EFFECT OF AMINO ACID CONCENTRATION ON DIET UPTAKE AND PERFORMANCE BY THE PEA APHID, ACYRTHOSIPHON PISUM (HOMOPTERA: APHIDIDAE)

Abstract

Can. Ent. 106: 149-156 (1974) The average rate of diet uptake by the 1st-3rd instar nymphs of the pea aphid, Acyrthosiphon pisum (Harris), on chemically defined diets containing 0.0-5.0% amino acids varied from 0.08 to 0.23 rl/aphid/24 h and that by 4th instar nymphs to adults varied from 0.15 to 0.74 rl/aphid/24 h. The presence of amino acids increased the acceptability of diets to a great extent, as uptake on such diets was 2-5 times more than that on amino acid free diets. Uptake was lowest on diets lacking amino acids, and highest on those containing 3.5 and 2.5% amino acids by 1st-3rd instar nymphs and 4th instar nymphs to adults respectively. It is suggested that certain amino acids, either alone or in combination, act synergistically with sucrose as phagostimulants. Methionine was slightly phagostimulatory to the pea aphid and enhanced the acceptability of a free amino acid diet and of a sucrose solution.As expected the rate of feeding increased as the aphids grew. Nymphs reached the adult stage, and reproduced on each diet, except on the one lacking amino acids. The longevity on different diets varied from 7 to 37 days. A concentration of 2 4 % amino acids, with an optimum at 3.5%, appears to be essential for the growth, survival, and larviposition of the pea aphid.Due to the punctures made in the stretched parafilm by aphids during feeding the rate of evaporation from fed sachets was significantly higher than that from unfed sachets. It is therefore suggested that in experiments where rates of feeding are measured by differential weighings of the sachets, these be renewed at 24-h intervals.

Acyrthosiphon pisum performance in response to the sugar and amino acid composition of artificial diets, and its relation to lucerne varietal resistance

“…They interfere with the settling behaviour of the aphid on a given diet, measured for example by the refusal rates ( Fig. The main factor is obviously the sugar/amino acid ratio, with optimal levels at 2.5% amino acids and 15 to 25% sucrose, as determined by Srivastava & Auclair (1971, 1974 for other biotypes of A. pisum. 3).…”

Biting off more than you can chew: sexual selection on the free amino acid composition of the spermatophylax in decorated crickets

“…Four of the five amino acids (excluding glutamine) are essential amino acids for insects [37], and must be acquired from dietary sources because they cannot be synthesized, yet are essential for growth and reproduction. Extensive research has revealed that insects respond to the phagostimulatory effects of a variety of amino acids, including alanine, serine, histidine, proline, valine, leucine, methionine, phenylalanine, tryptophan and threonine [17][18][19]. However, the effects of amino acids are frequently context-dependent, and the multivariate effect of different amino acids on feeding has received little attention.…”

“…The free amino acids occurring in the greatest concentration were glycine and proline, whereas those amino acids deemed essential [16] were found only at low concentrations. Free amino acids are known phagostimulants in insects [17][18][19][20][21], and are used by some species to assess nutritional quality of plant tissue [22]. Artificial 'gels' containing the four most abundant free amino acids found in the spermatophylax and fed to female Gryllodes resulted in increased feeding time relative to females fed control gels [14].…”

Biochemical basis of winter wheat resistance to the grain aphid, Sitobion avenae

“…Nutritional requirements of many aphid species are very similar to those of other insects, but recent studies (Srivastava etal., 1985) have shown that even biotypes of a single species may have different dietary needs for certain substances. Growth, survival, larviposition (Srivastava & Auclair, 1974), feeding site, and alate formation (Parry, 1977) are greatly influenced by the total amino acid concentration in the diet, and for A. pisum the optimum concentration of amino acids in the chemically defined diet appears to be 3.5~o, with a range of 2-4~ (Srivastava & Auclair, 1974), and that for M. persicae 2-4~o (Dadd & Krieger, 1968). For A. fabae alanine, proline and serine appear to act primarily as phagostimulant; histidine and methionine were essential for protein synthesis and did not act as phagostimulants, whereas omission of cysteine, phenylalanine or tyrosine failed to reduce diet intake (Leckstein & Llewellyn, 1974).…”