scholarly journals Reproduction, Survival Rate and Longevity of Apterous Parthenogenetic Females of Pea Aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), on Chemically-Defined Artificial Diets with Different Sucrose Concentration and pH.

1998 ◽  
Vol 42 (2) ◽  
pp. 88-90
Author(s):  
Shin Yamada ◽  
Ken-ichiro Honda
1996 ◽  
Vol 199 (6) ◽  
pp. 1269-1276 ◽  
Author(s):  
J Rhodes ◽  
P Croghan ◽  
A Dixon

Ingestion, excretion and respiration in aphids were studied using artificial diets labelled with radioactive sucrose or amino acids. The rate of ingestion of a 25 % w/v sucrose diet was 12.4 nl mg-1 h-1 and the honeydew excretion rate was 5.3 nl mg-1 h-1, about 43 % of the volume ingested during the same period. The concentration of sugars in the honeydew was equivalent to 0.53 mol l-1 sucrose and 69 % of the sucrose ingested was assimilated. The amino acid concentration of honeydew was 24.6 mmol l-1 and 94 % of the ingested amino acids were assimilated. Respiration was measured by collecting respired 14CO2 using a chamber which allowed the aphids to feed during the experiments on 14C-labelled artificial diets. While feeding on a 25 % w/v sucrose diet, sucrose was respired at the rate of 1.32x10(-6) mmol mg-1 h-1, equivalent to 0.354 µl O2 mg-1 h-1, which was 14.6 % of the rate of ingestion. There was no evidence that reducing the dietary sucrose concentration from 22 to 11 % w/v had any effect on the rate at which sucrose was respired. Amino acids were respired at a rate of 0.14x10(-6) mmol mg-1 h-1, which was 6.4 % of the rate of ingestion. Dietary sucrose was oxidised in preference to amino acids.


1997 ◽  
Vol 200 (15) ◽  
pp. 2137-2143 ◽  
Author(s):  
T Wilkinson ◽  
D Ashford ◽  
J Pritchard ◽  
A Douglas

Pea aphids, Acyrthosiphon pisum, containing their symbiotic bacteria (untreated aphids) and experimentally deprived of their bacteria by treatment with the antibiotic rifampicin (antibiotic-treated aphids) were reared on the plant Vicia faba. The sugars in the honeydew produced by untreated aphids comprised predominantly the monosaccharides glucose and fructose, while the honeydew of antibiotic-treated aphids contained considerable amounts of oligosaccharides of up to 16 hexose units. The honeydew and haemolymph of the aphids were iso-osmotic, and their osmotic pressure was significantly lower in untreated aphids (0.91­0.95 MPa) than in antibiotic-treated aphids (1.01­1.05 MPa) (P<0.05). For insects reared on chemically defined diets containing 0.15­1.0 mol l-1 sucrose (osmotic pressure 1.1­4.0 MPa), the osmotic pressure of the aphid haemolymph did not vary with dietary osmotic pressure, but was regulated to approximately 1.0 MPa in untreated and 1.3 MPa in antibiotic-treated aphids. The sugars in the aphid honeydew varied with dietary sucrose concentration; with monosaccharides dominant at low concentrations and oligosaccharides dominant at high concentrations of dietary sucrose. The lowest dietary sucrose concentration at which honeydew oligosaccharides were detected was 0.2 mol l-1 for the antibiotic-treated aphids and 0.3 mol l-1 for untreated aphids. These data indicate that the aphid, and not its associated microbiota, mediates the synthesis of oligosaccharides when the osmotic pressure of the ingesta is high.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guang Wang ◽  
Jing-Jiang Zhou ◽  
Yan Li ◽  
Yuping Gou ◽  
Peter Quandahor ◽  
...  

