Andermatt Kenya has realized a unpredecented demand for its baculovirus-based CRYPTEX® SC, a biological solution
specific for control of False Codling moth (FCM). The growth is notable considering that as the CEO – Hamish Ker says, Kenya needs a joint approach and a national focus. Predictably, the efforts are spearheaded by industry represented by the Kenya Flower Council, government agencies notably the Kenya Plant Health Inspectorate Service (KEPHIS) and the Pest Control Products Board with active participation of pest control products providers. “Being a naturally occurring pathogen, CRYPTEX® SC is environmentally friendly, suffers no resistance and is FCM specific, explaining its rising demand”, said Hamish Ker
“CRYPTEX® SC is safe to non-target organisms, including humans, beneficial insects, mammals, other arthropods and pollinators”, he explained, adding, “we have a CRYPTEX® SC solution to FCM”, that fits perfectly into the national focus.
What is CRYPTEX® SC ? CRYPTEX® SC is a suspension concentrate of a granulovirus (CrleGV) for the biological control of False Codling Moth Thaumatotibia leucotreta, the product is registered ( PCPB (CR) 1969) on Roses, Capsicum and Avocado.
Why CRYPTEX® SC?
• Cryptex® SC has been shown to control falsecodling moth (FCM) larvae on various crops.
. Cryptex® SC is highly compatible in weekly tank mixes.
. Cryptex® SCcan easily be integrated in IPM strategies and is suitable for residue free production.
. FCM is a quarantine pest for many export crops such as roses or avocados. Thus the use of Cryptex® SC in FCM control strategies becomes a key tool to maintain access to export markets allowing adherence to residue restrictions.
When to apply?
1st Cryptex®SC application approximately 10-14 days after the 1st main peak in FCM moth flight – apply min 200ml- Max 330ml/ha
- 2nd Cryptex® SC application approximately 10-14 days after the 2nd main peak in FCM moth flight – apply min200ml -Max 330ml/ha
- 3rd Cryptex® SC preventative application to follow the 2nd application at a dose rate of 35ml per ha
- Continue with the program as weekly preventative until such a time as FCM is no longer a risk to the far
What are baculoviruses?
Baculoviruses are classified as microbial biological control agents, the naturally occurring insect specific viruses. The pathogens are often very specific and target only one particular species of insects – in the case of CRYPTEX® SC it targets the FCM. The insect becomes infected with the baculovirus after ingestion of the virus particles. Once ingested,
baculoviruses replicate inside host cells causing the insect to become sick and eventually die.
Types of baculoviruses
There are two main classes of baculoviruses, nucleopolyhedroviruses (NPVs) and granuloviruses (GVs). The main difference between the two is the number of virions, also known as the number of virus particles. Nucleopolyhedroviruses contain several virions, whereas granuloviruses contain a single virion
What are the benefits of using a baculovirus?
Baculoviruses are naturally occurring insect specific pathogens that can be used for controlling certain types of insect pests. Baculoviruses are usually very specific and often control only one species of insect.
Baculoviruses that are used as biological control agents in Kenya have to be registered as plant protection products by PCPB that puts them under same stringent evaluations to demonstrate their safety and efficacy as the conventional
chemical insecticides. Baculoviruses with approval for use can be used in integrated pest management programmes and
on organically produced crops. They can be used alongside other forms of biological control, including macro biologicals,
microbial products, mating disruption, pheromones and also in programmes with other plant protection products. Baculoviruses have a unique mode of action, belonging to IRAC Group 31, meaning that using them as part of plant
protection programme is an excellent way to help prevent resistance developing to plant protection products and active
ingredients.
Mode of action of baculoviruses
Baculoviruses contain high concentrations of virus particles, also known as virions. Each virus particle is surrounded by a protein matrix called the occlusion body which helps protect the virus from environmental conditions, such as UV. The occlusion bodies containing the virus particles are sprayed onto the leaves where the virus particles must be ingested by the larvae of the target insect in order to be effective. Baculoviruses have no direct effects on adults, eggs or pupae.
Once ingested, the occlusion bodies that surround the virus particles dissolve due to the highly alkaline environment in
the larva’s midgut. The infective part of the virus called the occlusion derived virus (ODV) is responsible for the primary
infection in the midgut cells. Replication takes place in the nuclei of the midgut cells. Following the primary infection, cell to cell transmission occurs by the budded virus (BV). This is how the virus spreads throughout the insect’s body. Towards the end of the infection cycle, larval host cells produce new occlusion bodies to help protect the virus once it gets released back into the environment when the insect dies. Once released from the insect, these occlusion bodies can then be ingested by other larvae which will lead to another virus infection.
How do baculoviruses provide population control?
As well as being able to cause a direct effect on larvae when ingested, baculoviruses can also provide population control due to either the horizontal effect, the fitness effect or the vertical effect.
The horizonal effect takes place after an infected larva ingests a lethal dose of the virus and dies and the virus is released back into the field, where other larvae feed on the virus particles that have been released from the dying insect, leading to further insect mortality.
Baculoviruses can also cause a fitness effect. This is when an insect ingests a sublethal quantity. The insect may not have enough virus to be controlled after ingestion at the larval stage, but this can lead to a reduction in pupation or egg hatching of the next generation.
Finally, baculoviruses can also spread via the vertical effect. Again, this can happen when a sublethal quantity of virus is
ingested by the larva. The infected larva may not die from the virus,but the virus can get passed onto the insect’s offspring. The next generation can carry the virus infection which can cause an outbreak after activation due to stress factors such as heat and disease.
All three of these effects; horizonal, fitness and the vertical effect ultimately provide population control of codling moth.
Timing of baculoviruses
The two main factors determining the time taken for larvae to die after becoming infected by baculoviruses are the dosage of virus ingested and larval stage of the insect. A higher dose of the baculovirus will ensure that the larvae will ingest a higher viral load, ultimately leading to quicker death. The other factor that will influence mortality rate is the larval stage of the insect. Younger larvae will be controlled more quickly than older larvae as the smaller larvae are more susceptible to the baculovirus. Quicker mortality helps reduce the amount of damage caused by the pest.
