DNA gyrase inhibitors: Novobiocin enhances the survival of Pimpla turionellae (Hym., Ichneumonidae) larvae reared on an artificial diet but other antibiotics do not

Effects of novobiocin, nalidixic and oxolinic acids, which are potent antibacterial agents, on the survival and development of the hymenopterous endoparasitoid, Pimpla turionellae L. (Ichneumonidae) were investigated alone by rearing the larvae aseptically on chemically defined synthetic diets. Survival of the fifth instar larvae was not significantly affected by diets with different levels of antibiotics tested. A diet containing the lowest level of novobiocin significantly increased yields of pupae and adults. This level also significantly shortened the developmental time for fifth instar but had no significant effect on complete development of the larvae up to adult emergence. Oxolinic acid at the lowest level did not affect the survival but prolonged development of the insect. In general, the rate of development was significantly increased and the survival was decreased with high levels of the antibiotics. However, nalidixic acid caused a striking decrease in the survival at all tested levels. These results suggest that novobiocin and to a lesser extent oxolinic acid are compatible for addition to artificial diet for rearing P. turionellae , which is an important parasitoid used in biological control.     

Ni2+对不同发育阶段斜纹夜蛾虫体血淋巴能量物质的影响

研究了饲料中不同浓度的Ni2+(140mg/kg)对连续3个世代斜纹夜蛾Spodoptera litura Fabricius6龄末幼虫、蛹和成虫血淋巴中能量物质总糖、蛋白质和脂肪含量及血淋巴中热量值的影响。结果表明,Ni2+胁迫1个世代,6龄末幼虫、蛹和成虫血淋巴中的总糖含量均低于对照,而血淋巴中的蛋白质含量则在低浓度Ni2+胁迫下增高,在高浓度Ni2+胁迫下降低;只有受120mg/kg Ni2+胁迫的6龄末幼虫血淋巴的脂肪含量高于对照,而蛹和成虫血淋巴中的脂肪含量及热量值均低于对照。在Ni2+胁迫的第2、3代,6龄末幼虫、蛹和成虫血淋巴中的总糖、蛋白含量和热量值与饲料中Ni2+浓度的反应关系均表现为低浓度Ni2+胁迫增加而高浓度Ni2+胁迫降低的趋势;然而,血淋巴中的脂肪含量随饲料中Ni2+浓度的增加而降低。因此,重金属Ni2+对S.litura能量物质的影响与虫体内能量物质的种类和虫体的发育阶段有一定的关联。     

幼虫食物对甜菜夜蛾生长发育、繁殖及飞行的影响

报道了人工饲料、圆白菜和玉米苗三种食物对甜菜夜蛾Spodoptera exigua发育历期、蛹重以及成虫产卵和飞行能力的影响。幼虫取食人工饲料时发育历期最短,蛹最重(138 mg),产卵量最高(643粒);在12 h的吊飞测试中,成虫飞行距离最远(25.5 km),飞行时间最长(6.2 h),飞行超过10 km的个体占67.9%,超过5 h的占60.7%。幼虫取食玉米苗时发育历期最长,蛹最轻(52 mg),产卵量最低(416粒),成虫仅能飞行3.3 km,1.7 h,飞行超过10 km或5 h的个体均仅占4.2%,各项指标均显著低于人工饲料组。幼虫取食圆白菜时各项指标与人工饲料组基本相似(幼虫历期和蛹重除外),而显著优于玉米苗组(幼虫历期除外)。这些结果表明,幼虫食物对甜菜夜蛾的生长发育、产卵及飞行能力均有显著的影响,因而是影响其个体发育、种群增长及种群动态的重要因素之一。同时,由于取食本人工饲料的各项指标均优于其它两种食料植物,因而可作为饲养甜菜夜蛾的实用饲料。     

Effect of the bacterial DNA gyrase inhibitors, novobiocin, nalidixic acid, and oxolinic acid, on oxidative phosphorylation

