Biosynthesis and chemical mimicry of cuticular hydrocarbons from the obligate predator, Microdon albicomatus Novak (Diptera: Syrphidae) and its ant prey, Myrmica incompleta Provancher (Hymenoptera: Formicidae).

摘要: The cuticular hydrocarbons of larval Microdon albicomatus, a predatory syrphid fly, are qualitatively identical to those its prey, the pupae myrmicine ant, Myrmica incompleta. Eighteen hydrocarbon components were identified, including n-al kanes, 3-methyl alkanes, 11and 13-methyl single dimethyl alkane (5,17-di methyl pentacosane) and two Z-9-monoenes (23:1 25:1). worker M. incompleta also identified shown contain same as ant pupae, but in different relative abundances. A radiolabelling experiment using 1 14C-acetate with larvae indicated that fly biosynthesizes rather than procuring them from prey. Although most social insects maintain closed society excludes all their own conspecific colony members (Wilson, 1971), there numerous ex amples which inquilines have more or less successfully integrated themselves into life (Kistner, 1979). exact mechanism by they achieve this integration has long been subject interest, current thought implicates primarily chemical stimuli (Howard Blomquist, 1982; Stowe, 1988). Cuticular postulated be major class involved, hypothesized function process mimicry et al., 1978, 1980, 1982, 1982a, 1990; Bonavita-Couggourdan 1987; Vander Meer Wojcik, 1982). Most literature on deals highly host-specific termitophiles mutualistic rela tionship hosts. Since it species-specific profiles 1988) evolutionary pathway these termito philes would seem relatively straightforward. Compared termitophiles, however, myrmecophiles rarely at species level often not even generic level. Furthermore, many mutualists, either parasites predators hosts How hosts' could evolve systems is clear. Indeed, noted Howard al. (1990) some reportedly utilizing (Vander 1989) likely camouflage instead (that is, USDA-ARS, U.S. Grain Marketing Research Laboratory, 1515 College Avenue, Manhattan, KS 66502. Author whom reprint requests should submitted. 2 Department Entomology, 202 Plant Industry Building, University Nebraska-East Campus, Lincoln, NE 68583-0816. 3 Washington State University, Pullman, WA 99164-6432. Accepted for publication May 1990. This content downloaded 157.55.39.17 Thu, 01 Sep 2016 05:08:52 UTC All use http://about.jstor.org/terms 438 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY de novo biosynthesizing requisite hydrocarbons, passively acquiring hosts). Larvae known genus nests insects, North American live ants (Wheeler, 1908; Akre 1990). Biologies only few detail, every case immatures obligate brood (Van Pelt Van Pelt, 1972; Duffield, 1981; Garnett 1985; Host workers, attack apparently perceived brood. We earlier reported piperi Knab, common western possesses exactly principal host, Camponotus modoc Wheeler, we was bona fide In study, unable conduct any biosynthesis experiments directly demonstrate produced host. now report second associated an subfamily contains radiola belling data shows thus pro viding strong support camouflage. Materials Methods insects: Second third instars albicomatus Novak workers Provancher collected fallen log about 1000 m elevation Latah Co., Idaho July 1989 transported back laboratory vials containing small amount moistened plaster-of-paris/ charcoal mixture. Moist wood debris collection site added provide substrate. Insects used within weeks bio analyses. sample host preserved 70% ethanol, voucher specimens deposited T. James Insect Col lection Washington. analyses: killed freezing lipids tracted immersing three successive portions hexane one minute each time. our previous studies had individual quantities hydrocarbon, extraction 93 sample; brood, replicate samples five used, 15 individuals used. combined concentrated under gentle stream N2, isolated chromatography 3-cm "minicolumn" Biosil (Bio-Rad Laboratories, Richmond, California)4 described 1978). Mass spectral analyses conducted Hewlett-Packard 5790A GC 10 0.19 mm I.D. DB-5 bonded phase capillary column (J W Scientific, Folsom, California) connected 5970 Selective Detector (MSD) 9133 Data System. Ultrapure 4 article reports results research only. Mention proprietary product does constitute endorsement recommendation USDA. VOLUME 63, NUMBER 439 helium carrier gas, head pressure 3.5 kg/cm2 electron impact mass spectra obtained 70 eV. Analyses done temper ature programming, initial temperature 200?C, final 320?C program rate 5?C/minute. Signals MSD stored peak areas total ion trace extracted percent composition Retention times component equivalent chain length (ECL) values comparison n-alkane standards Individual char acteristic EI-MS fragmentation patterns (Jackson 1976; Nelson, Double bond locations alkenes preparing dithiomethyl ethers (Francis Veland, 1981) examining spectra. Stereochemistry parent alkene inferred retention time standards. INCORPORATION RADIOACTIVE ACETATE INTO CUTICULAR HYDROCARBONS albicomatus: l-14C-acetate, specific activity 40-60 mCi/mmole (Amersham Inc., Arlington Heights, Illinois) made up 100% ethanol 7.5 ixCi/ixl. Two replicates 14 second/third M placed tissue grinders insect saline solution, ?? l-14C-acetate added, homogenized medium speed 30 seconds, then incubated 23?C minutes method Bligh Dyer (1959). lipid extracts dried applied 0.25 silica gel thin layer Chromatographie plate (Aldrich, Milwaukee, Wisconsin). developed petroleum ether:ethyl ether:acetic acid (80:20:1, v/v) classes recognized co-chroma tographed (Sigma Chemical St. Louis, Missouri). hydro carbon band scraped liquid scintillation vial radioactivity assayed counting Pharmacia-LKB 1209 Liquid Scin tillation Counter (Gaithersburg, Maryland) equipped chemiluminescence discrimination 96% efficiency 14C.