A simplified laboratory rearing system for Aulacaspis yasumatsui Takagi (Hemiptera: Diaspididae) using detached Cycas revoluta leaf fragments

The cycad aulacaspis scale, Aulacaspis yasumatsui Takagi (Hemiptera: Diaspididae), is an invasive armored scale insect that causes severe cycad mortality worldwide. However, safe, contained, and reproducible laboratory rearing systems for this species remain limited. We developed a simplified rearing method using detached Cycas revoluta leaf fragments inserted into standard 15 mL centrifuge tubes. Leaf longevity was assessed under various cutting and hydration treatments, and the most effective approach—longitudinally splitting the midrib and maintaining fragments in distilled water—was incorporated into the final system. The optimized method preserved leaf viability for at least 63 days, sufficient for complete A. yasumatsui development. Survival from the second instar to adult emergence was 69% and 100% in females and males, respectively, with mean egg hatchability reaching 96%. Although fecundity on leaf fragments was lower than that reported for whole-plant systems, the developed method consistently supported successive generations under controlled conditions. This simplified system provides a practical, low-risk platform for biological studies and evaluation of biological and chemical control agents without the hazards of maintaining whole cycad plants.