Transmission of the frequency components of the vibrational signal of the glassy-winged sharpshooter, Homalodisca vitripennis, within and between grapevines

Evidence of Receptivity to Vibroacoustic Stimuli in the Spotted Lanternfly Lycorma delicatula (Hemiptera: Fulgoridae)

The spotted lanternfly Lycorma delicatula White (Hemiptera: Fulgoridae) is a polyphagous insect pest that invaded the United States in 2014, in Berks County, Pennsylvania. It has since spread to several northeastern states and poses a significant threat to northeastern grape production. Most studied species of Hemiptera are known to communicate intraspecifically using some form of substrate-borne vibrational signals, although such behavior has not yet been reported in L. delicatula. This report demonstrates that adult and fourth-instar L. delicatula were attracted towards broadcasts of 60-Hz vibroacoustic stimuli directed to a laboratory arena and test substrate, which suggests that both adults and fourth instar nymphs can perceive and respond to vibrational stimuli.

Responses of adult spotted lanternflies to artificial aggregations composed of all males or females

Spotted lanternflies (SLF) Lycorma delicatula are economically important invasive planthoppers discovered in North America in 2014. SLF are gregarious, but how they locate each other, or who finds whom and when, is poorly understood. Here we describe adult SLF behavior and phenology on their preferred host, Ailanthus altissima, under field conditions, in the context of both aggregation and mate-location, since SLF demonstrated aggregation prior to mating. We documented aggregation behavior of adults and found we could manipulate free-living SLF populations in both number and sex ratio by the placement of confined populations of SLF males or females on trees. Trap capture of arriving SLF was significantly higher on trees with confined SLF aggregations than on control trees, and was corroborated with photographic data, demonstrating the manipulation of attraction and aggregation behavior. Sex ratios of trapped SLF arrivals were significantly more male-biased on trees with confined males and more female-biased on trees with confined females, evidence that the male- and female-biased sex ratios observed on trees naturally can be explained by sex-specific conspecific signals. SLF sex ratios shifted over time in the same pattern over two consecutive years. A mark-release-recapture study over time found that 1) SLF behavior is density dependent and strongly influenced by natural populations, 2) released females were captured significantly more on trees with caged females, particularly prior to mating, and 3) released males were captured significantly more on trees with caged females starting at mating time. Photographic data revealed that most clustering behavior (a measure of courtship) of free-living SLF began on trees with caged females during mating time, but not on trees with caged males or controls. We describe adult male and female SLF phenology whereby 1) aggregation behavior occurs, 2) males and females arrive at different times, 3) females began to aggregate several weeks prior to mating, 4) males subsequently joined aggregations at the time of mating, and 5) aggregation continued into oviposition. Population density and aggregation behavior were found to be key factors in their natural history which can be manipulated, providing a foothold for future research. Possible mechanisms for future exploration are discussed.

Is It Time for Ecotremology?

Our awareness of air-borne sounds in natural and urban habitats has led to the recent recognition of soundscape ecology and ecoacoustics as interdisciplinary fields of research that can help us better understand ecological processes and ecosystem dynamics. Because the vibroscape (i.e., the substrate-borne vibrations occurring in a given environment) is hidden to the human senses, we have largely overlooked its ecological significance. Substrate vibrations provide information crucial to the reproduction and survival of most animals, especially arthropods, which are essential to ecosystem functioning. Thus, vibroscape is an important component of the environment perceived by the majority of animals. Nowadays, when the environment is rapidly changing due to human activities, climate change, and invasive species, this hidden vibratory world is also likely to change without our notice, with potentially crucial effects on arthropod communities. Here, we introduce ecotremology, a discipline that mainly aims at studying substrate-borne vibrations for unraveling ecological processes and biological conservation. As biotremology follows the main research concepts of bioacoustics, ecotremology is consistent with the paradigms of ecoacoustics. We argue that information extracted from substrate vibrations present in the environment can be used to comprehensively assess and reliably predict ecosystem changes. We identify key research questions and discuss the technical challenges associated with ecotremology studies.

Hay meadow vibroscape and interactions within insect vibrational community

Our experiences shape our knowledge and understanding of the world around us. The natural vibrational environment (vibroscape) is hidden to human senses but is nevertheless perceived and exploited by the majority of animals. Here, we show that the vibroscape recorded on plants in a temperate hay meadow is a dynamic low-frequency world, rich in species-specific vibrational signals. The overall vibroscape composition changed throughout the season and also depended on the plant species, as well as on the spatial position of individual plants within the meadow. Within the studied community, vibrationally signaling species sharing this communication channel avoided interference primarily by partitioning vibrational space on a fine temporal scale. The vibroscape is a reliable source of information in the environment and expands our understanding of ecological and evolutionary processes.

Performance of a Low-Cost Acoustic Insect Detector System with Sitophilus oryzae (Coleoptera: Curculionidae) in Stored Grain and Tribolium castaneum (Coleoptera: Tenebrionidae) in Flour

Reduction of postharvest losses is gaining increased priority in warm regions where insect infestation may cause rapid deterioration of staple commodities. Acoustic detection can be used to assess the likelihood of insect infestations in bags of grain, flour, and other commodities that are stored in small holdings in developing countries, enabling rapid targeting of treatments. A portable postharvest insect detection system was developed with the goal to provide low-cost capability to acoustically assess infestations in small-scale storage facilities. Electret microphones input pest insect sounds to a 32-bit microcontroller platform that digitized and stored the signals on a digital memory card transferable to a portable laptop computer. The insect sounds then were analyzed by custom-written software that matched their spectra to those of known pests. Infestations of Sitophilus oryzae (L) in 2.6-kg bags could be detected down to densities of 1.9 adults/kg in grain and Tribolium castaneum (Herbst) down to 3.8 adults/kg in flour in laboratory settings. Also, differences in the rates of sounds per insect in treatments with different numbers ranging from 5 to 50 insects suggested that the sound rates of adults of different species at different population densities may be noticeably affected by aggregation pheromones or other behaviorally active semiochemicals. Further testing is needed but previous experience with acoustic detection systems suggests that the prototype has potential for use in small storage facilities where early detection of infestations is difficult to provide.