Die invloed van temperatuur op die ontwikkeling en reproduksie van die valskodlingmot-eierparasitoïed, Trichogrammatoidea cryptophlebiae Nagaraja (Hymenoptera: Trichogrammatidae)

Matthee, Elsabe (2000-03)

Thesis (MSc)--University of Stellenbosch, 2000.

Thesis

ENGLISH ABSTRACT: The development time, survival and fecundity of Trichogrammatoidea cryptophlebiae Nagaraj a, an egg parasitoid of false codling moth, Cryptophlebia leucotreta Meyr., on . citrus were determined at 15,20,25 and 30°C. Using these values the intrinsic rate of increase (rm), mean generation time (T) and net replacement rate (Ra) were estimated at the respective temperatures. In addition, the data were used to estimate the minimum temperature required for development. The rmincreased from 15 (0,042) to 20°C (0,088) and then gradually decreased from 25 (0,069) to 30°C (0,012). The Ra was highest at 20°C (3,116 females/female), followed by 15°C (2,607 females/female), 25°C (1,894 females/female) and 30°C (1,092 females/female). T decreased as temperature increased from 7 days at 30°C to 22,79 days at 15°C. The estimated minimum temperature for development was 7,65°C which implies that this wasp should be able to survive and reproduce under normal winter conditions in the Western Cape.

AFRIKAANSE OPSOMMING: Die ontwikkelingstyd, oorlewing en vrugbaarheid van Trichogrammatoidea cryptophlebiae Nagaraj a, 'n eierparasitoied van valskodlingmot, Cryptophlebia leucotreta Meyr., op sitrus is bepaal by 15, 20, 25 en 30oe. Hierdie waardes is gebruik om die intrinsieke tempo van vermeerdering (rm), die gemiddelde generasietyd (T) en die netto vervangingstempo (Ro) te bepaal by die betrokke temperature. Die data is verder gebruik om die minimum temperatuur vir ontwikkeling te bepaal. Die rm waarde het toegeneem van 15°e (0,042) tot by 200e (0,088) en afgeneem van 25°e (0,069) tot 300e (0,012). Die Ro was die hoogste by 200e (3,116 wyfies/wyfie), gevolg deur 15°e (2,607 wyfies/wyfie), 25°e (1,894 wyfies/wyfie) en 300e (1,092 wyfies/wyfie). T het afgeneem met 'n toename in temperatuur en was 7 dae by 300e en 22,79 dae by 15°e. Die beraamde minimum temperatuur vir ontwikkeling was 7,65°e wat aandui dat hierdie wespe kan oorleef en voortplant by normale wintertoestande in die Wes-Kaap.

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