the agricultural sector.”

Saggi and Wu argue that relevant WTO rules therefore, “must seek to balance two competing objectives providing sufficient flexibility for sovereign governments to regulate imports from diseased regions,” while simultaneously culling out protectionist measures for which the threat of diseased imports simply serves as an excuse for keeping imports at bay. “Getting this balance right is tricky, in 1994, Uruguay Round negotiators drafted the Agreement on Sanitary and Phytosanitary Measures (SPS Agreement) to spell out in detail the requirements that a WTO member must follow when seeking to ban or restrict imports of agricultural goods.”

Summary – our journey began with the dawn of time mentioning microbes and bacteria, arrival of plant life, dinosaur era, the early hominins and their eventual adaptation to community life and trade. To say that as a species we have evolved through a ‘life-long’ learning curve into a civilised society in reality is a misnomer, one only has to look at history and the present day shenanigans to substantiate this fact.

We know that every country has its own endemic pest and disease problems, some have invaded other lands by wind and wing a natural phenomenon and also by the hand of man resulting in consequences on a catastrophic scale, which we have little chance of eradicating. Because (a) we cannot see the problem until it is too late and (b) we lack the technical knowledge of how to arrest the situation. Yes there are many chemical solutions that can be used, but not all are effective especially with the many of pests and diseases we have mentioned in these articles. Moreover, these chemicals are not only dangerous to human health they eek into the soil killing microbes, earthworms, nematodes and other much needed creatures.

It can be agreed that commerce is an important factor in the modern world, but our attention to detail has been lackadaisical to say the least. Countless goods have been exported in infested packaging worldwide – the pests and disease have escaped multiplying in their millions ravaging agriculture and forestry. Many nations are now spending billions to eradicate pests and disease and the cost is escalating, whilst poorer under developed countries whose national GDP is practically non-existent suffer in silence and starve.

As stated at the beginning “whatever course of action deemed necessary taken either by individuals, communities and/or sovereign nations, there will always be stiff opposition and the threat of sanctions of one description or another.” Yet nations continue to blame each other instead of looking closer to home, it is imperative that we find common ground to seek solutions to curb the never ending invasion of pests and disease world-wide, failure to do so will result in devastating consequences.

As a species we rely heavíly on an array of factors vital to our very existence including technology, transport, housing, energy, education, medicine, clean water, forestry and agriculture for our immediate needs. If these are not protected then we face the inevitable – a world of devastation, dire water scarcity, where famine and pestilence rampage amok. Is this a world we want our children’s children and their descendants to inherit?

Image courtesy of Thanh Nien News

It is nearly 2 years since covid 19 reared its ugly head – many countries are now in phase 4 and a new variant Omicron has emerged, over 5 million lives have been lost due to ignorance and official incompetency and the figures are climbing. In reality, nations government’s handling of C19 has been a blatant scandalous failure moreover, diseases including Smallpox, Tuberculosis, Syphilis and Chlamydia, Scarlet Fever, Measles, Mumps, Whooping Cough and Legionnaires disease once eradicated are now returning in many parts of the world.

We wrote this series of articles to highlight the problems man has created and battled with for aeons, a predicament that is now escalating unprecedentedly. If the powers that be are inept in controlling C19 when scientific knowledge is available, how can they solve this issue where idiosyncrasy and bureaucratic meddling will undoubtedly ensue; the popular myth (although untrue) “Nero fiddles while Rome burns” is appropriate here. American author Samuel Langhorne Clemens (Mark Twain) stated that “Fiction is obliged to stick to possibilities – Fact is not.” These articles are not fictional tales of realism, they are reality. Until next time, BW, Nik.

Article 64 – ‘Unseen enemies’ Part 3

Hi, and welcome to Taiga Bonzai, in this post we continue our journey bringing to light the catastrophic failures of mankind’s idiosyncratic actions.

