Lepidopteran larvae

Barbehenn R (2001) Roles of peritrophic membranes in protecting herbivorous insects from ingested plant allelochemicals. Arch Insect Biochem Physiol 47 86-99 Barbehenn RV, Martin MM (1998) Formation of insoluble and colloidally dispersed tannic acid complexes in the midgut fluid ofManduca sexta (Lepidoptera Sphingidae) an explanation for the failure of tannic acid to cross the peritrophic envelopes of lepidopteran larvae. Arch Insect Biochem Physiol 39 109-117... 

The second example, the selective effects of BT toxin on lepidopteran larvae and its use as a commercial product, is well known (9). However, the endogenous incorporation of the genes for expressing this toxin (10) into a crop plant would obviate the wasteful topical application of the commercial product. This bioengineering feat of transferring the allelopathic defense mechanism of one type of organism (bacteria) to another (plants) would be a great scientific achievement and commercial success. 

Lepidopteran larvae, UK, 1979 Near roadway Control site... 

Plant parts other than seeds have been less well studied and little attention has been placed on insecticidal modes of action of the defenses of the neotropical Meliaceae. Our study of the insect growth-reducing activity of 50 extracts of bark, leaf and wood of Central American Meliaceae showed the potent effect of these extracts against lepidopteran larvae and the potential for isolation of bioactive compounds from alarge number of these species. Extracts from the genera Trichilia and Cedrela (Xie etal., 1994 Ewete etal., 1996a Wheeler etal., 2001) show exceptional activity. Trichilia americana extracts have strong antifeedant activity to Spodoptera... 

Xie, S. Gunning, P, Mackinnon, S. et al. (1994). Biological activity of extracts of Trichilia species and the limonoid hirtin against lepidopteran larvae. Biochemical Systematics and Ecology 22 129-136. 

If not otherwise indicated the hosts or prey are lepidopteran larvae. B, behavioral evidence C, chemical evidence. 

Konno, K., Hirayama, C., and Shinbo, H., Unusually high concentration of free glycine in the midgut content of the silkworm, Bombyx mori, and other lepidopteran larvae, Comp. Biochem. Physiol., 115A, 229, 1996. 

Control of lepidopteran larvae in rice, fruit, vegetables, tea, cotton, beans, and forestry... 

Some lepidopteran larvae such as Helicoverpa zea and P. xylostella adapt themselves to plant Pis by changing digestive midgut proteinases from Pi-sensitive ones to Pi-insensitive ones when they are fed Pi-containing diets.83... 

Wing, K. D., Andaloro, J.T., McCann, S.F., and Salgado, V.L., A novel oxadiazine insecticide is bioactivated in lepidopteran larvae, Arch. Insect Biochem. Physiol., 37, 91,1998. 

Crystal solubilization is facilitated by an alkaline pH of susceptible insects. The typical midgut pH is between pH 9-11 in lepidopteran larvae [37-39]. In mosquito larvae, the pH inside the posterior midgut/gastric caeca is between 7-8, while the pH inside the anterior midgut is close to 11 [40]. Thus alkaline buffers are usually used for in vitro solubilization of lepidopteran and dipteran active B. thuringiensis crystals. Differential crystal solubility can be useful in partial separation of toxins. For example, CrylA toxins are fully soluble at pH 9.5, while the Cry2 proteins require a pH of 12 for complete solubilization [41]. Moreover, pH has different effects on Cry toxin pore-formation activities [42], and differences in the level of solubilization can contribute to toxicity differences... 

Toxicity to house fly is obviously quite good. Moderate efficacy is demonstrated against the corn rootworm beetles and mosquito larvae. For an insecticide of the prolan/DDT class, the potency demonstrated against the wild strain German cockroach is quite remarkable. Preliminary tests on the larval stage corn rootworm revealed soil activity of a monochloro compound, unlike most previously reported chemicals in this class. Overall, the spectrum of activity is quite broad, although other categories of insect pests must still be tested (e.g., lepidopteran larvae). 

Mrozik et al. [23] have identified a series of novel 4"-amino-4"-deoxyavermect-ins with excellent insecticidal activity. The most effective members of this class are 12 and 13 which show 1,500 fold higher activity than avermectin (abamectin) against beet armyworm, Spodoptera exigua and other lepidopteran larvae. 

Most B.t. strains are selectively toxic towards a variety of lepidopteran larvae. One B.t. subspecies, called israelensis. is highly toxic to dipteran larvae (2J. and is used for the control of mosquitoes and blackflies. Recently, a B,t. subspecies tenebrionis. expressing toxicity towards Coleoptera, has been isolated (3). 

Generally, it is not clear what kind of adaptive benefit S. americana and other insects derive by producing fatty acid conjugates such as the caeliferins or volicitin. Recent work by Mori et al. suggests that Af-acyl glutamines may play a role in nitrogen assimilation among Lepidopteran larvae. ... 

Hywel-Jones NL. Cordyceps khaoyaiensis and C. pseudomilitaris, two new pathogens of lepidopteran larvae from Thailand. Mycol Res. 98 939-942, 1994. 

Drimenol (53) can be produced from drimenyl pyrophosphate by fermentation processes, and can then be converted by inexpensive processes to antifeedants such as warburganal (55) and 9-hydroxydrimenal (57) (Scheme 3). The latter is a synthetic drimane which is a potent antifeedant against lepidopteran larvae [92]. 

BOWN, D.P., WILKINSON, H.S., GATEHOUSE, J.A., Regulation of expression of genes encoding digestive proteases in the gut of a polyphagous lepidopteran larva in response to dietary protease inhibitors. Physiol. Entomol, 2004, 29, 278-290. 

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