Melon fly

Isolation and identification of pyrazine alkaloids (Table III) have been achieved in most cases by a combination of gas chromatography and mass spectrometry (35,36,38,69,97,142). Methyl-, 2,3,6-trimethyl-, and tetramethylpyrazines (23a, 21a, and 22a) from the melon fly are identified by utilizing a solid sampling technique in conjunction with gas chromatography-mass spectroscopy (147). Methylpyrazines show the molecule ion as a base peak. Fragmentation proceeds mainly by the loss of HCN or CH3CN from the molecular ion (141). Eth-... 

Two of amides from melon flies of the genus Dacus (Table VIII) have been identified as V-isoamylacetamide (122) and V-(2-methylbutyl)acetamide (123) by comparison of their mass spectra and chromatographic properties with those of authentic samples 103). The third amide, previously reported neither as a component of an insect secretion nor as a synthesized derivative, was assigned as A-isoamyl-2-methoxyacetamide (124) from the mass spectrum, showing a molecular ion at m/z 159 and fragment ions at m/z 129 (M" — CHjO) and 102 (M + — C4Hg), and its structure was confirmed by comparison with a synthetic au-... 

Pheromone (sex attractant). Ether extract of the stem, produced equivocal effect on Aspiculuris tetraptera, female and male Dacus dorsalis, male Mediterranean fruit flies, and male and female melon flies " k Pheromone (signaling). Ether extract of the stem, produced equivocal effect on Aspiculuris tetraptera, female and male Dacus dorsalis, male Mediterranean fruit flies, and male and female melon flies " k Phospholipidemic effect. Oil, administered to phospholipids transfer protein knockout (PLTPO)-deficient mice, produced an increase of phospholipids and free cholesterol in the VLDL-LDL region of PLTPO mice. Accumulation of phospholipids and free cholesterol was dramatically increased in PLTPO/HLO mice compared to PLTPO mice. Turnover studies indicated that coconut oil was associated with delayed catabolism of phospholipids and phospho-lipids/free cholesterol-rich particles. Incubation of these particles with hepatocytes of coconut-fed mice produced a reduced removal of phospholipids and free cholesterol by SRBI, even though SRBI protein expression levels were unchanged . 

CN014 Keiser, I., E. J. Harris, D. H. Miyashita, M. Jacobson, and R. E. Perdue. Attraction of ethyl ether extracts of 23 2 bota-nicals to oriental fruit flies, melon flies, and Mediterranean fruit flies. LLoydia 195 38(2) 141-152. 

Methyl eugenol 013,4-dimethoxy-l-allylbenzene [95-15-2] was fust characterized in 1915 as a powerful attractant for the male oriental fruit fly, Dams dorsalis, and attracts at least 60 other closely related Dams spp. Raspberry ketone [5471-51-2] or l-(4-/>-hydroxyphenyl)-2-butanone [5471-51-2] (174) is an equally powerful attractant for the melon fly, Dams mmrbitae, and the Queensland fmit fly, D. tryoni, and at least 180 other closely related Dams spp. The acetyl ester (cue-lure) (175) is more volatile and is a synthetic parakairomone especially effective for monitoring infestations by these species. Methyl eugenol and cue-lure [3572-06-3] have been used successfully in "male annihilation" of the oriental fmit fly and the melon fly by applying them to fiber board blocks or pieces of twine together with malathion or naled insecticides and distributing them over infested areas at doses of 15 g of attractant and 1 g of the insecticide per ha. 

Metcalf R. L., Mitchell W. C. and Metcalf E. R. (1983) Olfactory receptors in the melon fly Dacus cucurbitate and the oriental fruit fly Dacus dorsalis. Proc. Natl. Acad. Sci. USA 80, 3143-3147. 

The volatiles of the pH 4.2 bait are dominated by aldehydes and ketones while those of the pH 9 bait are dominated by pyrazines. Figure 5 shows the structures of some of these pyrazines. It is interesting to note that some of these pyrazines have also been found in the rectal gland secretion of the male melon fly (77). 

Figure 7. Benzylacetojie and anisylacetone analogs tested as melon fly lures...

Table III. Melon Flies Attracted by Cue-lure and Related Compounds (19)...

All of the melon fly attractants have the same root—i.e., the 4-phenyl-2-butaiione structure. Of the many derivatives prepared and tested by our group, the only ones that showed promise were p-sub-stituted through an oxygen. 

Melon fly attractant 4-(4-hydroxyphenyl)-2-butanone acetate Melon fly 11-45... 

Compounds include alcohols, acids, esters, carbonyls, ketones, and other hydrocarbons. However, a particular ketone l-(4-hydroxy phenyl)-3-butanone has an odor very much like raspberry [7,30]. This particiilar ketone, i.e., raspberry ketone, is sold under trade names Frambinon (Dragoco) and Oxyphe-nylon (IFF). In Hawai, the acetate of raspberry ketone is used under the trade name of Cue-Lure CAS No. [3572-06-3] to attract the harmhil melon-fly, Dacus Curcurbitae. 

Drosophila melanogaster (Oregon R), Drosophila simulans (st pe), Drosophila mauritiana (wild type), Ceratitis capitata (Mediterranean fruit fly or Medfly), Dacus cucurbitae (melon fly), and Dacus dorsalis (Oriental fruit fly) were cultured by standard methods. 

Methyl-eugenol and cue-lure are highly active commercialized synthetic kairomone lures to the oriental fruit fly, Bactrocera dorsalis, and the melon fly, Bactrocera cucurbitae, respectively (e.g., Vargas et al., 2000) ... 

Vargas, R.I., Stark, J.D., Kido, M.H., Ketter, H.M., and Whitehand, L.C. 2000. Methyl eugenol and cue-lure traps for suppression of male oriental fruit flies and melon flies (Diptera Tephritidae) in Hawaii effects of lure mixtures and weathering. /. Econ. Entomol., 93, 81-87. 

Stark and Sherman (1989) developed toxicity data for the 3 tephritid fruit fly species mentioned earlier after exposure to the organophosphorous insecticide, acephate. They found that the oriental fruit fly was the most susceptible species, followed by the melon fly and Mediterranean fly (Table 5.1). Although these are pest species, for this example I will consider them to be beneficial species and invent an EEC of 1 pg/g. Quotient ratios based on the LD50 and the above-mentioned EEC indicate that acephate poses a hazard only to the oriental fruit fly (Table 5.1). 

By plotting the dose-response curves for these species after exposure to acephate and comparing the EEC to these curves, we see that the EEC predicted mortalities are 83, 7, and 1% for the oriental fruit fly, melon fly, and Mediterranean fly, respectively (Figure 5.4). 

The growth rates (k) for these species were determined to be 2.7484,1.6897, and 1.5992/week for the oriental, melon, and Mediterranean fly, respectively (modified from Vargas et al. 1984). Matrix models were developed for each species (controls) and with the predicted mortalities resulting from exposure to acephate (Figures 5.5 and 5.6). The recovery time interval was the endpoint of interest here. The Mediterranean fly was unaffected by 1% mortality, and therefore no graph is presented. However, the melon fly population had a recovery period of 2 weeks (Figure 5.6), while the oriental fruit fly had a recovery period of 7 weeks (Figure 5.5). 

FIGURE 5.6 Deterministic population projections for a melon fly control population and a population exposed to the acephate EEC resulting in 7% mortality. 

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