When incubated with isolated intact rat liver mitochondria, novobiocin and nalidixic acid act as uncouplers of oxidative phosphorylation; they stimulate oxygen uptake and inhibit ATP synthesis. Novobiocin is about as powerful an uncoupler as is 2,4-dinitrophenol, nalidixic acid is somewhat less powerful, and oxolinic acid exerts no inhibition whatsoever at the concentrations used. The three inhibitors are without effect on oxidative phosphorylation in Escherichia coli nor does novobiocin affect this process in a novobiocin-permeable mutant of yeast. While it would appear that oxolinic acid may be a relatively specific tool for the manipulation of the superhelicity of DNA in complex systems such as mammalian mitochondria and intact mammalian cells, the specificity of each of these inhibitors may depend upon the particular conditions and species used and such experiments require adequate controls on oxidative phosphorylation.     

Dietary Conjugated Linoleic acid (CLA) in House Fly,Musca domestica,with no Adverse Effects on Development

Conjugated linoleic acid (CLA) acts as a potent cancer inhibitor and biological modulator in several animal models by incorporation in the lipid fractions. Now we report the possibility of incorporation of dietary CLA into insect body lipids. Chemically-synthesized CLA from safflower seed oil was supplied to house fly (Musca domestica) larvae and adults with diet supplements at various levels. Amount of CLA in the pupa and adult body was proportional to the concentrations of CLA in the diet. CLA amount in pupae and adults was 0.17 mg/g and 0.41 mg/g of body, respectively, by 0.1% CLA diet (the lowest dosage), whereas it dramatically increased to 3.05 mg/g and 1.51 mg/g of body, respectively, by 10% CLA diet (the highest dosage). The dietary CLA did not show any adverse effects on the development of larvae and pupae, survivorship and fertility of adults, and eclosion of deposited eggs.     

Post-embryonic development of Ophyra aenescens (Wiedemann, 1830) (Diptera: Muscidae) with different diets, under laboratory conditions

The performance of various diets (bovine meat, fish-sardine, shrimp, dog faeces, and banana) in Ophyra aenescens development was evaluated. The biology was studied in an incubator (BOD) at 27 +/- 1 degrees C and 80 +/- 10% of RH. The developmental time from larvae to adult, the developmental time and viability of larvae and pupae, the weight of pupae as well as the sex ratio of the emerging adults were also determined. Beef and shrimp were the more efficient diets for rearing O. aenescens.     

Some effects on the aphid Myzus persicae of ingesting antibiotics incorporated into artificial diets

Ten antibiotics were incorporated individually at different concentrations into artificial diets fed to the aphid Myzus persicae. The survival and larviposition of apterous adult aphids, and the growth and development of larvae were severely affected by albamycin (sodium novobiocin), chloromycetin (chloramphenicol), ilotycin glucoheptonate (erythromycin glucoheptonate), and the tetracyclines aureomycin (chlortetracycline HCl), oxytetracycline HCl, and tetracycline HCl. Alata-production by the apterous adults that were maintained in groups on the diets was dramatically curtailed by these antibiotics, some at concentrations as low as 0·0001%. Mandelamine (methenamine mandelate), penicillin-G, streptomycin sulphate, and viomycin sulphate had a much lesser effect on larval growth, even when these antibiotics were incorporated into the diet at concentrations as high at 0·1%. The results are discussed in relation to the probable functions of the aphid's symbiotes in the nutrition of the aphid.     

Oil-soluble dyes incorporated in meridic diet of Diatraea grandiosella (Lepidoptera: Crambidae) as markers for adult dispersal studies