AbstractTrehalose serves multifarious roles in growth and development of insects. In this study, we demonstrated that the high trehalose diet increased the glucose content, and high glucose diet increased the glucose content but decreased the trehalose content of Acyrthosiphon pisum. RNA interference (RNAi) of trehalose-6-phosphate synthase gene (ApTPS) decreased while RNAi of trehalase gene (ApTRE) increased the trehalose and glucose contents. In the electrical penetration graph experiment, RNAi of ApTPS increased the percentage of E2 waveform and decreased the percentage of F and G waveforms. The high trehalose and glucose diets increased the percentage of E2 waveform of A. pisum red biotype. The correlation between feeding behavior and sugar contents indicated that the percentage of E1 and E2 waveforms were increased but np, C, F and G waveforms were decreased in low trehalose and glucose contents. The percentage of np, E1 and E2 waveforms were reduced but C, F and G waveforms were elevated in high trehalose and glucose contents. The results suggest that the A. pisum with high trehalose and glucose contents spent less feeding time during non-probing phase and phloem feeding phase, but had an increased feeding time during probing phase, stylet work phase and xylem feeding phase.


1983 ◽  
Vol 115 (12) ◽  
pp. 1615-1619 ◽  
Author(s):  
William D. Hutchison ◽  
David B. Hogg

AbstractCornicle length measuremetns of Acyrthosiphon pisum (Harris) nymphs reared in the laboratory were instar-specific and unaffected by rearing temperature. A multimodal analysis of cornicle lengths of field-collected aphids clearly detected four distribution peaks (i.e., instars) in five different field populations, and there was generaaly little overlap between successive instar distributions. However, third and fourth instars in the spring field sample could not be separated accurately due to the shorter cornicle length of nymphs that developed from overwintered eggs. Cornicle length proved to be a useful criterion for separating virginoparous A. pisum instars in samples collected in southern Wisconsin.


2006 ◽  
Vol 72 (3) ◽  
pp. 1956-1965 ◽  
Author(s):  
Anne-Marie Grenier ◽  
Gabrielle Duport ◽  
Sylvie Pagès ◽  
Guy Condemine ◽  
Yvan Rahbé

ABSTRACT Dickeya dadantii (Erwinia chrysanthemi) is a phytopathogenic bacterium causing soft rot diseases on many crops. The sequencing of its genome identified four genes encoding homologues of the Cyt family of insecticidal toxins from Bacillus thuringiensis, which are not present in the close relative Pectobacterium carotovorum subsp. atrosepticum. The pathogenicity of D. dadantii was tested on the pea aphid Acyrthosiphon pisum, and the bacterium was shown to be highly virulent for this insect, either by septic injury or by oral infection. The lethal inoculum dose was calculated to be as low as 10 ingested bacterial cells. A D. dadantii mutant with the four cytotoxin genes deleted showed a reduced per os virulence for A. pisum, highlighting the potential role of at least one of these genes in pathogenicity. Since only one bacterial pathogen of aphids has been previously described (Erwinia aphidicola), other species from the same bacterial group were tested. The pathogenic trait for aphids was shown to be widespread, albeit variable, within the phytopathogens, with no link to phylogenetic positioning in the Enterobacteriaceae. Previously characterized gut symbionts from thrips (Erwinia/Pantoea group) were also highly pathogenic to the aphid, whereas the potent entomopathogen Photorhabdus luminescens was not. D. dadantii is not a generalist insect pathogen, since it has low pathogenicity for three other insect species (Drosophila melanogaster, Sitophilus oryzae, and Spodoptera littoralis). D. dadantii was one of the most virulent aphid pathogens in our screening, and it was active on most aphid instars, except for the first one, probably due to anatomical filtering. The observed difference in virulence toward apterous and winged aphids may have an ecological impact, and this deserves specific attention in future research.


1971 ◽  
Vol 64 (2) ◽  
pp. 353-356 ◽  
Author(s):  
David H. Akey ◽  
Stanley D. Beck

Heredity ◽  
2002 ◽  
Vol 89 (5) ◽  
pp. 346-352 ◽  
Author(s):  
M C Caillaud ◽  
M Boutin ◽  
C Braendle ◽  
J-C Simon

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