Insects flour beetles

Because of the importance of safe insecticides in the protection of foods, additional tests have been run against German cockroaches, red flour beetles, and Mexican bean beetle larvae. The residual deposit test was used on the first two insects, and a dust test on the bean beetles. The procedure for the latter method is to incorporate the materials into dusts which are distributed on bean leaves (6) piperonyl cyclonene, which is superior to butoxide against this insect, was included in this series of tests. 

Direct behavioral evidence of how stored-product insects move among patches is limited, but what is available shows that stored-product pests readily leave patches of food, can find and exploit multiple patches, and that these processes are influenced by a variety of endogenous and exogenous factors. The time Cryptolestes ferrugineus spent in refugia has been shown to be influenced by strain, sex, and age (Cox and Parish, 1991 Cox et al., 1989, 1990). A variety of factors have been shown to influence the decision by red flour beetles to leave food patches, including insect density... 

Low levels of resistance have been reported for some populations of Indian meal moth, almond moth, and red flour beetle populations in stored peanuts in the southeastern United States (Zettler et al., 1989), but no assessments are available for phosphine resistance in insect populations in mills, warehouses, processing plants, and other structural facilities. Phosphine can be corrosive to metals, particularly copper, electrical wiring, and electronic equipment (Bond et al., 1984), which limits its application in food processing facilities and warehouses. A new formulation of phosphine, in which phosphine gas is combined with carbon dioxide and released from a cylinder, alleviates some but not all of the corrosive effects of phosphine and is labeled for use as a structural treatment. 

An aerosol formulation of the insect growth regulator hydroprene (Gen-trol) was labeled several years ago for use in the United States. There are no research reports with hydroprene aerosol, except for Bell and Edwards (1998), which describe a study conducted in Great Britain. In this study, aerosol applications of hydroprene (Protrol) prevented the development of eggs of the red flour beetle, T. castaneum, the confused flour beetle, T. confusum, and the almond moth, C. cautella, that had been placed in exposed dishes with food media. 

The status of resistance of stored-product insects to any of the aerosols used in the United States is uncertain, and no new assessments of resistance have been conducted in recent years. Indianmeal moth, P. interpunctella, and almond moth, C. cautella, populations in peanut warehouses in the southeastern United States showed low levels of resistance to dichlorvos (Arthur et al., 1988), but reflected an increase relative to earlier studies (Zettler, 1982). In other studies, 24% of red flour beetle and 64% of confused flour beetle populations collected from flour mills were resistant to dichlorvos (Zettler, 1991). 

Currently there are few insecticides registered as surface treatments to control stored-product insects. For years the organophosphate insecticide malathion was used as a surface treatment for structural facilities, but stored-product insects throughout the world have developed extensive resistance to malathion (Subramanyam and Hagstrum, 1996). Most of the resistance reports were generated from studies with bulk grains, but in the United States, resistance has been documented for field populations of the red flour beetle, T. castaneum (Herbst), and the confused flour beetle, T. confusum (DuVal), collected from flour mills (Arthur and Zettler, 1991, 1992 Zettler, 1991). Populations of the Indianmeal moth, the almond moth, and the red flour beetle collected from bulk peanuts and empty warehouses were also highly resistant to malathion (Arthur et al., 1988 Halliday et al., 1988). 

Campbell, J.F. and Runnion, C. 2003. Patch exploitation by female red flour beetles, Tribolium castaneum. J. Insect Sci. 3, 20. http //www.insectscience.Org/3.20... 

The lethality of ionizing radiation is proportional to the complexity of the organism. Humans, for example, cannot survive more than 800 r., but it may take 2 million r. to inactivate a microorganism. Insect life, of the type which infests field crops, show intermediate stability. Information gleaned from the best available sources (B15, Bl, H9) indicate that a 1000-r. exposure will kill all eggs, 1300 r. will kill all larvae, and 3,000 r. will destroy all young pupae. The resistance of insects to radiation increases with age. For example, to kill some adult species requires 50 to 60,000 r. Adult flour beetles succumb at 10,000 to 16,000 r. 

