Host discrimination in the aphid parasitoid Aphidius nigripes

1984 ◽  
Vol 62 (7) ◽  
pp. 1367-1372 ◽  
Author(s):  
Conrad Cloutier ◽  
Lothar A. Dohse ◽  
France Bauduin
Keyword(s):  
Time Dependent ◽  
Macrosiphum Euphorbiae ◽  
Time Interval ◽  
Host Discrimination ◽  
Initial Attack ◽  
Aphid Parasitoid ◽  
Potato Aphid ◽  
Aphidius Nigripes ◽  
Best Fitting ◽  
Increasing Function

Females of the solitary aphid parasitoid Aphidius nigripes do not consistently avoid superparasitizing their hosts, the potato aphid Macrosiphum euphorbiae. Tests were conducted in which two attacks separated by a time interval ranging from 1 to 24 h were allowed per host. No evidence of host discrimination was found when the interval was <2 h. For longer intervals, host discrimination was an increasing function of the length of the interval up to 24 h after the initial attack. Various mathematical models, permitting time-related rejection of parasitized hosts, were used to simulate the parasitoids–host distributions following two attacks. The best fitting models also had to incorporate time-dependent discrimination against hosts that had been attacked but not successfully parasitized. The results are discussed with respect to possible mechanisms of host discrimination in A. nigripes and its significance in intraspecific competition.

FECUNDITY, LONGEVITY, AND SEX RATIO OF APHIDIUS NIGRIPES (HYMENOPTERA: APHIDIIDAE) PARASITIZING DIFFERENT STAGES OF ITS HOST, MACROSIPHUM EUPHORBIAE (HOMOPTERA: APHIDIDAE)

1981 ◽  
Vol 113 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Conrad Cloutier ◽  
Jeremy N. McNeil ◽  
Jacques Regnière
Keyword(s):  
Sex Ratio ◽  
Direct Relationship ◽  
Developmental Stages ◽  
Macrosiphum Euphorbiae ◽  
Separate Experiment ◽  
Female Parasite ◽  
Potato Aphid ◽  
Aphidius Nigripes ◽  
Host Stage ◽  
Female Longevity

AbstractThe longevity and age specific fecundity, as well as the sex ratio of the progeny, were obtained for Aphidius nigripes Ashmead females given access to the five developmental stages of the potato aphid, Macrosiphum euphorbiae (Thomas). Neither female longevity nor fecundity, as measured by the total number of aphids parasitized, were significantly different for the various host stages. The percentage of females in the progeny decreased as the female parasite aged, and the overall sex ratio of progeny was significantly affected by the host stage attacked although no direct relationship with host size was evident. However in a separate experiment where parasitism was controlled (females not permitted to attack more than 10 hosts per day), the host stage (size) significantly affected the sex ratio of progeny, with more females emerging from larger than smaller hosts.These data indicate that all developmental stages of M. euphorbiae, when presented separately, are suitable to A. nigripes.

Development, Survival, and Fecundity of the Potato Aphid, Macrosiphum euphorbiae (Thomas), at Constant Temperatures

1962 ◽  
Vol 94 (6) ◽  
pp. 667-671 ◽  
Author(s):  
C. A. Barlow
Keyword(s):  
Life History ◽  
Macrosiphum Euphorbiae ◽  
Potato Aphid ◽  
Influence Of Temperature ◽  
Controlled Conditions ◽  
Influence Of Temperature On

Life-history and development of Macrosiphum euphorbiae (Thomas) have been studied by Smith (1919), Patch (1925), and MacGillivray and Anderson (1958). In most of these studies, considerable variation in temperature was experienced. The effects of different constant temperatures have never been reported. The following experiments were conducted to determine the influence of temperature on development, survival, and fecundity of M. euphorbiae under closely controlled conditions.

