Everything About Shot Hole Borer Treatment & Infestation

Seen shot holes in your trees lately? It may not be a hunter’s wrong shot. Look closely; it could be Shot Hole Borer Beetle Infestation by boring holes. They grow in tropical and subtropical as well as temperate climate conditions. These beetles can affect the vascular system, which would further disrupt nutrient transport. 

This article covers the complete account of the infestation and Treatment Of Shot Hole Borer Beetle. Read further to know the treatment strategy of Tree Doctor USA. 

Shot Hole Borer Beetle Infestation 

• The commonly attacking type of shot hole borer species is Polyphagous Shot Hole Borer (PSHB). These are small beetles yet have a big impact on trees. 
• The infestation begins with the female beetles boring into the bark while laying eggs. An ambrosia fungus is also introduced by the female beetle when it traverses the vascular system. 
• This fungus is the nutrient source of the growing larvae, and larva growth is a symbiotic relationship, and from here begins the infestation.

Here are the prominent signs and symptoms of infestation

• Small holes and tunnels are created in the wood.
• The borers also form lumps and craters on the surface.
• These beetles eat the wood, and sunken areas are created.
• All this weakens the structural weakness and gradually affects the overall health.
• Deteriorate the quality of fruits or no fruits
• Staining, gumming, sugary exudate, and frass on the outer surface of the bark
• If left uncontrolled, borer invasion spreads like termites and can even kill the tree

Consequences of Shot Hole Borer Infestation

• The transport of water and food gets disturbed as the vascular system is affected. The vascular damage causes wilting. 
• Dieback is another effect, where gradually the twigs, branches, shoots and roots start to die, ultimately leading to the decline of tree growth.
• The presence of fungus also interrupts the vascular system as the beetle creates galleries for them during invasion. Stains around the entry holes indicate the fungus growth. 
• Infestations that last for a long period or are left untreated lead to the death of the tree in many cases. 
• Along with dieback, canopy thinning is a subsequent impact as beetles continue to bore into new areas, increasing the damage.
• In an agricultural land, the commercial disruption could be very detrimental. In trees like avocado, the infestation causes heavy loss to the yield, which impacts the farmers’ livelihood.

Shot Hole Borer Beetle Treatment

Arborists use systematic trunk injection, pesticides, and Soil Surfactants as the major strategy for Shot-Hole Borer Beetle Treatment. 

Let us discuss each, one by one-

1. Systematic Trunk Injection-

It is a process of injecting a medicated compound into the vascular system of a woody plant. This injection quickly delivers the medicine and distributes it throughout the tree for a quick and efficient outcome of treating the infestation. This method works well for shot hole borers, which feed on tree sap. Tree-age (Emamectin Benzoate) is the commonly used compound here. 

2. Use Of Soil Surfactant-

reduces the water required for the borer beetle to survive. These chemicals prevent the borers from penetrating the soil. For example: Hydrofuse, TerraGuard. The active ingredients in the surfactant increase the absorption of water and nutrients in the plant, which leaves very little for the weeds.

3. Use Of Natural Enemies-

of the pests is one of the best strategies to control pest growth. Fungi and nematodes, specific to the borer beetle, can be used as a biological control option. 

Beauveria bassiana fungus is a commonly used strain of the fungus used as a biological pesticide. The nematode Heterorhabditis bacteriophora infects the larvae of the shot hole borer. 

The type of pesticide for shot hole borers should be specific to the beetle species. One should also consider the tree type and the extent of infestation. At this stage, consult an arborist who can give the right guidance for the suitable treatment against the pest. 

Management Strategy Treatment For Shot Hole Borers

Management Strategy includes a combination of preventive and control strategies that help in achieving a healthy tree without the growth of shot hole borers. The effective strategy for Polyphagous Shot Hole Borer (PSHB) is described below-

• Proactive Approach For Detection
  

Inspecting the trees regularly for symptoms is step one. One should know the symptoms that can help identify if the tree is prone to an insect attack. Symptoms like holes, staining and canopy size should be checked regularly.

• During The Infestation
  

At the early stage of infestation, removal of a branch or part of the bark could be removed so that the attack does not spread. In case the insect infestation is severe, contact and systemic insecticide application directly attack the borer beetle.
Neonicotinoids like imidacloprid and trunk-injected insecticides such as emamectin benzoate are used.

• Pruning And Removal
  

Remove and destroy heavily infested branches or, in severe cases, the entire tree to prevent the spread of shot hole borers. Proper disposal of infested wood is essential.

• Biological Control Method
  

Natural predators and parasites that feed on hole borers are released in and around the infested tree. This method uses predatory beetles or bio pests such as Beauveria bassiana.

• Cultural Practices
  

Maintain overall tree health through proper watering, fertilization, and pruning. Healthy trees are better equipped to resist infestations and recover from damage.

• Quarantine Measures
  

To prevent the contact of infested wood or trees to new areas lie under quarantine measures. This way, the pests will not spread to other areas.

• Integrated Pest Management (IPM)
  

is a holistic approach that includes judicious use of chemicals, biological methods, and some traditional practices. It minimizes the impact of shot hole borer infestations and preserves the health of trees in affected areas.

Conclusion

Shot hole borer infestations pose significant threats to trees, ecosystems, and economic interests. To mitigate the effect of infestation, Shot Hole Borer Beetle Treatment includes proactive management, early detection, and a combination of chemical, biological, and cultural control methods.