Browsing by Author "Atlihan, R"

Now showing 1 - 3 of 3

Biological Features and Life Table Parameters of the Mealy Plum Aphid Hyalopterus Pruni on Different Apricot Cultivars
(Springer, 2005) Özgökçe, MS; Atlihan, R
Development, survival, reproduction rate, and population growth parameters of the mealy plum aphid Hyalopterus pruni (Geoffroy) (Hom.: Aphididae) were evaluated on four different apricot cultivars (Tyrinte, Sakit, Colomer, and Bebeco) under field conditions in the Van region of Turkey. Experiments were carried out on exterior leaves of trees, 1.5-2 m above the ground. Plexiglas clip-cells (25 x 6 mm) with the upper side covered by muslin were used in the experiments. The mealy plum aphid performed better on Tyrinte than on the other cultivars tested. The fastest development time (first instar to adult; 9.4 days), highest daily reproduction rate (2.6 offspring/aphid/day), and highest total fecundity (48.1 offspring/aphid) were obtained on Tyrinte. The intrinsic rate of increase - a good indicator of the growth potential of a population - of individuals fed on Tyrinte was significantly greater than that of individuals fed on cvs. Colomer and Bebeco. While mean generation times (T.) of populations on different cultivars were close to each other, the net reproductive rate was the highest (29.45 offspring/aphid/generation) on Tyrinte and the population doubling time on Tyrinte was 18.7%, 25.2% and 26.3% faster than those of individuals on other cultivars tested. The results obtained in this study indicated that Tyrinte appeared to be the most susceptible to the mealy plum aphid among the cultivars tested.
Development, Fecundity and Prey Consumption of Exochomus Nigromaculatus Feeding on Hyalopterus Pruni
(Priel Publ, 2002) Atlihan, R; Özgökçe, MS
Development, survival and reproduction of Exochomus nigromaculatus (Goeze) were studied in the laboratory at four constant temperatures from 20degreesC to 35 +/- 1degreesC in 5degreesC increments, 60 +/- 5% r.h. and 16 h of artificial light (5000 lux). Development time from egg to adult ranged from 22.4 days at 20degreesC to 10.6 days at 35degreesC, and required 278 degree-days above a threshold estimated to be 9.11degreesC. Survival was highest at 25degreesC and lowest at 35degreesC. Longevity of females declined significantly with increasing temperatures, ranging from 120.7 days at 20degreesC to 46.6 days at 35degreesC. Mean generation time became shorter with increasing temperatures. The intrinsic rate of increase of individuals kept at 30degreesC was significantly greater than that of individuals kept at the other temperatures tested. Fourth larval instars and adults of E. nigromaculatus displayed a Type II functional response to Hyalopterus pruni densities. Searching rate of fourth instar larvae and adults was similar, but handling time was shorter for female adults. Results obtained in this study showed that the optimal temperature for population growth of E. nigmmaculatus was 30degreesC and this coccinellid predator may have potential as a biological control agent for H. pruni because of its feeding capacity.
The Effect of Temperature on Development and Fecundity of Scymnus Levaillanti
(Springer, 2000) Uygun, N; Atlihan, R
Development and fecundity of Scymnus levaillanti (Mulsant) were recorded at five constant temperatures ranging from 15 to 35 +/- 1 degreesC in 5 degreesC increments, 60 +/- 5% RH and 16 h of artificial light (5000 Lux). Developmental time (egg to adult) of S. levaillanti significantly decreased with increasing temperatures, ranging from 63.9 days at 15 degreesC to 11.1 days at 35 degreesC. Development from egg to adult required 305.2 DD above a developmental threshold estimated as 11.7 degreesC. Oviposition periods lasted 86.5, 76.1, 47.2, and 31.5 days at 20, 25, 30 and 35 degreesC, respectively. No eggs were deposited at 15 degreesC. Higher temperatures resulted in shorter generation times (T-O) and in decreased net reproductive rates (R-O) of the coccinellid. S. levaillanti kept at 30 degreesC produced 0.151 females/female/day, the highest per capita rate of population growth (r(m)). The `functional response' of larvae and adults of S. levaillanti matches well that described by Holling (1959) as Type 2. Daily number of eggs deposited by females increased to a plateau with increasing prey density. Results obtained here provide information about the biology of S. levaillanti, and its feeding capacity indicates that it may act as an important control agent.