Karthikeyan Chandrasegaran

In under a year, Ben has contributed to every major project in my lab—advancing our SIT program, building AI tool for mosquito morphometry & leading SDM to study how trap placement influences mosquito surveillance & inference. Ben’s efforts continue to shape our lab’s direction & future impact. 2/2

This #PostdocAppreciationWeek I want to celebrate @lefleur.bsky.social (Dr. Benjamin Nyman)

My lab at @ucrentomology.bsky.social wouldn’t be what it is today without Ben—he’s been a pillar in our formative years. Grateful to have him on the team. 1/2

Thank you so much, Martin!

Thank you! Really interesting work on Ae. albopictus and dengue dynamics. It’s great to see complementary findings—especially in how species-specific developmental trajectories influence vector competence across ecological contexts.

15/15
Can’t thank my amazing co-authors enough—Melody Walker, Jeffrey M. Marano, Spruha Rami, Adaline Bisese, James Weger-Lucarelli, Michael A. Robert, & Lauren Childs—for their expertise, insight, and partnership. Huge shout-out to Spruha and Adaline, who made standout contributions as undergrads!

14/15
Thanks to all members of the @thevinaugerlab.bsky.social & @lahonderelab.bsky.social labs, @vtbiochemistry.bsky.social & @fralinbiomed.bsky.social—for their support. This work was made possible with funding from the NIH, USDA NIFA, and @vtcezap.bsky.social.

13/15
This paper reflects 7 years of collaborative work—made possible by an incredible team. I’m deeply grateful to my mentors @thevinaugerlab.bsky.social and @lahonderelab.bsky.social for their guidance, trust, scientific vision, and unwavering support during my postdoc training.

12/15
This study integrates larval ecology, adult phenotype, neural and molecular mechanisms, and transmission modeling to show how early-life conditions shape mosquito vector potential—revealing lasting impacts on behavior, physiology, and epidemic risk from traits to transmission.

11/15
Modeling revealed that intervention timing, efficacy, & ecological feedback shape outbreak outcomes. High-efficacy adulticides reduced transmission, but sub-lethal larvicide exposure—especially when applied late—increased outbreak size by favoring survival of larger, more competent mosquitoes.

10/15
Populations skewed toward larger females, resulting from reduced larval competition under low-density conditions, produced faster and more extensive ZIKV outbreaks — demonstrating how developmental environments modulate transmission potential at the population scale.

9/15
To scale up our findings, we developed a transmission model informed by mosquito life history traits. By incorporating body size–dependent parameters shaped by larval ecology, the Larval Mass Model (LMM) revealed that outbreak dynamics depend not just on abundance, but on adult phenotypes.

8/15
Importantly, these transcriptional signatures had functional consequences. Large females—shaped by low-density larval environments & expressing this hub gene program—were more competent ZIKV vectors & had higher reproductive output. Early-life plasticity scales from genes to transmission risk.

7/15
These 7 hub genes are consistently expressed across mated and virgin females, indicating a mating-independent, body size–linked transcriptional program. They relate to chemosensation, reproduction, and virus transmission, linking larval growing conditions to adult behavior and vector potential.

6/15
To uncover molecular drivers of size-dependent traits, we profiled head transcriptome of large & small females. Body size—shaped by larval crowding—was linked to differential expression in chemosensory & salivary genes. Network analysis found 7 hub genes linking larval ecology to vector traits.

5/15
Since peripheral detection thresholds didn’t differ by size, we asked: where does behavioral divergence arise? Antennal lobe recordings showed CO₂ and host volatiles modulate each other’s representations in a size- and context-dependent manner—linking larval ecology to adult behavior.

4/15
To understand the basis of these behavioral differences, we tested peripheral olfactory responses. Both size classes detected host and plant volatiles at similar thresholds, but larger females showed higher response amplitudes—possibly due to larger antennae.

3/15
Responses to human odor (alone or with CO₂) were body size–dependent. Larger females were more attracted to host cues and less affected by repellents. These size-linked behaviors clustered in trait space, reflecting lasting effects of larval conditions on adult olfaction.

2/15
Mosquito life history is multidimensional and strongly mediated by body size. Larval crowding altered development time, survival, and fecundity, and these shifts co-varied with adult body size, forming distinct phenotypic clusters in multivariate trait space.

@bluethread.bsky.social
1/15
Larval competition... profoundly alters adult body size, survival, reproductive output, host-seeking behavior, olfactory neurophysiology, and vector competence."
In our new study, we trace how early-life environment reshapes adult disease risk in Aedes aegypti. #Preprint