Redhead Egg Parasitism of Canvasback Nests

1983 ◽  
Vol 47 (1) ◽  
pp. 213 ◽  
Author(s):  
Stephen H. Bouffard
Keyword(s):  
Egg Parasitism

Does risk of egg parasitism affect choice of oviposition sites by a moth? A field and laboratory study

2010 ◽  
Vol 11 (2) ◽  
pp. 135-143 ◽  
Author(s):  
Medhat M. Sadek ◽  
Bill S. Hansson ◽  
Peter Anderson
Keyword(s):  
Laboratory Study ◽  
Egg Parasitism ◽  
Oviposition Sites

scholarly journals Trichogramma galloi and Trichogramma pretiosum for the management of Duponchelia fovealis (Lepidoptera: Crambidae) in strawberry plants

2017 ◽  
Vol 52 (8) ◽  
pp. 690-693 ◽  
Author(s):  
Victor Dias Pirovani ◽  
Dirceu Pratissoli ◽  
Marcel Oliveira Tibúrcio ◽  
José Romário de Carvalho ◽  
Alixelhe Pacheco Damascena ◽  
...  
Keyword(s):  
Surface Area ◽  
Leaf Surface ◽  
Fragaria X Ananassa ◽  
Trichogramma Pretiosum ◽  
Field Release ◽  
Leaf Surface Area ◽  
Egg Parasitism ◽  
Ideal Number ◽  
Strawberry Cultivar ◽  
The Ideal

Abstract: The objective of this work was to determine the ideal number for field release of Trichogramma galloi and T.pretiosum for controlling Duponchelia fovealis (Lepidoptera: Crambidae) in strawberry (Fragaria x ananassa). The experiment was carried out in a greenhouse, where the strawberry cultivar 'Oso Grande' was infected with 100 eggs of D.fovealis distributed on the leaf surface area of each plant. A total of 1, 2, 4, 8, 16, 32, 64, and 128 female parasitoids were released per egg of D. fovealis. The greatest level of egg parasitism, with no differences for the species of Trichogramma, was observed at the densities of four and eight parasitoids per egg of D.fovealis, considered ideal for field release.

scholarly journals Trichogramma parasitoids alter the metabolic physiology of Manduca eggs

2012 ◽  
Vol 279 (1742) ◽  
pp. 3572-3576 ◽  
Author(s):  
Kristen A. Potter ◽  
H. Arthur Woods
Keyword(s):  
Manduca Sexta ◽  
Water Loss ◽  
Limited Resources ◽  
Metabolic Efficiency ◽  
Physiological System ◽  
Life Stages ◽  
Metabolic Rates ◽  
Developmental Constraints ◽  
Metabolic Physiology ◽  
Egg Parasitism

Egg parasitoids face unique developmental constraints. First, they have exceptionally limited resources to support themselves and their siblings through three life stages. Second, they develop within the physiological system of another species, which they modify to their own ends. We examined how these constraints affect the metabolic physiology of egg parasitism, and whether parasitoids retool their host eggshell to account for their different metabolic demands. Higher-conductance eggshells allow more oxygen to reach the developing parasitoids, but also allow more water to leave the egg. We used Manduca sexta (Lepidoptera: Sphingidae) eggs and Trichogramma (Hymenoptera: Trichogrammatidae) parasitoids from southeastern AZ, USA. Compared with unparasitized Manduca eggs, eggs parasitized by Trichogramma had lower peak metabolic rates and approximately 50 per cent lower metabolic efficiency. However, developing Trichogramma were far more efficient than typical transfer efficiencies between tropic levels (approx. 10%). Even within a few hours of parasitization, eggs containing more Trichogramma had lower per-parasitoid metabolic rates, suggesting that parasitoid larvae have mechanisms for rapidly adjusting their metabolic rates based on number of siblings. Parasitoids also appear to control the conductance of their host eggshell: their different metabolic demands were mirrored by shifts in rates of water loss.

