Wright Cynthia R, Setzer William N
Nat Prod Commun. 2014 Aug;9(8):1185-92.
Drosophila mojavensis wrigleyi and D. mojavensis sonorensis are geographically separated races of cactophilic fruit flies. D. mojavensis sonorensis inhabits the Sonoran Desert and utilizes necrotic rots of Stenocereus thurberi Engelm. as a food source and to oviposit while D. mojavensis wrigleyi inhabits Santa Catalina Island, California and utilizes the necrotic rots of Opuntia littoralis (Engelm.) Cockerell. The objectives of this study were to determine the volatile compositions of the necrotic cacti and to determine if the volatile components show either selective toxicity or attraction toward the fruit flies. The volatile chemical compositions of field-rot specimens of both necrotic cacti were obtained by dynamic headspace (purge-and-trap) and hydrodistillation techniques and analyzed by gas chromatography - mass spectrometry. The volatile fraction of necrotic S. thurberi early rot was dominated by carboxylic acids (84.8%) and the late rot by p-cresol (32.6% in the dynamic headspace sample and 55.9% in the hydrodistilled sample). O. littoralis volatiles were dominated by carboxylic acids (86% in the dynamic headspace sample and 89.1% in the hydrodistilled sample). Fifteen compounds that were identified in the necrotic rot volatiles were used to test insecticidal activity and olfactory preference on the cactophilic Drosophila species, as well as D. melanogaster. Differences in toxicity and olfactory preference were observed between the different taxa. Both races of D. mojavensis exhibited toxicity to benzaldehyde and 2-nonanone, while butanoic acid and palmitic acid were tolerated at high concentrations. D. m. wrigleyi demonstrated a greater olfactory preference for anisole, butanoic acid, 2-heptanone, and palmitic acid than did D. m. sonorensis, while D. m. sonorensis demonstrated a greater preference for hexadecane, octanoic acid, and oleic acid than did D. m. wrigleyi.
莫哈韦果蝇（Drosophila mojavensis wrigleyi）和索诺兰果蝇（D. mojavensis sonorensis）是仙人掌嗜食性果蝇在地理上相互隔离的种群。索诺兰果蝇栖息于索诺兰沙漠，以图伯氏巨人柱（Stenocereus thurberi Engelm.）的坏死腐烂部位作为食物来源并在其上产卵，而莫哈韦果蝇栖息于加利福尼亚州的圣卡塔利娜岛，以海滨仙人掌（Opuntia littoralis (Engelm.) Cockerell）的坏死腐烂部位为食。本研究的目的是确定坏死仙人掌的挥发性成分，并确定挥发性成分是否对果蝇表现出选择性毒性或吸引力。通过动态顶空（吹扫捕集）和水蒸馏技术获取两种坏死仙人掌田间腐烂样本的挥发性化学成分，并采用气相色谱 - 质谱联用仪进行分析。图伯氏巨人柱早期腐烂的挥发性成分以羧酸为主（占84.8%），晚期腐烂则以对甲酚为主（动态顶空样本中占32.6%，水蒸馏样本中占55.9%）。海滨仙人掌的挥发性成分也以羧酸为主（动态顶空样本中占86%，水蒸馏样本中占89.1%）。在坏死腐烂挥发性成分中鉴定出的15种化合物用于测试对仙人掌嗜食性果蝇以及黑腹果蝇的杀虫活性和嗅觉偏好。不同分类群之间观察到毒性和嗅觉偏好的差异。莫哈韦果蝇的两个种群对苯甲醛和2 - 壬酮均表现出毒性，而丁酸和棕榈酸在高浓度下可耐受。与索诺兰果蝇相比，莫哈韦果蝇对茴香醚、丁酸、2 - 庚酮和棕榈酸表现出更强的嗅觉偏好，而索诺兰果蝇对十六烷、辛酸和油酸的偏好则强于莫哈韦果蝇。
