Kairomones VS Pheromones - Bioglobal's Reflection and Visions

Semiochemicals including pheromones and kairomones have existence since the evolution of insects and their establishment on earth. Insects developed the ability to use these chemicals as a communication medium, and developed and evolved to use these chemicals for mating, alarms, food location and cohabitation with other species and plants.

Pheromones being semiochemicals are the most common type about whom progressive growers from respective countries are aware of or have some knowhow-based knowledge. Pheromones are used in mating, signaling the readiness of a female prepared to mate. Pheromones are not limited to insects as animals also produce and emit pheromones. Pheromones can be released by males to signal or alarm other males for territorial protection, warning other males to not enter or remain in another male’s position. Unless otherwise specified, the term ″pheromone″ used herein is referred to insect sex pheromone only.

Bioglobal & Pheromones

Bioglobal has been involved with pheromones for last three decades. Bioglobal, designed and developed, and produced pheromone treatments for codling moth, oriental fruit moth and light brown apple moth. These mating disruption products have been registered in Australia, New Zealand, South Africa, China and other countries. Bioglobal is the company that has successfully obtained the first registrations of the mating disruption dispensers for controlling codling moths and orential fruit moths in China, which was an ice-breaking endeavor. 

Against these, Bioglobal products have proven to be a successful control method. The pheromones are used to disrupt the mating process. In this manner, the males cannot locate and breed with females and drastically reducing the mated females laying eggs in the host crop.

Pheromones are a long-term strategy and prevent the likelihood of ″outbreaks″ occurring. Bioglobal has developed controlled release dispensers that can emit pheromones for the seasonal crops.

Further development and research have been conducted by Bioglobal to expand the product range and application methods.

Bioglobal can see benefits of pheromones being used in broadacre mono cultures and has had successful results for rice stem-borers. 

Bioglobal mating disruption dispensers for controlling oriental fruit moths.

Pheromones can be used to support or augment current pest control treatments and the application methods modified to meet the conditions or farm operations. A quick spray type pheromone product is flexible in application and used for short term needs.

Pheromones are not only limited to mating disruption but also can be used to signal a food source. Worker bees emit a pheromone when they have found a food source. This attracts other bees from the hive. Bioglobal developed a bee attractant that improves pollination. The bee pheromone is applied to the crop to attract extra bees resulting quicker and improved pollination which can lead to higher crop yields.

Bioglobal & Kairomones

The drawback for pheromones, it mainly gives the desired effects for control on males, not females. It does not have any affect to females or mated females and pheromones are species dependent and do not affect other species. Knowing this, Bioglobal has developed and continues to develop semiochemicals products that have an effect on females and males, and not limited to a single species.

These semiochemicals are called ″kairomones″.

Kairomones are part of a subclass of semiochemicals called allelochemicals.

Allelochemicals are divided into three groups, 

1) allomone - benefits the emitter and are mainly alarm, repellent or defensive. They can be attractive to lure prey to the predator.

2) synomone - benefits the emitter and receiver. Floral scents and nectar can attract predators to the host for protection, and 

3) kairomone - benefits the receiver, such as a plant emitting a volatile scent to communicate an attract to other species or help predators locate pests. This can be used to lure pests to a location for control. 

Since 2000, Bioglobal has been actively determined to develop and continue development in the Kairomone group. The potential for pest control and crop damage reduction is greater as kairomones are not limited to the species sex or species type. A suitable kairomone formulation can be attractive to both female and males and attractive to multiple species. Since 2004, Bioglobal has obtained kairomone formulation patents in Australia, Mexico, South Africa, New Zealand and China.

Kairomones are used in nature to signal plant to plant, plant to species.

Pests have evolved to lock in on the volatile chemicals emitted by plants to locate a food source as nectar or a suitable host to lay eggs. These volatiles can be emitted by the flower - floral volatiles or the plant leaf and body - green leaf volatiles.

Kairomones are not only emitted by host plants but also by deceased animal who will attract flies and carnivores. As do rotting or decaying fruits and plant material.

The kairomones used by Bioglobal in its research and development of insect management products are mainly those involved in the location of food.