Mark-release-recapture experiments to study insect dispersal require the release of marked insects that can be easily identified among feral conspecifics. Oil-soluble dyes have been used successfully to mark various insect species. Two oil-soluble dyes, Sudan Red 7B (C.I. 26050) and Sudan Blue 670 (C.I. 61554), were added to diet of the southwestern corn borer, Diatraea grandiosella Dyar, and evaluated against an untreated control diet. Survival, diet consumption, larval and pupal weight, development time, fecundity, longevity, and dry weight of the adults were measured. Adults reared on the three diets were also tested for mating success. Some minor effects were observed for southwestern corn borers reared on the marked diets. Eggs, larvae, pupae, and adults were all reliably marked and readily identifiable. Adults retained color for their entire life span. Adults from each diet mated successfully with adults from the other diets. F1 progeny from the different mating combinations survived to the second instar but tended to lose the marker after 3-4 d on untreated diet. Both Sudan Red 7B and Sudan Blue 670 can be used to mark southwestern corn borer adults and thus should be useful for mark-release-recapture dispersal studies. The dyes will also be useful for short-term studies with marked larvae and oviposition behavior.     

The interaction of trimethoprim and quinolones against Gram-negative fish pathogens

The effect of combination of trimethoprim with other non-sulphonamide antibacterial agents, in particular oxolinic acid and nalidixic acid, was evaluated against Gram-negative fish pathogens. The species included Aeromonas salmonicida, Yersinia ruckeri , some Vibrio spp. and Escherichia coli as a reference. The extent of synergy found by other workers with these substances against human Gram-negative bacteria was not apparent here. Some positive interaction between trimethoprim and oxolinic acid was found with Aer. salmonicida, Y. ruckeri and E. coli and between trimethoprim and nalidixic acid with Y. ruckeri in double disc diffusion tests but was not supported by fractional inhibitory concentration indices. The combinations were not effective in preventing emergence of resistance in passage on a drug gradient. Trimethoprim-resistant isolates of Aer. salmonicida were inhibited by low levels of oxolinic acid but the converse did not apply.     

Comparison of the growth and development of beet armyworm,Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) on two different diets

Beet armyworm (Spodoptera exigua (Hübner)) (Lepidoptera: Noctuidae) is the most economically important sugar beet (Beta vulgaris) pest worldwide. In this study, a comparison was made between two different diets: one was based on Merkx diet (Holidic diet) and the other was based on sugar beet leaf (Oligidic diet). Results showed that the whole development time from larvae to adult between two diets (Merkx and leaf) was not significantly different. For example, developmental time from first instar larvae to adult in Merkx diet was 11.33?days, whilst developmental time of larvae to adult when larvae fed with sugar beet leaf was 10.33?days. However, analysis of variance showed that in some cases like development time of the first instar, third instar and fifth instar larvae and pupae was significantly different between two treatments (p?<?0.05). Larval weight showed differences when larvae fed on Merkx diet and sugar beet leaves. For example, significant differences were shown between first, third and fourth instar larvae weight when larvae fed on Merkx diet and sugar beet leaves (p?<?0.05). However, significant differences were not observed between weight of second and fifth instar as well as pupae weight when larvae fed on Merkx diet and sugar beet leaves (p?>?0.05).     

Sodium polyacrylamide polyacrylate, a gelling agent in diets for cabbage looper, omnivorous looper and western avocado leafroller

Ingredient substitutions for agar or carrageenan in artificial diets for lepidopterous larvae were evaluated. A sodium polyacrylamide polyacrylate gelling agent, Water-Lock G-400, was compared with agar for solidifying diets of the cabbage looper, Trichoplusia ni (Hübner), omnivorous looper, Sabulodes aegrotata (Gueneé), and the western avocado leafroller, Amorbia cuneana Walsingham. Water-Lock G-400 is considerably less expensive than agar or carrageenan, it does not require heating to gel, and it is made from a dependable supply of agricultural starch. Sabulodes aegrotata pupae from larvae reared on agar were significantly heavier than those reared on Water-Lock G-400. However, the remainder of the variables observed (larval survival, developmental times, fecundity, sex ratio and pupal weights for A. cuneana and T. ni) were all independent of diet. Decreasing the total amount of ingredients in a Water-Lock-G-400 diet produced fewer and smaller T. ni pupae than did an agar diet when the larvae were reared using a mass production protocol. However, these lower values were still above acceptable levels for mass production and reduced the cost of diet production by 65%.Further ingredient substitutions impaired larval development (i.e., replacing pinto beans with soy protein or combinations of soy protein and -cellulose), while others did not (i.e., excluding pinto beans and reducing water content and replacing pinto beans with -cellulose or corn cob grits). Moisture control by adding corn cob grits to diets increased the yield of pupae, while removing water from diets increased survivorship and the yield of pupae.     

