Hi welcome to Taiga Bonzai, we continue our journey through the alphabet starting with the letter ‘R’.

Introduction – all trees and shrubs have some form of defence, some highly toxic and dangerous to domestic animals and humans. Whilst others are not considered harmful. Yet some whom work with these plants do not take adequate precautions, hence with negative results.

Rhododendron – Spp. family Ericaceae. Contains approximately 1,024 species of trees and shrubs. Both evergreen and deciduous and found throughout the world, from north America, Europe and Asia. They are a common addition to any bonsai collection, due to their colourful showy flowers that bloom from late spring to early summer.

All Rhododendron species including, Rhododendron obtusum, Rhododendron simsii, Rhododendron indicum and Rhododendron luteum are poisonous. They contain Andromedotoxins that are water-soluble diterpenoid compounds in the leaves flowers and nectar.

If any part of the plant is ingested symptoms include, salivation, a burning sensation in the mouth, emesis, diarrhoea, muscular weakness, impaired vision and dyspnea. Hypotension and atrioventricular block, a serious cardiovascular effect that may have fatal results.

Rosary Pea – Abrus precatorius. family Fabaceae. Known by other names including the ‘Jequirity bean’ is native to warm and tropical regions and also found in bonsai. Those with children and domestic pets are advised not to keep such a plant due to its very nature.

This species with its frond-like leaf formation and bright red fruit is extremely poisonous as it contains the toxin abrin. This is similar in structure to ricin the toxin in Ricinus communis or ‘Castor bean’ plant and some claim that abrin has a higher toxicity level. Abrin is found in all parts of the plant but, it is the seeds that attract the most attention and if crushed, chewed and ingested abrin is released and can be fatal.

Rowan – Sorbus aucuparia. family Rosaceae. Native to the northern hemisphere are also found in more temperate climes including Africa and Asia. Its growth can be prolific portraying grey bark, compound frond-like leaves and scented flowers white to cream with orange to red berries.

This combination makes the species very attractive to bonsai collectors. Nonetheless, rowan tree berries are poisonous as they contain parasorbic acid, which is used as a food preservative and in cosmetics. Symptoms can include, eye and respiratory problems, skin irritation and abdominal pain. However, if they are cooked the parasorbic acid is transformed into sorbic acid, which is not poisonous if ingested.

Snowberry – Symphoricarpos alba family Caprifoliaceae. Also know as the ‘ghost berry’ and ‘wax berry’, a genus of approximately 15 species native to north America are found in other parts of the world.

They are members of the honeysuckle family Caprifoliaceae used in bonsai for their fragrance and decorative flowers and coloured fruit, white, pink and red depending on the species.

The white berries of Symphoricarpos contain the following toxins, viburnin, chelidonine, saponins, tannins, terpenes, tryglycerides and coumarins. If ingested the symptoms are vomiting, blood in urine and delirium. However, the toxic combination has a powerful emetic effect – a gastrointestinal irritant, which causes the victim to expel the berries undigested.

Spindle tree – Euonymus europaeus. family Celastraceae. A native to Europe is a deciduous tree or shrub noted for its colour changes during the season. It has leaves that change from dark green to yellow to red to purple and flowers yellow to green grown in clusters.

The fruit, which can be pink, red or purple when ripe open to reveal its orange coloured seeds. This colour change make it a popular specimen for bonsai. However, the fruits are poisonous, a cocktail of toxins including, alkaloids theobromine, caffeine and terpene. Poisoning in children is quite common as the brightly coloured fruits are attractive. Ingesting the fruit can cause liver and kidney damage and can be fatal.

Spurges – Euphorbia Spp. family Euphorbiaceae. A genus with over 500 species of trees and shrubs including Euphorbia tirucalli, a tall growing shrub native to semi-arid tropical climates. It has a wide distribution throughout Africa and is common in the dry states of north America in particular California.

In bonsai E.tirucalli is not one of the most favoured of specimens although it can be found, because of the problems of shaping and pruning. For example, merely cutting a branch or twig causes the plant to ooze a sticky white toxic latex.

This latex when in contact with skin is extremely irritating causing redness and a burning sensation. If in contact with the eyes the result is severe pain and temporary blindness. If ingested symptoms are burning to the mouth, lips and tongue and can be fatal.

