Program Results

Introduction to the event

This project investigated the behavioral ecology, population genetics, and management strategies of invasive ants, with a focus on Dolichoderus thoracicus (the black cocoa ant). Across the project period, research activities contributed to 11 peer-reviewed journal articles spanning topics such as behavioral observation, molecular marker development, bait efficacy evaluation, insecticide resistance, and cryptic species identification.

A key study published in Myrmecological News revealed, for the first time, that D. thoracicus relies exclusively on trophic eggs for intra-colony nutritional transfer—overturning the common assumption of trophallaxis as the dominant food-sharing mechanism in ants. This finding has significant implications for ant control strategies and was recognized with the journal’s Best Paper Award in 2024. Another study provided genomic evidence for cryptic invasion and intraspecific hybridization in D. thoracicus populations in Taiwan. Using genome-wide markers, researchers identified the coexistence of two genetically distinct lineages—one native and one introduced—and documented hybridization between them in certain regions. This work, published in the Journal of Economic Entomology and featured on the cover, highlights the ecological and management significance of hidden introductions within native-range populations.

Additionally, a study on Odontomachus troglodytes, a newly introduced ant species from Africa, revealed supercolony-like traits in Taiwan—including polygyny, polydomy, and lack of inter-nest aggression—marking the first such case in the subfamily Ponerinae and raising important concerns about its invasive potential.

Additional research contributions include: (1) development of microsatellite markers for D. thoracicus to support future studies on population structure and gene flow, (2) evaluation of biodegradable boric acid baits for Linepithema humile control, (3) characterization of insecticide resistance genes in Blattella germanica, (4) assessment of population genetic variation in Paramesotriton hongkongensis under urbanization and habitat fragmentation, and (5) the identification of cryptic species and description of a new species within Reticulitermes termites in California.

Internationally, the project PI organized or co-organized three major conferences and gave invited presentations at leading global venues, reinforcing Taiwan’s visibility in entomological research. On the educational side, four new courses were offered—covering Genetics, Urban Entomology, Myrmecology, and Evolutionary Biology—featuring contributions from guest lecturers at the University of California, Riverside, and Virginia Tech. Three undergraduate students mentored through the project received funding from the Ministry of Science and Technology (MOST) Subsidy Program for Undergraduate Student Research, highlighting the project's effectiveness in cultivating early-stage research talent.

The project also advanced public-sector collaboration through work with the Taichung District Agricultural Research and Extension Station to develop integrated control methods for D. thoracicus. Outreach efforts included public lectures and the translation of research findings into practical guidance and policy tools.

Overall, the project delivered impactful, cross-disciplinary outcomes, including 11 peer-reviewed articles, 10 invited talks, participation in 3 international events, and meaningful contributions to research training and sustainable pest management.

圖一：疣胸琉璃蟻工蟻以營養卵進行營養交換的路徑圖。Diagram illustrating trophic egg transfer among Dolichoderus thoracicus workers.

圖二：疣胸琉璃蟻隱蔽入侵與種內雜交研究登上 Journal of Economic Entomology 封面。Study on cryptic invasion and hybridization in Dolichoderus thoracicus featured on the cover of Journal of Economic Entomology.

圖三：原產非洲的外來種穴鉅針蟻（Odontomachus troglodytes）。Odontomachus troglodytes, an invasive trap-jaw ant species native to Africa.