Detection of Solenopsis invicta nest using spectrum analysis technology

Abstract: Solenopsis invicta, wihich originated in Brazil, Argentina, Paraguay and the Panama Canal, has been spreading at the speed of 200 km every year since they invaded Mobile, Alabama in the United States from 1918 to 1931. Recently, Solenopsis invicta has indicated a tendency to rapidly spread all over the world, including China. They are polyphagous insects, but prefer high protein or high fat foods, such as the larvae of some small insects or vertebrates and seeds or fruits with high oil. Therefore, they are severely dangerous to human health, public security, agriculture, forestry production, and the ecological environment in the invaded areas.Solenopsis invicta is social insect of the family Formicidae, Hymenoptera with the habit of gregarious nesting. They are strongly offensive against intruders, and they will attack the intruders in full strength once their nest is disturbed. Thus, some experts think that the threat of Solenopsis invicta in China cannot be ignored and that corresponding measures should be imminently taken to prevent the Solenopsis invicta invasion. Research on the detection method of a Solenopsis invicta nest to eliminate Solenopsis invicta from the source is of practical significance to the prevention of a Solenopsis invicta disaster. Therefore, finding out the location of a nest of Solenopsis invicta is of more practical value than only exterminating Solenopsis invicta.The feasibility of detection of a nest of Solenopsis invicta based on spectrum analysis technology was examined by using an optical spectrum instrument with reflect characteristics. A differential coefficient method and a logarithmic method to analyze original spectral reflectivity were used. The method of using character factors was studied to get the best waveband for distinguishing the ant nest from other things. An Eculidean distance method was used to calculate the average distance, and effective band of the nest of Solenopsis invicta's recognized effect. In addition, the average of the Euclidean distance of different features is greater than the average of the Euclidean distance of the same feature, and the samples, which were collected and measured by the laboratory hyper-spectral imager to verify the reliability of the selected band. Finally, the results were compared with the traditional method. We randomly selected eight sample points in the Wushan Square of South China Agricultural University. Using the traditional method and a spectrum analytical method to prove it, we got the same result. However, it is more convenient and faster to get the information by using the spectrum analytical method.As a result, the effective wavebands to recognize the Solenopsis invicta nest mostly concentrate on 701-1 510 nm, which are mainly red light bands and near-infrared bands. Additionally, the observation shows that the original spectrum and the logarithmic method could be used to distinguish the nest of Solenopsis invicta from common soil and grass. Moreover, the latter can make it clearer than the others, while the spectrum first-order differential method and the logarithmic after a differential transformation could distinguish between grass and ant nest soil, or grass and common soil, but not between Solenopsis invicta nest soil and common soil. This observation may provide useful information for detecting the Solenopsis invicta nest.