Diols have been rarely observed in insect cuticular lipids (Buckner, 1993). Odd-carbon-number diols (C23-C29) were the major lipid class (55%) of the larval cuticular lipids from the flour beetle, Tenebrio molitor (Bursell and Clements, 1967). The major diol constituent was 8, 9-pentacosanediol. For the cuticular lipids of M. sexta larvae, very small amounts (<1%) of 7,8- and 8,9-C27 diols and 8,9- and 9,10-C29 diols were identified (Espelie and Bernays, 1989). Hydroxy n-alkanols are diols with a hydroxyl functional group on the C, position (terminal) of the alkyl chain, but are technically not alcohol derivatives of hydrocarbons. There are a few reports of the occurrence of insect hydroxy -alkanols (Buckner, 1993 Nelson and Blomquist, 1995 Buckner et al., 1996). In a structure analysis study of beeswax, the major alcohol moieties of the diester fraction were identified as 1,23-tetracosanediol (42.2%), 1,27-octacosanediol (26.0%) and 1,25-hexacosanediol (20.2%) (Tulloch, 1971). The hydroxy n-alkanols comprised 16% of the cuticular lipids of FI. zea pupae and were identified as C30-C36 even-chain n-alcohols with hydroxyl groups on carbon numbers 11, 12, 13, 14, or 15 (Buckner et al., 1996). Mass spectral analysis indicated the presence of unsaturation in the alkyl chain of the major diol components. 

The multiresistant strains now extant also show a certain cross-tolerance, but not resistance, to the third-generation insecticides such as the juvenile-hormone mimics and other so-called insect growth regulators, as was found in strains of the housefly, flour beetle and tobacco budworm. Resistance to the JH mimic methoprene and Monsanto-585 has been induced by laboratory selection of Culex taxsalis (28) and Culex pipiens (29), and to Monsanto-585 in Culex quinquefasstatus (30). Whatever insect or IGR is chosen, the result of exposure to selective doses in successive generations is usually the development of resistance, repeating our previous experience with chemosterilants, and the... 

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... 

Insect pest infestation causes losses in quantity and quality of food commodities and changes in chemical composition, affecting the nutritive value of the produce (Howe, 1965 Scott, 1991 Swaminathan, 1977). Insect activity also leads to contamination of the produce (Table II). The flour beetles (Tribolium spp.) contaminate foodstuffs with their secretions, which contain 2-ethyl 1,4-benzoquinone and 2-methyl-1,4-benzoquinone. T. castaneum quinone secretions not only impart off-odors to food commodities but are also considered to cause liver and spleen tumors in mice (El-Mofty et al., 1992). However, Hodges et al. (1996) demonstrated that unlike in wheat flour, the accumulation of quinone secretions of T. castaneum adults in rice was negligible at less than 1 ppm, and hence, they claimed that T. castaneum infestation in rice is not likely to be a health risk. Males of R. dominica secrete aggregation pheromones (dominicalures) that contribute to the characteristic sweetish or musty odor in grain infested with R. dominica (Khorramshahi and Burkholder, 1981). However, Seitz and Sauer (1996)... 

During an infestation by larvae of the Egyptian cotton leafworm Spodoptera littoralis (Boisd) in the summer of 1978, it was noticed that shrubs of Physalis peruviana L. (cape gooseberry) were not attacked, whereas other Physalis and Nicandra spp. suffered heavy damage. Asher and co-workers demonstrated that withanolide E (118) and 4(3-hydroxywithanolide E (119), isolated from P. peruviana, as well as several related steroids, had insect antifeedant properties. Further studies on other withanolides showed antifeedant effects and species-specific activity on three insects, S. littoralis (Boisd.) (Lepidoptera), the Mexican bean beetle, Epilachna varivestis Muls. (Coleoptera) and the red flour beetle, Tribolium castaneum (Herbst) [62]. 

Coleoptera. The confused flour beetle, Tribollum confusum, was the first phytophagous insect we found that produces an appreciable amount of a sterol other than cholesterol from radiolabeled dietary C28 and C29 phytosterols. We found this insect produced large quantities of 7-dehydrocholesterol, equivalent to as much as 70% of the total tissue sterols isolated (12). It was further determined that cholesterol and 7-dehydrocTfolesterol were in equilibrium in this flour beetle. Another new intermediate, 5,7,24-cholestatrien-3B-ol was identified as an intermediate between desmosterol and 7-dehydrocholesterol (Figure 3). We found very similar pathways of sterol metabolism to exist in the closely related flour beetle, Tribolium castaneum (13). However, another flour beetle, Tenebrio moHtor, nad only about one-third or less of the levels of 7-dehydrocholesterol as the two Tribolium species, but still much higher levels of this sterol than has been found in most species. Fucosterol 24,28-epoxide was also implicated as an intermediate in the synthesis of cholesterol from sitosterol in T. mol i tor (14). 

S. Characterization of two chitin synthase genes of the red flour beetle, Tribolium castaneum, and alternate exon usage in one of the genes during development. Insect Biochem. Mol. Biol. 2004, 34, 291-304. 

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