Absorption and metabolism of galactose and galactitol in Anthonomus grandis

Galactitol is a significant metabolite of galactose in fasted adults of Anthonomus grandis; this is the first time that galactitol has been found to be a metabolite of galactose in an insect in vivo. Galactitol is not metabolized, and galactose, at best, is poorly metabolized by the boll weevil to trehalose and glycogen. Because sizeable quantities appear in the haemolymph when fed, galactose and galactitol must be readily absorbed through the gut.     

Hemolymph analysis of irradiated and Dimilin-treated boll weevils, Anthonomus grandis

Analyses were conducted to determine the effects of irradiation, chemosterilization with Dimilin (diflubenzuron), and infection with three strains of Staphylococcus aureus on the chemistry of the hemolymph of adult boll weevils, Anthonomus grandis. The 7-fold decrease of sodium in the blood was associated with the loss of nerve conductivity and resultant decrease in muscular activity of γ-irradiated and Dimilin-fed 5- and 8-day-old adult weevils. Concomitantly, magnesium increased 4-fold and calcium increased 2-fold. Blood enzyme levels increased 40–60% in all treatments. Alpaline phosphatase increased 2-fold and serum glutamic oxaloacetic transaminase 2000-fold in the hemolymph of day old adults infected with Staphylococcus aureus.     

Uric acid in nucleic and amino acid synthesis in the boll weevil, Anthonomus grandis

When uric acid-2-¹⁴C was injected into the boll weevil, Anthonomus grandis, it was metabolized to RNA, DNA, amino acid, and ¹⁴CO₂ at the end of 2 hr. The free amino acids, lipoamino acids, and protein amino acids were all labelled with the free amino acids showing the highest specific activity. Incorporation in DNA was slight, but it was extensive in RNA; cytidylic acid showed the greatest amount of incorporation.     

Phenological adaptations in diapause termination by cecropia from different latitudes

Populations of Hyalophora cecropia (L.) that originated at five different latitudes in Illinois all emerged bimodally as adults. These geographical strains differed in the emergence dates of both their early and late emerging groups although they were all exposed to the same environmental conditions outdoors at urbana. The emergence dates became progressively earlier with strains originating either to the north or the south of Urbana. We suggest that this is so because the suitable growing season for cecropia is cut short by cold to the north and by the onset of hot summer weather to the south. Intraspecific hybrids between latitudinal strains do not necessarily have intermediate emergence dates.

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Zusammenfassung Cecropiapopulationen, welche aus fünf verschiedenen Breiten in Illinois stammten, hatten alle eine zweigipflige Falterschlüpfkurve. Die Herkünfte aus verschiedenen Breiten unterschieden sich im Schlüpfzeitpunkt der frühen und der späten Schlüpfgruppen, obwohl sie in Urbana gleichen Umweltbedingungen ausgesetzt waren. Dies zeigt, dass in diesen Herkünften genetisch fixierte quantitative Unterschiede in der zur Beendigung der Diapause notwendigen Menge an Umweltstimulation bestehen. Das Schlüpfdatum war zunehmend früher bei Herkünften, welche entweder nördlich oder südlich von Urbana herstammten. Dies könnte darin begründet sein, dass die günstige Entwicklungszeit für Cecropia im Norden durch kaltes Wetter und im Süden durch den Beginn des heissen Sommerwetters unterbrochen wird. Intraspezifische Hybriden zwischen Herkünften aus verschiedenen Breiten haben nicht notwendigerweise intermediäre Schlüpfzeiten, wie dies in der Literatur vorausgesagt wird.

     

Analysis of Cry8Ka5-binding proteins from Anthonomus grandis (Coleoptera: Curculionidae) midgut

Biotech crops expressing Bacillus thuringiensis Cry toxins present a valuable approach for insect control. Cry8Ka5, which is highly toxic to the cotton boll weevil (Anthonomus grandis), was used as a model to study toxin-ligand interactions. Three Cry-binding proteins were detected after toxin overlay assays. Following de novo sequencing, a heat-shock cognate protein and a V-ATPase were identified, whilst a ∼120 kDa protein remained unknown. Additional Cry8Ka5-binding proteins were visualized by two-dimensional gel electrophoresis ligand blots.     