Effects of dietary variation on growth,composition, and maturation of Manduca sexta (Sphingidae: Lepidoptera)

Most studies linking dietary variation with insect fitness focus on a single dietary component and late larval growth. We examined the effects of variation in multiple dietary factors over most life stages of the sphingid moth, Manduca sexta. Larvae received artificial diets in which protein, sucrose, and water content were varied. The relationship between larval size, growth and consumption rates differed significantly across diets. Larvae on control and low-sucrose diets grew most rapidly and attained the largest pupal and adult sizes. Conversely, larvae on low-water and low-protein diets initially grew slowly, but accelerated in the fifth instar and became pupae and adults comparable to control animals in size. There were no fundamental differences in protein:carbohydrate consumption patterns or strategies among experimental diets and larval instars. However, inadequate dietary water appeared to be more important for early than late instar larvae. Larvae on all artificial diets showed increasing fat content throughout all stages, including wandering and metamorphosis. Compensatory feeding among low-water and low-protein larvae was correlated with significantly higher fat content in larvae, pupae and adults, whereas low-sucrose animals were substantially leaner than those on the control diet. These differences may have strong effects on adult physiology, reproduction, and foraging patterns.     

Gypsy moth (Lymantria dispar) larval development and survival to pupation on diet plus extractables from green ash foliage

Gypsy moth, Lymantria dispar L., rate of larval development, molting, pupal weight and survival were studied on an artificial diet containing different concentrations of green ash ethyl acetate extractables (EtOAc Exts). Insects were reared on experimental diets from egg to pupa. Addition of EtOAc Exts to artificial diet significantly prolonged larval development and reduced their survival compared to larvae reared on control diet. Weights of pupae were significantly reduced when larvae were reared on diet containing the lowest dosage of EtOAc Exts (i.e., 0.01%) versus on control diet. EtOAc Exts in diet (e.g., 0.01, 0.06 and 0.2%) frequently caused incomplete ecdysis which invariably resulted in larval death. Impaired feeding, locomotion and excretion are likely causes of death. The combination of these results with our earlier findings of repellents and feeding deterrents against gypsy moth larvae (GML) in green ash foliage shows that the non-host status of green ash to the highly polyphagous GML involves three orders of chemical defense: repellents, feeding deterrents and inhibitors of nutritional and developmental physiology. As the insect becomes sequentially exposed to these orders of defense, it incurs higher costs because the adverse effects become less reversible.     

Mutations affecting gyrase in Haemophilus influenzae.

Mutants separately resistant to novobiocin, coumermycin, nalidixic acid, and oxolinic acid contained gyrase activity as measured in vitro that was resistant to the antibiotics, indicating that the mutations represented structural alterations of the enzyme. One Novr mutant contained an altered B subunit of the enzyme, as judged by the ability of a plasmid, pNov1, containing the mutation to complement a temperature-sensitive gyrase B mutation in Escherichia coli and to cause novobiocin resistance in that strain. Three other Novr mutations did not confer antibiotic resistance to the gyrase but appeared to increase the amount of active enzyme in the cell. One of these, novB1, could only act in cis, whereas a new mutation, novC, could act in trans. An RNA polymerase mutation partially substituted for the novB1 mutation, suggesting that novB1 may be a mutation in a promoter region for the B subunit gene. Growth responses of strains containing various combinations of mutations on plasmids or on the chromosome indicated that low-level resistance to novobiocin or coumermycin may have resulted from multiple copies of wild-type genes coding for the gyrase B subunit, whereas high-level resistance required a structural change in the gyrase B gene and was also dependent on alteration in a regulatory region. When there was mismatch at the novB locus, with the novB1 mutation either on a plasmid or the chromosome, and the corresponding wild-type gene present in trans, chromosome to plasmid recombination during transformation was much higher than when the genes matched, probably because plasmid to chromosome recombination, eliminating the plasmid, was inhibited by the mismatch.     