 Tamarac – Larix laricina. family Pinaceae. Known as the black, eastern, red and American larch, is native to north America and Canada. This species is both coniferous and deciduous due to its needle leaf structure that is shed in the autumn.

The Tamarac has more medicinal qualities as opposed to toxicity for example. Tea made from the bark was used as a laxative, a remedy for rheumatism and skin ailments.

However, this species is prone to attack from the fungal pathogens including Lachnellula willkommii and contact with it should be avoided. It is also argued that oil from the leaves in contact with the skin can cause dermatitis nonetheless, it is a popular species found in many a collection.

Titoki – Alectryon excelsus. family Sapindaceae. Formerly known as the New Zealand oak is as its name suggests native to this antipodean realm. Like its European counterparts it has a twisted trunk with branches radiating in all directions and its apex is formed into a canopy.

Its flowers are relatively small and purple in colour and it’s fruit are a pink to grey capsule that when ripe, open up to reveal a bright red pulp with a black seed. The Titoki seen in some bonsai collections is poisonous, it contains tannins and cyanide producing poisons in the bark, leaves and fruit. If ingested can cause; vomiting, gastroenteritis, diarrhoea, delirium, kidney failure and at worse fatality.

Tea tree (Chinese) – Camellia sinensis family Theaceae. This is an evergreen shrub that if left to its own devices can grow in access of 5 metres (16ft) in height. Producing white flowers with bright yellow stamens surrounded by glossy green leaves and fruit having a hard green shell and a single brown seed contained within.

There are many cultivars of the tea tree that are used to make a refreshing beverage partaken by countless individuals including, the Camellia sinensis assamica (Assam, India) strain. Nonetheless, the tea tree is considered poisonous because it contains caffeine and tannin toxins that are addictive.

It is argued that consuming five cups a day are sufficient to produce addiction and reduced intake or withdrawal. Causing; dizziness, headaches, palpitations, indigestion, constipation and insomnia. Moreover, excessive intake or over indulgence can be harmful to pregnant women.

In the next article on this subject ‘toxicity’ we continue with the letter ‘U’, until next time, BW, Nik.

Hi welcome to Taiga Bonzai, we continue our journey through the alphabet discussing the toxicity of trees and shrubs, some of which are used in bonsai horticulture.

Introduction – some of the species mentioned here are endemic to tropical and sub-tropical regions, others are found in the northern hemisphere.

Umbrella tree – Schefflera arboricola. (syn. Heptapleurum arboricolum) also a member of the Araliaceae family is native to Taiwan, but can be found world-wide as a house plant and also in bonsai. S. arboricola should not be mistaken for S. actinophylla, because of the height difference.

Moreover, S. arboricola has different leaf colour and patterns, some variegated with cream to white flowers with yellow edges or centres. Although much depends on the individual cultivar. S. arboricola is poisonous and carries the same toxins as S. actinophylla. Leaf consumption can cause mouth tingling and numbness, vomiting and abdominal pain and sap when in contact with skin can cause irritation and rash.

Viburnum – Lantana. family Adoxaceae. Also known as the ‘wayfaring tree’ is a deciduous shrub native to Europe, but can be found in Asia and northern Africa and is a relatively common specimen in bonsai.

It’s oval dark green leaves have a downy or hair like covering on the underside and flowers that are creamy white in colour and green fruit. These ripen to a bright red eventually turning black when mature. The berries if consumed although mildly toxic can cause vomiting, diarrhoea and abdominal pain if ingested in large quantities.

Viburnum – Opulus. family Adoxaceae. Is often referred to by its common name the ‘Guelder rose’ and is native to Europe, northern Africa and central Asia. This deciduous shrub has three lobed leaves that are opposite to each other having an appearance similar to maples.

The flowers in clusters are white in colour with their centre being fertile surrounded by an infertile ring that are produced in early summer; the fruit that is bright red. The berries if consumed although mildly toxic can cause vomiting, diarrhoea and abdominal pain if ingested in large quantities.

Virginia creeper – Parthenocissus quinquefolia. family Vitaceae. Is native to north America, Canada, Mexico, Guatemala and Europe. It is a prolific deciduous climbing vine reaching heights of over 30m. (100ft) It attaches itself to smooth surfaces by small adhesive pads.

