Using Flight Mills to Measure Flight Propensity and Performance of Western Corn Rootworm, <em>Diabrotica virgifera virgifera</em> (LeConte)

Abstract

The western corn rootworm, Diabrotica virgifera virgifera (LeConte) (Coleoptera: Chrysomelidae), is an economically important pest of corn in the northern United States. Some populations have developed resistance to management strategies including transgenic corn that produces insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt). Knowledge of western corn rootworm dispersal is of critical importance for models of resistance evolution, spread, and mitigation. Flight behavior of an insect, especially over a long distance, is inherently difficult to observe and characterize. Flight mills provide a means to directly test developmental and physiological impacts and consequences of flight in the laboratory that cannot be obtained in field studies. In this study, flight mills were used to measure the timing of flight activity, total number of flights, and the distance, duration, and speed of flights taken by female rootworms during a 22-h test period. Sixteen flight mills were housed in an environmental chamber with programmable lighting, temperature, and humidity control. The flight mill described is of a typical design, where a flight arm is free to rotate about a central pivot. Rotation is caused by flight of an insect tethered to one end of the flight arm, and each rotation is recorded by a sensor with a time-stamp. Raw data are compiled by software, which are subsequently processed to provide summary statistics for flight parameters of interest. The most difficult task for any flight mill study is attachment of the tether to the insect with an adhesive, and the method used must be tailored to each species. The attachment must be strong enough to hold the insect in a rigid orientation and to prevent detachment during movement, while not interfering with natural wing motion during flight. The attachment process requires dexterity, finesse, and speed, making video footage of the process for rootworms of value. Disciplines Disciplines

Flight performance and the factors affecting the flight behaviour of Philaenus spumarius the main vector of Xylella fastidiosa in Europe

“…Despite the broad variety of flight-mill designs, most are based on the same principle: an insect is tethered to an arm, which is connected to some kind of stand, and then, the insect flies in a circular trajectory, allowing continuous measurement of flight parameters 32 . This tool has been applied to study the dispersal ability of insect pests with severe impacts, such as the red palm weevil 33 and the western corn rootworm 34 . An interesting application of flight mills is their use in describing how a plant pathogen may modify the flying ability of its vector, such as the Asian citrus psyllid, when infected with Candidatus Liberibacter asiaticus 11 .…”

Movement Ecology of Adult Western Corn Rootworm: Implications for Management

“…The most powerful approach combines tethered-flight assays with genomic and transcriptomic tools. While not trivial, tethered-flight experimentation with western corn rootworm is within reach of most laboratories [363]. The recent publication of this species' transcriptome [364] and genome [365] will help make genetic studies of the biological components of western corn rootworm movement ecology far more tractable than they have been up to now.…”

Dispersal of Neophilaenus campestris, a vector of Xylella fastidiosa, from olive groves to over‐summering hosts

“…Despite the broad variety of flight mill designs, they are all based on the same principle: an insect is attached to an arm, which is connected to a stand, then the insect flies describing a circular trajectory, allowing continuous measurement of flight parameters (Minter, 2018). This tool has been applied to study the dispersal ability of serious insect pests, such as the red palm weevil (Avalos et al, 2014) or the western corn rootworm (Yu et al, 2019). An interesting application of flight mills is to describe how a plant pathogen may modify the flying ability of its vector such as the Asian citrus psyllid when infected with Candidatus liberibacter asiaticus (Martini et al, 2015).…”

“…In flight mill studies, an insect is attached to an arm and it flies in a circular trajectory allowing continuous measurement of flight parameters (Minter et al., 2018). Flight mills have been largely used to study the dispersal ability of serious insect pests, such as the red palm weevil (Ávalos‐Masó et al., 2014) or the western corn rootworm (Yu et al., 2019). They also have been used to describe how several factors (humidity, temperature, age, sex, mated, no mated, etc.)…”