Selected Essential Oils Act as Repellents Against the House Cricket, Acheta domesticus

The house cricket, Acheta domesticus, is found globally. It is an agricultural pest causing economic damage to a wide variety of crops including cereal seedlings, vegetable crops, fruit plants, and stored grains. Additionally, crickets act as mechanical vectors of pathogens by harboring bacteria, fungi, viruses, and toxins, causing foodborne illnesses. They can contaminate stored grains, packaged foods, or animal feed due to deposition of their feces, lowering the quality of the food and creating food safety risks. Synthetic insect repellents, such as pyrethroids and carbamates, have been used previously in integrated pest management practices to control crickets. Though successful as repellents, they have been associated with health and environmental risks and concerns. The use of organic green repellents, such as plant essential oils, may be a viable alternative in pest management practices. In this study, we tested the effects of 27 plant-based essential oils on the behavior of A. domesticus. A. domesticus were introduced into an open arena to allow them unrestricted movement. A transparent plastic bottle containing an essential oil treatment was placed in the arena to allow voluntary entry by the crickets. Following a predetermined observation period, the number of crickets that entered the bottle was recorded, and percent entry was calculated as the proportion of individuals inside the bottle relative to the total number in the arena. Analysis of the percentage entry into the bottles allowed for a comparative assessment of repellency of the selected essential oils examined in this study. Essential oils that elicited high levels of entry into the bottle were categorized as having weak or no repellency, while those that demonstrated reduced entry were classified as moderate or strong repellents. Our results indicated that A. domesticus responded with strong repellent behavior to nearly half of the essential oils tested, while four essential oils and two synthetic repellents evoked no significant repellent responses. Four strong repellent essential oils, namely peppermint, rosemary, cinnamon, and lemongrass, were tested at different concentrations and showed a clear dose-dependent repellent effect. The results suggest that selected essential oils can be useful in the development of more natural "green" insect repellents.