Effects of host (Boettcherisca peregrina) copper exposure on development, reproduction and vitellogenesis of the ectoparasitic wasp, Nasonia vitripennis

Effects of copper (Cu) accumulation by the flesh fly Boettcherisca peregrina (R.-D.) (Diptera: Sarcophagidae) on the ectoparasitic wasp Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae) were investigated experimentally by exposing host larvae to contaminated diets with final Cu concentrations of 400 μg/g and 800 μg/g diet fresh weight (DFW), respectively. Results showed that Cu can be transferred along food chains to secondary consumers (parasitoids) in small amounts, resulting in negative effects on parasitoid growth and development (body weight and developmental duration) as well as fecundity (number of offspring per female). Copper exposure also inhibited vitellogenesis of parasitoids from Cu-contaminated host pupae. It is suggested that the decreased fecundity and inhibition of vitellogenesis of N. vitripennis resulted from poor host nutritional state rather than from direct effects of Cu stress.     

Fatty acid profile of the cabbage looper, Trichoplusia ni, and the effect of diet and rearing conditions

The fatty acids, palmitic (16:0), palmitoleic (16:1), stearic (18:0), oleic (18:1), linoleic (18:2), and linolenic (18:3) were measured by GLC in Trichoplusia ni (Hübn.) from larvae reared on three different diets. The effect of rearing temperature and humidity on the levels of these fatty acids in pupae and pharate adults was determined. T. ni tended to accumulate 18:3 somewhat in proportion to its level in the diet. The respective levels (relative percentage) of this fatty acid in the diet and in the pupae were: bean leaves, 73·6 and 56·7; the diet based on lima beans, 10·2 and 3·5; and a meridic diet containing wheatgerm oil, 5·6 and 1·8. Pupae from larvae reared on a diet marginal in 18:3 content produced adults with deformed wings when reared at 30°C and normal wings when reared at 23 or 24°C, but there was no difference in their tissue level of 18:3. The phospholipids of last instar larvae, pharate pupae, pupae, pharate adults, and emerged adults are made up mostly of 18:0, 18:2, and 18:3 while the triglycerides of these stages contain relative large quantities of 16:0, 16:1, and 18:1. Pupal rearing temperature did not appear to influence the level of 18:3 in these two fractions enough to account for the degree of deficiency expressed as adult wing deformity. Both high (95%) and low (20%) relative humidity have an adverse effect on wing development but this effect can be overcome by 18:3 supplementation of the larval diet.     

金银花尺蠖幼虫、蛹和成虫的营养成分分析

【目的】了解金银花尺蠖Heterolocha jinyinhuaphaga Chu幼虫、蛹和成虫的主要营养成分,评价其营养价值,为金银花尺蠖的食用开发提供理论依据。【方法】采用国家标准检测方法,测定金银花尺蠖幼虫、蛹和成虫的水分、蛋白质、脂肪、总糖、氨基酸、脂肪酸、微量元素和维生素的含量,分析金银花尺蠖幼虫、蛹和成虫的氨基酸分、必需氨基酸指数、必需氨基酸与非必需氨基酸的比值、不饱和脂肪酸与饱和脂肪酸的比值,并与常见食物进行比较分析。【结果】结果表明,金银花尺蠖幼虫、蛹和成虫的水分含量分别为72.93%、64.92%和56.16%;蛋白质含量分别为50.64%、60.12%和48.38%;脂肪含量分别为21.98%、23.84%和20.60%;总糖含量分别为3.32%、5.35%和2.79%;总氨基酸含量分别为394.31、413.54和356.09 mg/g;必需氨基酸总含量分别为158.80、166.83、132.67 mg/g;必需氨基酸占总氨基酸的比例分别为40.27%、40.34%和37.26%;必需氨基酸与非必需氨基酸的比值分别为67.43%、67.62%和59.38%;必需氨基酸指数分别为1.02、1.07和0.87;不饱和脂肪酸的含量分别为68.45%、69.09%和66.29%,其P/S值分别为2.17、2.24和1.95;必需脂肪酸含量分别为34.35%、34.77%和32.71%;微量元素Zen的含量分别为11.29、98.42、66.98 mg/100 g,Fe的含量分别为32.31、19.84、13.04 mg/100 g,幼虫中Cu的含量为18.54 mg/100 g,蛹和成虫中均不含Cu;维生素以B6的含量最高,分别为7.93、25.82、26.21 mg/100 g。【结论】金银花尺蠖具有较高的营养价值和食用价值,具有极大的开发潜力。     

