Toxicity, metabolism and distribution of lindane in lepidopterous larvae

1. Lindane was generally more toxic when ingested than when applied topically to similar sized larvae of Mamestra brassicae (L) (4th-instar), Spodoptera littoralis (Boisd) (4th-instar), Pieris brassicae (L) (3rd-instar), and Bombyx mori (L) (2nd-instar).

2. In vivo metabolism of ingested ¹⁴C-lindane decreased in order of S. littoralis > P. brassicae > B. mori (based on the recovery of metabolised ¹⁴C-lindane form the larva and frass) and followed the order of increasing susceptibility.

3. ¹⁴C-lindane was regurgitated after ingestion; its effects on insecticidal action are discussed.

4. The causes of variation in interspecies susceptibility with particular reference to concepts of resistance as influenced by polyphagy versus monophagy are discussed.