Survival of boll weevil （Coleoptera： Curculionidae） adults after feeding on pollens from various sources

The survival of overwintering boll weevil, Anthonomus grandis grandis （Boheman）, adults on non-cotton hosts in the Lower Rio Grande Valley （LRGV） of Texas was examined from 2001 to 2006. The success of the Boll Weevil Eradication Program, which was reintroduced into the LRGV in 2005, depends on controlling overwintering boll weevil populations. Laboratory studies were conducted using boll weevil adults that were captured in pheromone traps from September through March. The number of adults captured per trap declined significantly in the field from fall to the beginning of spring （3.5-7.0-fold）. The proportion of trapped males and females did not differ significantly. The mean weight of boll weevil adults captured in September was 13.3 mg, while those of captured adults from November to February were significantly lower and ranged from 6.7 to 7.8 mg. Our results show that boll weevil adults can feed on different plant pollens. The highest longevity occurred when adults were fed almond pollen or mixed pollens （72.6 days and 69.2 days, respectively） and the lowest when they fed on citrus pollen or a non-food source （9.7 days or 7.4 days, respectively）. The highest adult survival occurred on almond and mixed pollens [88.0%-97. 6% after 1st feeding period （10 days）, 78.0%-90.8% after 3rd feeding period （10 days）, 55. 0%-83.6% after 5th feeding period （10 days）, and 15.2%-32.4% after lOth feeding period （10 days）]. The lowest adult survival occurred on citrus pollen [52.0%-56.0% after 1st feeding period （10 days）, 13.3% after 3rd and 5th feeding periods （10 days）, and 0 after 6th feeding period （10 days）]. Pollen feeding is not a behavior restricted to adult boll weevils of a specific sex or physiological state. Understanding how boll weevil adults survive in the absence of cotton is important to ensure ultimate success of eradicating this pest in the subtropics.     

Syntheses of Several Compounds Related to Helminthosporol and their Plant Growth-regulating Activities

Several compounds related to helminthosporol (I), a natural plant-growth promoter, were prepared from I and their plant-growth regulating activities were examined together with those of the derivatives reported in the previous paper, using rice and lettuce seedlings. Among the compounds tested, helminthosporic acid (III) exhibited marked elongation effect to the shoot growth of rice and lettuce seedlings, whereas the effect of I was specific to the former. Results of the biological test are reported in details.     

Interactions between dietary nitrogen and simulated autumn conditions on diet consumption and reproductive development in the boll weevil, Anthonomus grandis

ABSTRACT. Dietary nitrogen content and short-day, cool scotophase temperature were investigated for effects on diet consumption and reproductive development in the female boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae). Experimental weevils were maintained from the day of adult eclosion on cottonseed flour diets on a LD10:14 h, 27:15C cycle. Control weevils were maintained under long-day conditions (LD13:11) at a constant 27C.
Diets containing 4% and 1.7% N were labelled with a ¹⁴C-amino acid mixture and fed to individual females for 24 h to permit determinations of diet consumption rate, amino acid absorption, and reproductive allocation of the assimilated amino acids.
Females fed the 1.7% N diet under long-day, 27C laid 50% fewer eggs than females fed the 4% N diet under the same regimen. Egg production was depressed further by the 1.7% N diet when combined with short-day, and cool scotophase temperatures. These latter conditions delayed, but did not prevent, attainment of a high rate of egg production by females fed the 4% N diet.
The short-day, cool temperature regimen also stimulated diet consumption but reduced the allocation of absorbed ¹⁴C amino acids towards oogenesis.     

Plant Growth-regulating Activities of 4-Methoxybenzophenones

4-Methoxybenzophenones showed diverse plant growth-regulating actions; inhibition of shoot and root growth, induction of chlorosis, and a disturbance in phototropism or geotropism. No clear relationship was found between the inhibitory activities and Hammett’s σ of the substituents. A brief discussion of the relationship between the growth-inhibitory activity and the absorption wavelength explains the mode of action.     

