Effects of pesticides on Apis cerana from passion fruit in Hainan island

The passion fruit not only has ornamental and edible value but also possesses certain medicinal properties, making it a highly popular tropical fruit. The use of pesticides during its cultivation, the quality and safety of the product, and its impact on wild insects in the ecological environment have always been topics of great concern to consumers. In this study, samples were collected from eight different regions of Hainan Island, including seven types of samples from passion fruit orchards and residual detection was conducted on 12 chemicals. The results showed that the pesticide detection rate of 12 chemicals ranged from 1.41% to 70.59%. Baoting region had the highest total pesticide detection rate (63.16%), with the highest detection rate of thiamethoxam residues, particularly during the first survey period (Time Point 1) (54.5%). The total pesticide detection rate was highest in passion fruit leaves, especially pyraclostrobin in the Time Point 1 (77.5%). Thiamethoxam residues were detected in all sample tissues, but no pesticide residues were detected in honey, and fluopimomide was not detected in all samples. Furthermore, The highest rate of thiamethoxam exceedance occurred in Baoting region especially during Time Point 1 (54.55%). The dietary intake risk assessment of passion fruit and honey is acceptable. Despite this, pesticide use affected honeybee colonies, with the Wuzhishan region most affected. The acute contact toxicity to Apis cerana of the four neonicotinoid insecticides measured showed that thiamethoxam had the highest toxicity, with a 48-hour LD50 value of 0.000754 μg a.i./bee, while acetamiprid had the lowest toxicity, with a 48-hour LD50 value of 0.225195 μg a.i./bee. The toxicity of the four tested neonicotinoid insecticides to adult A. cerana worker bees was all highly toxic. Therefore, it is recommended to use pesticides rationally during the passion fruit flowering period with caution to avoid harm to A. cerana pollination. These results ensure that the fruit consumed by consumers meets food safety standards. Additionally, testing the risk of pesticides to bees can assess the potential impact of pesticide use on bee populations, thereby taking measures to protect bees and maintain ecological balance.百香果兼具观赏与食用价值，还具备一定药用功效，是广受喜爱的热带水果。其种植过程中的农药使用、产品质量安全，以及对生态环境中野生昆虫的影响，始终是消费者高度关注的议题。本研究从海南岛8个不同区域采集样本，涵盖百香果种植园的7类样品，并针对12种化学物质开展残留检测。结果显示，12种化学物质的农药检出率介于1.41%至70.59%之间。保亭区域的农药总检出率最高，达63.16%，其中噻虫嗪（thiamethoxam）残留检出率居首，尤其在首次调查阶段（时间点1）检出率达54.5%。百香果叶片的农药总检出率最高，其中时间点1的吡唑醚菌酯（pyraclostrobin）检出率达77.5%。所有样品组织中均检出噻虫嗪残留，但蜂蜜样品未检出任何农药残留，所有受试样品均未检出氟噻唑吡乙酮（fluopimomide）。此外，噻虫嗪残留超标率最高的区域仍为保亭，尤其在时间点1的超标率达54.55%。百香果与蜂蜜的膳食摄入风险评估结果处于可接受范围。尽管如此，农药使用仍对蜂群造成了影响，其中五指山区域受影响最为严重。本次测试的4种新烟碱类杀虫剂对中华蜜蜂（Apis cerana）的急性接触毒性结果显示：噻虫嗪毒性最高，48小时半数致死剂量（LD50）为0.000754 μg 有效成分/蜂；啶虫脒（acetamiprid）毒性最低，48小时LD50为0.225195 μg 有效成分/蜂。4种受试新烟碱类杀虫剂对中华蜜蜂成年工蜂均表现为高毒。因此，建议在百香果花期合理用药并保持谨慎，以避免对中华蜜蜂授粉活动造成危害。上述结果可确保消费者食用的百香果符合食品安全标准。此外，针对农药对蜜蜂的风险开展检测，可评估农药使用对蜂群的潜在影响，进而采取措施保护蜜蜂、维持生态平衡。