This plant normally seen growing on the sides of buildings has striking colours throughout the seasons. The leaves change from various greens to yellow to orange to red and purple and this colour change makes the species attractive to bonsai.

The flowers are small and greenish white in colour, which change into purple/black berries in the autumn. The sap, leaves and berries are poisonous because they contain the toxin oxalic acid. Prolonged skin contact can be dangerous and ingesting any part even small amounts can cause kidney damage and death to humans.

White cedar – Spp. family Cupressaceae. Include Chamaecyparis thyoides – Atlantic white cypress, Cupressus lusitanica – Mexican white cedar, Thuja occidentalis – Northern white cedar, Thuja plicata – western red cedar and Cryptomeria japonica – Japanese cedar. Cedars are conifers and are found in many parts of the world, from northern climes to temperate zones.

They have many uses for example, grown as barriers, wind breaks, dense hedging in parks and gardens and are a common species in bonsai. However, all cedars carry toxins the primary irritant being plicatic acid and some are more potent than others for example.

The western red cedar and Japanese cedar have the highest content of plicatic acid and exposure to it can cause severe asthma, rhinitis or conjunctivitis, that can be progressive. In addition, plicatic acid in contact with skin can cause a hypersensitivity reaction, a type of response seen in tuberculin skin tests.

Willow – Salix alba. family Salicaceae. Is a species native to Europe, but is also found in western and central Asia. Within this genus are: Salix alba Vitellina – a willow with yellow shoots and Salix alba var. Britzensis, Cardinal and Chermesina having orange to red shoots.

The willow a medium sized deciduous tree can be in a weeping form or with a dome shaped crown with long thin leaves pointed at the end. (5–10cm long x 0.5–1.5cm wide) It is often found in bonsai in designs that include slanting (Shakan) and (Fukinagashi) wind swept.

Male and female trees each produce their own flowers in the form of catkins that appear in the spring and when mature are wind pollinated. However, the willow contains salicylate toxins in the bark that if ingested can cause the following. Ulcers, nausea, vomiting, stomach bleeding, kidney inflammation, tinnitus and skin rash.

Wisteria – Spp. family Fabaceae. Includes various species of climbing vines. (Plants that climb by their shoots) Wisteria brachybotrys, Wisteria brevidentata, Wisteria floribunda, Wisteria frutescens, Wisteria macrostachya, Wisteria sinesis, Wisteria venusta and Wisteria villosa.

These Wisteria types are predominantly native to the eastern north America, China, Japan and Korea. Although these species are found in bonsai, arguably the most common is the Wisteria sinesis that when in bloom has a striking floral display for example.

The great wisteria at the Ashikaga flower park in Tochigi, Japan, which covers more than 1,990 square meters over half an acre. Wisteria flowers are between 10 to 80cm in length and produced in pendulous racemes and are either purple, violet, pink or white.

All parts of the wisteria are poisonous, they contain the toxin saponin and if ingested the symptoms are: nausea, vomiting, abdominal pain, diarrhoea, severe gastroenteritis, dizziness, confusion, speech problems and collapse.

In the next article on ‘Toxicity’ we conclude our journey through the alphabet with ‘X’, ‘Y’ and ‘Z’. Until next time, BW, Nik.

Hi welcome to Taiga Bonzai, we continue our journey through the alphabet discussing the toxicity of trees and shrubs, some of which are used in bonsai horticulture.

Introduction – some of the species mentioned here are endemic to tropical and sub-tropical regions. Yet they can be found quite easily at garden centres and nurseries.

Xanthorhiza – Simplicissima. family Ranunculaceae. The only member of the genus Xanthorhiza, is native to the eastern states of north America. In the wild this shrub grows in sandy soil to a height of approximately 90cm. Its leaves are in a spiral configuration up to 18cm in length with flowers (6 to 20cm) that are produced in star shaped forms of reddish brown to purple.

This attractive plant although used for ground cover in gardens, is uncommon in bonsai as its main stem does not produce a large girth. Xanthorhiza is poisonous, its contain the toxin berberine, which can cause nausea, dyspnoea, diarrhoea, nephritis, urinary tract disorders, skin and eye irritation.

Xanthoceras – Sorbifolium. family Sapindaceae. Native to northern China is a flowering and fruiting species of small tree growing to approximately 8m and can be seen in bonsai collections although uncommon.

