Tobacco hornworm. Manduca sexta

Fang N., Teal R E. A. and Tumlinson J. H. (1995) PBAN regulation of pheromone biosynthesis in female tobacco hornworm moths, Manduca sexta (L.). Arch. Insect Biochem. Physiol. 29, 35 -4. 

There emerges a very complex picture of three hormones synthesized and secreted at variable rates, competing for carrier binding proteins, presumed receptor proteins, epoxide hydratase and carboxyl esterase enzymes (35,36). It is possible experimentally to measure tEe timing of critical periods for larval determination and to measure total levels of JH at these critical periods although both measurements involve extreme difficulty. Approaches to this were described recently by G.B. Staal (3 7) using third instar larvae of the tobacco hornworm moth, Manduca sexta, which were allatectomized and raised on JH impregnated diets as an experimentally reproducible method of JH therapy. 

Insects use camouflage coloration as a means of avoiding predation. The green color of the tobacco hornworm larvae, (Manduca sexta) can be separated into constituent blue and yellow components. The water soluble blue component is the biliprotein, insecticyanin. The yellow color is derived from lipoprotein bound carotenes. This lipoprotein, lipophorin, is the major lipid transport vehicle in insect hemolymph. In addition to transporting dietary lipid, lipophorin is also involved in the transport of lipophilic insecticides. Nearly all the recovered radioactivity in hemolymph from topically applied [14c] ddt is associated with lipophorin. Lipophorin of adult M. sexta is larger, less dense and is associated with small amounts of a third, adult specific, apoprotein. Alterations in adult lipophorin density, lipid content and apoprotein stoichiometry can be caused by injection of the decapeptide, adipokinetic hormone. 

In 1985 Prestwich and Wawrzdnczyk synthesized the enantiomers of JH I (95% ee), and bioassayed their binding affinity to the JH binding protein of the tobacco hornworm moth, Manduca sexta.22 The natural (+)-JH I showed only twice the relative binding affinity as that of (—)-JH I. Despite the previous conclusion of Loew and Johnson, it was generally believed that (—)-JH I was bioactive to some extent. 

Isol. from developing embryos of the tobacco hornworm moth Manduca sexta. Part of the juvenile hormone complex essential to the devolopment of insects. Oil. [ot] +13.8° (c, 0.92 in MeOH). 1.4752. The nat. hormone is known to be (E,E) but the abs. config. of the epoxide function is currently unknown. The synthetic prod, was (10/ , 115) as shown. 

Analyses of solvent rinses of the pheromone glands from calling female tobacco hornworm moths, Manduca sexta (L.) revealed the presence of the following compounds 9 -16 AL, 11Z-16 AL, 11E-16 AL, 16 AL, 10E,12Z-16 AL, 10E,12E-16 AL, lOE,12E,14Z-16 AL, lOE,12E,14E-16 AL, 11Z-18 AL, 13Z-18 AL 18 AL and IIZ,13Z-18 AL. The two trienals (which are new compounds) were identified by mass and PMR spectral analyses and by ozonolysis. Three isomeric conjugated triene aldehydes, 10E,12 ,14Z-16 AL, 10E,12Z,14E-16 AL and 10E,12E,14E-16 AL, two of which are components of the sex pheromone, were stereoselectively synthesized. In a wind tunnel, male tobacco hornworm moths exhibited the same behaviors in response to a blend of all the synthesized components, the gland rinse, or a calling female. Both 10E,12Z-16 AL and lOE,12E,14Z-16 AL are required to stimulate males to complete the characteristic reproductive behaviors. 

The tobacco hornworm moth, Manduca sexta (L.), (Lepidoptera Sphingidae) occurs over the greater part of the United States, the West Indies, Mexico, Central America, and parts of South America. 

The 29-fluorophytosterols, members of a new class of selective pro-insecticides, have been synthesized and examined m vivo in tobacco hornworms. Dealkylation at C-24 of the steroid side chain by insects releases the latent poison fluoroacetate, resulting in dose-dependent reductions in growth rate, maximum weight, and survival when fed at 1 to 100 ppm to Manduca sexta. 

The 29-fluorophytosterols (Fig. 3) all showed significant impairment of growth and development of larval tobacco hornworms when fed at 1 to 100 ppm to Manduca sexta. It is clear that the A22 sterols and were more toxic and caused more severe... 

Cuticular diterpenes-duvanes and labdanes. Cutler have found that the cuticular diterpenes of green tobacco have both allelopathic and insect-deterrent effects (38). Present in the cuticle are duvane and/or labdane diterpenes (Figure 3) The levels of these specific cuticular components are believed to be responsible for the observed resistance of some types of tobacco to green peach aphids Myzus persicae (Sulzer), tobacco budworm Heliothis virescens (F.), and tobacco hornworm Manduca sexta (L.) (39). 

We initiated this line of research by testing isolated compounds for their effects upon two Insects, the grasshopper (Melanoplus bivitattus or 11.. sanouinipes) and the tobacco hornworm, Manduca sexta. We could thereby test for activity against adult... 

