Biological Control of Invasive Hemiptera in Eucalyptus Ecosystems

Invasive true bugs of the order Hemiptera, notably the bronze bug (Thaumastocoris peregrinus), have emerged as major pests of Eucalyptus plantations worldwide. Their sap-feeding behaviour causes leaf bronzing, reduced vigour and increased susceptibility to secondary pathogens. Chemical control offers only temporary suppression and can harm non-target organisms, while mechanical methods are labour-intensive and often impractical at scale. Biological control, centred on the introduction and augmentation of specialised natural enemies—primarily egg-parasitoid wasps—represents a sustainable alternative that integrates ecological knowledge of pest life cycles, climatic constraints and host-parasitoid interactions. Success depends on understanding pest invasion routes, thermal biology, reproductive rates and field establishment of agents. Regional trials have demonstrated that optimising release timing according to temperature-driven development rates and ensuring adequate habitat conditions can achieve long-term suppression. Coordination among forestry managers, quarantine officers and research institutions has led to tailored control programmes in South America, Africa and Europe, highlighting the global importance of this approach. Continuous monitoring and adaptive management remain essential to mitigate potential non-target impacts and to respond to emerging pest lineages.

Research from Nature Portfolio

Recent studies have reconstructed global invasion pathways of the bronze bug through mitochondrial DNA analyses, identifying distinct haplotypes that underlie at least two independent introductions from native Australian populations. These findings inform targeted surveillance and early detection strategies in vulnerable regions. Complementing this, foundational work has quantified temperature-dependent development and life table parameters of the bronze bug under controlled conditions, establishing critical thermal thresholds and degree-day requirements for each life stage. This knowledge underpins predictive models of population dynamics and guides the timing of biological control releases to coincide with peak pest vulnerability.

Biological Control of Invasive Hemiptera in Eucalyptus Ecosystems publication trend

The graph below shows the total number of articles in biological control of invasive hemiptera in eucalyptus ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Hemiptera: An order of insects characterised by piercing-sucking mouthparts, many of which feed on plant sap.

Biological control: The use of living organisms to suppress pest populations, reducing damage and reliance on chemical pesticides.

Parasitoid: An organism, typically a wasp or fly, whose larvae develop within or on a host, ultimately causing host death.

Degree-day: A unit measuring accumulated heat exposure above a base temperature, used to predict insect development rates.

Arrhenotokous parthenogenesis: A form of reproduction in which unfertilised eggs develop into males, enabling rapid population increase.

References

1. One maternal lineage leads the expansion of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) in the New and Old Worlds. Scientific Reports (2020).
2. Thermal requirements, fertility life table and biological parameters of Cleruchoides noackae (Hymenoptera: Mymaridae) at different temperatures. PeerJ (2023).
3. Biological parameters, life table and thermal requirements of Thaumastocoris peregrinus (Heteroptera: Thaumastocoridae) at different temperatures. Scientific Reports (2019).
4. Establishment in the Field of Cleruchoides noackae (Hymenoptera: Mymaridae), an Exotic Egg Parasitoid of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae). Florida Entomologist (2017).
5. Oviposition behaviour of mated or unmated Cleruchoides noackae (Hymenoptera: Mymaridae). PLOS ONE (2020).