ECOLOGICAL OBSERVATIONS ON CHRYSOCHARIS LARICINELLAE (HYMENOPTERA: EULOPHIDAE), A PARASITE OF THE LARCH CASEBEARER (COLEOPHORA LARICELLA)

1967 ◽  
Vol 99 (6) ◽  
pp. 631-641 ◽  
Author(s):  
F. W. Quednau
Keyword(s):  
Biological Control ◽  
Host Species ◽  
Fourth Instar ◽  
Host Acceptance ◽  
Temperature Threshold ◽  
Influence Of Temperature ◽  
Control Value ◽  
Coleophora Laricella ◽  
Influence Of Temperature On ◽  
Host Pupa

AbstractAn account is given of host acceptance, the influence of temperature on fecundity and longevity, and searching capacity of Chrysocharis laricinellae (Raczeburg), a parasite of the larch casebearer, Coleophora laricella (Hübner).Fourth-instar case-bearing larvae were the preferred stages for attack. The size of the parasite progeny varied directly with the size of the host. Fecundity of progeny reared from small hosts was significantly less than that of progeny reared from large hosts. Not all parasite adults could successfully oviposit through the tough skin of the host pupa. C. laricinellae showed poor searching capacity. Superparasitism was common at low host densities of the casebearer and resulted in either one parasite emerging or in total parasite mortality. A sex ratio where females predominated resulted when sufficient numbers of preferred stages of the host were presented to mated C. laricinellae. The temperature threshold for attacking hosts was 55°F, and for development of the parasite 40°F. At 50°F the adults lived 4 months on the average.Therefore C. laricinellae is able to survive in the field without alternate hosts and at very low host densities. The parasite seems to depend on a continuing supply of suitable instars of host species in sufficient numbers to be effective. If C. laricella is the only available host species in the ecosystem the biological control value of this chalcid must be rated as poor.

scholarly journals Temperature effects on Trichogramma pretiosum Riley and Trichogrammatoidea annulata De Santis

2003 ◽  
Vol 46 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Arlei Maceda ◽  
Celso L Hohmann ◽  
Honório R. dos Santos
Keyword(s):  
Temperature Effects ◽  
Entire Temperature Range ◽  
Temperature Threshold ◽  
Trichogramma Pretiosum ◽  
Degree Days ◽  
Parasitoid Species ◽  
Influence Of Temperature ◽  
Anagasta Kuehniella ◽  
Influence Of Temperature On ◽  
Lepidoptera Pyralidae

The influence of temperature on lifetime attributes of Trichogramma pretiosum Riley and Trichogrammatoidea annulata De Santis (Hymenoptera: Trichogrammatidae) was evaluated at four constant temperatures (15, 20, 25, and 30º C), RH 70 ± 10%, photophase 14 h. Anagasta kuehniella (Lepidoptera: Pyralidae) eggs were used as hosts. Developmental times of both parasitoid species were similar when exposed to 20, 25, or 30º C. T. annulata, however, developed slightly faster than T. pretiosum at 15º C. Emergence rates of both species were above 89%. The temperature threshold for T. pretiosum and T. annulata was 11º C and the number of degree-days required for their development was 126.9 and 122.3, respectively. Parasitization was maximal at 25º C. T. annulata, however, parasitized significantly more hosts than T. pretiosum in the entire temperature range. Temperature had no effect in brood size.T. annulata progeny consisted predominantly of males, except at 15º C, whereas in T.pretiosumitconsisted predominantly of females, except at 30º C. Parental females lived longer than males.