Honeydew as a source of host-searching kairomones for the aphid parasitoid Aphidius nigripes (Hymenoptera: Aphidiidae)

1984 ◽  
Vol 62 (8) ◽  
pp. 1513-1520 ◽  
Author(s):  
Yves Bouchard ◽  
Conrad Cloutier
Keyword(s):  
Filter Paper ◽  
Initial Response ◽  
Response Level ◽  
Aphid Parasitoid ◽  
Potato Plants ◽  
Treated Area ◽  
Aphidius Nigripes ◽  
Locomotory Behavior ◽  
High Concentrations ◽  
Aphid Honeydew

The parasitoid Aphidius nigripes spent more time searching on potato plants previously infested with aphids than on fresh plants, suggesting the presence of searching stimulants on infested plants. Water extracts of aphid honeydew applied to the surface of foliage or to filter paper discs increased searching time and affected the locomotory behavior of parasitoids. When crossing a honeydew-treated area on filter paper, female parasitoids exhibited arrestment, antennal examination, abdominal protraction, reduced walking speed, and increased turning. Upon losing contact with honeydew-contaminated substrate, parasitoids often exhibited a klinotactic response which drove them back to the treated area. The time spent by individual parasitoids within a honeydew-treated area on filter paper decreased with successive visits, but the initial response level was restored when the insect was prevented from contacting honeydew for 1 h. The retention response exhibited by parasitoids contacting a honeydew-treated area increased with honeydew concentration, but levelled off at high concentrations. Naive parasitoids were more responsive to the retention effect of honeydew than experienced individuals.

scholarly journals Tomato Below Ground–Above Ground Interactions: Trichoderma longibrachiatum Affects the Performance of Macrosiphum euphorbiae and Its Natural Antagonists

2013 ◽  
Vol 26 (10) ◽  
pp. 1249-1256 ◽  
Author(s):  
Donatella Battaglia ◽  
Simone Bossi ◽  
Pasquale Cascone ◽  
Maria Cristina Digilio ◽  
Juliana Duran Prieto ◽  
...  
Keyword(s):  
Tomato Plant ◽  
Integrated Control ◽  
Macrosiphum Euphorbiae ◽  
Aphidius Ervi ◽  
Aphid Parasitoid ◽  
Trichoderma Longibrachiatum ◽  
Indirect Defenses ◽  
Plant Growth Promoting ◽  
Below Ground ◽  
Species Specific

Below ground and above ground plant–insect–microorganism interactions are complex and regulate most of the developmental responses of important crop plants such as tomato. We investigated the influence of root colonization by a nonmycorrhizal plant-growth-promoting fungus on direct and indirect defenses of tomato plant against aphids. The multitrophic system included the plant Solanum lycopersicum (‘San Marzano nano’), the root-associated biocontrol fungus Trichoderma longibrachiatum strain MK1, the aphid Macrosiphum euphorbiae (a tomato pest), the aphid parasitoid Aphidius ervi, and the aphid predator Macrolophus pygmaeus. Laboratory bioassays were performed to assess the effect of T. longibrachiatum MK1, interacting with the tomato plant, on quantity and quality of volatile organic compounds (VOC) released by tomato plant, aphid development and reproduction, parasitoid behavior, and predator behavior and development. When compared with the uncolonized controls, plants whose roots were colonized by T. longibrachiatum MK1 showed quantitative differences in the release of specific VOC, better aphid population growth indices, a higher attractiveness toward the aphid parasitoid and the aphid predator, and a quicker development of aphid predator. These findings support the development of novel strategies of integrated control of aphid pests. The species-specific or strain-specific characteristics of these below ground–above ground interactions remain to be assessed.

scholarly journals ANALYSIS OF THE TIME‐DEPENDENT BEHAVIOUR OF COMPOSITE CROSS‐SECTIONS BY LAPLACE‐TRANSFORM

2005 ◽  
Vol 11 (3) ◽  
pp. 203-209
Author(s):  
Erich Raue ◽  
Thorsten Heidolf
Keyword(s):  
Laplace Transform ◽  
Cross Sections ◽  
Composite Structures ◽  
Time Dependent ◽  
Time Interval ◽  
Final State ◽  
Long Time ◽  
Time Dependent Behaviour ◽  
Linear Differential ◽  
Dependent Behaviour

Composite structures consisting of precast and cast in‐situ concrete elements are increasingly common. These combinations demand a mechanical model which takes into account the time‐dependent behaviour and analysis of the different ages of the connected concrete components. The effect of creep and shrinkage of the different concrete components can be of relevance for the state of serviceability, as well as for the final state. The long‐time behaviour of concrete can be described by the rate‐of‐creep method, combined with a discretisation of time. The internal forces are described for each time interval using a system of linear differential equations, which can be solved by Laplace‐transform.

scholarly journals Potato aphid Macrosiphum euphorbiae performance is determined by aphid genotype and not mycorrhizal fungi or water availability