Bioglobal first commercial kairomone product was a ″Blow fly″ attractant used to prevent fly strike in sheep. A selected blend of kairomones emitted by a decaying carcass proved to be highly successful attractant and provided protection to the flock by providing an attractive lure away from the flock location.

Bioglobal then investigated and conducted research on kairomones that could be used for large monoculture broadacre crops. Such a product would be used to reduce crop damage, pest resistance and high population numbers.

Bioglobal after many trials and redesigns developed ″Bioattract-Heli″. Bioglobal Registered Bioattract-Heli product in South Africa before 2010 and obtained the exemption of this product in Australia in 2011.

Bioattract-Heli has been created to primarily attract Heliothis moths in host crops such as cotton, wheat, corn, etc. especially H. armigera.

Bioattract-Heli a selected blend of floral and green leaf volatiles that has proven to be attractive to both male and female Heliothis moths. The volatile formula is impregnated into a patented release substrate for controlled release and blended into a feeding stimulant. Bioattract-Heli does not contain any toxicants, a small amount of pesticide is added by farmers prior to use and applied to 1 to 2% of the host crop foliage. The pest species then feeds on the Bioattract-Heli and death occurs by consuming the pesticide laced Bioattract-Heli. Both male and females require a food and water source during the adulthood life stage and the Bioattract-Heli is designed to be effective during the adulthood stage.

This is highly beneficial in crop protection, have a product to target females helping to reduce and or eliminate females laying eggs and reducing the next generation. The reduced population of males prevent localized mating. Bioattract-Heli uses those natural ″kairomones″ the pest will utilize in nature. Resistance cannot be developed to kairomones.

Green dips are BioAttract-Heli mixed with small amount of pesticide that is sprayed in row on the leaves of cotton.

The mode of action of kairomone products is completely different from those of chemical pesticides, therefore, they can be easily used to mitigate pesticide resistance. This will be rightly ideal for forming synergy with world leading chemical pesticide inventors.

Bioattract-Heli or kairomone type products are neither a standalone control treatment nor should they be. Kairomone products are best used as a part of Integrated Pest Management plan or to supplement the existing treatments.

Using Kairomone products for a standalone treatment would be too difficult to manage. Kairomone product can be affected by weather events, background odor competition arising from crop growing stages and flowering, and behavior particulars of species variety, including adult insect emergence, flight, feeding and egg laying behaviors. These naturally influential parameters make the formulation and validation of kairomone products a tremendously challenging process.

Practical applications of Bioattract-Heli have been optimized for reducing current pesticide applications, a ″swift knockdown″ for infestation control and a reduction treatment to reduce subsequent generations.

It would be ideal to have a kairomone product that can be a magic solution, however, such a product would be difficult to obtain and too expensive to use. Bioglobal aims to develop kairomone products that reduce operating costs to the grower, reduces pesticide usage, and maintain or improve crop yield. A kairomone product must also be flexible or adaptable to different applications and environments. 

Bioglobal has also developed kairomone products that are ″slow release″ type used for monitoring both female and male populations, products to lure pest for control trapping which is useful for growers that have no pesticide control and developed niche customized products to attract predators for natural biological control.

Research into kairomone technology has been limited to a few companies and a few dedicated researchers.

The research and development conducted by Bioglobal has extended far beyond the fascinating but challenging formulation. Bioglobal has extensive practical application experience. A formula maybe applied to substrate, blended with emulsions, used in traps, applied to host plants, used in cottage and large broadacre farms. Each time creating or modifying a product to enhance the efficacy, applications easier, and reducing costs whist maintaining or improving crop yield.

Beginning 2012, Bioattract-Heli has been widely validated and used in China by growers of rice, cotton, grain legume, wheat, maize, soybeen, tobacco and other cereal crops to manage noctuid moth infestations including adult Heliothis (Helicoverpa armigera and Helicoverpa punctigera), Armyworms (Mythimna convecta, Persectania ewingii, Spodoptera exempta), Native budworm (Helicoverpa punctigera), Cutworms (Agrotis spp.), Cnaphalocrocis medinalis and other adult moth pests.

Since 2015, Bioattract-Heli has been recognized and recommended as a green insect management technology by China National Center for Agricultural Technology Extension and Service and seven provincial-level official plant protection institutions.  

