Noctuid larvae

The adverse effects of PPO on noctuid larvae result from reduced bioavailability of amino acids caused by the covalent binding of oxidized chlorogenic acid to protein. When dietary protein (casein) was treated with PPO and chlorogenic acid, a substantial reduction in in vitro protein digestibility occurred. This reduction in digestibility may result from alkylation of lysine and/or protein cross-linking, which may impair the ability of the insect s trypsin to hydrolyze the protein. 

Speare AT. Further studies of Sorosporella uvella, a fungous parasite of noctuid larvae. J Agric Res 18 399-439, 1920b. 

PPO, POD, and LOX activities are immediately released when noctuid larvae masticate foliage. Depending upon substrate availability, these activities persist in the gut during digestion, and often persist in the faeces (79 unpubl. data). The pH-activity profiles of these enzymes permit their action in the basic environment of the digestive fluid. PPO and POD are resistant to inactivation by a variety of proteases (e.g., insect and bovine trypsin and chymotr3rpsin, cathepsin, pepsin, and pronase)(79 unpubl. data). This extensive action provides the appropriate time frame for significant depreciation of nutritional quality by the above mechanisms. 

Critical Complications in the Use of Oxidative Enzymes as Bases of Resistance against Noctuid Larvae... 

Our knowledge of how to most effectively utilize PPO, POD, and LOX as antinutritive bases of resistance against noctuid larvae is insufficient. A number of other critical enzymatic and chemical... 

Insects also require an exogenous source of phytosterols (27). The glycoalkaloid tomatine is an effective precipitator of certain phytosterols such as sitosterol and cholesterol, and as such may provide a means of reducing sterol intake for noctuid larvae (97). 

The feasibility of using these antinutritive plant systems as multiple-factor/multiple-mechanism resistance against noctuid larvae remains to be determined. It is possible that such a multiple onslaught against nutrient acquisition is redundant. In other words, perhaps merely the use of PPO and chlorogenic acid is sufficient. It also remains to be determined whether this proposed multiple-factor/multiple-mechanism of resistance renders the insects detoxicative systems more susceptible to traditional control tactics, and whether the evolution of resistance to such multiple antinutritive factors is more difficult than to insecticides. 

After 24 hours, the non-cyclic CLOTHI 8 represented even 90 % and the cyclic ring systems A-desmethyl THIAM 9, and THIAM 6 only 5 % each, suggesting either metabolic break-down or ftister elimination of THIAM 6 compared to CLOTHI 8. The veiy same experiments using S pg THIAM 6 revealed similar results as shown before. The data obtained provided strong evidence that the parent THIAM 6 is not only rapidly metabolized in plants but also (within minutes) converted to CLOTHI 8 in noctuid larvae. 

Tachinids parasitize winter moth caterpillars, codling moth caterpillars, noctuid moths, small ermine moths, beetle larvae. 

Larvae the larvae of the noctuid moths have the same number of thoracic legs and abdominal feet as the tortrix caterpillars, but their head is rounded and the mouth parts point downwards. When the caterpillar is disturbed it curls up in a C shape. 

Diafenthiuron has a useful spectrum of activity that cannot be found in insecticides of other chemical classes at the recommended rate of 300-400 g-a.i. ha [60] it controls not only the important sucking insect complex of cotton, especially the cotton whitefly, cotton aphid, cotton leafhoppers, but also tetranychid and tarsonemid mites and young larvae of noctuids [61]. 

Euplectrus sp. are naturally gregarious ectoparasitoids that develop on noctuid and geometrid larvae (137-139). Euplectrus puttleri and Euplectrus kuwanae are host specific (140, 141). In contrast, Euplectrus plathypenae has several lepidopteran host species (142, 143). All three species arrest the development of their hosts. Recent studies have shown that Euplectrus comstockii also arrests the development of it s hosts (Coudron, T. A., USDA,... 

Hirai, K. (1982) Directional flow of male scent released by Pseudaletia separata Walker and its repellent effect on adults and larvae of four noctuid and one phycitine moth. /. Chem. Ecol., 8, 1263-70. 

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