Blue Bug Insect Diagnostics help producers identify insect pests in vineyards and orchards. By Jorisna Bonthuys.
Do you have an insect problem, or is there an insect you are interested in and want to know more about? Do you know the names of the insects in your vineyard or orchard?
“These are the kinds of questions our team of seasoned insect experts can help producers answer,” says Caro Kapp (35).
She manages the Blue Bug Insect Diagnostics (formerly known as the “IPM Initiative”) in the Department of Conservation Ecology and Entomology at Stellenbosch University (SU).
Blue Bug offers a paid commercial service for insect and mite identiﬁcation. The service was designed with vine growers, viticulturists and fruit producers in mind.
“We help producers and their advisors to identify insect pests early on, and to respond with timely and appropriate measures,” Kapp explains.Read More
“We help producers and their advisors to identify insect pests early on, and to respond with timely and appropriate measures.”
Solving insect “mysteries”
Kapp identiﬁes adult insects and their larvae based on samples sent to the Department. These samples arrive in different shapes and sizes.
Kapp employs various identiﬁcation and diagnostic tools and methods to help identify “mystery” insects. These include dissecting infested fruit to identify the bug life in and on it, and studying insects under a microscope. Sometimes she even rears unknown larvae to aid her in the search for their identity. (But adult insects are easier to identify than larvae, she explains.)
“If the samples are damaged, or the insect only recently hatched from its egg, it may be tricky to identify the species,” she says. “In such cases, DNA sequencing provides reliable information.”
The accuracy of any diagnosis or identiﬁcation depends on the written information provided and the condition in which the specimen arrived. “We sometimes only have a partial wing pattern to work with,” Kapp says. “I often feel like Sherlock Holmes solving insect mysteries with only a few clues.”
Kapp, currently enrolled as a PhD student, received her MScAgric (Nematology) cum laude in 2014. She started working in the Department in 2018 as the manager of the Insect Pest ID Service. Her current research focuses on nematode communities as bioindicators of the effects of soil amendments on soil health in deciduous fruit orchards and vineyards.
Kapp works closely with Prof Pia Addison, who heads up Blue Bug. Together, they zoom in on major insect pests and emerging threats to inform best practice on farms.
Addison ﬁrst thought of establishing an insect and pest identiﬁcation service in 2008, which was initially established as an industry-funded project. Hortgro (including SATI) and Winetech provided some initial funding for this project.
In 2014, a paid identiﬁcation service was formalised in the Department. At the time, scientists working in this service started collaborating with SU’s Plant Disease Clinic (in the Department of Plant Pathology) and Vironostix (in the Department of Genetics).
Since then, Blue Bug has grown signiﬁcantly. Addison says: “The service is uniquely positioned to assist the industry with pest-related questions that require scientiﬁc expertise.”
The specimens sent to Blue Bug are preserved, and data on it is captured for future reference. Kapp also compiles reports for clients, based on her ﬁndings.
Understanding insect-related farming risks
“To effectively control insect pests, you must ﬁrst be able to identify them,” Addison says.
Globally, market restrictions regarding phytosanitary pests and pesticide residues are becoming stricter. At the same time, the threat of phytosanitary pests spreading to the local fruit-producing region needs to be managed.
This is why producers must monitor insect populations and understand their related risks, Addison says.
They should be on the lookout for the various fruit ﬂy species, the fall armyworm and the polyphagous shot hole borer, Kapp says. Other insects that require continued vigilance are false codling moth, vine mealybug and thrips.
The accurate identiﬁcation of false codling and codling moth caterpillars often requires examination under a microscope and a certain level of expertise. “They look very similar to the casual observer,” Addison says. “It is therefore crucial to identify these insects accurately.”
Insect populations are never static – they are affected by the season and the conditions. “The situation is always changing,” Addison says. “Farmers must keep track of what is going on.
More stringent global market restrictions regarding phytosanitary pests and pesticide residues warrant the growing need for producers’ monitoring of insect populations, and their understanding of related risks.
“The insects that farmers ﬁnd might look similar, but they could, for instance, be speciating. That is not something you will see in an insect trap but something we (at Blue Bug) might pick up.”
“If an insect pest speciates (changes into a new species due to spatial isolation for many years) then current control measures to manage it may not work anymore on populations that have changed to a new species. For example, if two populations cannot interbreed anymore, they may no longer respond to commercial pheromones, or the sterile insect technique will not work for the ‘new’ populations.
“This is an example of why producers need to actively monitor pest insects and their biocontrol agents to make sure they know what they are dealing with,” Addison says.
Ultimately, stressed vines offer an open invitation to several insect species to attack, Kapp emphasises.
Monitoring insect populations is vital to managing and reducing insect-related risks on farms, she believes.
Combining sound insect identiﬁcation and management techniques with integrated pest management can go a long way towards the management of vineyards and orchards with as few chemicals as possible, she adds.
Apart from insect identiﬁcation and bud mite analysis, Blue Bug Insect Diagnostics also offers technical workshops and consultations with industry role-players. Furthermore, the service is investigating opportunities to expand their insect identiﬁcation work, such as through the use of machine learning and the development of a user-friendly application that can be employed in the ﬁeld.
“Consider our team part of your ﬁrst line of defence against pests,” Kapp concludes.