CUBE ChatShaala Summary – 02 November 2025
Today’s session revolved around Soumy’s interest model system—fruit flies—and Seethalekshmi’s adventures with trapping fruit flies at NITK Surathkal. The discussion opened with an intriguing observation—fruit flies are not attracted to tomatoes*. This sparked a series of questions about the biological and chemical factors that influence attraction and the botanical nature of fruits and vegetables.
Soumy presented the experiment conducted between 22nd and 27th October, under a room temperature of 27°C, concluding that fruit flies showed no attraction towards tomatoes. This observation led to a broader question—is a tomato truly a fruit?*
The group explored this by revisiting basic botanical principles:
- Fruits develop from fertilized ovaries of flowers.
- Ovules within the ovary transform into seeds.
- Thus, cucumber and tomato qualify as fruits, while onion, which develops from a bulb, is not.
This distinction further emphasized that the term “vegetable” is not scientific but rather culinary.
Both Seethalekshmi and Sneha illustrated how fruit formation varies among species, using diagrams of floral structures showing stigma, ovary, and ovule transformation.
Data recorded from fruit fly traps at 12 PM revealed consistent observations:
- Tomato traps showed minimal attraction.
- Cucumber attracted more fruit flies.
- Onion traps showed little to no activity.
This prompted deeper thinking about chemical cues and volatiles responsible for attracting fruit flies and whether ripening stages or environmental factors could alter these outcomes.
TINKE Moments (This I Never Earlier)
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Realizing that “fruit” is a scientific term derived from fertilization, unlike the culinary idea of “vegetables.”
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Linking fruit fly behavior to botanical classifications, highlighting how biology and observation-based reasoning can converge.
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Understanding that fruit fly attraction is not universal to all fruits—it may depend on the type of fruit and its chemical signals.
Gaps & Misconceptions Identified
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Confusion between biological and everyday definitions of fruits and vegetables.
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The assumption that all fruits attract fruit flies, which today’s experiment contradicted.
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Limited understanding of volatile compounds emitted during fruit ripening and their role in insect attraction.
Provocative Questions for the Community
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If tomatoes are fruits, why are fruit flies not drawn to them? -
Can onions ever be considered fruits under any developmental condition? -
What specific chemicals make cucumbers more attractive to fruit flies than tomatoes? -
Can studying fruit fly preferences help us understand plant reproductive biology better?
What I Learned
Today, I learned how scientific curiosity begins with simple questions—like whether fruit flies prefer certain fruits—and how these questions lead us to rethink definitions we take for granted.
The discussion bridged botany, zoology, and environmental science, revealing how classroom knowledge and citizen science can come alive through experiments conducted in everyday settings like hostel rooms!
Photographs during Chatshaala
Reference