Asian Longhorned Beetle

Detection and Survey Tools 

Research Issue

Anoplophora glabripennis (ALB, Coleoptera: Cerambycidae), was inadvertently introduced into North America, probably in solid wood packing material associated with imports from eastern China or Korea where it is native The first established population in North America was discovered in New York in 1996.  Infestations have since been found in Illinois, New Jersey, Massachusetts, and Ontario, Canada.  Because of its wide host range and its ability to attack and eventually kill apparently healthy trees, ALB has the potential to cause serious economic and ecological damage nationwide.  Therefore, eradication programs under the direction of the USDA Animal and Plant Health Inspection Service (APHIS) and the Canadian Food Inspection Agency (CFIA) have been underway at all North American infested sites since their discovery.  Intensive surveys are conducted to locate all infested trees, which are then cut down and chipped. 

The eradication program relies on accurate location and destruction of all infested trees.  Infested trees can be difficult to identify during the initial stages of infestation.  Early signs of attack include oviposition pits, sap leakage from egg-laying sites, and frass or boring dust produced by larval feeding and expelled through the egg-laying site.  Initial attacks occur in the upper branches of trees where cryptic oviposition pits are particularly difficult to see.  Later, circular exit holes made by emerging adult beetles, and crown dieback become evident.  However, by the time exit holes are visible, beetles have already emerged and potentially spread to other trees. 

Currently, locating infested trees is based entirely on visual surveys.  Initially, surveys were conducted from the ground using binoculars; however, in 1999 ground-based surveys were supplemented using bucket trucks and tree climbers, revealing many more infested trees.  Nevertheless, visual surveys are not very effective and are extremely costly, labor intensive, and time consuming.  More sensitive means of detection are necessary to locate newly infested trees.  A simple detection device that can be easily operated by a single user from the ground and which is highly sensitive to very low levels of beetles present inside upper branches of trees, would greatly facilitate survey and detection and enhance the eradication program. 

The adults of several insect species including many bark beetles and woodborers produce sounds that are used in mate attraction and recognition. Audible sounds are also produced incidentally by moving and feeding activities of wood-infesting insects within trees or logs.  Vibrational cues may be exploited for detection of insects hidden within their hosts through the use of acoustic technology.  Acoustic monitoring has been used for decades to detect insects including termites and pests in stored products.  Development of practical methods for acoustic detection of this beetle requires the solution of technical problems involving transmission of resonant frequencies in wood and high background noise levels in the urban environments where most infestations have occurred. Rapid advances in computing and electronics have allowed for the development of automated acoustic-based recognition systems.  Such systems could be designed for hand held use for the detection and recognition of pest species.  In many instances it is sufficient to be able to detect the presence of insect pests without precise species identification.  However, to impose regulatory action against quarantined pests it is important to accurately detect and identify the quarantined species.  

Our Research

The goal of this project was to develop a field deployable, easily used, hand-held instrument that could detect the presence of ALB larvae at ports of entry and potential areas of infestation.  The instrument would perform the analyses necessary to distinguish ALB feeding vibrations from those of other similar insects that could also be infesting trees and wood products.   

Studies were conducted in collaboration with researchers at the Oak Ridge National Laboratory.  We recorded feeding sounds from ALB larvae as well as larvae of several native woodborers including: cottonwood borer, linden borer, locust borer, red oak borer, sugar maple borer, and whitespotted sawyer in order to identify unique acoustic signal descriptors associated with ALB.

We developed filter algorithms that match sounds of feeding larvae in both trees and cut logs.  The algorithms were incorporated into a data collection and analysis system and installed on a laptop computer.  The analysis of the data is completed in real time and results are displayed on the computer’s screen in real time.  We compared acoustic vibration data for ALB larvae feeding in trees of different species, at different distances from the sensor, and for different sizes and ages of ALB larvae.  

Expected Outcomes

The results of our research may lead to the development of a field deployable, easily used, hand-held instrument that could detect the presence of ALB larvae at ports of entry and potential areas of infestation.  This would ultimately lead not only to improved applications for detection of important, hidden insect pests but also to new insights into insect behavior. 

Research Results

Overall, feeding sounds of woodborer larvae were quite similar but ALB feeding sounds do have unique signal descriptors.  Older larvae feed deeper in the sapwood of the tree and their feeding produced larger amplitude vibrations.  The amplitude of larval feeding vibrations diminished with distance between the sensor and the larva.  In trees, vibrations appeared to move most strongly with the wood grain.

The acoustic detection system was successful in detecting the presence of infestations in sample logs and in trees in natural settings in China.  We recorded ALB larvae feeding in infested elm, poplar, and willow trees in China.  Recordings have been of larvae that were feeding at distances of up to 7 m away from the sensor.  A Generation II system was assembled at ORNL that can be used in the field.  The Generation II system incorporates the same data acquisition and analysis hardware and software on a “belt-worn” format computer.  “Belt-worn” computers are much smaller, lighter, and more portable than laptop computers and are carried in a mesh “belt” worn around the user’s waist.  This Generation II system paves the way to produce an inexpensive, hand-held instrument for detection of the ALB. 

Research Participants

Principal Investigators:

• Robert A. Haack, US Forest Service Northern Research Station Research Entomologist 
• Therese M. Poland, US Forest Service Northern Research Station Research Entomologist 

Research Partners:

• Glenn Allgood, Oakridge National Laboratory
• Cyrus Smith, Oakridge National Laboratory

For further details log on website :
https://www.nrs.fs.fed.us/disturbance/invasive_species/alb/risk_detection_spread/detection_survey_tools/