Introduction – according to the Botanical Gardens Conservation International (BGCI) and its network of 500 member organisations, there are 60,065 species of trees in the world, many are rare and threatened with extinction. If we multiplied the number of tree species with the number of known pests and disease all with different triggers, the statistics would not only be bewildering but also incomprehensible. Here we highlight more increasing problems the world has to face beginning with a few examples of the many deadly diseases for which at this juncture there is little or no control.

DiseaseArmillaria Root – according to Guido Schnabel of the Clemson University School of Agricultural, Forest and Environmental Sciences, “Armillaria root rot caused by the fungus Armillaria tabescens wreaks havoc on rootstocks, killing young and old peach and cherry trees before spreading to neighbouring trees.” “Between 1987 and 1992 Armillaria root rot caused an estimated $3.86 million to the peach industry and between 2000 and 2002, more than $1.5 million in damage to the Georgia peach industry.”

The first symptoms of an Armillaria infection are chlorotic leaves, stunted growth and sudden collapse of shoots, an obvious sign that infection is there is due to the presence of clusters of mushrooms around the base of an infected plant. Fungi sprouting from an A. mellea infection are honey-coloured to dark brown and have a domed cap. “Depending on species, the mushrooms may or may not have an annulus around the stalk or caps that are more disc-shaped.”

Armillaria mellea

This devastating disease can be caused by other Armillaria species as well, A. mellea is the primary pathogen in northern states causing premature peach tree decline, with the potential for significant annual losses. In Michigan, the predominant fungus is A. ostoyoe found in tart cherry orchards, unfortunately there is no ‘silver bullet’ solution to protect trees and Armillaria infections have taken many prime orchard sites out of production causing a huge loss of revenue.

Anthracnose – high on the list of devastation is widespread and considered an important disease in most countries. It is caused by a group of fungi in the genus Colletotrichum, that attacks leaves, twigs, flowers and fruits of a great number of tree and shrubs.

Anthracnose disease

Apple scab is a common disease of apple and crabapple tree varieties, as well as Mountain ash Sorbus and pear. It is caused by a fungus Venturia inaequalis that infects leaves and fruit, leaving the latter unsuitable for eating. Leaf spots are olive green at first, later turning dark brown to black. Infected fruit turns colour in a similar fashion, ending up brown, corky and deformed.

Apple Scab disease

Thousand canker disease – affects many plants including walnuts Juglans sp. It is mainly found in the Western United States however, black walnuts trees in Tennessee were found to be infected in the summer of 2020. It is vectored by walnut twig beetles Pityophthorus juglandis and forms small cankers around their galleries. As time progresses these small cankers coalesce to girdle branches and stems and trees can be infected for years before symptoms become visible for example, foliage in the upper branches of declining trees wilt and become yellow. Once a tree begins to decline it is often dead within a few years and at present there are no chemical management solutions to control the disease.

Walnut twig Beetle

Thus far we have given examples (albeit in brief) of the devastation caused by some of the many thousands of insects and disease, adding more examples would probably substantiate the argument further, but this task has already been accomplished. In the book ‘Taiga Bonzai – Simplifying The art’ (Revised Edition), 2 chapters reveal extensive information on these subjects, c.13 concentrates on ‘Pest and Disease’ and c.14 discusses ‘Toxicity’ nevertheless, we will return to this topic in part 4.

We now turn our attention to plants needed for our survival namely fruit and vegetables starting with one of the world’s oldest fruits the humble apple, the bureaucracy over production, the controversy surrounding it and the diseases that attack various species of this particular fruit.

The appleMalus domestica, its ancestor Malus sieversii originated in Central Asia 4 thousand years ago. Today there are 7,500 apple varieties throughout the world – 2,500 of which are grown in the United States. In the 2019/2020 crop year, China was the leading producer of apples its production amounted to 41 million metric tons, the European Union came in second place with approximately 11.48 million metric tons.