Its mid-green leaves 12–30cm in length are pinnate with flowers 10–20cm long containing 5 white petals arranged in panicle form, that appear in spring. The fruit a leathery pod splits open in three sections when ripe to reveal the black seeds, which resemble a small horse chestnut seed.

Originally the flowers, leaves and fruits were eaten raw with little or no side effects evident. Nonetheless, it would be prudent for those with sensitive digestive systems to cook them before consumption.

Yew – Taxus Spp. family Taxaceae. Yews are widely used in landscaping, ornamental horticulture and bonsai in which over 400 cultivars have been created including. The Japanese yew Taxus cuspidata, Pacific yew Taxus brevifolia and Canadian yew Taxus canadensis.

All these various species have derived from the European yew Taxus baccata considered as Europe’s oldest living tree of which, a specimen can be found in St Cynog’s church yard in Wales, dated to approximately 5000 years. The yew majestic and sombre in its appearance has a reputation as a harbinger of bad tidings for example.

The yew tree often found in church graveyards as a symbol of sadness was also made into longbows, a weapon used in the battle of Agincourt 1415 by the English in their defeat of the French cavalry.

Yews are relatively slow-growing and can reach heights of 20m (66ft), with a trunk girth averaging 5m. (16ft) The bark is reddish brown with lanceolate, flat dark-green leaves positioned in a frond-like form on the stem. The fruit consists of a bright red cone called an Aril in which a single seed is contained, these are subsequently consumed by birds who disperse them via their digestive system.

All parts of the yew with the exception of the Aril are highly poisonous to humans as they contain the toxin taxane, that can cause the following if ingested. Low blood counts, arthralgias and myalgias, pain in the joints and muscles, peripheral neuropathy – numbness and tingling of the hands and feet.

In addition, hair loss, mouth sores, nausea, vomiting, diarrhoea and in some cases the results can be fatal. Moreover, male and monoecious yews in this genus release extremely small cytotoxic pollen, causing headaches, lethargy, aching joints, itching, and skin rashes and asthma.

Zanthoxylum – Kauaense. family Rutaceae. Is a genus containing approximately 250 species of coniferous and deciduous trees and shrubs, indigenous to temperate and sub-tropical regions. It is known as the ‘prickly ash’ and is a common species in bonsai.

The bark has limpet shaped protrusions containing sharp thorns at the centre. Its bright green leaves are oval to oblong in shape with 6 to 8 in pairs on a single stem. The fruit are dull red berries tightly arranged in a cluster, that when ripe are used to make the spice Sichuan pepper.

According to Asian herbal remedies, the bark was extensively used as a remedy for rheumatism, toothache and colic. Zanthoxylum is not considered poisonous to humans, but it does have the toxin Sesamin.

This toxin can cause digestive issues including, nausea, diarrhoea and abdominal pain. Other symptoms may include Anaphylaxis, an extreme case of allergy caused by Sesamin. All edible parts of the tree must be properly prepared prior to ingestion.

Zelkova – Serrata Spp. family Ulmaceae. Often know as the Japanese or Chinese elm has two varieties, Japan and mainland eastern Asia Zelkova serrata var. serrata, and in Taiwan Zelkova serrata var. Tarokoensis. Z. serrata is a deciduous tree that in the wild can reach a height in excess of 30m (100ft +) and is favoured for its ornamental characteristics.

Z. serrata has a short fat trunk from which many branches radiate in a typical broom style. (Hokidachi) Its leaves are round to oblong in different shades of green, (Depending on the species) that change through the seasons to yellows, oranges and reds.

The flowers in clusters are yellowish-green, which turn brown as they mature. Z. serrata a popular species is regularly found in bonsai collections. Z. serrata has in the past been used for herbal remedies including stabilising the womb during child birth nonetheless, it would be prudent to seek advice before ingesting parts of this species.

The trees and shrubs mentioned in the compiled list are all toxic to some degree for example. In the beginning of this discussion information was given on the Acacia, a native of the African savanna, that have an abundance of thorns for protection. They also use poison in their leaves as a second line of defence against predation, predominantly from browsing wildlife.

Flora once indigenous to specific climate zones are now common place throughout the world in parks, gardens and bonsai, due to their discovery and availability. These species cultivated for their fruit and flowers and other uses, all have some form of defence.

