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1.
Biscuits are flour-based products,which areconsumed by majority of people,both old and young,throughout the world and most especially by children,teenagers and mid-adults(Majumder,1970).It can beserved as a desert or snacks and as a breakfast foodwhentaken with beverages.Its ready-to-serve state andlong shelf life contribute to its acceptability by themasses.Wheat as humanfoodis used principallyintheformof flour for baked products such as bread,bis-cuits,pastries and crackers(Kent,1983).In th…  相似文献   

2.
Two field strains of the Indianmeal moth, Plodia interpunctella (Hübner); red flour beetle, Tribolium castaneum (Herbst); and lesser grain borer, Rhyzopertha dominica (F.), and one field strain of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), were collected from hard red winter wheat stored on farms in northeastern Kansas. Fifty eggs of P. interpunctella and 25 beetle adults of each species were exposed to 100 g of untreated wheat or wheat treated with various rates of spinosad, to determine susceptibility of the field and corresponding insecticide-susceptible laboratory strains. Mortality of beetle adults and P. interpunctella larvae was assessed after 7 and 21 d postinfestation, respectively. Field strains of P. interpunctella, C. ferrugineus, and T. castaneum were less susceptible to spinosad than the corresponding laboratory strains. The LD50 and LD95 values for P. interpunctella and C. ferrugineus field strains were 1.7-2.5 times greater than values for corresponding laboratory strains. Adults of both laboratory and field strains of T. castaneum were tolerant to spinosad, resulting in <88% mortality at 8 mg/kg. The LD50 and LD95 values for the field strains of T. castaneum were 2.0-7.5 times greater compared with similar values for the laboratory strain. The field and laboratory strains of R. dominica were highly susceptible to spinosad, and one of the field strains was relatively less susceptible to spinosad than the laboratory strain. Our results confirm a range of biological variability in field populations, which is consistent with findings for other compounds, and underscores the need to adopt resistance management programs with stored grain insect pests. The baseline data generated on the susceptibility of the four insect species to spinosad will be useful for monitoring resistance development and for setting field rates.  相似文献   

3.
The effects of eight diets (atta flour, wheat flour, self-rising flour, rice flour, custard powder, corn flour, tapioca starch, and potato starch) on the development of the red flour beetle, Tribolium castaneum (Herbst), reared at 29-31 degrees C and 66-70% RH were assessed. Five pairs of male and female T. castaneum were reared on the respective diets for 28 d before the experimental setup was dismantled and adult counts were recorded. In another experiment, the insects were allowed to mate and oviposit in each flour or starch type over a period of 7 d before being removed. The counting of pupae and adult emergence began on the day of emergence and was continued on a daily basis until day 140. Proximate analysis was performed for chemical composition of each diet, and the numbers of new adults that developed were found to be positively correlated (r2 = 0.97; P < 0.05) with the protein content and negatively correlated (r2 = 0.93; P < 0.05) with the carbohydrate content. For T. castaneum, the suitable diets were ranked as follows: atta flour > wheat flour > self-rising flour > rice flour > custard powder > corn flour > tapioca starch > potato starch. T. castaneum larval development to the pupal and adult stages developed significantly faster in atta flour (P < 0.05) than in the other diets, and the greatest number of progeny was produced from beetles reared on atta flour. Fewer adults emerged from wheat flour, self-rising flour, and rice flour, and no new emergences were recorded for the remaining diets. Developmental rate was much slower in beetles reared on diets in which a low number in progeny was produced. These data illustrate that different diets can influence the sustainability of these insects and affect their development and growth.  相似文献   

