m-Aminophenylacetylene shortened the eggsac-carrying stages in the wolf spider through enhancing the synthesis of prostaglandins.

Spiders are important predatory enemies that control a range of insect pests in the rice ecosystem. m-Aminophenylacetylene (m-A) has been demonstrated to induce maternal care behaviors in Pardosa pseudoannulata, protecting young spiders and promoting population growth. Here the roles of m-A on other reproduction stages were evaluated by injecting m-A into virgin and postreproductive female spiders. When injected into virgin females, m-A can prolong the first pulli-carrying stage of the females after mating and breeding offsprings. In postreproductive females, m-A injection shortened the eggsac-carrying stages, especially in the second and third stages. Transcriptomic analysis showed that differentially expressed genes between the control female and m-A-injected female were enriched in the arachidonic acid (AA) metabolism pathway. Real-time quantitative PCR (qPCR) confirmed the upregulation of cyclooxygenase-II (COX-II), prostaglandin E synthase 2 (PGES2), and prostaglandin E synthase 3 (PGES3) genes involved in PGE₂ (prostaglandin E₂) synthesis. In a reverse validation experiment, the sequential injection of m-A followed by a COX inhibitor aspirin restored the shortened eggsac-carrying stage to normal level. The findings indicated that m-A enhanced PGs synthesis, leading to a reduced eggsac-carrying stage. The eggsac-carrying stage can be fatal when female spiders encounter their enemies, so the shortening of the stage by m-A would reduce the potential threat. These findings are significant for developing environmentally friendly control strategies.