The UK has been producing apples since the Roman occupation (AD 43 to AD 410) however, production is now in serious decline due to bureaucracy and trade problems with the EU, hence growers are given payments to burn their orchards. Natural England and the National Trust claimed 60% of England’s orchards had disappeared since the 1950s and have launched a £500,000 project aimed at halting the decline. The crisis has been even worse in some areas such as Devon, which has lost almost 90% of its orchards. According to David Bullock, the head of nature conservation at the National Trust, “Traditional orchards have been disappearing at an alarming rate. We are in real danger of losing these unique habitats.” (https://www.theguardian.com April 2009)

The orchard – Apples trees need space to grow, dwarf varieties require a minimum of 5m, standard trees need a distance of 9 to 11m. But this distance is inadequate because, as the trees mature they spread out, thus the risk of cross contamination from bacterium and fungal spores increases. In 2017 the total area harvested in the world for apples was 4,933,841 hectares. But, apples are not the only fruit produced, other varieties include apricot, pear, peach, plum and damson, hence the land mass required increases – these varieties predominantly cultivars are also susceptible to attack, thus the orchard becomes the playground for disease.

Such diseases include: Fire Blight a contagious disease affecting apples, pears, and some other members of the family Rosaceae. It is a serious concern to apple and pear producers and is believed to be indigenous to North America, from where it spread world-wide. Powdery mildew Podosphaera leucotricha a fungus that forms a dense white fungal growth (mycelium) on the host tissue affecting leaves, buds and shoots. Black Rot and FrogEye Leaf Spot Botryosphaeria obtusa attack fruit, leaves and bark of apple trees, Phytophthora Rot a soil-borne fungal disease by the pathogen Phytophthora sojae causes seed rot and attacks roots and stems; trees infected by such pathogens are usually destroyed.

However, there are apple tree varieties that are said to be disease resistant for example, Liberty, Freedom, Dorsett Golden, Enterprise, Goldrush, Pristine, Arkansas Black and Williams Pride which are American cultivars. European apple trees include, Topaz, Herefordshire Russet and Otava, but can the claims of being disease resistant to all insects and pathogens be substantiated – in short the answer is probably not. But arguably much depends on a particular climate zone; arid, humid, wet and cold. Moreover, these zones harbour other pests for example, the Round headed apple tree borer, European red mites, Red banded and oblique banded leaf rollers, Rosy aphids, Woolly aphids, Green fruit worms, Leafhoppers and Japanese beetles.

Horticultural methods – Generally speaking there are two schools of thought when growing crops either by conventional methods or organic. Conventionally grown is an agriculture term referring to a method of growing edible plants such as fruit and vegetables. This method of cultivation often use fertilizers and pesticides which allow for higher yield, out of season growth, greater resistance, longevity and greater mass. It is opposite to organic growing methods which attempt to produce crops without the use of synthetic chemicals (fertilizers, pesticides, antibiotics, hormones) or genetically modified organisms. (GMO)

Organic versus Conventional – people have very strong opinions on which method of horticulture is better, some advocate a preference for organic because it is healthier, tastes better and growers refrain from using pesticides. But there are negatives to this approach, fruit and vegetable yields will suffer due to the inevitable onslaught of pests and disease during the growing season for example. Many insects attack Brassica species the most common are diamondback moth Plutella xylostella also called cabbage moth, tobacco cutworm, aphids and many others. Hence more is planted to compensate for the loss and although organically grown food is preferable and more beneficial to consumers because it does not contain chemicals; it is more expensive.

Conventionally grown (GMO) – uses seeds that have been genetically modified to grow plants that have a faster growth rate, higher yields, are said to be pest and disease resistant and are cheaper to buy nonetheless, there are negatives to this approach. The use of synthetic pesticides and fertilizers on fruit and vegetables may eradicate many known pests and disease, but also kills insects that are beneficial for example, the lady bird beetle Coccinellidae a predator extremely proficient in eradicating aphids and scale colonies.