Their toxicity ranges from mild, meaning having little effect on humans and domestic pets, to being potentially fatal as in the Manchineel tree Hippomane mancinella. Commonly known in Spanish as ‘manzanilla de la muerte‘ in English ‘the little apple of death‘. Which the conquistadors found to their cost when they invaded the Caribbean from 1519 to 1521.

Even the most toxic of bonsai specimens, the European Yew – Taxus baccata can be handled, providing we refrain from ingesting any part of it and ensuring that any body part in contact, predominantly the hands and the tools we use are thoroughly cleaned.

As to a particular species’ poisonous capabilities we are basically unconcerned, probably due to its benign appearance or attractiveness and addition to a bonsai collection. Nonetheless, this article was written in order to shed some light on floral toxicity and the potential hazards that exist.

These articles on ‘toxicity’ ‘A to Z’ concludes our journey through the alphabet discussing the defence mechanisms of trees and shrubs. But, like all flora they are vulnerable, prone to attack from pests and disease; a topic to turn to in the next article. Until next time, BW, Nik.

Hi welcome to Taiga Bonzai, in this article we discuss poisonous lepidoptera with arguably the Monarch Butterfly Danaus plexippus and Pipevine Swallowtail Battus philenor being the most well known.

Introduction – although the Monarch and Pipevine butterflies and a large variety of moths are toxic. It is the larval stage (caterpillars) where they are most dangerous to humans, animals and a vast variety of trees, shrubs and horticulture in general, due to the huge devastation they cause.

Caterpillars of most species eat plant material (often leaves), but not all; some (about 1%) eat insects, and some are even cannibalistic. Others feed on animal products. For example, clothes moths feed on wool, and horn moths feed on the hooves and horns of dead ungulates.

Caterpillars are typically voracious feeders and many of them are among the most serious of agricultural pests. In fact, many moth species are best known in their caterpillar stages, because of the damage they cause to fruits and other agricultural produce. Whereas the moths are obscure and do no direct harm.

Etymology – caterpillars have soft bodies that can grow rapidly between moults. Their size varies between species and instars (moults) from as small as 1 millimetre (0.039 in) up to 14 centimetres (5.5 in). Some larvae of the order Hymenoptera (ants, bees, and wasps) can appear like the caterpillars of the Lepidoptera. Such larvae are mainly seen in the sawfly suborder.

However while these larvae superficially resemble caterpillars, they can be distinguished by the presence of prolegs on every abdominal segment. An absence of crochets or hooks on the prolegs. (these are present on lepidopteran caterpillars) One pair of prominent ocelli on the head capsule, and an absence of the upside-down Y-shaped suture on the front of the head.

Lepidopteran caterpillars can be differentiated from sawfly larvae by: the numbers of pairs of pro-legs; sawfly larvae have 6 or more pairs while caterpillars have a maximum of 5 pairs. The number of stemmata or simple eyes, sawfly larvae have only two, while caterpillars usually have twelve. (six each side of the head)

Defence – many animals feed on caterpillars as they are rich in protein. As a result, caterpillars have evolved various means of defence. These include defence against physical conditions such as cold, hot or dry environmental conditions. Some Arctic species like Gynaephora groenlandica have special basking and aggregation behaviours apart from physiological adaptations to remain in a dormant state.

Appearance – of a caterpillar can often repel a predator, its markings and certain body parts can make it seem poisonous, or bigger in size and thus threatening, or non-edible. Some types of caterpillars are indeed poisonous or distasteful and their bright colouring warns predators of this. Others may mimic dangerous caterpillars although they are not actually dangerous.

Many caterpillars are cryptically coloured and resemble the plants on which they feed. An example of caterpillars that use camouflage for defence is the species Nemoria arizonaria (shown below). If the caterpillars hatch in the spring and feed on oak catkins they appear green. If they hatch in the summer they appear dark coloured, like oak twigs.

Chemical defences – more aggressive self-defence measures have evolved in some caterpillars. These measures include having spiny bristles or long fine hair-like setae with detachable tips. These cause serious consequences as described in the previous article. (Unseen invasion 4 the ‘Pine knot-horn‘ or ‘Maritime pine borer‘ )  

Moreover, venom which is among the most potent defensive chemicals in any animal is produced by the South American silk moth genus Lonomia. Its venom is an anticoagulant powerful enough to cause a human to hemorrhage to death. In Brazil 354 cases were reported between 1989 and 2005 with lethality ranging up to 20% with death caused most often by intracranial hemorrhage. This chemical is being investigated for potential medical applications.

