Pest management with Mainman – the season so far

Mainman is a novel insecticide for the management of insect pests in ornamental crops. Adrian Jackson of Belchim Crop Protection Ltd provides an insight into the product’s pest control potential and feeds back the views and practical experiences of some UK ornamental growers.

Text and photos: Adrian Jackson

Since its discovery in 1992, the insecticide molecule flonicamid has been extensively studied and is now available in many parts of the World for the control of pests in a wide range of food and ornamental crops. In the UK, flonicamid is available to ornamental growers as the commercial product Mainman. During this year’s field and nursery crop walks, we have encountered a range of pest species including aphids, Thrips and whiteflies. During busy times of the year when plant sales reach their peak staff may be diverted to other duties such as picking, labelling and packing of plants for despatch, resulting in less time monitoring crops for signs of pest activity. As a consequence I receive several requests each year for advice on curative measures to control pests that previously went unnoticed. A comprehensive pest control strategy should be put in place, which acts as a route map, so that at all levels of the crop protection management process, questions of how, why, when, and if, can be answered readily, and the correct decisions made and acted upon without delay. Pesticides and biological control measures usually play their part in a pest control programme, albeit to differing degrees depending on the prevailing circumstances.


Mainman fits well within IPM programmes on pot & bedding plant nurseries

In the UK, Mainman can be used in all protected and outside ornamental crops in accordance with Extension of Authorisation 0045/2013 (Chemicals Regulation Directorate, UK). More specifically, Mainman is used on pot plants, bedding plants, poinsettia, herbaceous perennials, cut flowers, ornamental trees, container and field-grown shrubs, ornamental grasses and Christmas trees. Mainman is primarily used for the control of aphids, probably because of its widely publicised efficacy against this particular group of pests. Susceptible species include the melon-cotton aphid, the potato aphid, the glasshouse-potato aphid and the peach potato aphid. Mainman also has activity against the glasshouse whitefly (Trialeurodes vaporariorum) and the non-indigenous tobacco whitefly (Bemisia tabaci), and can provide a useful reduction of mealybugs, capsids and Thrips. The reduction of Western Flower Thrips (Frankliniella occidentalis) is considered as a secondary benefit rather than a primary use. Mainman’s pest activity range coupled with a sound safety record towards beneficial insects and mites, makes the product a good choice for inclusion in a comprehensive pest management plan.


Chris Styles (Style Roses) checks his standard roses for signs of aphid activity following a spring application of Mainman

Mode of Action
Flonicamid was re-classified in December, 2016 following new scientific evidence regarding its mode of action. As a consequence, flonicamid was transferred from IRAC (Insecticide Resistance Action Committee) mode of action classification Group 9C to Group 29 where it is the sole occupant. Essentially flonicamid acts as a neuro-transmission inhibitor in the neurone at the basal part of chlordotonal organs. Evidence so far suggests that flonicamid binds to specific proteins associated with certain neuro-membrane channels. This binding process ultimately prevents the passage of potassium ions through these channels, and consequently the nerve fails to repolarise. This causes various toxicological symptoms including impaired mobility, cognitive, and feeding functions. Flonicamid-induced symptoms differ markedly from those induced by other classes of insecticides. More specific symptoms induced by flonicamid include staggered ‘drunken’ walks, travelling in small circles over the same route several times, and an increase in leg flicks and antennal movements. Once the insect pest obtains a toxic dose, which is usually within the first hour of feeding, the stylets are retracted, resulting in dehydration, starvation and death. The time to death may vary between two to seven days depending on environmental factors, the pest species and whether the pest is adult or juvenile. There is a marked increase in the efficacy of flonicamid when taken up by ingestion compared to the lower levels of activity which occur through contact.