Intergration of Pesticides, Pheromones and Kariomones

Bioglobal has the advantage of both knowledge and skill for designing semiochemical products, both pheromone and kairomone formulations.

Through practical experience and developing products, Bioglobal understands the path of future, and sustainable crop protection will be a mix of technologies. Each having benefits and limitations.

Chemicals pesticides are easy to use and mass produced but limited by pest resistance and chemical residue concerns.

Pheromone treatments can be expensive and prevent pest populations but cannot achieve a swift knockdown control.

Kairomone products are not widely available, only limited commercial ones, can be affected by natural background competition such as flowering but attractive to males and females and multi-species, and can be used to achieve a swift knockdown control.

Bioglobal products, pheromone and kairomone have been designed to be a standalone but are enhanced when all three technologies are combined for their best attributes. A pheromone treatment can be enhanced with kairomone/ pesticide treatment. A pesticide treatment can be enhanced with kairomones during emergence and flights. A pesticide treatment can be enhanced with kairomones during emergence and flights with pheromones applied at the time of crop flowering. This Integrated Pest Management approach will develop further as the use of pheromone and kairomones into broadacre monoculture become accepted for long term, safe and sustainable pest control.

Bioglobal has assisted cotton growers to develop and integrate Bioattract-Heli into their pest control methods. When Bioattract-Heli is applied to the second and third flights and prior to plant flowering, results in the existing population to reduce to a lower level that would not be achieved by using pesticide alone. Treatments thereafter only require a reduced pesticide application until harvest.

Bioattract-Heli not only can enhance pesticide efficacy but reduce operational cost to the growers and increase their capacity to treat bigger areas. Kairomones do not require the standard full cover application to be effective. Normally a selected row or designated area are used for the treatment. Many more hectares can be treated in the same given duration of time than would be treated by a standard pesticide application.

Cotton bollworms killed by ingesting BioAttract-Heli (green color particles in the plate) mixed with small amount of pesticide.

This has become a very important aspect that growers must consider. Energy or fuel costs and consumption have recently impacted profit margins and resulted in higher sale price. As are carbon dioxide emissions and chemical pollution.

Kairomone do not necessarily need to be applied on the host plant. A substitute plant or trap plant can be used and it need not be in the host crop area. This follows traditional farming practices where trap-crops and crop-trapping is used in horticulture and cottage farming.

When Bioattract-Heli used in broadacre, it is applied to a single row every 100 meters. This is basically a very long and thin crop-trapping method. Moths are attracted to those plants that have the Bioattract-Heli applied.

There are many variations of application patterns and should be explored for the optimized control treatment. This unique interval row spray method makes sprays more convenient on densely planted and tall crops.

To assist growers about the best application timing of kairomone and pheromone treatments, surveillance or monitoring is usually required for the host crop area. This is used to determine the presence and quantity of a given pest. This early warning mechanism is a valuable tool for any effective treatment. An accurate prediction or forecasting can be used to indicate correct application time to prevent excessive crop damage occurring.

Bioglobal has designed and manufactured reliable pheromone and kairomone monitoring lures for this purpose. These can be produced in short term (1 month) duration needs or long term duration ( > 3 months). Short term lure use common ″first order″ release functions that have a gradual decay in the release rate. These are used for crops only require specific duration when the host crop is susceptible to attack. After the duration, the lure needs to replaced. This can be difficult for broadacre farmers, the area and distance to travel for maintaining, and replenishing short term lures is not practical.

Bioglobal has designed and manufactured monitoring lures that can have a much longer duration, typically 3 to 6 months. By utilizing our knowledge and skills, Bioglobal produces monitoring lure that has a ″zero order″ release action. The release rate maintains a very constant release rate throughout the lures duration. By maintaining a constant release rate, the attraction is also maintained as a constant. This is particularly helpful for growers in large areas or have crops that are susceptible for a long period such as orchards or broadacre rotational crops.

Bioglobal kairomone lures use patented applications for controlled release. These are a blend of volatiles combined together to create the attraction.

