Spinosyn D is a member of the spinosyn family of insecticides, derived from the fermentation of the soil actinomycete Saccharopolyspora spinosa with DT50 value of 14.5 days when incubated aerobically in moist soil[1]. Spinosyn D is a minor component of commercial insecticide spinosad,along with its more abundant counterpart Spinosyn A[2].
In vivo, [14C]Spinosyn D was orally administrated into (25mg/day) goats for 3 days by capsule. Within 24 hours of the last dose, 20% for Spinosyn D was found in the tissues and milk - predominantly the fat, and excretion of the 14C was mainly via the faeces, 76% from Spinosyn D were found in excreta and intestine. 0.94mg [14C]Spinosyn D was dosed orally by capsule to 10 Leghorn laying hens, each weighing 1.4kg, daily for 5 days. Within 24 hours of the last dose, for Spinosyn D approximately 82% of the applied 14C was accounted for (78% in the excreta, 0.6% in eggs, 0.8% in fat, 1.2% in liver, 0.5% in muscle and 0.2% in kidney)[3]. The persistence and residual toxicity of Spinosyn D was evaluated on tomato foliage. Initial residues were 59.12mg/g when applied at 100% maximum field registered concentration (MFRC) (720mg/L active ingredient) and 45.88mg/g at 50% MFRC. After 40 days, residues decreased to 20.71mg/g and 15.39mg/g, respectively. Spinosyn D caused less 10% mortality in E. varians adults within 10 days of exposure to treated tomato leaves, with no mortality from older residues[4].
References:
[1] Saunders DG, Bret BL. Fate of spinosad in the environment. Down to Earth.1997.52: 14–20.
[2] Zhao C, Huang Y, Guo C, et al. Heterologous Expression of Spinosyn Biosynthetic Gene Cluster in Streptomyces Species Is Dependent on the Expression of Rhamnose Biosynthesis Genes. J Mol Microbiol Biotechnol. 2017;27(3):190-198.
[3] Kirst H A. The spinosyn family of insecticides: realizing the potential of natural products research. J Antibiot (Tokyo). 2010 Mar;63(3):101-11.
[4] Morales S, Martínez A M, Figueroa J I, et al. Foliar persistence and residual activity of four insecticides of different mode of action on the predator Engytatus varians (Hemiptera: Miridae). Chemosphere. 2019 Nov:235:76-83.