Physiological Effects of Nondialyzable Melanoidin in Rats

The absorption and excretion of melanoidins, a mixture of the low- and high-molecular weight components (LMM and HMM), and the LMM component prepared from a l-lysine^d-glucose system, at pH 7.4 and 9.0, respectively, and the effects of these melanoidins on cholesterol metabolism were examined in rats. Weanling male rats of the Wistar strain weighing about 50 g were fed diets containing 10% casein (10C) with 3% of a melanoidin or 25% casein (25C) with 4% of the melanoidin for 12 weeks, and the 25C diet including 3% of the melanoidin or LMM for 8 weeks. The growth and organ weights of the melanoidin-supplied groups were not different from those of the control ones. In rats given the melanoidin diets with both protein levels, the kidneys became dark brownish due to the accumulation of the melanoidin, though the accumulated amount was extremely small (nearly 0.5 mg/g wet kidney), and gel filtration chromatography of a water extract of the kidneys on Sephadex G-75 showed that the deposited melanoidin was the LMM component. Most of the ingested melanoidin, however, was excreted in the feces, and on comparison of the gel chromatographic patterns, the melanoidin groups were found to have more fecal LMM than the control ones. When rats were provided with LMM, HMM increased in their feces. The addition of melanoidin suppressed the level of plasma total cholesterol and elevated the fecal excretion of total lipids and total cholesterol. The urinary contents of protein and total creatinine did not differ from those in the control groups.     

Distribution and probable physiological role of esterases in reproductive,digestive, and fat-body tissues of the adult cotton boll weevil,Anthonomus grandis Boh

Polyacrylamide gel electrophoresis was used to examine gut, Malpighian tube, fat-body, testes, and ovariole tissues of the adult cotton boll weevil, Anthonomus grandis Boh. Esterases for which the inheritance has been reported previously by Terranova using whole-body homogenates were detected in dissected tissues and the probable physiological function of each allozyme is suggested. EST-1 occurs most frequently in ovarioles and female fat bodies. EST-2 is most often found in fat bodies and may be important in lipid turnover. No sex difference was observed. EST-3^S is found in fat bodies and reproductive tissue, while EST-3^F is always located in gut tissues, indicating that EST-3 is not controlled by a single autosomal locus with two codominant alleles as previously reported. EST-4, the most abundant esterase, can be detected in gut tissue at any age and is probably involved in digestion. EST-5 contains four allozymes which appear most frequently in testes and may be important during reproduction.     

Esterases of laboratory-reared and field-collected cotton boll weevils,Anthonomus grandis Boh.: Polymorphism of adult esterases and formal genetics of esterase II

The esterases of the cotton boll weevil were separated by polyacrylamide gel electrophoresis into four major regions. These were named Est I–IV in order of migration from anode to origin. Polymorphism was observed in all regions. The Est II region was shown to consist of no more than two bands (fast and slow). The inheritance of the fast and slow bands of Est II was demonstrated to be controlled by codominant autosomal alleles. Analysis of the gene frequency of the Est II region showed that one field population was consistent with the Hardy-Weinberg law (P=0.995), while a second field population was not at equilibrium (P<0.001).This work was supported in part by a Faculty Research Grant from Memphis State University.     

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.     

Molecular cloning of alpha-amylases from cotton boll weevil,Anthonomus grandis and structural relations to plant inhibitors: an approach to insect resistance

