From Insect Pheromones to Mating Disruption: Theory and Practice

First high-resolution vertical-looking radar for long-term automatic observation of high-flying insects in Asia

BACKGROUND

The increasing occurrence of migrant insect pests poses a serious threat to the sustainability of agriculture and to food security. Continuous monitoring of high-flying insects plays a crucial role in developing effective pest management strategies and implementing successful control measures.

RESULTS

The present study established vertical-looking radar (VLR) monitoring of insects in Henan Province, China, with a unit incorporating up-to-date high frequency digitization technology and rapid target-finding procedures. This radar produced detailed information on target identification (size, shape, wingbeat frequency) and flight behavior (flight time, height, track speed, track direction, body alignment, and climb rate) for insects flying at altitudes of from 70 m to 1810 m above the ground. The lowest detection range for insects is lower than that (150 m) normal in previous VLR systems. The VLR-inferred tracking of small insects could also provide accurate estimates of wind velocity.

CONCLUSION

The VLR achieved long-term automatic observation of high-flying insects for the first time in Asia. This provided a unique tool for automatic long-term monitoring of high-flying insects to help to answer some basic scientific questions, such as the impacts of climate change on insect populations, and provide surveillance information for insect pest control in this region. The three-step target identification method and the performance calibration protocol for the VLR established in this study are both straightforward and reliable. These methods can be easily implemented and adapted for use in other settings, making them valuable tools for enhancing radar-based entomological research and monitoring. © 2025 Society of Chemical Industry.

Functional types of long trichoid sensilla responding to sex pheromone components in Plutella xylostella

Sex pheromones, which consist of multiple components in specific ratios promote intraspecific sexual communications of insects. Plutella xylostella (L.) is a worldwide pest of cruciferous vegetables, the mating behavior of which is highly dependent on its olfactory system. Long trichoid sensilla on male antennae are the main olfactory sensilla that can sense sex pheromones. However, the underlying mechanisms remain unclear. In this study, 3 sex pheromone components from sex pheromone gland secretions of P. xylostella female adults were identified as Z11-16:Ald, Z11-16:Ac, and Z11-16:OH in a ratio of 9.4 : 100 : 17 using gas chromatography - mass spectrometry and gas chromatography with electroantennographic detection. Electrophysiological responses of 581 and 385 long trichoid sensilla of male adults and female adults, respectively, to the 3 components were measured by single sensillum recording. Hierarchical clustering analysis showed that the long trichoid sensilla were of 6 different types. In the male antennae, 52.32%, 5.51%, and 1.89% of the sensilla responded to Z11-16:Ald, Z11-16:Ac, and Z11-16:OH, which are named as A type, B type, and C type sensilla, respectively; 2.93% named as D type sensilla responded to both Z11-16:Ald and Z11-16:Ac, and 0.34% named as E type sensilla were sensitive to both Z11-16:Ald and Z11-16:OH. In the female antennae, only 7.53% of long trichoid sensilla responded to the sex pheromone components, A type sensilla were 3.64%, B type and C type sensilla were both 0.52%, D type sensilla were 1.30%, and 1.56% of the sensilla responded to all 3 components, which were named as F type sensilla. The responding long trichoid sensilla were located from the base to the terminal of the male antennae and from the base to the middle of the female antennae. The pheromone mixture (Z11-16:Ald : Z11-16:Ac : Z11-16:OH = 9.4 : 100 : 17) had a weakly repellent effect on female adults of P. xylostella. Our results lay the foundation for further studies on sex pheromone communications in P. xylostella.

Deciphering Plant-Insect-Microorganism Signals for Sustainable Crop Production

Agricultural crop productivity relies on the application of chemical pesticides to reduce pest and pathogen damage. However, chemical pesticides also pose a range of ecological, environmental and economic penalties. This includes the development of pesticide resistance by insect pests and pathogens, rendering pesticides less effective. Alternative sustainable crop protection tools should therefore be considered. Semiochemicals are signalling molecules produced by organisms, including plants, microbes, and animals, which cause behavioural or developmental changes in receiving organisms. Manipulating semiochemicals could provide a more sustainable approach to the management of insect pests and pathogens across crops. Here, we review the role of semiochemicals in the interaction between plants, insects and microbes, including examples of how they have been applied to agricultural systems. We highlight future research priorities to be considered for semiochemicals to be credible alternatives to the application of chemical pesticides.