TOTAL GLYCOGEN IN THE PEA APHID, ACYRTHOSIPHON PISUM (HARR.) (HOMOPTERA, APHIDIDAE)

1965 ◽  
Vol 43 (2) ◽  
pp. 225-227 ◽  
Author(s):  
P. N. Srivastava

In the pea aphid, Acyrthosiphon pisum (Harr.), the amount of glycogen increases steadily as the aphid grows from larval to adult stage. The newly born larva, however, lacks the glycogen reserve.

1972 ◽  
Vol 104 (6) ◽  
pp. 927-936 ◽  
Author(s):  
J. L. Auclair ◽  
P. N. Srivastava

AbstractPerformance of the pea aphid, Acyrthosiphon pisum (Harris), on a holidic diet containing different metal ions was studied by individually incorporating into the diet a salt of the metal ion to be tested. The performance of the pea aphid was markedly improved when the diet contained iron; the first-generation adults reproduced, and the second-generation nymphs moulted twice or thrice, but did not reach the adult stage. Molybdenum, boron, and copper, at certain concentrations, induced the production of some live nymphs, but manganese, zinc, calcium, and cobalt did not. However, the presence of zinc, cobalt and calcium, at most of the concentrations used, slightly improved growth and reduced mortality. Furthermore, the presence of calcium appeared essential for development to the adult stage. Tolerance to all these metals was fairly high, but sodium molybdate at a concentration of 50.0 mg, and sodium borate at concentrations of 40–100 mg/100 ml of diet, appeared to reach toxic levels.Iron was found to be essential for reproduction and a range of 53–211 μg of elemental iron per 100 ml of diet appeared to be optimum. It is suggested that a synergistic effect between at least some of these metals is required for continuous reproduction of the pea aphid.


2003 ◽  
Vol 56 ◽  
pp. 185-189 ◽  
Author(s):  
X.Z. He ◽  
Q. Wang ◽  
D.A.J. Teulon

The effect of parasitism by Aphidius eadyi Stary González and Hall on reproduction of pea aphid Acyrthosiphon pisum (Harris) was studied in the laboratory Aphids attacked as 1st and 2nd instars became mummies in the 4th instar; parasitised 3rd instar nymphs became mummies in the adult stage without producing any progeny Parasitised 4th instar nymphs and adults produced progeny but had a shorter reproductive period and produced fewer (Plt;00001) progeny than unparasitised aphids Parasitised 4th instar nymphs and adults had significantly lower intrinsic rates of increase (rm) net reproductive rates (R0) shorter generation time (T) and longer doubling time (DT) than unparasitised aphids The potential impact of the parasitoid on host population growth is discussed


2005 ◽  
Vol 58 ◽  
pp. 202-207 ◽  
Author(s):  
X.Z. He ◽  
Q. Wang ◽  
D.A.J. Teulon

The effect of parasitism by Aphidius ervi Haliday (Hymenoptera Aphidiidae) on development survival and reproduction of pea aphid Acyrthosiphon pisum (Harris) (Hemiptera Aphididae) of different ages was studied in the laboratory Aphids parasitised when 1 and 2 days old (1st and 2nd instar) died at the 4th instar However those parasitised when 3 to 6 days old (3rd and 4th instar) could reach the adult stage following parasitism and those that were parasitised after 4 days old (late 3rd instar) were still able to produce progeny In comparison with the unparasitised aphids the parasitised aphids had a significantly shorter reproductive period and produced significantly fewer progeny and thus had significantly lower intrinsic rates of increase net reproductive rates shorter generation time and longer doubling time The potential impact of the parasitoid on host population growth is discussed


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.


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