4.
5.
We have accumulated spontaneous mutations in the absence of natural selection in Drosophila melanogaster by backcrossing 200 heterozygous replicates of a single high fitness second chromosome to a balancer stock for 44 generations. At generations 33 and 44 of accumulation, we extracted samples of chromosomes and assayed their homozygous performance for female fecundity early and late in adult life, male and female longevity, male mating ability early and late in adult life, productivity (a measure of fecundity times viability) and body weight. The variance among lines increased significantly for all traits except male mating ability and weight. The rate of increase in variance was similar to that found in previous studies of egg-to-adult viability, when calculated relative to trait means. The mutational correlations among traits were all strongly positive. Many correlations were significantly different from 0, while none was significantly different from 1. These data suggest that the mutation-accumulation hypothesis is not a sufficient explanation for the evolution of senescence in D. melanogaster. Mutation-selection balance does seem adequate to explain a substantial proportion of the additive genetic variance for fecundity and longevity.  相似文献   

6.
In Tribolium flour beetles and other organisms, individuals migrate between heterogeneous environments where they often encounter markedly different nutritional conditions. Under these circumstances, theory suggests that genotype-by-environment interactions (GEI) may be important in facilitating adaptation to new environments and maintaining genetic variation for male traits subject to directional selection. Here, we used a nested half-sib breeding design with Tribolium castaneum to partition the separate and joint effects of male genotype and nutritional environment on phenotypic variation in a comprehensive suite of life-history traits, reproductive performance measures across three sequential sexual selection episodes, and fitness. When male genotypes were tested across three nutritional environments, considerable phenotypic plasticity was found for male mating and insemination success, longevity and traits related to larval development. Our results also revealed significant additive genetic variation for male mating rate, sperm offence ability (P(2)), longevity and total fitness and for several traits reflecting both larval and adult resource use. In addition, we found evidence supporting GEI for sperm defence ability (P(1)), adult longevity and larval development; thus, no single male genotype outperforms others in every nutritional environment. These results provide insight into the potential roles of phenotypic plasticity and GEI in facilitating Tribolium adaptation to new environments in ecological and evolutionary time.  相似文献   

7.
The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is a major pest of stored grain and cereal crops. It is also an important model species in genetic, ecological, and evolutionary research. The majority of its genome was recently sequenced and published. However, the genomic sequence of the small Y-chromosome is still undetermined, which hinders the development of molecular sex identification methods. Traditional methods for sexing adult forms of Tribolium beetles are troublesome. Therefore, a method for molecular sex identification in the red flour beetle was developed. One sex-linked randomly amplified polymorphic DNA marker was converted into a sequence-characterized amplified region (SCAR). The SCAR was aligned with the T. castaneum reference whole-genome sequence and fully matched a fragment of a single contig of unknown genomic location. The novelty of the method is that the fragment consists of shorter DNA fragments that are also present at other locations around the genome, but the particular order of these fragments within the sequenced region appeared to be Y-specific and this property was utilized for marker development. A set of three primers for multiplex PCR reaction was designed resulting in amplification of different length Y-specific and not-Y-specific (control) DNA fragments in a single PCR, which allows to distinguish males from females. The primers successfully sexed pre-sexed pupae and adult beetles from six laboratory strains, showing that the order of the repeated fragments is conserved in the species and is not strain-specific.  相似文献   

8.
The present study is the first attempt to investigate the effect of parental ageing of Cheilomenes sexmaculata (Fabricius) on total developmental period, developmental rate, adult weight on emergence, longevity, egg to adult survival and age‐specific survivorship of the offspring. Young parents (10–20 day old) produced offspring with the shortest total developmental period, highest development rate, highest weight on emergence, greater longevity and highest survival. Age‐specific survivorship of the offspring of younger parents declined later than the offspring of middle (30–40 day old) and old (50–60 day old) aged parents. This study would help in understanding the effect of parental ageing on future generations of predaceous ladybird beetles and would be helpful in designing mass multiplication programme of the bioagent, C. sexmaculata, in the laboratory.  相似文献   

