Identifying and monitoring emerging cicada pests and their parasitoids in <i>Acacia crassicarpa</i> plantations in Sumatra for sustainable control

Abstract The non‐periodical cicadas (Hemiptera: Cicadidae) are emerging pests of young Acacia crassicarpa (Fabaceae) plants, especially in Sumatra, Indonesia. We studied non‐periodical cicadas and their parasitoids in A. crassicarpa plantations aiming to develop new sustainable control methods. The monitoring of non‐periodical cicadas and the parasitism rate by a cicada parasitoid recovered in the field and on an orthopteran alternative host were evaluated. The total percentage of viable cicada eggs (i.e., originated cicada nymphs) recovered and the average diameter of twigs damaged by cicadas were calculated. Dundubia spiculata was the most numerous cicada species collected and the parasitoid Megaselia scalaris (Diptera: Phoridae) was recovered from a group of cicada species collected in the field. Non‐periodical cicadas laid eggs on lateral and leader twigs of A. crassicarpa which, infested with eggs, dried and died due to the blockage of vascular tissues. Cicada eggs were also found on Pometia pinnata (Sapindaceae) trees. Damage by non‐periodical cicadas was higher on stands with 3‐month‐old plants in the first monitoring (first week of December 2019) and similar on those with 2‐, 3‐, and 4‐month‐old plants in the second (first week of January 2020). The number of plants monitored per hour was higher in stands with younger plants in the first and second monitoring. The area monitored in hectares decreased as the age of host plants ( A. crassicarpa ) increased, while the number of infested twigs collected increased with the stand age. More than one oviposition mark was found per plant. A phorid fly fully accepted and parasitized all orthopteran individuals offered. The identification and monitoring of cicadas and their natural enemies in A. crassicarpa plantations in Sumatra contribute to sustainable control methods.