Flavonoids from Gutierrezia grandis

Thirteen flavonoids, including three new compounds, were isolated from Gutierrezia grandis. The structures of the new compounds were 3,5,7,3′,4′-pentahydroxy-6,8-dimethoxyflavone, 5,7,3′-trihydroxy-3,6,8,4′,5′-pentamethoxyflavone and 5,7,3′,5′-tetrahydroxy-3,6,8,4′-tetramethoxyflavone 3′-O-glucoside.     

Endo-polymethylgalacturonase of boll weevil larvae, Anthonomus grandis: An initiator of cotton flower bud abscission

Pectinases of boll weevil larvae were fractionated by gel filtration, (NH₄)₂SO₄ precipitation, and hydroxylapatite chromatography. A fraction rich in endo-polymethylgalacturonase (endo-PMG) was able to macerate anther tissue and initiate abscission when injected into cotton flower buds. By partially destroying the cuticular permeability barrier, ethyl acetate and other solvents enhanced the abscission-initiating ability of the enzyme fraction. Growth regulator imbalances and degradation products resulting from endo-PMG action are probably the ultimate causal agents of abscission in flower buds.     

Bacterial genera isolated from field-collected (Diapausing) and laboratory-reared cotton boll weevils, Anthonomus grandis (Coleoptera: Curculionidae)

Little data exist on the bacterial flora of the cotton boll weevil, Anthonomus grandis, which is a common insect pest to cotton farmers in the United States. This investigation determined the total numbers of aerobic and anaerobic bacteria in diapausing field-collected boll weevils and active adult laboratory-reared boll weevils. Identifications were made of aerobic genera isolated from field-collected and laboratory-reared boll weevils that had previously been surface sterilized. The genera found, in order of decreasing frequency, in the field-collected boll weevils were Lactobacillus, Erwinia, Flavobacterium, Enterobacter, and Pseudomonas. The genera found, in order of decreasing frequency, in the laboratory-reared boll weevils were Lactobacillus, Pseudomonas, Streptococcus, Erwinia, Enterobacter, and Flavobacterium, Lactobacillus was the most frequently found genus in both groups.     

Phagocytic and humoral immunity of the adult cotton boll weevil, Anthonomus grandis (Coleoptera: Curculionidae), to Serratia marcescens

This investigation determined phagocytic, lysozymal, and bactericidal defensive responses of adult laboratory-reared cotton boll weevils, Anthonomus grandis. Phagocytosis was first demonstrated in boll weevils at 3 hr following injection of live Serratia marcescens. Maximum phagocytosis was found in 16.4% of plasmatocytes at the end of 16 hr postinjection. Lysozyme activity was demonstrated in both inoculated and uninoculated boll weevils. Peak lysozyme activity of 6.9 μg/ml was found at 48 hr following inoculation of heat-killed Serratia marcescens. Bactericidal activity was demonstrated in inoculated boll weevils but not in uninoculated boll weevils. Peak bactericidal activity occurred at 24 hr following inoculation of heat-killed Serratia marcescens. Lysozymal and bactericidal activities were shown to be separate functions.     

Fine structure of median neurosecretory cell in diapause and non-diapause brains of the silkworm, Bombyx mori

Electron micrographs of the larval brain of the silkworm, Bombyx mori, show that the largest median neurosecretory cell of the diapause egg producer may participate in the production of lipo-granules, and that of the non-diapause egg producer in the production of electron-lucent vesicles. It was found that there were ribosome-like particles in the diapause median neurosecretory cell, and they gradually developed into highly dense particles and lined up along the smooth-surfaced endoplasmic reticulum. They finally became lipo-granules.     