In vitro influence of temperature on the biological control activity of the fungus Duddingtonia flagrans against Haemonchus contortus in sheep

2012 ◽  
Vol 112 (2) ◽  
pp. 473-478 ◽  
Author(s):  
Rodrigo Buske ◽  
Janio Morais Santurio ◽  
Clarissa Vasconcelos de Oliveira ◽  
Liziane Aita Bianchini ◽  
José Henrique Souza da Silva ◽  
...  
Keyword(s):  
Biological Control ◽  
Haemonchus Contortus ◽  
Duddingtonia Flagrans ◽  
Control Activity ◽  
Influence Of Temperature ◽  
Influence Of Temperature On

Influence of Temperature on Development of Hemlock Woolly Adelgid (Homoptera: Adelgidae) Progrediens

2002 ◽  
Vol 37 (2) ◽  
pp. 166-176 ◽  
Author(s):  
Scott M. Salom ◽  
Alexei A. Sharov ◽  
Warren T. Mays ◽  
David R. Gray
Keyword(s):  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Early Summer ◽  
Temperature Threshold ◽  
Degree Days ◽  
Influence Of Temperature ◽  
Complete Development ◽  
First Instar ◽  
Influence Of Temperature On ◽  
Median Point

There are three generations of hemlock woolly adelgid, Adelges tsugae Annand, that develop on the secondary host Tsuga spp. Two of these generations, the progrediens and sexupara, are present concurrently in the spring. Sistens are present from early summer until the following spring. Constant temperature studies were conducted to quantify the influence of temperature on hemlock woolly adelgid progrediens development and to develop a degree-day model. Progrediens development in the field also was sampled to test the accuracy of the model. Hemlock woolly adelgid progrediens developed at temperatures ranging from 4 to 22°C. Duration of first-instar progrediens was less dependent on temperature than in the other nymphal stages and may have been a result of the difficulty in determining the median point of settled first-instar nymphs and the inability to distinguish progrediens from sexuparae at this stage. Duration of development from second stadium to adult was highly dependent on temperature. Using this range of progrediens stages, it was determined that the low temperature threshold was 3.9°C and requires 222 degree-days to reach the adult stage. The number of degree-days needed to complete development in the field ranged from 110 to 123% of degree-days required to complete development in the laboratory.

The effect of temperature on high-resolution TEM image contrast

1995 ◽  
Vol 53 ◽  
pp. 640-641
Author(s):  
T. Geipel ◽  
W. Mader ◽  
P. Pirouz
Keyword(s):  
Form Factor ◽  
Inelastic Scattering ◽  
Accurate Method ◽  
Waller Factor ◽  
Effect Of Temperature ◽  
Specimen Thickness ◽  
Influence Of Temperature ◽  
Debye Waller Factor ◽  
Influence Of Temperature On ◽  
Atomic Form Factor

Temperature affects both elastic and inelastic scattering of electrons in a crystal. The Debye-Waller factor, B, describes the influence of temperature on the elastic scattering of electrons, whereas the imaginary part of the (complex) atomic form factor, fc = fr + ifi, describes the influence of temperature on the inelastic scattering of electrons (i.e. absorption). In HRTEM simulations, two possible ways to include absorption are: (i) an approximate method in which absorption is described by a phenomenological constant, μ, i.e. fi; - μfr, with the real part of the atomic form factor, fr, obtained from Hartree-Fock calculations, (ii) a more accurate method in which the absorptive components, fi of the atomic form factor are explicitly calculated. In this contribution, the inclusion of both the Debye-Waller factor and absorption on HRTEM images of a (Oll)-oriented GaAs crystal are presented (using the EMS software.Fig. 1 shows the the amplitudes and phases of the dominant 111 beams as a function of the specimen thickness, t, for the cases when μ = 0 (i.e. no absorption, solid line) and μ = 0.1 (with absorption, dashed line).

The Influence of Temperature on Successful Reproductions of Burbot, Lota Lota (L.) Under Hatchery Conditions

2010 ◽  
Vol 25 (1) ◽  
pp. 93-105 ◽  
Author(s):  
Daniel Żarski ◽  
Dariusz Kucharczyk ◽  
Wojciech Sasinowski ◽  
Katarzyna Targońska ◽  
Andrzej Mamcarz
Keyword(s):  
Lota Lota ◽  
Influence Of Temperature ◽  
Influence Of Temperature On
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