Anthonomus grandis, the cotton boll weevil, causes severe cotton crop losses in North and South America. Here we demonstrate the presence of starch in the cotton pollen grains and young ovules that are the main A. grandis food source. We further demonstrate the presence of -amylase activity, an essential enzyme of carbohydrate metabolism for many crop pests, in A. grandis midgut. Two -amylase cDNAs from A. grandis larvae were isolated using RT-PCR followed by 5 and 3 RACE techniques. These encode proteins with predicted molecular masses of 50.8 and 52.7 kDa, respectively, which share 58% amino acid identity. Expression of both genes is induced upon feeding and concentrated in the midgut of adult insects. Several -amylase inhibitors from plants were assayed against A. grandis -amylases but, unexpectedly, only the BIII inhibitor from rye kernels proved highly effective, with inhibitors generally active against other insect amylases lacking effect. Structural modeling of Amylag1 and Amylag2 showed that different factors seem to be responsible for the lack of effect of 0.19 and -AI1 inhibitors on A. grandis -amylase activity. This work suggests that genetic engineering of cotton to express -amylase inhibitors may offer a novel route to A. grandis resistance.     

Production of Ribotides of 4-Hydroxy- and 4-Aminopyrazolo[3, 4-d]pyrimidine by Brevibacterium ammoniagenes

Brevibacterium ammoniagenes ATCC 6872 was previously reported to accumulate large amounts of IMP, AMP, ADP, ATP, GMP, GDP and GTP from the corresponding purine bases. The organism was also reported to convert various derivatives of purine and 8-azapurine to the corresponding ribotides.

Using the similar process, ribotidation of pyrazolo[3, 4-d]pyrimidines was attempted, and it was found that the same organism was able to produce remarkable amounts of 4-hydroxy-1-β-d-ribofuranosylpyrazolo[3, 4-d]pyrimidine 5′-monophosphate (HPP-RP) from 4-hydroxypyrazolo[3, 4-d]pyrimidine (HPP, allopurinol) and 4-amino-1-β-d-ribofuranosylpyrazolo[3, 4-d]pyrimidine 5′-monophosphate and 5′-diphosphate from 4-amino-pyrazolo[3, 4-d]pyrimidine.

The crystals of HPP-RP (Na-salt) were isolated from the cultured broth of Br. ammoniagenes incubated with HPP, and characterized based on UV-spectra, IR-spectrum, NMR and others.

It was also found that HPP-RP was converted to the corresponding riboside by hydrolysis in aqueous solution (pH 4.0 ~ 9.0) for 6 hr at 140°C. The hydrolysis of HPP-RP was also accomplished with various organisms.     

Inhibitory Activities of 3-Thiophenecarboxylic Acid and Related Compounds on Plant Growth

3-Thiophenecarboxylic acid (1) showed strong growth-inhibitory activity toward the following plants but not Glycine max Merrill; Brassica campestris subsp. rapa Hook. fil. et Anders, Sesamum indicum L., Lactuca sativa L. var. longifolia Lam, Echinochloa utilis Ohwi et Yabuno and Allium tuberosum Rottler. Compound 1 strongly inhibited the growth of roots of S. indicum and L. sativa even at the low concentration of 5.0 × 10^?5 m. The growth-inhibitory activity of 1-related compounds (2–6) on S. indicum was also studied. Among the compounds, 3-thiopheneacetic acid (6) showed the strongest inhibitory activity, but 3-thiophenecarboxaldehyde (2), 3-thiophenemethanol (3), and 3-thiophenecarboxamide (5) showed no activity. The radicles of plants treated with these active compounds showed negative geotropism.     

植物防御反应的两种信号转导途径及其相互作用

植物遭到病虫害时质膜两侧的离子发生跨膜交换、释放钙离子、产生大量的活性氧并产生蛋白质磷酸化,通过水杨酸、茉莉酸以及乙烯信号转导途径激活了PR1、BGL2等防御相关基因.这些基因的表达产物如蛋白酶抑制剂(proteinase inhibitor,PI)等能够抑制植食性昆虫的消化酶以及增加细胞壁厚度,从而增强了对昆虫和病原菌等的抵抗力.植物的各种防御信号途径之间既存在拮抗作用又有协同作用,共同组成了一个复杂的防御体系,在一定程度上有效地抵御各种生物胁迫.     