Ent-labdane derivatives from gutierrezia grandis

Two new diterpenes, 3α-angeloyloxy-18-hydroxy-13-furyl-ent-labda-8(17)-ene and 3α-hydroxy-18-angeloyloxy- 13-furyl-ent-labda-8(17)-ene and an only recently reported third diterpene, 3α, 18-dihydroxy-13-furyl-ent-labda-8(17)-ene, were isolated from the leaves of Gutierrezia grandis. Their structures were determined by mass spectral, IR, ¹H NMR and ¹³C NMR data was well as chemical evidence.     

Highly oxygenated flavonoid aglycones from gutierrezia grandis

Twelve known and nine new highly oxygenated flavonoid aglycones, some of which exhibit 2′-oxygenation, were isolated from Gutierrezia grandis.     

Uptake and loss of water in diapause and non-diapause eggs of crickets

ABSTRACT. In laboratory-laid eggs of the striped ground cricket, Allonemobius fasciatus DeGeer (Gryllidae), water absorption occurs at an early stage of embryogenesis (stage II) at 30°C but is delayed until later stages at lower temperatures. This is related to the variation in diapause stage at different temperatures. No egg developed beyond stage VII (the end of anatrepsis) without water absorption.
A. fasciatus shows seasonal variation in the stage of water absorption. At 30°C, eggs collected in August absorb water at the early stage while many of those collected in September avert diapause and absorb water at a later stage.
Diapause also influenced the water absorption of eggs in A. socius Scudder. Eggs of short-day females enter diapause and absorb water at stage II, while those of long-day females develop without diapause and absorb water at a later stage (around stage IV).
The susceptibility to desiccation (r.h. 50%) was examined at 20°C with A. fasciatus eggs. The percentage water loss and mortality of eggs varied with the time and duration of exposure to desiccation. Eggs are most sensitive to desiccation during the first several days after being laid and during the period of water absorption.     

RNA content and RNA synthesis in diapause and non-diapause eggs of Bombyx mori

Changes in amount of RNA and its synthesis were studied in diapause and non-diapause eggs of Bombyx mori. In non-diapause eggs, the amount of total RNA began to increase at the stage of late gastrula and increased constantly thereafter. The synthesis of total and ribosomal RNA commenced at the onset of gastrulation, and after two days it levelled off. In contrast, the amount of total RNA in diapause eggs did not change essentially, and only a low level of total and ribosomal RNA synthesis was detected. On the other hand, if diapause eggs were activated by hot HCl treatment 24 hr after oviposition, the results obtained were essentially similar to those for non-diapause eggs, except that there was a lag of two days after acid treatment. These findings indicate that a significant control of ribosomal and other RNA occurs in relation to diapause and development.     

Characterization of the quinone reductase activity of the ferric reductase B protein from Paracoccus denitrificans

The ferric reductase B (FerB) protein of Paracoccus denitrificans exhibits activity of an NAD(P)H: Fe(III) chelate, chromate and quinone oxidoreductase. Sequence analysis places FerB in a family of soluble flavin-containing quinone reductases. The enzyme reduces a range of quinone substrates, including derivatives of 1,4-benzoquinone and 1,2- and 1,4-naphthoquinone, via a ping-pong kinetic mechanism. Dicoumarol and Cibacron Blue 3GA are competitive inhibitors of NADH oxidation. In the case of benzoquinones, FerB apparently acts through a two-electron transfer process, whereas in the case of naphthoquinones, one-electron reduction takes place resulting in the formation of semiquinone radicals. A ferB mutant strain exhibited an increased resistance to 1,4-naphthoquinone, attributable to the absence of the FerB-mediated redox cycling. The ferB promoter displayed a high basal activity throughout the growth of P. denitrificans, which could not be further enhanced by addition of different types of naphthoquinones. This indicates that the ferB gene is expressed constitutively.     