The host range of the tobacco hornworm (Manduca sexta) is limited to selected members of the family Solanaceae. In an effort to better understand the chemical basis for the host plant selection process, we have undertaken an examination of both hornworm preferred and non-preferred members of the Solanaceae. Our investigations have shown this tc be a complex system involving the subtle interaction between such behavioral modulators as (1) Ovipositional stimulants (2) Feeding stimulants and imprinters (3) Anti-feedants (A) Repel-lants (5) Insecticides. The results of these investigations will be discussed. 

Experiments conducted with the tobacco hornworm, Manduca sexta and the aquatic plant, Lemna minor are consistent in finding that canavanine does not affect whole organism ability to incorporate [ Hjleucine into trichloroacetic acid-insoluble materials (see Table I). Such determinations evaluate the balance between reactions fostering protein synthesis and those responsible for the turnover and degradation of proteins. If the treatment time is reduced to 30 min, so as to accentuate synthetic reactions over those of catabolism, the result is the same. 

The wild tomato, Lycopersicon hirsutum f, glabratum is covered with trichomes which contain 2-tridecanone. The level of this compound is much lower in the domesticated tomato, U esculentum. This exudate proved to be toxic to Manduca sexta (tobacco hornworm) and to Heliothis zea (121). The density of glandular trichomes, which secrete 2-tridecanone, was influenced... 

Rosenthal, G.A. Dahlman, D.L. Robinson, G.W. L-Arginine kinase from tobacco hornworm, Manduca sexta (L.). Purification, properties, and interaction with L-canavanine. J. Biol. Chem., 252, 3679-3683 (1977)... 

Chamberlin, M.E. Mitochondrial arginine kinase in the midgut of the tobacco hornworm (Manduca sexta). J. Exp. Biol., 200, 2789-2796 (1997)... 

Fig. 6. Induction of insect control in transgenic tobacco. The PR-L promoter was fused to the Btk gene and the construct was used to transform tobacco. Both plants are from seeds of a transformed line Bt-13. One plant was sprayed with water and the other with an inducing agent. The plants were challenged after 7 days with Manduca sexta (tobacco hornworm). Control, untransformed plants treated with the inducer do not show insect tolerance. 

Gyorgyi T. K., Roby-Shemkovitz A. J. and Lerner M. R. (1988) Characterization and cDNA cloning of the pheromone binding protein from the tobacco hornworm Manduca sexta a tissue specific, developmental regulated protein. Proc. Natl. Acad. Sci. USA 85, 9851-9855. 

JH can be inactivated by opening of the epoxide ring to a diol 45, or by hydrolysis to the free acid 47, and sometimes further by phosphorylation of the diol (Scheme 5). As the isolation and identification of enzymes involved in hormone synthesis and catabolism advances, a JH diol kinase has been isolated from the tobacco hornworm Manduca sexta that converts JH I diol into the phosphate 48.91 This enzyme is probably the first example of a phosphotransferase directly involved in the catabolism and inactivation of a lipid-soluble hormone. It was much less active in catalysing the phosphorylation of JH II or JH III diols and was inactive with the free JH acids.91... 

In foliage, the concentrations of serine proteinase inhibitors are lower than that in seeds however, the induction of serine proteinase inhibitors has been reported in many plants including tobacco and tomato, and the inhibitors have been proven to function as a plant defense system.79-81 Leaf damage by the tobacco hornworm Manduca sexta was much bigger in tomato plant line deficient in proteinase inhibitor induction than in those that can induce proteinase inhibitor on herbivory.82... 

Recent investigations have been focused on the identification of the protein-pigment complexes of insects. For example, in the tobacco hornworm, Manduca sexta, a blue biliprotein, insecticyanin, has been found in the hemolymph, epidermal cells and eggs (6). 

These compounds can be also effective antifeedants and here the glycosylation pattern is of crucial importance. Rutin [91] is a feeding stimulant to the tobacco hornworm, Manduca sexta. 

Animals. Adult male cockroaches (Periplaneta americana) were reared at 24°C and fed rat chow and water ad lib. For 24 hours prior to dissection they were isolated in individual containers. Fireflies (Photinus pyralis) were caught locally and either used immediately, or the whole insects were frozen at -80°C until use. Tobacco hornworms (Manduca sexta) were reared on an artificial diet and utilized in the 3rd or 4th day of the final larval instar. 

In addition to studying the chemical composition of fly cuticles, we have also used solid state C-NMR to measure the relative abundance of four major carbonaceous components, gravimetric analysis to determine moisture content, and ash analysis for mineral content of cuticles from three developmental stages of a single species, the tobacco hornworm, Manduca sexta (Fig. 2). There are substantial differences in composition between the larval, pupal... 

Manduca sexta (Linnaeus) tobacco hornworm larva FI, GR, T 102... 

Phalaraksh C, Lenz E M, Nicholson J K, et al. (1999). NMR spectroscopic studies on the haemolymph of the tobacco hornworm, Manduca sexta Assignment of H and NMR spectra. Insect Biochem. Molec. Biol. 29 795-805. 

Free and Conjugated Ecdysteroids in the Tobacco Hornworm, Manduca sexta, at Various Developmental Stages... 

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