【目的】 红棕象甲Rhynchophorus ferrugineus是世界范围内棕榈种植区最具毁灭性的入侵害虫之一。在红棕象甲饲养过程中，发现幼虫取食的甘蔗上较少发生微生物滋长, 推测幼虫取食的分泌物具有抑制微生物生长的作用。本文测定了取食分泌物对几种细菌和真菌的抑制活性。【方法】 利用无菌水萃取幼虫取食过的甘蔗作为处理组，并以无菌水萃取幼虫未取食过的甘蔗作为对照进行抑菌试验，测试了幼虫取食分泌物对4种细菌的生长抑制活性和2种真菌孢子萌发抑制活性，同时测定了蛋白酶K以及热处理后对幼虫取食分泌物抑菌活性的影响。此外，还测定了幼虫体表分泌物和排泄物的抑菌活性明确抑菌分泌物的来源。【结果】 幼虫取食过的甘蔗萃取液相比对照对大肠杆菌Escherichia coli、金黄色葡萄球菌Staphylococcus aureus、苏云金芽孢杆菌Bacillus thuringiensis的生长都有极强的抑制作用（P<0.000 1），且能够抑制95%以上的球孢白僵菌Beauveria bassiana和金龟子绿僵菌Metarhizium anisopliae的孢子萌发（P<0.000 1），但对粘质沙雷氏菌Serratia marcescens的抑制作用不显著（P>0.05）。对萃取液分别进行蛋白酶K和高温处理（100 ℃）后，取食分泌物的抑菌活性仍然没有减弱，说明分泌物中的抗菌物质不是蛋白质或者多肽，具有较强的热稳定性。幼虫体表分泌物和排泄物不仅对大肠杆菌和金黄色葡萄球菌的生长没有抑制作用，反而促进了这2种细菌的生长，说明抗菌物质可能是幼虫取食过程中分泌至食物中的。【结论】 红棕象甲幼虫在取食过程中分泌抗菌物质到食物中，可以有效抑制微生物的生长，且抗菌活性表现出较强的稳定性，从而保证食物和生存环境的安全。本研究丰富了昆虫应对环境病原微生物的外部防御策略，也为开发昆虫源的抗微生物药物奠定了基础。

 [Aim]  To clarify the antimicrobial properties of the feeding secretions of red palm weevil, Rhynchophorus ferrugineus, larvae, and assess the effect of these secretions on various bacteria and fungi. [Methods]  The effects of aqueous extracts of sugarcane that had been consumed by R. ferrugineus larvae on four bacteria, and two fungi, species, and on the germination of fungal spores, were compared to those of freshly squeezed sugarcane juice. In addition, the effects of proteinase K and heat treatment on the antimicrobial activity of larval feeding secretions were determined. Finally, the antimicrobial activity of larval body surface secretions and excretions was tested to clarify the source of antimicrobial activity. [Results]  Compared to the control, sugarcane extract that had been consumed by larvae strongly inhibited the growth of Escherichia coli, Staphylococcus aureus, and Bacillus thuringiensis (P<0.000 1), and suppressed the germination of > 95% of Beauveria bassiana and Metarsiana anisopliae spores (P<0.000 1). However, it had no significant inhibitory effect on Serratia marcescens (P>0.05). Treatment with proteinase K and high temperature (100 ℃) did not affect the antimicrobial activity of larval feeding secretions, indicating that the active antimicrobial substances are not proteins or peptides. Larval body surface secretions and excretions not only did not inhibit the growth of E. coli and S. aureus, but promoted the growth of these two bacteria, indicating that the active antibacterial substances are probably secreted into the food during feeding. [Conclusion]  R. ferrugineus larvae secrete antimicrobial substances into food during ingestion that can effectively inhibit the growth of microorganisms. The antimicrobial compounds responsible have strong thermal stability. These results improve understanding of the strategies insects use to defend themselves against environmental pathogens, and lay a foundation for the development of insect-derived antimicrobial drugs.