9.
In holometabolous animals such as Drosophila melanogaster, larval crowding can affect a wide range of larval and adult traits. Adults emerging from high larval density cultures have smaller body size and increased mean life span compared to flies emerging from low larval density cultures. Therefore, adaptation to larval crowding could potentially affect adult longevity as a correlated response. We addressed this issue by studying a set of large, outbred populations of D. melanogaster, experimentally evolved for adaptation to larval crowding for 83 generations. We assayed longevity of adult flies from both selected (MCUs) and control populations (MBs) after growing them at different larval densities. We found that MCUs have evolved increased mean longevity compared to MBs at all larval densities. The interaction between selection regime and larval density was not significant, indicating that the density dependence of mean longevity had not evolved in the MCU populations. The increase in longevity in MCUs can be partially attributed to their lower rates of ageing. It is also noteworthy that reaction norm of dry body weight, a trait probably under direct selection in our populations, has indeed evolved in MCU populations. To the best of our knowledge, this is the first report of the evolution of adult longevity as a correlated response of adaptation to larval crowding.  相似文献   

10.
In our previous comparison of the postnatal growth of two laboratory strains of the musk shrew (Suncus murinus), the large shrews originating in Bangladesh (BAN strain) and the small shrews from Nagasaki, Japan (NAG strain), we found that differences in the 120-day adult body weight of the two strains (BAN: males 135.3g and females 82.0g; NAG: 52.9 and 34.2g, respectively) reflect both an approximately 2.5 times longer linear growth phase and an approximately 1.5 times higher growth rate during this phase in the BAN strain. We examined the postnatal growth (from 5 to 120 days after birth) of the F1 hybrids of a cross between the two strains and compared our findings with the above-mentioned growth data for the parent strains. A growth equation composed of linear and monomolecular functions was fitted to the growth data for the shrews. The growth trajectories of both sexes of the F1 hybrids were situated roughly midway between those of the two parent strains throughout the entire growth process. The adult body weight of the F1 shrews at 120 days of age averaged 86.0g in the males and 51.7g in the females. The growth phase lasted approximately 60 days in the males and approximately 40 days in the females of both the F1 shrews and the parent strains. The duration of the linear growth phase of the F1 hybrids (29.8 days in the males and 19.0 days in the females), however, was approximately intermediate between the parent strains (BAN: males 33.4 days and females 26.1 days; NAG: 18.8 and 13.9 days, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

11.
Yuchiro Hiraizumi 《Genetics》1985,110(3):453-464
Starting from four basic strains of Drosophila melanogaster, two laboratory strains (cn bw, Tokyo) and two isofemale lines (B-102, B-103) originated from a wild population in Texas, we constructed by repeated backcrosses through females for 20 or more generations a total of 16 strains of all possible combinations between the chromosome sets and cytoplasmic classes. Females from these 16 synthesized strains were then examined for their reproductive performance during their entire life span.---The chromosome set from the cn bw strain was found to associate with the highest female productivity when the age of females was very young, but these females ceased their reproduction and died relatively earlier, resulting in a smaller number of total progeny. The B-102 and B-103 chromosome sets, on the other hand, were associated with the lowest productivity when the females were young, but they lived and continued reproduction longer, resulting in a larger number of total progeny. The Tokyo chromosome set was associated with female productivity intermediate between the other two groups.---Cytoplasmic factors were found to affect the productivity of young females, with the cytoplasm from the cn bw strain associated with the highest productivity. Longevity was not cytoplasmically affected.---There was a clear interaction in female productivity between the Tokyo chromosome set and the cytoplasm from the Texas isofemale lines; the lifetime female productivity, as well as longevity, associated with the Tokyo chromosome set was found to increase considerably when it was substituted into the cytoplasm of the Texas isofemale lines. This chromosome-cytoplasm interaction appeared to be independent of the two systems of hybrid dysgenesis.  相似文献   

