Hi, welcome to Taiga Bonzai, we have written articles on a selection of pests and disease recently. As a result our followers (horticulturists and bonsai enthusiasts) have asked for further research on this subject.

Introduction – in the last article we concluded our discussion on the ‘Toxicity’ of various shrubs and trees and their potential to be mildly irritant to being potentially fatal. However, all flora regardless of their ability to defend themselves are prone to attack from pests and disease. This increasing problem creating havoc on the world’s horticulture production and effect on society, is not a new phenomenon; it is the result of mankind’s actions.

Since the dawn of time – mankind’s actions have caused catastrophic consequences in many ways, the world is facing unprecedented challenges that will be extremely difficult to resolve. Have we reached the point of no return? Some believe that we have past it, others are more complacent, ‘These situations need to be addressed but they can be resolved’.

During our travels around the globe we have been privy to some extraordinary and amazing locations, returning to them at a later date we note that many have been destroyed. Piles of rubble, barren land, some are now heavily polluted – rife with pestilence and disease. Such experiences do not wane, they remain strong and clear in the mind. How have we arrived at this juncture? Follow our journey as we try to shed some light on the issue.

The beginning – according to scientific research vegetation had evolved on Earth approximately 700 million years ago with fungi and bacteria approximately 1,300 million years prior. This evidence is based on the earliest fossils of those organisms. The general consensus is that organisms also called microbes are beneficial for example, they keep nature clean by helping break down dead plants and animals into organic matter.

Mankind’s contribution – the hunter-gatherer culture developed among the early hominins of Africa, with evidence of their activities dating as far back as 2 million years. According to Richard B. Lee & Richard Daly (Cambridge Encyclopedia: Hunters and Gatherers) “Was humanity’s first and most successful adaptation, occupying at least 90 percent of human history“.

In addition, it is understood that through archaeology, anthropology, genetics, linguistics and the advent of writing from primary and secondary sources, this information is relatively common knowledge.

Colin Tudge in his book ‘Neanderthals, Bandits and Farmers: How Agriculture Really Began’. New Haven, CT: Yale University Press (1998) contends that “The Neolithic saw the Agricultural Revolution begin between 10,000 and 5000 BC in the Near East Fertile Crescent” (Mesopotamia). During this period humans began the systematic husbandry of plants and animals and agriculture advanced.

Many humans transitioned from nomadic to a settled life style as farmers in permanent settlements. The relative security and increased productivity provided by farming allowed communities to expand into increasingly larger units, fostered by advances in transportation.

However, Alina Polianskaya of ‘ Inews.co.uk‘ (March 15th 2018) points out that “Early humans may have been trading with each other much earlier than previously thought. Scientists excavated ancient artefacts at Middle Stone Age sites dating back 300,000 years at the Olorgesailie Basin, in southern Kenya. They uncovered weapons made of materials that could not be found there, suggesting hominins at the time may have exchanged goods with others.”

In his paper ‘Evolution: What Makes a Modern Human’ Nature. 485 (7396) (2012) Chris Stringer tells us that “Modern humans spread rapidly from Africa into the frost-free zones of Europe and Asia around 60,000 years ago.” This notion is supported by Adam Hart-Davis in his work ‘History: The Definitive Visual Guide’. New York: DK Publishing.

He contends that “The rapid expansion of humankind to North America and Oceania took place at the climax of the most recent ice age. At the time, temperate regions of today were extremely inhospitable. Yet, by the end of the Ice Age, some 12,000 years ago, humans had colonised nearly all ice-free parts of the globe“.

The Silk Road – a network of trade routes connecting China and Far East with the Middle East and Europe, was established when the Han Dynasty in China officially opened trade with the West in 130 BC. Although these Silk Road routes were protected from exterior forces by the Han and other countries under signed treaties, pests and disease also travelled with the traders.

This lead to infection, sickness and often death, because those who came into contact with these infectious bacteria had no immunity for example. October 12, 1492, the day when Christopher Columbus landed on the island of Guanahaní (San Salvador now part of the Bahamas.) The beginning of what was yet to come.

The Silk Road routes remained in use until 1453 AD, when the Ottoman Empire boycotted trade with China and closed them. It has been nearly 600 years since the Silk Road was used for international trade, but the routes have had a lasting impact on commerce, culture and history that resonates today and are being reopened.

International trade is arguably the most important factor in the modern world, as nations rely on others to supply the many types of commerce they need. Agreements are signed to lessen the bureaucracy nonetheless, international trade does bring problems as we shall find out in this series.

Yet some countries enforce stringent rules on imports for example, Australia probably has the strictest regulations on what is imported. Meat products, fruit and plant material including seeds from many countries including Asia and Middle East are prohibited.

However, some are permitted if the exporter is registered and has the required documentation. Unlike the rest of the world Australia (although having its own disease problems) is free of many other known diseases and has been since 1872, due to stringent pre and post-border measures. Meanwhile the rest of the world continues to battle with disease containment.

Today much has changed, we have advanced – science and technical horticultural knowledge has allowed us to become adept in food production. New plant species have been introduced, more variety and apparently more taste – but have we gone too far?

The reason why this question is asked is because for every action there is a reaction often resulting in irreversible consequences. Now pests and disease endemic to a particular part of the world are now commonplace in many other regions where flora has no defence.

How this phenomenon occurred is partly due to the fact that pests and disease are able to migrate via wind and wing over vast areas for example. The locust derived from the Latin locusta, in the family Acrididae a swarming insect that devastates vast areas of crop land is able to fly up to 2000 metres covering 200km per day.

Between June 2019 and February 2022, a major outbreak of desert locusts began developing, threatening food supplies in East Africa, the Arabian Peninsula and the Indian subcontinent. The outbreak was the worst to hit Kenya in 70 years, and the worst in 25 years for Ethiopia, Somalia, and India.

However, pests and disease are transmitted by other means including packaging, cross contamination, from animals, by dust suspended in the air and by food and water. But in the main it is the consequence of our actions, for which mankind is ultimately responsible. In the next article of ‘Unseen invasion’ we look at some examples of this, until next time, BW, Nik.