It has killed more than six million pine trees across the country and biological control programs are currently being used to combat its deleterious effects on Chinese ecology.

[1] In North America, this bark beetle attacks white fir (Abies concolor) and various species of spruce (Picea) and pine (Pinus).

Upon successfully reaching the cambium layer, a pair of beetles mate and the female excavates a vertical gallery, on one side of which she lays her eggs in small clusters.

With the arrival of warmer weather in spring, the beetles bore their way out of the trunk and disperse, finding suitable host trees by detecting the ethanol, monoterpenes and pheromones.

Extensive research has revealed that male beetles demonstrate a clear preference for larger females, which are associated with higher levels of fecundity.

This indicates that males rely on dual cues for mate selection: the physical dimension of the female's habitat (tunnel size) and her acoustic emissions.

Females chosen through these chemical cues have faster oviposition rates and larval development, and the pairs have less aggressive courtships and longer copulation time.

These beetles produce sound, specifically through a method called stridulation, to facilitate various essential life functions, including mate attraction, nutrient/habitat acquisition, and intraspecies competition.

Phonotaxis experiments have revealed that male beetles are attracted to louder agreement chirps, indicating that sound volume, which positively correlates with female body size, plays a crucial role in mate selection.

[8][6][9] Furthermore, the relationship between D. valens and its fungal associates is not based on specialized internal structures for carrying these fungi; instead, it involves external symbiotic interactions that vary with environmental factors.

Therefore, the ecological relationships between D. valens, its fungal associates, and mites highlight a multifaceted system of interaction that influences forest health and the dynamics of tree diseases.

[8] The symbiotic relationships between Dendroctonus valens and various yeasts play a critical role in the beetle's survival, development, and ecological interactions.

Such interactions enhance the bark beetle's ability to counteract host plant defenses and facilitate the yeast's dispersal and outbreeding opportunities.

[6] The ecological roles of yeasts associated with D. valens are multifaceted, ranging from pheromone transformation, which aids in beetle communication, to the assimilation of complex sugars like cellobiose and d-xylose, which are not typically found in soluble form in nature.

nitratophila from the Ogataea clade have been identified as significant for their ability to transform verbenol to verbenone, a process crucial for beetle communication and interaction with their environment.

[6] Studying these relationships is crucial for understanding the complex dynamics between bark beetles, their microbial symbionts, and their host plants, shedding light on the intricate web of ecological interactions that define their survival and proliferation.

α-Pinene has been shown to be particularly toxic to D. valens, leading to physiological, behavioral, and metabolic stress by increasing the number of lysosomes and mitochondria in the beetle's midgut cells.

[10] The microorganisms associated with D. valens, including strains of Pseudomonas sp., Serratia sp., and the yeast Candida piceae, play a crucial role in enabling the beetle to colonize host plants successfully.

The symbiosis between D. valens and these microorganisms is a vital adaptation, allowing the beetle to bypass the plant's chemical defenses and access the nutrients and habitat within.

This relationship highlights the complex interactions between insect herbivores, their host plants, and associated microbial communities, underscoring the importance of these microorganisms in the ecological success of D.

Here, forests have been widely planted to reduce erosion and prevent million of tonnes of soil being washed each year into the Yellow River.

The primary concern is that while these traps reliably bait and capture adults during flight, they can also attract beetles to the area, leading to tree attacks.