3.5 SUPPRESSION OF SPRUCE BUDWORM POPULATIONS BY TRICHOGRAMMA MINUTUM RILEY, 1982–1986

1990 ◽  
Vol 122 (S153) ◽  
pp. 56-81 ◽  
Author(s):  
S.M. Smith ◽  
D.R. Wallace ◽  
G. Howse ◽  
J. Meating
Keyword(s):  
Choristoneura Fumiferana ◽  
Host Density ◽  
Spruce Budworm ◽  
Mass Rearing ◽  
Egg Parasitoid ◽  
Curvilinear Relationship ◽  
Egg Masses ◽  
Trichogramma Minutum ◽  
Egg Parasitism ◽  
Release Timing

AbstractThe ability of the egg parasitoid, Trichogramma minutum Riley, to suppress outbreak populations of the spruce budworm, Choristoneura fumiferana (Clemens), was studied annually near Hearst, Ont., from 1982 through 1986. Timing of broadcast parasitoid-releases was linked to spruce budworm moth emergence and oviposition. These phenological relationships were predicted from a regression based on larval development at least 2 weeks before expected emergence; this allowed sufficient time to regulate (program) parasitoid emergence during mass-rearing. Emergence of caged spruce budworm adults was used to monitor moth eclosion in the field. Pheromone traps provided daily information on the activity of male moths and helped to synchronize the parasitoid releases with spruce budworm oviposition. Information on parasitoid activity was obtained from sentinel (laboratory-reared) and naturally occurring spruce budworm egg masses. A curvilinear relationship between the rate of parasitoid release and parasitism of sentinel egg masses was developed. Two parasitoid releases, 1 week apart, early in the oviposition period of spruce budworm, significantly increased parasitism of host eggs by 14–83% and reduced larval populations correspondingly from 42 to 82%. Single releases were less effective and increased parasitism by 0.3–52% (single ground release, 1986). Two parasitoid releases, combined with a spring application of Bacillus thuringiensis Berliner to larval populations, was the most effective strategy and resulted in 83% egg parasitism and 93% larval reduction. Release rates greater than 12–16 × 106 ♀ ♀ T. minutum per hectare were not warranted based on impact and costs. The effects of release timing, weather, host density, and parasitoid quality on the future successful use of T. minutum are discussed.

The role of tending ants in host plant selection and egg parasitism of two facultative myrmecophilous butterflies

2014 ◽  
Vol 101 (11) ◽  
pp. 913-919 ◽  
Author(s):  
Alexandra Bächtold ◽  
Estevão Alves-Silva ◽  
Lucas A. Kaminski ◽  
Kleber Del-Claro
Keyword(s):  
Host Plant ◽  
Host Plant Selection ◽  
Plant Selection ◽  
Egg Parasitism

Influence of intercropping on the abundance, distribution and parasitism of Chilo spp. (Lepidoptera: Pyralidae) eggs

1997 ◽  
Vol 87 (5) ◽  
pp. 507-513 ◽  
Author(s):  
P. Päts ◽  
B. Ekbom ◽  
H. Skovgård
Keyword(s):  
East Africa ◽  
Chilo Partellus ◽  
Field Experiments ◽  
Plant Density ◽  
Coastal Areas ◽  
Positive Density ◽  
Abundance Distribution ◽  
Significant Difference ◽  
Egg Parasitism ◽  
Lepidoptera Pyralidae

AbstractTwo of the most common and serious pests of maize and sorghum in the coastal areas of East Africa are the pyralid species, Chilo partellus (Swinhoe) and C. orichalcociliellus (Strand). Maize monocrop (with high and low plant density) and maize/cowpea mixed intercrop field experiments were conducted in Kenya to test if intercropping decreased the number of egg batches laid, altered the distribution of the egg batches and influenced egg parasitism. There was no significant difference in the number of egg batches per plant between treatments and the egg batches were randomly distributed on and among plants in most of the plots for all three treatments. There was a tendency for higher egg parasitism in the intercrop. The proportion of eggs parasitized was significantly correlated with total number of eggs per plot suggesting a positive density dependent response. It is concluded that intercropping does not affect C. partellus nor C. orichalcociliellus oviposition behaviour but egg parasitism is likely to be augmented.

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