Submitted to: Comparative Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 18, 1998
Publication Date: N/A
Interpretive Summary: Very long-chain dimethyl-branched primary alcohols (VLDMA; C36-C54) and their acetate esters were characterized in the internal lipids of developing mid-stage pupae of two Coleoptera species; the boll weevil, Anthonomus grandis and the sunflower stem weevil, Cylindrocopturus adspersus, and of two Diptera species; the screwworm, Cochliomyia hominivorax, and the house fly, Musca domestica. The major component was 26,38-dimethylpentacontanol in the boll weevil, 28,38-dimethylpentacontanol in the sunflower stem weevil, and 26,36-dimethyloctatetracontanol in both the screwworm and house fly. These alcohols were 6-10 carbons longer than similar alcohols reported for Lepidoptera. No terminally-branched or trimethyl-branched alcohols similar to those characterized in Lepidoptera were detected.
Technical Abstract: We had previously characterized, for the first time, very long-chain methyl-branched alcohols (VLMA) and their acetate esters, with carbon chain lengths from 36 to over 48, during metamorphosis in pupae (developing pupae; pharate adults = formation of the adult form of the insect) of agricultural pests representative of major lepidopteran pests on crops throughout the U.S.: the cabbage looper, Trichoplusia ni, the tobacco hornworm Manduca sexta, the southern armyworm Spodoptera eridania, the banded sunflower moth Cochylis hospes, the southwestern corn borer Diatraea grandiosella, the sunflower moth Homoeosoma electellum, the corn earworm Helicoverpa zea and the tobacco budworm Heliothis virescens. No other reports of these novel compounds have appeared. We now show that similar VLMA, but of longer chain-length, are present in developing pupae of Coleoptera and Diptera. Our unpublished results show that diapause prevents the biosynthesis of the VLMA further tieing their presence to som unknown function in metamorphosis. The biological function and fate of these alcohols, unique at least to insects which have complete metamorphosis, remains unknown. However, their rapid synthesis and buildup during metamorphosis suggests a unique and essential role in the formation of the adult form of the insect. Other orders of insects which do not have complete metamorphosis have not yet been studied.