Studies on the Relations of Insect and Host Plant: I. Effects of Water Stress in Host Plants on Infestation by Aphis fabae Scop., Myzus persicae (Sulz.) and Brevicoryne brassicae (L.)

Nature ◽  
1967 ◽  
Vol 213 (5080) ◽  
pp. 1051-1052 ◽  
Author(s):  
C. H. WEARING ◽  
H. F. VAN EMDEN
2017 ◽  
Vol 47 (3) ◽  
pp. 237-246 ◽  
Author(s):  
Genimar Rebouças JULIÃO ◽  
Emmanuel Duarte ALMADA ◽  
Flávia Regina Capellotto COSTA ◽  
Marco Antônio Alves CARNEIRO ◽  
G. Wilson FERNANDES

ABSTRACT Topographic gradients in terra firme forests are associated with pronounced changes in soil texture, soil nutrients and distance to the water-table, thereby creating different hydric and nutritional conditions for plants and their associated herbivore community. The aim of this study was to investigate galling species and host plant richness and gall species composition across topographic habitats differing in nutrient and water stress in the Brazilian Amazon rainforest. Nineteen 250 x 3 m plots were randomly sampled in the valley, slope, plateau-slope transition, and plateau habitats in terra firme forests. All individual dicotyledonous plants 1 to 3 meters high were examined for the presence of insect galls. Galling species and host plant richness differed significantly among the studied habitats and were higher in slope habitats (drier habitats), as expected. More humid areas (valleys) showed the lowest richness of galling species, and a lower number of understory host plants. PERMANOVA and PERMDISP results demonstrated that the gall species composition differed significantly in the valley, slope, plateau-slope transition, and plateau areas. However, these structural differences in species composition could be due to unequal dispersion of variability among forest habitats. Our data suggested that spatial heterogeneity, such as a mosaic of local water status and nutrient availability resulting from the topographic conditions, can affect host plants and their associated galling insects.


1991 ◽  
Vol 81 (4) ◽  
pp. 417-427 ◽  
Author(s):  
Chris Hodgson

AbstractDispersal of apterae from their natal plant was monitored for three aphid species (Myzus persicae (Sulzer), Brevicoryne brassicae (Linnaeus) and Megoura viciae Buckton), each on a different host plant. Some movement off the plant occurred even in the initial parental and second generations, when the plant appeared to be growing normally and when crowding was unlikely to be the cause. However, in most experiments the most marked increase in apterous dispersal coincided with a reduction or even cessation of plant growth. In nearly all the experiments this dispersal occurred when the population on the natal plant exceeded about 20 adults and their offspring per plant. The main emigrants were fourth instar apterae and prelarviposition adult apterae. The implications of this behaviour are discussed, and it is argued that apterous dispersal might be common in aphids, allowing a fuller utilization of the environment than would be likely by alate dispersal alone.


Author(s):  
Emily Mooney ◽  
Maria Mullins ◽  
James Den Uyl ◽  
Samantha Trail ◽  
Phuong Nguyen ◽  
...  

AbstractDeclining snow cover is reshaping ecological communities. Early loss of snow cover initiates changes in key interactions that mediate herbivore abundance, i.e., top-down and bottom-up effects. In this study, we used a field experiment to test the effects of host plant water stress and phenology on the multitrophic interactions that determine aphid abundance. The aphid, Aphis asclepiadis, in our study system colonizes the flowering stalks of the host plant Ligusticum porteri and relies on a protection mutualism with ants. We added snow and water to replicate host plants and tested for a variety of phenological and physiological responses to these treatments. Relative to host plants in ambient conditions, both water and snow addition reduced key signals of water stress (senescence and abscisic acid levels) and increased seed set. While aphid colonies were generally larger with reduced host plant water stress, the ant–aphid mutualism interacted with plant quality in complex ways. Without ant tending, we did not detect differences in aphid colony growth with host plant treatment. When tended by ants, aphid colony growth was greatest on host plants with snow addition. Host plant quality also altered the benefits exchanged in this mutualism. Ant-tended colonies hosted by plants with snow addition produced honeydew enriched in trehalose, which may have decreased both ant and natural enemy abundance. Our results suggest that early loss of snow reduces aphid abundance by creating low-quality, water-stressed host plants, and this effect may be exacerbated by natural enemies and the costs of ant attendance.


1983 ◽  
Vol 115 (2) ◽  
pp. 215-217
Author(s):  
M. L. Sharma ◽  
L. M. Thériault

Several chemosterilants have been tested against insects (Borkovec 1966). As a result, a total or partial sterility and decrease in fecundity have been noticed in several insects. Amongst Aphididae, Brevicoryne brassicae L., Myzus persicae Sulzer, Aphis fabae Scop., Macrosiphum euphorbiae Thomas, and Acyrthosiphon pisum (Harris) have been tested to determine the effects of chemosterilants like tepa, thiotepa, and metepa (Bonnemaison 1966; Bhalla and Robinson 1966, 1968; Chawla et al. 1973, 1974; Sharma et al. 1980; Steffan and Stüben 1976). In all previous work, either viviparae or their nymphal instars were the object of chemosterilant treatment and up to 95% reduction in fecundity was observed. Nothing to date has been described on the effect of chemosterilants on the sexuparae or sexuales of Aphididae. To continue with the results obtained by Sharma and Thériault (1980) and Sharma et al. (1980) on the viviparae, this paper describes the effects of 0.5% thiotepa [Tris (1-aziridinyl) phosphine sulphide] on sexuparae of the pea aphid, Acyrthosiphon pisum (Harris), and their progeny.


1971 ◽  
Vol 61 (1) ◽  
pp. 97-111 ◽  
Author(s):  
A. F. G. Dixon ◽  
S. D. Wratten

Adults of Aphis fabae Scop. can weigh from as little as 200 μg to as much as 1 800 μg (Way & Banks, 1967), a remarkable range in size for a single species. An extensive range in size also occurs among the adults in other species of aphid (Murdie, 1969a, b; Dixon, 1970). Small individuals result when aphids develop either under crowded conditions or on a mature host-plant; large aphids result when the nymphs are reared in isolation or on young or senescent host-plants (Way & Banks, 1967; Murdie, 1969a, b; Dixon, 1970). A small adult produces fewer nymphs and also smaller nymphs than average (Murdie, 1969b; Dixon, 1970). When aphids are overcrowded or feed on host-plants of poor quality, many aphids reach maturity that might otherwise fail to mature because of the ability of the species to produce viable adults of a great variety of size, including very small adults (Way & Banks, 1967).


Sign in / Sign up

Export Citation Format

Share Document