Yellow-striped scarab

The yellow-striped scarab (Bolax flavolineata) is a significant agricultural pest belonging to the family Scarabaeidae. Recognized for its impact on various crops, this beetle species is a subject of concern for agronomists, particularly in tropical and subtropical regions where environmental conditions favor its proliferation and high reproductive rates.

The host range of Bolax flavolineata is relatively broad, encompassing both industrial and horticultural crops. Sugar cane, maize, and various leguminous species are frequently documented as targets. The pest affects both the subterranean parts of the plants via larval feeding and the aerial parts through the consumption of leaves by adult beetles.

Regarding its biology, the beetle undergoes complete metamorphosis. Females deposit eggs in moist soil rich in organic matter. Upon hatching, the larvae reside in the rhizosphere, where they graze on lateral and primary roots. After completing three larval instars, they transition into the pupal stage within a protected earthen cell, eventually emerging as adults to complete the cycle.

Damage caused by this insect is cumulative and often insidious. Larval root feeding significantly reduces the hydraulic conductivity of the root system, leading to wilting, stunted growth, and death of the host plant. Aerial damage by adults, while often less lethal, causes significant defoliation and can serve as an entry point for various plant pathogens.

Management strategies must prioritize an integrated pest management (IPM) approach to minimize chemical reliance. Key actions include:

• Utilizing pheromone or light traps to monitor and suppress adult population density.
• Applying microbial control agents like Metarhizium anisopliae to target soil-dwelling larvae.
• Implementing cultural practices such as timely cultivation and crop rotation to disrupt larval development.
• Applying systemic soil insecticides in high-risk areas during periods of peak oviposition.