Manduca sexta larvae

Kanost MR, Zepp MK, Ladendorff NE, Andersson LA 1994 Isolation and characterization of a hemocyte aggregation inhibitor from hemolymph of Manduca sexta larvae. Arch Insect Biochem Physiol 27 123—136... 

Yun H. K., Jouni Z. E. and Wells M. A. (2002) Characterization of cholesterol transport from midgut to fat body in Manduca sexta larvae. Insect Biochem. Molec. Biol. 32, 1151-1158. 

Long-carbon-chain secondary alcohols (.ver-alkanols) are not common constituents of insect cuticular lipids (Buckner, 1993). Espelie and Bemays (1989) reported that the cuticular lipids of Manduca sexta larvae reared on tomato or potato foliage contained... 

Espelie, K.E. and Bemays, E. A. (1989). Diet-related differences in the cuticular lipids of Manduca sexta larvae.J. Chem. Ecol., 15,2003-2017. 

Animals. Manduca sexta larvae were reared on an agar-based diet (11) at 28 C and 60% relative humidity with a 16-h photophase. The Indian meal moth, Plodia interpunctella Hubner, and American cockroach, Periplaneta americana L., were taken from laboratory cultures. Dissection was performed under anesthesia by cooling to 5°C (12). 

Figure 1. Antifeeding effects of para-octopamine versus meta-octopamine (a positional isomer with little activity as an agonist of insect adenylate cyclase), when sprayed on tomato leaves which were then fed to first instar Manduca sexta larvae.

Proteinase By a search (Google) on the Internet, inserting the term proteinase inhibitor tobacco provides numerous references to it, including the following Johnson, R., J Narvaez, G. An, and C Ryan Expression of proteinase inhibitors I and II in transgenic tobacco plants effects on natural defense against Manduca sexta larvae Proc. Natl. Acad. Sci. U.S.A. 86 (1989) 9871-9875. A search for other proteinases provides similar references. 

Lepidopteran larvae exposed to anthranilic diamides exhibit rapid feeding cessation, general lethargy, constrictive muscle paralysis, and regurgitation. One of the earliest symptoms observed was reduction in heart rate. Manduca sexta larvae showed greater than a 50% decrease in heart beat frequency ten minutes following injection with Rynaxypyr (30 ng). Among anthranilic diamides evaluated, similar rank potency was found for this cardio-inhibitory effect and lepidopteran toxicity. 

Lepidopteran larvae exposed to anthranilamides exhibit rapid feeding cessation, general lethargy, and partial paralysis. Further, dorsal vessel (heart) studies with DP-012, revealed a rapid cardio-inhibitoiy effect in Manduca sexta larvae. Contraction frequency was attenuated in a dose-dependent manor with injection of 3 ng/g (body weight) attenuating the contraction by 27%. As shown in Table II, the rank potency for anthranilamides is comparable to its lepidopteran toxicity with DP-012 > DP-010 > DP-002. 

Dahl et al. demonstrated that the release of methanol dramatically increases and can be substantially greater than the release of -2-hexenal when Manduca sexta larvae attacks Nicotiana attenuata plants [54]. Similar results were also obtained during monitoring VOCs induced by Euphydryas aurinia caterpillars feeding on Succisa pratemis leaves [55]. The emission of ethanol, acetaldehyde, acetic acid, ethyl acetate, 2-butanone, 23,-butanedione, and acetone from Arabidopsis roots has been identified by both PTR-MS and GC-MS [56]. The rapid release of 1,8-cineole and a monoterpene was demonstrated after compatible interactions of Pseudomonas syringae DC3000 and Diuraphis noxia with roots. But mechanical injuries to roots did not release any wound-induced VOCs, and the VOCs released were basically the same for the infected and noninfected roots. 

Jassbi AR, Zamanizadehnajari S, Kessler D, Baldwin IT (2006) A new acyclic diterpene glycoside from Nicotiana attenuata with a mild deterrent effect on feeding Manduca sexta larvae. Z Naturforsch 61b 1138 1142... 

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. 

Examples of Type 1 include Manduca sexta, whose larvae live on Nicotiana and other solanaceous plants. The alkaloids present in these plants, such as nicotine or hyoscyamine, are not stored but are degraded or directly eliminated with the feces (182). In addition, it has been postulated that nicotine may either not diffuse into nerve cells or that the acetylcholine recpetor no longer binds nicotine as in normal animals... 

EH was initially identified as a circulating neuropeptide that was thought to act back on the CNS to trigger ecdysis behaviors. In pharate adult Manduca sexta. large amounts of EH accumulate in the CC-CA complex prior to ecdysis and are released into the hemolymph late in the molt. A set of laterd brain neurosecretory cells (NSCs) that projected to the CC-CA were found to contain EH-like activity CLL). It was clear, however, that these cells were not responsible for EH release in larvae or pupae since in these stages release of the hormone comes from the ventral nervous system Q). The recent discovery of the cells responsible for this release has prompted a re-evaluation of the route by which EH triggers ecdysis. 

Figure 1. Clearance of L-canavanine and L-canaline from insect hemolymph. Clearance was determined by automated amino acid analysis involving a single sample for each time point using the pooled hemolymph of five larvae. The administered dose to H. virescens was 5 mg L-canavanine/g fresh body weight ( ) or 3.8 mg L-canaline/g fresh body weight ( ). Manduca sexta received 1 mg L-canavanine/g fresh body weight ( ). Redrawn from (17).

Manduca sexta and Leptinotarsa decemllneata. For 2-trldecanone to be effective as a resistance mechanism, larvae on the resistant plant must be exposed to lethal quantities of the toxin. The role... 

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