Larval mannitol diets increase mortality, prolong development and decrease adult body sizes in fruit flies...

Area of Science:

• Insect Physiology
• Developmental Biology
• Toxicology

Background:

• Understanding how dietary compounds affect insect development is crucial for linking growth, timing, and body size.
• High-sugar diets are known to prolong development and decrease adult body size in Drosophila melanogaster.

Purpose of the Study:

• To investigate the effects of mannitol, a polyol sweetener, on the development of Drosophila melanogaster.
• To determine if delaying mannitol exposure impacts its developmental effects, indicating a sensitive developmental period.

Main Methods:

• Larvae of Drosophila melanogaster were fed varying concentrations of mannitol.
• Developmental timing, adult body size, and mortality rates were assessed.
• The impact of delayed mannitol introduction (past the third instar) was evaluated.

Main Results:

• Increasing mannitol concentrations led to prolonged larval development and smaller adult body sizes in both male and female fruit flies.
• Mannitol exposure increased mortality in a concentration-dependent manner, with effects observed as early as 48 hours post-hatching.
• Delaying mannitol introduction by 72 hours (to the third instar) mitigated adverse effects on survival, pupariation, and eclosion.

Conclusions:

• Mannitol disrupts holometabolous insect development, similar to high-sugar diets.
• A sensitive developmental period exists for mannitol's adverse effects, as delayed exposure reduces negative outcomes.
• Dietary polyols represent a potential factor influencing insect growth and development.