12.
Malathion resistance in the red flour beetle, Tribolium castaneum (Herbst), is a worldwide problem and is very stable once it becomes widespread in natural populations. In the absence of insecticide the proportion of resistant phenotypes may rapidly decline but the development of resistance does not always involve reduced fitness. Malathion-specific resistance in T. castaneum seems not to involve any loss of fitness in laboratory or field conditions. Susceptible beetles were in competition with resistant beetles at different initial frequencies and modifications of susceptible gene frequency were estimated in these laboratory populations over 10 generations. A significant decrease in susceptible gene frequency was observed in Tribolium populations over time. The selection coefficient of the susceptible allele was estimated and the fitness of susceptible alleles in all tests was observed to range from 0.89 to 0.93 compared with the fitness of resistant genotypes, which was assumed to be 1. Data provided evidence that the resistant strains exhibited fitness advantages in the absence of malathion. We also compared the biotic potential (fecundity and developmental time) of the susceptible strain, the homozygous malathion-specific resistant strain, and their hybrids. Malathion-specific resistant strains showed an 8 -23% increase in biotic potential relative to the susceptible strain. These findings are consistent with those of malathion-specific resistance in T. castaneum; the fitness of the insects seems independent of the genetic background and the fitness of the resistant insects is not affected by this resistance mechanism.  相似文献   

13.
14.
Abstract  As eucalypt pollens contain low concentrations of lipid, enhancing pollen diets with fatty acids was hypothesised to improve honey bee longevity. Different concentrations of linoleic and oleic acid added to eucalypt pollen were trialled in small cages containing approximately 1400 bees each. Bees fed diets of redgum ( Corymbia calophylla (Lindl.) Hill & Johnson, formerly Eucalyptus calophylla ) pollen had the lowest mortality of 22 diets tested for 6 weeks and had life spans (50%) greater than 42 days. Linoleic acid mixed with a redgum diet in concentrations >6% corresponded to life spans of 24–25 days. Bee longevity appeared to be more sensitive to oleic acid as life spans decreased to 15–21 days when diets had concentrations >2%. The life spans of bees fed soya bean flour were 26 days on low (0.6% lipid) fat, 19 days on defatted and 20 days on full-fat diets. Bees fed lupin flour had a life span of 23 days. Adding redgum pollen to lupin flour caused increased mortality, but addition of pollen to soya bean flour was beneficial. Thus, beekeepers who choose to utilise soya bean or lupin flours as protein substitutes to pollen will have bees with reduced longevity. Bees fed redgum pollen that had been dried, crushed, irradiated and hermetically stored in a cool room for several years had similar longevity to bees fed fresh-collected and frozen redgum pollen.  相似文献   

15.
Viability of allografts exchanged between the field-collected individuals of the common frog, R. temporaria , was long in tadpoles grafted during and immediately after closing of operculum; median survival time (MST) was 26 and 18 days, respectively. This probably reflected the immaturity of the host immune system and temporary tolerance to weak transplantation antigens. Allograft viability was the shortest in tadpoles grafted at foot-paddle stage (MST, 11 days). It was independent from the origin and size of the grafts. Such rate of rejection might reflect a maximal immunological potential of the host and the absence of any suppressor factors in response to highly polymorphic frog transplantation antigens. A gradual prolongation of allograft viability was observed in animals grafted at final stages of metamorphosis, in froglets, and in sexually mature adults (MST: 13, 17, and 28 days, respectively). In particular age groups viability of allografts from sibling donors was longer and from nonsibling ones shorter than MST values cited above.
Immunological memory of transplantation antigens did not disappear during the host metamorphosis, as MST (10 days) of second-set allografts in metamorphosing hosts sensitized during larval life was considerably shorter than the viability of the sensitizing grafts in the same age group.
The ontogeny of the response to alloantigens reflecting the immunological potential and the appearance of self-tolerance can be realized in different ways, depending on a particular amphibian species.  相似文献   

16.
B. M. Matsumoto 《BioControl》1974,19(3):325-329
The adult longevity of the California strain ofVenturia canescens (Gravenhorst) [Hymenoptera: Ichneumonidae], a larval parasite of the Mediterranean flour moth,Anagasta kuehniella (Zeller) [Lepidoptera: Phycitidae] was studied. The effects of the presence or absence of food (honey streak) in relationship to the ovipositional exertion as influenced by the presence or absence of hosts was considered. It was found that in the absence of any food, their longevity was drastically reduced and ovipositional exertion had no effect on this curtailment. However, in the presence of food, ovipositional activity was a major factor in the curtailment of adult longevity.  相似文献   

