Cabbage moth

By the beginning of the 1990s, houseflies, Colorado potato beetles, cockroaches, peach aphids, cabbage moths and several other insect species became insensitive to all the insecticides used. 

A unique semi synthetic pathway in which a genetically modified plant with the ability to produce moth sex pheromones precursors was used to synthesize sex pheromones of the cabbage moth. ... 

Cabbage moth, Mamestra brassica, 47, 51 Codling moth, Carpocapsa pomonella, 20 Codling moth, Laspeyresia pomonella, 303 Diamondback moth, Plutella xylostella,... 

On account of its multitude of species (worldwide around 150,000), butterflies often use a mixture of compounds with a defined composition (pheromone complexes) to secure species-specificity and exclude cross-attraction. Remarkable in this connection is the effect of (llZ)-hexadecenol on males of the cabbage moth. Whereas the corresponding acetate is the sex attractant released by the female, the corresponding free alcohol acts as an antagonist. The latter is not produced by a female moth, which is not just in the mood for mating, but by an evolutionarily related butterfly species, which in this way warns of infidelity , i.e. prevents cross-copulation. Such types of species separation are ubiquitous in the insect world. 

In a few Lepidoptera, like the silkworm moth Bombyx mori), hehothide species as the corn earworm (Helicoverpa zea) and the cabbage moth (Mamestra brassicae) it has been demonstrated that a neuronal hormone (PBAN, pheromone biosynthesis activating neuropeptide) is synthesised by a cephalic organ in their brain, dependent on the day/night rhythm. This mediator controls the sex pheromone production in these moths. [161, 170]... 

Muscalure 20, the pheromone of the housefly has been prepared from oleic acid or erucic acid, similarly (Z)-l 1-heneicosene 21, the synergist of muscalure was obtained [189]. The intermediate 22 for the pheromone of the Cabbage looper was prepared using (Z)-methyl-4-octenedioate [166bJ, that was obtained by partial ozonolysis of (Z,Z)-l,5-cyclooctadiene. Similarly disparlure 23, the sex attractant of the gypsy moth, has been synthesized by two successive crossed-couplings with (Z)-4-octene dioate [191],... 

Behavioral and Hormonal Chemicals. Sex pheromones, which attract pests to traps, are used effectively to control some insect pests, like the grape berry moth (46) and cabbage looper. With other Insect pests, sex pheromones have been effectively used to monitor the size of pest insect populations to determine when pesticide treatments should be made. 

Fig.i General biosynthetic pathways for the production of alcohol, aldehyde, and acetate ester pheromone components in female moths. Top production of saturated fatty acids. Middle production of monounsaturated fatty acids and limited chain shortening produces intermediate compounds that can be reduced to an alcohol. Aldehyde and acetate ester pheromones are produced by an oxidase and acetyl-transferase, respectively. Bottom biosynthetic pathway for the production of the acetate ester pheromone components in the cabbage looper moth, Trichoplusia ni. The CoA derivatives are reduced and acetylated to form the acetate esters. Additional pheromone components include 12 OAc and ll-12 OAc... 

Mahar AN, Jan ND, Mahar AQ, Mahar GM, Hullio MH, Lajar AG. Efficacy of entomopathogenic bacterium Photorhabdus luminescens and its metabolites against diamondback moth Plutella xylostella larvae on Chinese cabbage and artificial diet. Pak J Nematol. 2008 26 69-82. 

FIGURE 2 Pheromone structures of the American cockroach (periplanone B), the brownbanded cockroach (supellapyrone), bark beetles (ipsdienol enantiomers), and the cabbage looper moth (six acetates). 

FIGURE 3 Pheromone biosynthetic pathways commonly used in moth sex pheromone glands to produce precursors for specific blends of acetates, alcohols, or aldehydes. Cascades of precursors are produced by combinations of unique A- -desaturases and limited chain-shortening steps. The six precursors for the cabbage looper blend (Figure 2) are in boldface type. 

In contrast to pheromones that involve single complex compounds, many moth species have been found to utilize a specific blend of relatively simple fatty acid-derived compounds. It appears that the evolution of a unique enzyme, A1 desaturase, used in combination with 2-carbon chain-shortening reactions (Figure 3) has allowed moth species to produce a variety of unsaturated acetates, aldehydes, and alcohols that can be combined in almost unlimited blends to impart species specificity. For example, biosynthetic precursors for the six-component pheromone blend of acetates for the cabbage looper moth (12) (Figure 2) can be determined easily from the cascade of acyl intermediates produced by the A11-desaturase and chain-shortening reactions (Figure 3). 

From late spring onward, various moths and butterflies, such as the large cabbage white, may lay their eggs on brassica plants. The resulting caterpillars can be picked off by hand, if wasps have not removed them first. 

Many Insects have become specialists on crucifers and a few related plant families. These Include flea beetles, leaf beetles, cabbage root fly, aphids, cabbage butterflies and the dlamondback moth. At the same time, several polyphagous Insects such as the cabbage looper, armyworms and aphids are major pests of crucifers. Comparative studies on these specialists and generalists have provided valuable Information on host recognition and possible resistance mechanisms. 

---