These toxic species including the Cinnabar moth Tyria jacobaeae and monarch Danaus plexippus caterpillars, usually advertise themselves with the danger colours of red, yellow and black. Any predator that attempts to eat a caterpillar with an aggressive defence mechanism will learn and avoid future attempts.

Caterpillars cause much damage, mainly by eating leaves. Such damage is enhanced by monocultural farming practices, especially where the caterpillar is specifically adapted to the host plant under cultivation. For example, the Cotton bollworm, Helicoverpa armigera is a major pest of cotton Gossypium spp. maize, Zea mays, pulses, Fabaceae tomatoes, Solanum lycopersicum and sorghum bicolour throughout most of the world.

This species of moth is a recent arrival 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. Caterpillars have been the target of pest control through the use of pesticides, biological control and agronomic practices.

Such approaches are defeated over time via the evolution of resistance mechanisms in the insects, many species have become resistant to pesticides. Until next time, BW, Nik.

Hi welcome to Taiga Bonzai, in this post we discuss horticulture in other parts of the world, where nations are having difficulty in controlling pests and disease.

Introduction – horticultural methods in general have two schools of thought when growing crops, either by (a) conventional methods (organic) or (b) genetically modified organisms. (GMO)

Conventional – is an agriculture term referring to a method of growing edible plants such as fruit and vegetables without the use of synthetic chemicals. (fertilizers, pesticides, antibiotics, hormones)

GMO – method of cultivation often use fertilizers and pesticides which allow for higher yield, out of season growth, greater resistance, longevity and greater mass.

Organic versus GMO – 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.

Whereas GMO use 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.

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. 

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 bicolour 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. 

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 oviposition begins. This is 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, we 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’. Until next time, BW, Nik.

Hi, welcome to Taiga Bonzai in this post we share some of the comments we have received regarding the articles ‘Unseen invasion’.

Introduction – the viewpoints of our readers are many and varied with all having concerns on the ever increasing problem of pests and disease that are threatening our very existence. But to discuss them all at length would make this article far too long therefore, we will take a small selection 10 in total in reverse order and we thank all whom have commented on our articles. In addition, there were also questions that will be answered at the end.

• 10. Amy Hardcastle – “I had heard of the problem with declining insect populations but I did not realise the situation was so severe, I do now! Thank you.”
• 9. Leon Sanchez – “Your posts Unseen Invasion: ‘Portugal confirmed its first case in 2019 on lavender’ certainly shows the severity of the problem with the deadly disease Xylella fastidiosa, congrats.”
• 8. Gillian P. Simmonds – “Taiga bonzai certainly knows how to get people’s attention on topics that most fail to understand, we do have problems and I do agree they need to be addressed, please keep writing.”
• 7. Jonas Olsson – “Great work, you have given the powers that be a strong clear message will they listen! I sincerely hope they do otherwise we will be in serious trouble.”
• 6. Lilian Gough – “Many bloggers write good work but yours is on another level, your work is artistic informative and a pleasure to read if only there were more like you.”
• 5. Heinz Muller – “Unseen invasion really drive the message home here’s hoping the bureaucrats take note, very good articles.”
• 4. Andrew Billings – “Talent is a hard to find in these days especially on subjects such as yours – you are able to get the message across, enjoyable reading, I look forward to more.”
• 3. Galen Jonak – “It’s hard to come by well-informed people on this topic however, you seem like you know what you’re talking about! Thanks”
• 2. Taren Vanlier – “May I simply say what a relief to uncover a person that really understands what they are talking about on the internet. You actually know how to bring an issue to light and make it important. A lot more people really need to check this out and understand this side of the story. I can’t believe you’re not more popular given that you certainly possess the gift.”
• 1. Dalton Beitz – “I’m amazed, I must say. Seldom do I come across a blog that’s both educative and entertaining and without a doubt, you have hit the nail on the head. The issue is an issue that not enough men and women are speaking intelligently about. I am very happy that I stumbled across this in my search for something concerning this.”