New nalidixic acid resistance mutations related to deoxyribonucleic acid gyrase activity.

In Escherichia coli K-12 mutants which had a new nalidixic acid resistance mutation at about 82 min on the chromosome map, cell growth was resistant to or hypersusceptible to nalidixic acid, oxolinic acid, piromidic acid, pipemidic acid, and novobiocin. Deoxyribonucleic acid gyrase activity as tested by supercoiling of lambda phage deoxyribonucleic acid inside the mutants was similarly resistant or hypersusceptible to the compounds. The drug concentrations required for gyrase inhibition were much higher than those for cell growth inhibition but similar to those for inhibition of lambda phage multiplication. Transduction analysis with lambda phages carrying the chromosomal fragment of the tnaA-gyrB region suggested that one of the mutations, nal-31, was located on the gyrB gene.     

Effects of diet on female fecundity and larval development in the carrion beetle Necrophila japonica

The carrion beetle subfamily Silphinae (Coleoptera: Silphidae) contains dominant macroinvertebrates of soil ecosystems in temperate zones. However, their feeding habits, which determine the role of each species in the ecosystem, have not been sufficiently studied. Moreover, although a diet shift from necrophagy on vertebrate carcasses to predatory feeding on invertebrates is known to occur in this subfamily, the processes and mechanisms of this shift have also been inadequately addressed. We examined female fecundity and larval development on various diets in a Silphinae species, Necrophila (Eusilpha) japonica (Motschulsky). The experimental diets included a meat diet and various invertebrate diets, which reflect the ‘ancestral’ feeding habit in Silphinae, necrophagy, and the ‘derivative’ feeding habit, predatory feeding. Female fecundity was significantly higher on the meat diet (minced beef) than on an insect larvae diet (mealworms and dipteran larvae) but did not significantly differ from that on an earthworm diet. Larval developmental performance was significantly higher on the earthworm diet than on the meat and insect larvae diets. Our results for larval development were consistent with those of previous stable isotope analyses of the same species, in which isotopic values of larval samples agree with those of hypothetical consumers that utilize earthworms. The consistency of results among different methods indicates that N. japonica larvae are most likely earthworm feeders. In contrast, our results for the female fecundity experiment differed from those of previous stable isotope analyses, in which vertebrate carcasses unlikely serve as the staple diet of adults in the field; thus, the feeding habits of N. japonica adults remain unresolved. Our observations that females and larvae performed best on the meat and earthworm diets, respectively, may indicate that, in Silphinae, the diet shift from necrophagy to predatory habits occurs earlier in larvae than in adults.     

四种食料植物对八字地老虎生长发育和繁殖的影响

研究了油菜、甜菜、白菜和莴苣 4种食料植物对八字地老虎Agrotisc nigrumLinnaeus幼虫发育历期、蛹期、蛹重、成虫寿命和产卵量的影响。幼虫取食油菜时发育历期最短 (1 5 4d) ,蛹最重 (2 0 3 5mg) ,产卵量最多 (3 89 5粒 ) ,甜菜次之。幼虫取食莴苣时发育历期最长 ,蛹最轻 (1 3 6 1mg) ,产卵量最少(1 44 7粒 )。 4种食料植物对寄主的蛹期和成虫的寿命没有显著的影响