New aspects in investigations of diapause and non-diapause dormancy types in insects and other arthropods

The paper resumes consideration of the problem posed by the Russian ecologist A.M. Emme (1953) on the need for a comparative study of diapause and quiescence (a non-diapause type of dormancy) in insects and other arthropods. The problem has recently become important due to the scarcity of eco-physiological studies of non-diapause dormancy, whose role in life cycle regulation remains unclear, and to the fact that most attention is now paid to diapause (as the leading adaptation in the control of seasonal development of arthropods). Analysis of data available for insects and acariform mites revealed the prospects of a comprehensive study of non-diapause forms of dormancy known presently (the common stage-independent quiescence, modified stage-specific quiescence, and post-diapause quiescence). The combination of post-diapause quiescence and diapause proper, revealed in many recent insects and acariform mites (mainly Prostigmata), may correspond to the initial ancestral state of dormancy in arthropods, representing a universal adaptation to both predictable and unpredictable environmental changes. This hypothesis gives a reasonable explanation of the possible dual nature of winter dormancy in oribatid mites (in contrast to the existing contradictory interpretations of their hibernal dormancy as only quiescence or only diapause).     

不同林龄尾巨桉人工林的生物量及其分配特征

根据1,2,3,5,8a共5个不同年龄的15块1000 m2尾巨桉样地(3次重复)调查资料,利用18株不同年龄和径阶的样木数据,建立以胸径(D)为单变量的生物量回归方程。采用样木回归分析法(乔木层)和样方收获法(灌木层、草本层、地上凋落物)获取不同林龄尾巨桉人工林的生物量,分析了其组成、分配及不同林龄生物量的变化趋势。结果表明:林分总生物量随林龄而增加,1,2,3,5年生和8年生尾巨桉人工林生物量分别为12.49,47.75,64.51,105.77和137.51 t/hm2,其中活体植物占85.60%—97.61%,地上凋落物占2.39%—14.40%;层次分配方面乔木层占绝对优势,占54.80%—91.56%,且随林龄的增加而增大,其次为凋落物,灌木层和草本层生物量较小,分别占1.02%—6.47%和0.28%—24.33%,均随林龄的增加呈递减趋势;乔木层以干所占比例最高,占51.07%—98.48%,且随林龄而增加,枝、叶、根分别占5.76%—11.80%,2.17%—21.01%和6.72%—14.87%,均随林龄而下降;灌木层以枝所占比例最高,为37.89%—56.79%,叶和根分别占16.35%—34.24%和19.52%—39.52%,随林龄的变化均不大;草本层分配1—5年生以地上所占比例较大,8年生地下所占比例高达63.87%;尾巨桉人工林乔木层各器官、地上凋落物及总生物量具有良好的优化增长模型,其总生物量的增长模型为Y=-1.693×104+3.337×104X-1.761X2;8年生尾巨桉人工林总生物量与30年生的木莲人工林持平,低于热带雨林,但其年均净生产量高达17.19 t/hm2,是一个光合效率高、固碳潜力大的速生丰产优良造林树种。     

Linoleic acid peroxidation initiated by Fe-reducing compounds recovered from Eucalyptus grandis biotreated with Ceriporiopsis subvermispora

This work evaluates linoleic acid peroxidation reactions initiated by Fe³⁺-reducing compounds recovered from Eucalyptus grandis, biotreated with the biopulping fungus Ceriporiopsis subvermispora. The aqueous extracts from biotreated wood had the ability to reduce Fe³⁺ ions from freshly prepared solutions. The compounds responsible for the Fe³⁺-reducing activity corresponded to UV-absorbing substances with apparent molar masses from 3 kDa to 5 kDa. Linoleic acid peroxidation reactions conducted in the presence of Fe³⁺ ions and the Fe³⁺-reducing compounds showed that the rate of O₂ consumption during peroxidation was proportional to the Fe³⁺-reducing activity present in each extract obtained from biotreated wood. This peroxidation reaction was coupled with in-vitro treatment of ball-milled E. grandis wood. Ultraviolet data showed that the reaction system released lignin fragments from the milled wood. Size exclusion chromatography data indicated that the solubilized material contained a minor fraction representing high-molar-mass molecules excluded by the column and a main low-molar-mass peak. Overall evaluation of the data suggested that the Fe³⁺-reducing compounds formed during wood biodegradation by C. subvermispora can mediate lignin degradation through linoleic acid peroxidation.