The questions – there were many on pests and disease for example, how to eradicate them and by what methods, the protection of forests and woodland, tighter restrictions on importation, new phytosanitary regulations and will there be any detriment to bonsai horticulture.

1. Eradicating pests and disease – “What methods of eradicating pests and disease are currently in use and what is the success rate?”

For aeons agriculturists and horticulturists around the globe have been trying to halt the onslaught of pest and diseases that have devastated crops, forests and woodland. Many of these unwanted entities have arrived either by wind (pathogens) and wing (Insects) and through packaging in more recent times.

To date over 1 million species of insects have been discovered and described, but it is estimated that approximately 10 million exist on earth. There are 60,065 species of trees on the planet that we know of and more are being discovered. For each tree species there are over 100 pathogens, (60,065 X 100) plus.

Many we know of and are able to eradicate via insecticide and fungicide, but many chemicals are no longer effective and/or are not available for general public use for obvious reasons. Pesticides widely used include Cypermethrin, Glyphosate, Lambda Cyhalothrin, Chlorpyriphos, Cypermethrin Acetamiprid and Profenos Cypermethrin.

However, insects can become immune for example, the cotton bollworm Helicoverpa armigera has documented resistance to 49 pesticides. Pathogens are able to mutate and many are not affected by fungicide sprays and in some cases there is no chemical cure. Hence the success rate is minimal to say the least. Science has to find solutions that are safe not just for humans but also the environment.

2. Woodland and forest protection – “What methods or practises are in place to protect forests and woodland?”

Practically all foresters are knowledgeable regarding the health and status of their plants and are able to detect problems quite quickly when symptoms appear. However, there are diseases that attack tree root and water conducting systems for which the signs are not visible until it is too late for example.

Armillaria and Xylella fastidiosa, Anthracnose and Fire blight are visible as they attack foliage and small branches. Infected trees die within a short space of time, hence they are normally removed and burnt to avoid further contamination.

The World Trade Organization (WTO formed on January 1st 1995 with 164 members) is an intergovernmental organization that regulates and facilitates international trade between nations. Governments use the organization to establish, revise and enforce the rules that govern international trade.

However, there are 14 countries who are not members including, Aruba, Eritrea, Kiribati, Kosovo, Marshall Islands, Micronesia, Monaco, Nauru, North Korea, Palau, the Palestinian Territories, San Marino, Sint Maarten and Tuvalu.

Therefore, it is extremely difficult to enforce rules and regulations further if there is stiff opposition, because trade rules for agriculture remain an extremely sensitive issue. This is particularly the case when agricultural imports carry the threat of disease. Nonetheless, under the rules of the WTO member countries are allowed to restrict the importation of agricultural products from diseased regions should potential risks be apparent.

4. New phytosanitary regulations – “What do these new rules entail and can they be enforced?”

Every country on the planet is a sovereign nation and has the supreme right to make or change laws as it so desires, regardless of what treaties or agreements are in place. However, the nations in the EU block have to abide by the rules laid down by the commission, but the UK has parted company with the block and has no obligation to adhere to any mandate.

The latter passed new phytosanitary regulations in January 2021 due to diseases that are now rife in Europe, any country wishing to trade with the UK has to abide these new measures. Such mandates are regulatory in other nations including Australia, North America, Canada and Russia.

5. A detriment to bonsai horticulture – “Will these new restrictions have an effect on the bonsai fraternity?”

We are researching and monitoring new laws and what we can divulge is the from the 1st January 2022 according to the UK’s Department for Environment Food and Rural Affairs

“All plants, plant products and other objects categorised as either ‘regulated and notifiable’ or ‘regulated’ must be accompanied by a Phytosanitary Certificate – All plants, plant products and other objects categorised as ‘regulated’ will require pre-notification, but only if instructed to do so upon submitting a customs import declaration.”

Since leaving the EU, importing goods from the UK has and is an arduous affair with more paperwork and additional import duty costs and these new regulations now in situ just exacerbate the issue. Meaning purchasing bonsai products from the UK will not be impossible, but extremely tedious and time consuming.

No doubt the EU will probably reciprocate due to their petty minded bureaucracy because of the UK’s actions. However, there are many bonsai outlets on mainland Europe and other countries where the restrictions although in force are less rigid. Until next time, BW, Nik.