scholarly journals Ecological Studies on Anagrus incarnatus Haliday (Hymenoptera : Mymaridae), an Egg Parasitoid of the Rice Planthoppers : I. Functional Response to Host Density and Mutual Interference

10.5109/23794 ◽  
1984 ◽  
Vol 29 (1) ◽  
pp. 59-66
Author(s):  
Sujin Chantarasa-ard ◽  
Yoshihiro Hirashima ◽  
Tadashi Miura
Keyword(s):  
Functional Response ◽  
Host Density ◽  
Egg Parasitoid ◽  
Mutual Interference ◽  
Ecological Studies ◽  
Rice Planthoppers

scholarly journals Functional response and mutual interference of Diaeretiella rapae (Hymenoptera: Aphidiidae) on Brevicoryne brassicae (Homoptera: Aphididae)

2006 ◽  
Vol 17 (2) ◽  
pp. 90-97 ◽  
Author(s):  
Yaghoub Fathipour ◽  
Ali Hosseini ◽  
Ali Talebi ◽  
Saeid Moharramipour
Keyword(s):  
Logistic Regression ◽  
Functional Response ◽  
Host Density ◽  
Handling Time ◽  
Mutual Interference ◽  
Brevicoryne Brassicae ◽  
Least Square ◽  
Diaeretiella Rapae ◽  
Type Ii ◽  
Per Capita

Functional response and mutual interference are the most important behavioural characteristics that reveal different aspects of host–parasitoid interactions. In this study, functional response and mutual interference of the parasitoid wasp, Diaeretiella rapae (M’Intosh) attacking the cabbage aphid, Brevicoryne brassicae (Linnaeus) were investigated. Logistic regression was used to distinguish the shape of the functional response (type II or III). Nonlinear least-square regression was used to estimate the attack rate (a) and handling time (Th). Nicholson’s model and linear regression were used to determine per capita searching efficiency and interference coefficient, respectively. Logistic regression suggested a type II response on B. brassicae nymphs. The per capita parasitism decreased significantly from 80.80 (67.33%) to 11.85 (9.88%) as parasitoid densities increased from 1 to 8 females. Consequently, the per capita searching efficiency decreased significantly from 1.173 to 0.205 as parasitoid densities increased from 1 to 8. The rate of parasitism increased as the host density increased from 2 to 50, and subsequently the parasitoid density decreased from 8 to 1. Therefore, different host–parasitoid ratios could affect the efficacy of D. rapae.

scholarly journals Permanence of a Discrete Periodic Volterra Model with Mutual Interference

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Lijuan Chen ◽  
Liujuan Chen
Keyword(s):  
Functional Response ◽  
Sufficient Conditions ◽  
Mutual Interference ◽  
Volterra Model

This paper discusses a discrete periodic Volterra model with mutual interference and Holling II type functional response. Firstly, sufficient conditions are obtained for the permanence of the system. After that, we give an example to show the feasibility of our main results.

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.

Tick (Acari: Ixodidae) ecological studies in Tanzania

1986 ◽  
Vol 76 (2) ◽  
pp. 229-246 ◽  
Author(s):  
R. J. Tatchell ◽  
E. Easton
Keyword(s):  
Seasonal Variation ◽  
Host Density ◽  
Dar Es Salaam ◽  
Rhipicephalus Appendiculatus ◽  
Amblyomma Variegatum ◽  
The Other ◽  
Theileria Parva ◽  
Ecological Studies ◽  
Adult Abundance

AbstractTicks were regularly collected from cattle along transects in Sukumaland and the Southern Highlands, Tanzania, and from locations near Tabora, Mbeya, Arusha and Dar es Salaam from 1973 to 1976. Marked seasonal variation in abundance occurred in Rhipicephalus appendiculatus Neumann in the Southern Highlands (but not in Sukumaland) and in Amblyomma variegatum (F.) near Tabora. It was possible to detect Theileria parva antibodies in cattle sera from the Southern Highlands only during the season of R. appendiculatus adult abundance. Despite this there was no evidence of enzootic instability of the disease. The results demonstrate that the behaviour and distributions of these and the other species of ticks found are not fixed and constant but vary according to a complicated interplay of factors as yet imperfectly understood, such as climate and vegetation and host density, susceptibility and grazing habits.

scholarly journals Reproductive efficiency of the bethylid waspCephalonomia tarsalis:the influences of spatial structure and host density

2016 ◽  
Vol 107 (2) ◽  
pp. 139-147 ◽  
Author(s):  
P.A. Eliopoulos ◽  
A. Kapranas ◽  
E.G. Givropoulou ◽  
I.C.W. Hardy
Keyword(s):  
Spatial Structure ◽  
Host Density ◽  
Parasitoid Wasp ◽  
Mass Rearing ◽  
Mutual Interference ◽  
Host Population ◽  
Biological Pest Control ◽  
Offspring Production ◽  
Chemical Studies ◽  
High Degree

AbstractThe parasitoid waspCephalonomia tarsalis(Ashmead) (Hymenoptera: Bethylidae) is commonly present in stored product facilities. While beneficial, it does not provide a high degree of biological pest control against its host, the saw-toothed beetleOryzaephilus surinamensis(L.) (Coleoptera: Silvanidae). A candidate explanation for poor host population suppression is that adult females interfere with each other's foraging and reproductive behavior. We used simple laboratory microcosms to evaluate such mutual interference in terms of its overall effects on offspring production. We varied the density of the hosts and also the spatial structure of the environment, via the extent of population sub-division and the provision of different substrates. Production ofC. tarsalisoffspring was positively influenced by host density and by the isolation of females. With incomplete sub-division within microcosms offspring production was, in contrast, low and even zero. The provision of corrugated paper as a substrate enhanced offspring production and partially mitigated the effects of mutual interference. We recommend simple improvements to mass rearing practice and identify promising areas for further behavioral and chemical studies towards a better understanding of the mechanisms of mutual interference.

Functional Response of Anisopteromalus calandrae (Hymenoptera: Pteromalidae): Influence of Host Numbers Versus Host Density

1992 ◽  
Vol 27 (4) ◽  
pp. 375-382 ◽  
Author(s):  
Lincoln Smith ◽  
John W. Press
Keyword(s):  
Functional Response ◽  
Sitophilus Oryzae ◽  
Host Density ◽  
Handling Time ◽  
Rice Weevil ◽  
Anisopteromalus Calandrae

The functional response of Anisopteromalus calandrae (Howard) was measured on rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), in wheat at 30° C. Four female parasitoids, with males, were allowed to oviposit during their lifespan on 166 to 678 weevils per container. The data were fit by Rogers' (1972) random parasitoid model with rate of parasite search a = 0.32 lifespan−1 and handling time Th= 0.0027 lifespan. Volume of grain, in the range of 0.19 to 3.1 l wheat, had no effect on number of hosts parasitized when host numbers were held constant at 222, 398, and 572 weevils per container. Therefore, it may be more appropriate to consider numbers of hosts present rather than host density when studying functional response within a patch of uniformly distributed hosts.

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