Karyotypic analysis of the cotton boll weevil, Anthonomus grandis Boheman

The diploid chromosome number of the cotton boll weevil, Anthonomus grandis Boheman, is 44. Both C‐ and N‐banding techniques of mitotic cells demonstrated constitutive heterochromatin in the p arm of the eight largest chromosomes, the p arm of the X chromosome, and the centromeric region of autosomal groups A–D. Neither the y nor the group E autosomes appeared to contain constitutive heterochromatin. Supernumerary chromosomes were not found in the boll weevil. Restriction endonuclease banding of primary spermatocytes revealed a rod‐shaped Xy tetrad in which the X and y were terminally associated. The p arm of the large, submetacentric X was C‐band positive. While two of the autosomal tetrads were typically ring‐shaped in primary spermatocytes, the remaining 19 autosomal tetrads were rod‐shaped. This revised version was published online in July 2006 with corrections to the Cover Date.     

Green leaf volatiles enhance aggregation pheromone of boll weevil, Anthonomus grandis

Enhancement of an insect pheromone response by green leaf volatiles is reported for the first time in the boll weevil, Anthonomus grandis Boh. (Coleoptera: Curculionidae). Single cell recordings from antennal olfactory receptors revealed a class of cells selectively responsive to six carbon alcohols and aldehydes (i.e., green leaf volatiles). Field tests with released weevils demonstrated enhanced trap captures with trans-2-hexen-l-ol, cis-3-hexen-l-ol, or l-hexanol paired with grandlure, the boll weevil aggregation pheromone, when in competition with grandlure alone. Although dose-response curves constructed from electroantennograms were indicative of similar populations of receptor cells for selected six carbon alcohols, one of the compounds tested, cis-2-hexen-l-ol, was inactive in field tests. Trans-2-hexenal was active in single cell recordings, but was also inactive in field tests. In tests in cotton fields with indigenous weevil populations, trans-2-hexen-l-ol not only enhanced pheromone trap captures, but also extended the longevity of attractiveness of pheromone-baited traps. The combined electrophysiological and field data support across-fiber coding of green leaf volatiles by boll weevil olfactory receptors. The results are discussed with regard to the chemistry of the host plant of the boll weevil, cotton (Gossypium hirsutum L.), and potential economic significance for boll weevil eradication/suppression.

---

Résumé Pour la première fois, l'augmentation de la puissance de la phéromone d'agrégation sous l'action de l'odeur verte est signalée chez A. grandis. Les enregistrements unitaires de cellules des récepteurs olfactifs des antennes a mis en évidence une catégorie de cellules réagissant sélectivement aux alcools et aux aldéhydes à 6 carbones (c'est-à-dire aux substances volatiles des feuilles vertes). Des essais dans la nature ont montré une augmentation des captures par les pièges de grandlure (phéromone d'agrégation du charançon) renforcés par du trans-2-hexen-l-ol, du cis-3-hexen-l-ol, ou du l-hexanol.Bien que les courbes des réponses en fonction des doses construites à partir des électroantennogrammes indiquent des catégories de cellules réceptrices identiques pour les alcools à 6 carbones examinés, l'une de ces substances, cis-2-hexen-l-ol, s'est révélée inactive dans la nature. Le trans-2-hexenal qui était actif avec des enregistrements unitaires de cellules, était lui aussi inactif dans la nature. Dans des essais dans des champs de coton avec des populations indigènes de charançons, le trans-2-hexen-l-ol a, non seulement augmenté l'efficacité des pièges à phéromone, mais a prolongé leur attractivité. Les résultats d'électrophysiologie combinés aux données de la nature appuient le modelage transversal des substances vertes volatiles des feuilles par les récepteurs olfactifs du charançon. Ces résultats sont interprétés en relation avec la chimie de la plante-hôte de A. grandis, le coton, Gossypium hirsutum L., et leur possibilité d'utilisation économique pour l'éradication du charançon.