|A511 Life Sciences Annex
Baton Rouge, LA 70803
Insect social behavior and evolution: Research in our lab centers on the behavior, ecology, and evolution of social insects, with an emphasis on termites. Termites (Order Blattodea) evolved eusociality 50 million years earlier than social species in Hymenoptera (ants, bees, wasps), and they are a classical and important group for understanding the evolution of eusociality. We apply integrative approaches combining perspectives from chemical ecology and genetics. Big questions of interest include:
Social evolution is integrated with the evolution of chemical communication, which is the oldest and the primary form of communications and plays an essential role in regulating fundamental behaviors. However, little is known about how chemicals are perceived in the peripheral sensory system and how chemosensory information is processed in the brain of termites. We integrate microscopic and transcriptomic approaches to characterize the chemosensory system in termites, including illustration of antennal sensilla and brain organization in different castes, and investigation of the spatial-temporal expression of chemosensory related genes. This information lays the foundation for both mechanistic studies of chemical perception and comparative studies of chemosensation across insect taxa.
Foraging behavior in subterranean termites
Subterranean termites present unique evolutionary history, ecological niches, and economic importance. They are wood-feeding insects that nest underground and construct extensive tunnels in soil to explore for food. The foraging behavior is a collective activity performed by workers in response to a variety of social and environmental conditions. While mechanisms of foraging behavior have been better understood in Drosophila and some social hymenopterans, the molecular basis of this behavior remain unknown in termites. Using the Formosan subterranean termite (Coptotermes formosanus) as a model system, we investigate the environmental/social regulation and molecular mechanisms of foraging behavior in termites.
Honey bee health (with Kate Ihle)
We are collaborating with Dr. Kate Ihle from the USDA Bee Lab to study honey bee health from the perspectives of genetics and breeding. We integrate molecular biology and chemical ecology approaches to understand mechanisms underlying queen health.
Stored rice IPM (with Blake Wilson)
We are collaborating with Dr. Blake Wilson to develop best management practices for insect pests of stored rice. This research will provide information for reducing impact of stored grain pests to the Louisiana rice industry by identifying more effective and efficient
RESEARCH PROJECTS PRIOR TO LSU
Cannibalism or burial
The exploration of death cues in social insects was pioneered by E. O. Wilson in 1958. Since then, postmortem accumulation of fatty acids has been demonstrated to trigger corpse removal in several ants. As a part of my Ph.D., I identified the dynamic changes of death cues in termites. Immediately after death, the corpse releases a blend of volatiles, 3-octanone and 3-octanol, which attract live workers to retrieve and consume the bodies. The early death cue decreases quickly as the corpse decomposes. Correspondingly, the accumulation of late death cues (fatty acids, phenol, indole) elicits a behavioral switch from cannibalism to burial. The dynamic change in death cues balances nutritional rewards and pathogenic risks. This postmortem chemical communication highlights unique adaptations in termites to their ecological and social niche.
Reproductive conflict widely occurs in eusocial species where workers are reproductively totipotent. It is particularly true in termites during the process of reproductive succession, as conflict arises when the number of ergatoids exceeds the limit that colony can sustain. Termites resolve the conflict by killing excessive ergatoids, a previously poorly studied behavior. We addressed several questions including who kill the ergatoids, whether the attack is sex-specific, and whether it is age-dependent. Observations and experiments showed that policing behavior in R. flavipes is a concerted effort carried out by both ergatoids and workers, and the policing by ergatoids is age-dependent. Specially, older ergatoids attack younger ones, and workers are then recruited to cannibalize the injured ergatoids. This study provided the first empirical evidence of policing behavior in termites.
Before becoming a social insect enthusiast, I studied earthworm diversity when I was a Master’s student, and Maillard reaction when I was an undergraduate at China Agricultural University in Beijing.
Ngo K, Castillo P, Laine RA, Sun Q. 2021. Effects of menadione on survival, feeding, and tunneling activity of the Formosan subterranean termite. Insects. 12(12), 1109; https://doi.org/10.3390/insects12121109
Castillo P, Le N, Sun Q. 2021. Comparative antennal morphometry and sensilla organization in the reproductive and non-reproductive castes of the Formosan subterranean termite. Insects. 12(7):576; ; https://doi.org/10.3390/insects12070576
Shi J, Zhang C, Huang S, Merchant A, Sun Q, Zhou C, Haynes KF, and Zhou X. 2021. Managing corpses from different castes in the eastern subterranean termite. Annals of the Entomological Society of America, https://doi.org/10.1093/aesa/saaa060
Sun Q, Haynes KF, Zhou X. 2021. Temporal changes in cuticular hydrocarbons during worker-reproductive transition in the eastern subterranean termite (Blattodea: Rhinotermitidae). Annals of the Entomological Society of America, https://doi.org/10.1093/aesa/saaa027
Sun Q, Hampton JD, Merchant A, Haynes KF, Zhou X. 2020. Cooperative policing behavior regulates the reproductive division of labor in a termite. Proceedings of the Royal Society B. 287(1928): 20200780. PDF
Sun Q, Haynes KF, Zhou X. 2018. Managing the risks and rewards of death in social insects. Philosophical Transactions of the Royal Society B, 373(1754), 20170258. PDF
Sun Q, Haynes KF, Hampton JD, Zhou X. 2017. Sex-specific inhibition and stimulation of worker-reproductive transition in a termite. The Science of Nature, 104(9-10): 79. PDF
Sun Q, Haynes KF, Zhou X. 2017. Dynamic changes in death cues modulate risks and rewards of corpse management in a social insect. Functional Ecology, 31(3): 697-706. PDF
Yin Z, Sun Q, Zhang X, Jing H. 2014. Optimised formation of blue Maillard reaction products of xylose and glycine model systems and associated antioxidant activity. Journal of the Science of Food and Agriculture, 94(7): 1332-1339.
Sun Q, Haynes KF, Zhou X. 2013. Differential undertaking response of a lower termite to congeneric and conspecific corpses. Scientific Reports, 3: 1650. PDF
Sun Q and Zhou X. 2013. Corpse management in social insects. International Journal of Biological Sciences, 9(3): 313-321. PDF
Sun Q, Yin Z, Jing H. 2009. Color characteristics and radical scavenging activity of four model systems of Maillard reaction between amino acids and monosaccharides. Food Science, 30(11): 118-123.
ENTM 4100 Insect Behavior (3 credits, offered fall semester, odd years)
This course provides comprehensive overview of the principles of animal behavior using insects as examples, ranging from mechanisms and functions of behavior to their ecological and evolutionary significance. We also cover recent research on insect behavior, integrative approaches for studying behavior, and how this knowledge can be applied to solve human challenges.
ENTM 7008 Special Topics in Entomology - Insect Chemical Ecology (1 credit, to be offered in fall 2022)
This course offers a fundamental introduction to insect chemical ecology, and introduces methods used to study the interaction of insects with their chemical environment. Students will have hands-on opportunities for chemical collection and behavioral analysis, and participate in discussion of recent research.
ENTM 4099 Undergraduate Entomological Research (1-3 credits, offered every semester)
We host and mentor undergraduate students to conduct independent research projects in our lab in the areas of insect social behavior, genetics, chemical ecology, or urban pest management. Students will be trained in literature review, experimental design and performance, data analysis, as well as writing and presentation of research.