17.
Genetically modified, mass reared insects present novel possibilities for the future of insect control. One concern about manipulation of insects is a possible loss of strain quality due to the introduction of a foreign gene of any sort into the insect genome. Eight transgenic strains of screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), were compared with the wild-type parental laboratory strain in laboratory culture. Measurements of average fertility, fecundity, larval productivity, and longevity were analyzed. Two transgenic strains had significantly lower larval productivity than controls, one of which was explained by a homozygous lethal insertion of the transgene. Another strain produced significantly fewer eggs than controls. Overall strain characteristics, including measurements from egg, larva, pupa, and adult stages, were compared. Transgenic colonies did not consistently show significantly lower individual or aggregate strain quality characteristics than the control parental colony; hence, the presence of the transgene used to produce the strains tested did not incur a discrete cost to the colonies of laboratory-reared C. hominivorax.  相似文献   

18.
Sisodia S  Singh BN 《Genetica》2002,114(1):95-102
The genetic response of body size to temperature in the laboratory provides an interesting example of phenotypic plasticity. We found that females of Drosophila ananassae reared to adulthood at 18°C showed significant increase in body weight as compared to females reared at 25°C. At a given temperature, early productivity and lifetime productivity were the highest when the rearing and test temperature were the same. The effect of test temperature was highly significant for total productivity and early productivity. The interaction between test temperature and development temperature was also highly significant. Effect of development temperature was not significant. The females reared at 18°C showed greater body weight but their productivity was not significantly higher than smaller females reared at 25°C. Thus, the usually close relationship between size and fecundity is lost when the size change is due to rearing temperature. These findings provide evidence for adaptive plasticity in D. ananassae. We also found a negative correlation (trade-off) between longevity and productivity, the first report of such a trade-off between longevity and productivity in D. ananassae.  相似文献   

19.
d-Limonene was investigated for contact and fumigant toxicity, ovicidal effects, oviposition-deterrent, development inhibition, and feeding-deterrent activities against three stored-product beetles (Coleoptera): lesser grain borer, Rhyzopertha dominica (F.); rice weevil, Sitophilus oryzae (L.); and red flour beetle, Tribolium castaneum (Herbst). Contact and fumigant toxicity decreased as larvae aged. Contact toxicity was similar for adults of the three species tested, but R. dominica was most susceptible to fumigant activity. T. castaneum oviposition decreased as concentration of d-limonene increased and d-limonene reduced oviposition up to 92.3% at the concentration of 2.14 mg/cm2. Hatching of d-limonene-treated eggs of T. castaneum was reduced by 94.5% with no subsequent larval and adult survival at 2.14 mg/cm2 concentration. A flour disc bioassay indicated 87.7 to 96.8% feeding-deterrency by d-limonene toward all three insect species tested at the highest concentration of 60.0 mg/g food. These results suggest that d-limonene can be effectively used to suppress populations of stored-product beetles.  相似文献   

20.
研究了乌苏里鸣螽的生物学特性。该虫在河北省秦皇岛市 1年发生 1代 ,以滞育卵在土内越冬 ,翌年 3月下旬~ 6月上旬孵化为若虫。若虫共 7龄 ,1龄期 1 3~ 2 9d ,2龄期 8~ 2 0d ,3龄期 7~ 1 3d ,4龄期 6~ 9d,5龄期 6~ 9d ,6龄期 5~ 1 5d ,7龄期 1 2~ 1 7d。 6月下旬~ 8月中旬羽化为成虫 ,雌成虫产卵自 7月上旬至 9月下旬结束。成虫平均寿命 81 2 5d。  相似文献   

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