Protective role of DTPA against Hylotrupes bajulus L. infestations by targeting metal ion incorporation in larval mandibles

The house longhorn beetle, Hylotrupes bajulus L., is a recognized wood pest with larvae capable of infesting and damaging various wood species. The larvae’s wood-cutting capability is attributed to the metal-reinforced chitin in their mandibles, which provides enhanced mechanical strength. This reinforcement is due to the presence of metal ions such as zinc (Zn) and manganese (Mn) bound to the chitin structure. The present study investigates the potential of diethylenetriaminepentaacetic acid (DTPA), a chelating agent, to sequester these crucial metal ions thereby affecting the larvae’s feeding capability. Wood samples treated with varying doses of DTPA showed significant larval mortality, with a 100% rate at a dose of 6 g/l. Electron microscopic analyses of deceased larvae revealed an absence of Zn in their mandibles, suggesting that DTPA effectively reduces its bioavailability, hindering mandible strengthening. The toxicity profile of DTPA is lower compared to many traditional wood treatments, indicating a potential for reduced environmental impact. However, the full spectrum of DTPA’s preservation capabilities and its interactions with other organisms require further investigation.