The difficulty with combining different volatiles is they have different diffusion and evaporation rates. The volatiles can vary greatly from each other either slowly or very quick, and if left in a single medium or substrate, the fast volatiles will deplete before the slower volatiles and affect the actual blend ratios and resultant attraction.

Bioglobal patent kairomone lure retards the fast volatiles to a slower release rate. By using creative and tailor-made multi-substrate medium, many fast volatiles that would be too impractical to use can be incorporated into the lure.

When using Bioglobal pheromone and kairomone products, it may not be easy to assess the direct efficacy contribution in a very short period of time. In the perfect experiment, a protocol used to directly compare pheromone / kairomone products to existing chemical treatment is easy to collect data and analysis, and make conclusions. These trials are conducted over relative short time or single season and can be misleading and mainly focused to measure an efficacy and compared to known treatment efficacy. Little consideration is given to the long term efficacy and growers operational parameters.

For example, pesticide X, what has been the affects of using the pesticide to 5 or 10 years, has the application interval shortened, has the required dosage increased, how far has the pesticide resistance extended.

When each type of technology is scrutinized and compared over much longer duration, it becomes apparent that no single technology can maintain efficacy performance alone.

When including a pheromone or kairomone technology into the control program, the assessment should reflect the full combination of the mixture of technologies used focusing on the overall output and outcomes at harvest thus providing a preliminary result of the overall full effectiveness.

Ideally, this needs to be a continuous assessment for a longer duration that incorporates overwintering, multiple seasons, crop rotations, etc.

Bioglobal continues, constantly looking to develop different products and trying different application methods. When pheromone usage began, the application was given as 500 dispensers per hectare. This is difficult to apply and time consuming. This has led to many people to conduct research on their application rates and methods. Twenty years, alternative rates have confirmed. Large pheromone emitters such as puffers, ropes, have challenged this initial application knowledge. This resulted to only few pheromone emitters are required per hectare. 

Bioglobal is seeking to improve on this further, developing application methods that will reduce the application burden.

The future

Currently, the knowledge and skills for pheromone and kairomone technology is limited to developed countries. Even developed countries, the tools for application are not widely available. The information and literature is well documented, but it still requires a skilled professional to determine when, where and how much is to be used. Developing countries are very limited to these aspects and resources.

If the combined efforts from many professionals contributed to developing simple and easy application tools, the acceptance and usage of pheromone and kairomone would be greatly increased. 

It could be envisaged software or smart phone applications could be used by all growers. Application timing, location and product mix could be determined by inputs such as, pest type, crop type, crop layout, time of year, etc.

Algorithms could be used that know the dispersion patterns, volatile duration, concentrations required. All combining will tell the grower how to optimize a combined kairomone / pheromone / chemical pesticide control philosophy for a sustainable outcome.

Such a tool would enhance the skill, knowledge and confidence in these technologies and applications. Or, maybe the future is conducting research and developing products those semiochemicals that have an inhibiting effect for mating, olfactory and oviposition. This would change mating disruption to mating inhibition.

A semiochemical that ″blocks″ the landing response for oviposition, effective camouflaging the host crop or just simply fools the pest to incorrectly recognizing the host crop for a less attractive plant species.

But we need not wait, Bioglobal has developed products that can be used today to improve and assist the current situations and needs. Bioattract-Heli has already proven record and there are many more situations where kairomone technology it could be used have yet to be discovered. Bioglobal’s kairomone products are adaptable and easily modified to include other volatiles. Growers can use them to experiment and explore their advantages, learn and develop knowledge and skills for their application integration.

Males and females of oriental fruit moths that have been caught by Bioglobal SemioLure-OFM with delta trap.

The active ingredients used by Bioglobal to formulate kairomone products are basically food grade additives. Compared with pheromones, these food additives are safer, more economical and easier obtainable in the commercial market. These bring clear advantages such as more affordable by growers, greater potential to be applied in plant protection and more lenient regulatory requirements resulted in quicker market entry. After more than 20 years focus and dedication, Bioglobal’s kairomone technology has reached the commercially scalable stage.

By taking advantages of its unique expertise in both pheromones and kairomones, Bioglobal is actively exploring the synergistic effects of the two technologies for the purpose of creating more powerful kairomone Plus pheromone OR pheromone Plus kairomone products.