Additional problems arise because conventional horticulture often results in the soil being malnourished moreover, over spraying of pesticides can lead to greater resistance creating ‘super pests’ that cannot be eradicated. This will eventually lead to the development of stronger pesticides causing serious side effects in those whom consume the product.

Other nations Nilaparvata lugens the brown plant hopper (BPH), is a planthopper species that feeds on rice plants Oryza sativa L. These insects are among the most serious pests of rice a major staple crop for more than half the world’s population. They damage rice directly through feeding and also by transmitting two viruses, rice ragged stunt virus and rice grassy stunt virus. Up to 60% yield loss is common in rice cultivars attacked by this insect. BPH is found throughout Australia, Bangladesh, Bhutan, Burma (Myanmar), Cambodia, China, Fiji, India, Indonesia, Japan, North and South Korea, Laos, Malaysia, India, Nepal, Pakistan, Papua New Guinea, Philippines, Sri Lanka, Taiwan, Thailand, and Vietnam. 

Nilaparvata lugens

The brown plant hopper is dimorphic and can be either ‘macropterous’ (long wings) or ‘brachypterous’ (short wings) forms. The macropterous forms are migrants and invade new fields/paddies, adults usually mate on the day of emergence, and the females start laying eggs from the day following mating. Brachypterous females lay 300 to 350 eggs, whereas macropterous females lay fewer eggs; the eggs hatch in about six to nine days.

In Asia, India has the largest area for rice cultivation occupying 29.4 % of the global area, but has the lowest yield. The conventional paddy growing practices are in crisis due to social, biological and technical setbacks, yet there is a growing demand for rice due to ever burgeoning population. Rice demand in 2010 was estimated to be 100 million tonnes and this would increase by 50% in 2025 to assure food security in the world’s rice-consuming countries. However, with water becoming scarce many fields are drying out and coupled with increasing infestations of Nilaparvata lugens causing yield loss, it will difficult to fulfil the demand.

The cotton bollworm Helicoverpa armigera is a major pest of cotton Gossypium spp. maize, Zea mays, pulses, Fabaceae tomatoes, Solanum lycopersicum and sorghum bicolor throughout most of the world, but has only recently arrived in the Americas where it is rapidly spreading. It has documented resistance to 49 pesticides and is one of the most polyphagous and cosmopolitan pest species. 

Helicoverpa armigera

This species of Lepidoptera is found in Asia, Australia, New Zealand, Europe, Africa and South America. The adults emerge from the soil in the first 3 weeks of May and 2-6 days later and oviposition begins; a period lasting between 5-24 days. Within this time frame, a female may lay up to 3180 eggs up to 457 in 24 hours singly and mainly at night on various crops. Including, chickpeas, cotton, maize, okras, tobacco, tomatoes; when temperatures rise to 25°C, the eggs will hatch in 3 days and larvae immediately begin crop infestation and devastation. When fully fed, the larvae descend to the soil after 1-7 days pupate in an earthen cell 2-8 cm below the surface.

Pesticides – of which there are many used to control Helicoverpa armigera including, Lambda Cyhalothrin, Chlorpyriphos, Cypermethrin Acetamiprid and Profenos Cypermethrin, but as stated previously this pest has documented resistance to 49 pesticides. Moreover, as these articles thus far have pointed out many pests and disease cannot be eradicated.

In 2020 global pesticide usage was estimated to increase from 2 million tonnes to 3.5 million tonnes with China being the main user 1,763,000 tons followed by America 407,779 tons, Brazil 377,176 tons and Argentina 196,009 tons. One may argue that pesticides are beneficial for crop production, but extensive use of pesticides can possess serious consequences because of their bio-magnification and persistent nature.

Diverse pesticides directly or indirectly pollute air, water, soil and overall ecosystem which cause serious health hazards for living beings, one only has to look at the tens of thousands of lawsuits filed against Monsanto (now part of Bayer) over their chemical ‘Roundup’. In the final article of this series part 4 we look at the arguments in the attempt to halt the global invasion of pests and disease; until next time, BW, Nik.