Stephen Carr (Lowater Nursery) closely examines the glasshouse Hebe for signs of the melon-cotton aphid, Aphis gossypii

Grower demonstration trial
Mainman users span the length and breadth of the UK. Many started their journey with Mainman soon after the product gained its ornamental crop approval in 2013, but for some 2017 has been the first year of evaluation. For one grower in Lincolnshire, the annual infestation of woolly aphid on his ready-grown beech hedging, prompted him to review the current insecticide strategy by consulting with Belchim Crop Protection Ltd and establishing a demonstration trial with Mainman. Under the guidance of Adrian Jackson, Belchim’s Ornamental Crop Manager, frequent inspections of the crop were made by checking the newly expanding leaves with a hand lens in order to detect the first woolly aphid activity. After noting the first activity, there was a period of about two weeks when the temperatures declined significantly, which did not markedly affect the rate of aphid development, but did slow down crop growth. This resulted in a few more larger aphids on the leaves with a bit more protective wool, which made the test more challenging. At the end of the cold spell, the first of two Mainman sprays were applied with a knapsack sprayer. Over a three week period following the first application, aphids were collected and assessed under a stereo microscope for signs of flonicamid toxicity. The second application of Mainman was applied three weeks after the first. Although there were flonicamid-poisoned aphids at all assessments, the majority of dead aphids following the first spray were mainly of juvenile stages. However once the second treatment was applied, the proportion of dead to live aphids increased with each successive assessment and the population was completely under control at the end of the six week period.


Flonicamid has activity against a wide range of aphid species

Testimonials
The product has become a key component of traditional pesticide programmes as well as being a second line of defence in biological pest control programmes to support aphid predators and parasitoids that struggle to keep pace with developing aphid populations, or when early season environmental conditions are not conducive to beneficial insect activity.


Paul Dyer (Newey Perennial Plugs & Liners) is on the look-out for the Elder aphid (Aphis sambuci) in his Sambucus crop

For Stephen Carr, Finished Plant and Technical Manager at Lowater Nursery (Warsash, Hampshire), Mainman has become a vital tool for the management of the melon-cotton aphid (Aphis gossypii) in the glasshouse Hebe production in the spring. “Our mild winters enable Aphis gossypii to overwinter in the glasshouse, which means that they have a head start on the biologicals”, commented Stephen. “Mainman is applied to slow down the development of aphid populations in specific areas, keeping them in check during the spring when conditions are sub-optimal for the establishment of aphid predators and parasites. We find that once the temperatures start to increase, the dynamics inside the glasshouse start to change and the biological control agents begin to assert greater dominance, and eventually take over. Very often we find that aphids begin to develop in the crop around August and September. We use Mainman to prevent these aphids becoming an overwintering population. In all cases Mainman is used in a spray program in conjunction with other chemical controls and our biological control programme. Mainman is safe to the beneficial insects we use, and therefore it fits nicely within our integrated pest management strategy”.

At Style Roses, the use of insecticides is an important and necessary practice that has to be carried out to protect the vast range of specimen containerised standard roses against the main rose-infesting aphids. “I decided to give Mainman a try for the first time this spring, and I wasn’t disappointed” explained Chris Styles, owner of Style Roses, Lincolnshire. “As soon as I identified aphids up the stem and starting to appear around the flower buds, it was time to spray. If you leave it too late, quality will be compromised. When I heard that you could no longer use Aphox, I had to find an alternative. Mainman seemed the right alternative. After seeing the results this year, I intend to add it to my aphid control programme in the future”.


Flonicamid has a good level of safety towards aphid predators and parasitic wasps compared to pyrethroids and neonicotinoids

For Paul Dyer of Newey Perennial Plugs & Liners, based near Chichester in West Sussex, Mainman offers an interesting and unique alternative to old established insecticides such as pirimicarb. “Mainman is likely to become even more important on our nursery now that pirimicarb is being withdrawn. Currently, we tend to use Mainman as a spot treatment when aphids are seen. We have applied the product to a range of nursery stock liners under protection and we have never seen any crop damage, which is important in light of the fact that we grow such a wide range of species” commented Paul.

At Greenleaf Nursery in Southam, Warwickshire, Peter Healey exploits a range of different insecticides to combat aphids and whiteflies. “Because we grow a range of plants which are prone to whiteflies and aphids, we need a selection of insecticides that offer preventative and curative activity. Mainman is an important part of our strategy because of its efficacy against both pests. In particular, we find it very useful on trailing basket plants and Fuchsias”, commented Peter.

For more information
Belchim Crop Protection
info@belchim.com
www.belchim.com

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