Yellow mealworm

Attractive Compounds. The female-produced sex pheromone of the yellow mealworm beetle, Tenebrio molitor, is (R)-4-methyl- 1-nonanol [316] 163 (Scheme 18). Careful investigations on the biosynthesis of this compound [317] revealed that it is produced through a modification of normal fatty acid biosynthesis (Fig. 1, Fig. 2) propanoate serves as the starter, while formal chain elongation with acetate, propanoate, and acetate (accompanied by removal of the oxygens) produces 4-methylnonanoate which yields the pheromone alcohol after reduction. The structures and role of proteins that are present in the hemolymph or secreted by the tubular accessory glands of T. molitor, and that may carry lipophilic chemical messengers (like pheromones) are under investigation [318,319]. 

The sex pheromone emitted by the female yellow mealworm beetles, Tenebrio molitor L. (Coleoptera Tenebrionidae), 4-methyl-1-nonanal is well known. However, it was observed that males emit a pheromone that attracts females, which was identified as (Z )-3-dodecenyl acetate. 

Several pheromones may be involved in mediating the mating behavior of the yellow mealworm, Tenebrio molitor L. (reviewed in Plarre and Vanderwel, 1999), but only one has been identified to date. Tanaka et al. (1986, 1989) identified the female-produced male attractantas(4/ )-(+)-4-methylnonan-l-ol(4-methylnonanol). Females produce the pheromone through a modification of normal fatty acid biosynthesis (Islam et al., 1999 Bacala, 2000). Initiation of the pathway with one unit of propionate results in the uneven number of carbons in the chain incorporation of another unit of propionate during elongation provides the methyl branch reduction of the fatty acyl intermediate produces the alcohol pheromone (Figure 6.8). 

Bacala R. (2000) In vitro studies of sex pheromone biosynthesis in the yellow mealworm beetle, Tenebrio molitor (Coleoptera Tenebrionidae). MSc thesis. Univ. of Manitoba, 133 pp. 

Griffith O., Vakili R., Currie R. W. and Vanderwel D. (2003) Effects of mating on the sex pheromone of female yellow mealworm beetles (Tenebrio molitor L.). J. Chem. Ecol. In preparation. 

Tanaka Y., Honda H., Ohsawa K. and Yamamoto I. (1989) Absolute configuration of 4-methyl-l-nonanol, a sex attractant of the yellow mealworm, Tenebrio molitor L. J. Pesticide Sci. 14, 197-202. 

Epoxide rings of alkene and arene compounds are hydrated to form trans-diols. The enzymes that catalyze the addition of a molecule of water to an epoxide ring to yield diols are called epoxide hydrolases (also known as epoxide hydrases). Epoxide hydrolase activity has been detected in numerous species of insects. Enzymatic epoxide hydration of certain cyclodiene insecticides and their analogs has been demonstrated in the housefly, blowfly (Calliphora erythrocephala), yellow mealworm (Tenebrio molitor), Madagascar cockroach (Gromphadorhina portentosa), southern army worm (Spodoptera eridania), and red flour beetle (Tribolium castaneum). Epoxide hydrolase is also important in the metabolism of juvenile... 

Sequestration in insects This is another resistance mechanism in which GSTs were found to be involved in pyrethroid resistance. Kostaropoulos et al. (2001) have reported that GST confers protection against deltamethrin by binding to the insecticide in the yellow mealworm ijenebrio monitor). 

Redfem, R.E., McGovern, T.P. and Bcroza, M. (1969). Juvenile hormone activity ol Sesame and related compounds in tests nn the yellow mealworm. / Econ. Entomoi. 63. 540-545. 

As early as 1934 Wigglesworth showed that the evolutionary differentiation of insects is regulated by a centre in the brain. In 1956 Williams obtained from Cecropia moth a highly active extract which produced anomalies in the metamorphosis of experimental insects. Following this first description of the action of juvenile hormone, Gilbert and Schneiderman (1958), then Williams et al. (1959) described the juvenile hormone action of lipid extracts obtained from different mammalian organs. The pure active substance was isolated first by Schmialek (1961) from feces of the yellow mealworm, Tenebrio Molitor, and identified as famesol (1), known as an intermediate product in steroid biosynthesis. Six years later, Roeller and co-workers (1967) elucidated the structure of the juvenile hormone isolated from the male of Cecropia. The hormone was ascribed the structure methyl ( , )-3,11-dimethyl-10,ll-epoxy-7-ethyl-2,6-tridecadienoate (2), and was called C,g-JH. Independent of these workers, Meyer et al. (1968) isolated also from Cecropia another juvenile hormone, ( , )-10,11-epoxy farnesenate (3), called C,g-JH. 

Figure 3 shows an example of protein treatment with deuterated solvent for H/D exchange. The bovine albumin digest (Figure 3A) was treated directly on the MALDI sample plate as described above and a second spectrum was acquired (Figure 3B). Results of the PMF identification on the first spectrum querying the SWISS-PROT and TrEMBL databases for mammalian species allowed the identification of bovine albumin (ALBU BOVIN, P02769) at the first rank and Yellow mealworm ecdysone receptor (002035). In the case of bovine albumin, 10 peaks out of 22 were matched in both spectra (Table 7).

To see whether other types of enzyme—protein inhibitor association also stabilize the enzyme, an amylase—amylase inhibitor system was studied by DSC. Complexes between either of two a-amylase inhibitors from wheat flour, designated 0.19 and 0.28, and the a-amylase from yellow mealworm (Tenebrio molitor L.), a pest that feeds on wheat flour, were used. Doth complexes natured at higher temperatures than the free enzyme, but the extent of stabilization differed (Silano and Zahnley, 1978). Both free inhibitors were heat-stable (Td = 93 C). 

Thermal stabilization resulting from protein-protein association between two inhibitor molecules from wheat flour and a-amylase from yellow mealworm (Tenebrio molitor) larvae has been investigated by differential scanning calorimetry. Thermograms (plots of heat flow versus temperature) for the two... 

R)-(-l-)-4-Methyl-l-nonanol is a sex pheromone of the yellow mealworm Tenebrio molitor (Coleoptera). Using [l- C]propionic acid, at what positions in the molecule would one expect to find C labelling ... 

Yellow mealworm Coleoptera The cosmopolitan yellow mealworm is one of the largest secondary pests that infests stored cereal products. The... 

Dark mealworm appearance. Adults lay white, bean-shaped, and sticky eggs from 276 (yellow mealworm) to 462 (dark mealworm) in a... 

Both enantiomers of Bower s compound, a potent analog of an insect juvenile hormone [161] (Scheme 20), were prepared in 96% e.e. using A. niger epoxide hydrolase. Interestingly, subsequent biological tests revealed that the (6R) antipode was about 10 times more active than the (6S) conterpart against the yellow mealworm Tenebrio molitor. 

---