2017 ◽  
Vol 24 (6) ◽  
pp. 1015-1024 ◽  
Author(s):  
Alison Jane Karley ◽  
Matthew Emslie-Smith ◽  
Alison Elizabeth Bennett
Keyword(s):  
Water Availability ◽  
Mycorrhizal Fungi ◽  
Macrosiphum Euphorbiae ◽  
Potato Aphid

BEHAVIOURAL EFFECTS OF IMIDACLOPRID, A NEW NICOTINYL INSECTICIDE, ON THE POTATO APHID, MACROSIPHUM EUPHORBIAE (THOMAS) (HOMOPTERA, APHIDIDAE)

1997 ◽  
Vol 129 (2) ◽  
pp. 241-249 ◽  
Author(s):  
G. Boiteau ◽  
W.P.L. Osborn
Keyword(s):  
Macrosiphum Euphorbiae ◽  
Walking Ability ◽  
Potato Aphid ◽  
Cumulative Mortality ◽  
Behavioural Effects ◽  
Potato Aphids ◽  
Probing Behaviour ◽  
Flight Propensity ◽  
Significant Mortality

AbstractAdult potato aphids, Macrosiphum euphorbiae (Thomas), caged on potato terminal leaflets treated systemically with imidacloprid solutions ranging between 5.4 × 10−4 and 5.4 × 10−8 mL per mL water showed a significant reduction in the distance they travelled, time taken to travel a given distance, and flight propensity but no significant differences in the frequency or duration of short probing behaviour. The frequency of adult apterous potato aphids colonizing untreated potato leaflets or leaflets treated with an imidacloprid solution (5.4 × 10−4 mL per mL water) was not significantly different, indicating no repellency. Potato aphids moving from systemically treated to untreated leaflets did not recover much and their reduced walking ability was maintained for days. A 3-day exposure to vapour from an imidacloprid solution (5.4 × 10−4 mL per mL water) did not produce significant mortality or changes in nymphal production. The daily cumulative mortality obtained by caging potato aphids on potato leaflets placed in an imidacloprid solution (5.4 × 10−7 mL per mL water) was similar to that obtained in the field, on 20-day-old plants treated at planting with imidacloprid applied at 0.02 g Ai/m. None of the rates of imidacloprid tested stimulated the dispersal of apterous or alate potato aphids.

Potato Aphid, Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae)

2008 ◽  
pp. 3008-3011
Author(s):  
J. Howard Frank ◽  
J. Howard Frank ◽  
Michael C. Thomas ◽  
Allan A. Yousten ◽  
F. William Howard ◽  
...  
Keyword(s):  
Macrosiphum Euphorbiae ◽  
Potato Aphid

NONADIABATIC TRANSITION OF THE FISSIONING NUCLEUS AT SCISSION: THE TIME SCALE

2012 ◽  
Vol 21 (05) ◽  
pp. 1250031 ◽  
Author(s):  
N. CARJAN ◽  
M. RIZEA
Keyword(s):  
Time Dependent ◽  
Time Interval ◽  
Short Time Interval ◽  
Excitation Energies ◽  
Nonadiabatic Transition ◽  
Dependent Potential ◽  
Sudden Approximation ◽  
Transition Times ◽  
Short Time ◽  
Neutron Multiplicities

A time-dependent approach to the scission process, i.e., to the transition from two fragments connected by a thin neck (deformation αi) to two separated fragments (deformation αf) is presented. This transition is supposed to take place in a very short time interval ΔT. Our approach follows the evolution from αi to αf of all occupied neutron states by solving numerically the two-dimensional time-dependent Schrödinger equation with time-dependent potential. Calculations are performed for mass divisions from AL = 70 to AL = 118(AL being the light fragment mass) taking into account all neutron states (Ω = 1/2, 3/2, …, 11/2) that are bound in 236 U at αi. ΔT is taken as parameter having values from 0.25×10-22 to 6×10-22 s. The resulting scission neutron multiplicities ν sc and primary fragments' excitation energies [Formula: see text] are compared with those obtained in the frame of the sudden approximation (ΔT = 0). As expected, shorter is the transition time more excited are the fragments and more neutrons are emitted, the sudden approximation being an upper limit. For ΔT = 10-22 which is a realistic value, the time dependent results are 20% below this limit. For transition times longer than 6×10-22 s the adiabatic limit is reached: No scission neutrons are emitted anymore and the excitation energy at αf is negligible.

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