Biocontrol Science and Technology (2002) 12, 555-567

Abera T. Haile, S.A. Hassan, C.P.K.O. Ogol, J. Baumgärtner, S. Sithanantham, J.C. Monje and C.P.W. Zebitz (2002)
Temperature-dependent development of four egg parasitoid Trichogramma species (Hymenoptera: Trichogrammatidae)
Biocontrol Science and Technology 12 (5), 555-567
Abstract: Trichogramma species have been successfully utilized for biocontrol of several lepidopteran pests worldwide. The development, survival and progeny production of two Kenyan species' Trichogramma bournieri Pintureau and Babault and Trichogramma sp. nr. mwanzai Schulten and Feijen (collected from Kenya), Trichogramma evanescens Westwood (Germany) and Trichogramma chilonis Ishii (India) was studied at four constant temperatures (13, 18, 25 and 34°C) with the aim of assessing the relative biotic potential of the two native species for biocontrol of Helicoverpa armigera and Plutella xylostella in Kenya. The study was conducted at the Institute for Biological Control (BBA), Darmstadt, Germany. The Trichogramma species tested showed variations in fertility, developmental time, percent emergence, progeny production and sex ratio at the four temperature regimes. Fertility decreased as temperature increased from 25 to 34°C. T. chilonis and T. evanescens completed development at all temperatures tested, but T. bournieri and T. sp. nr. mwanzai failed to complete development at 13°C. The developmental period for all the species decreased as the temperature increased. The duration of development from oviposition to adult emergence varied from 8 days to 12 weeks shorter at 34°C than at 13°C for T. chilonis and T. evanescens. For the various temperatures tested, a linear model was satisfactory for egg to adult development at P = 0.05 for T. chilonis and T. evanescens. The lower temperature thresholds for development and duration in degree-days were 8.83°C and 188 for T. chilonis and 9.23°C and 192 for T. evanescens, respectively. For all temperatures tested, T. sp. nr. mwanzai had the highest preimaginal survivorship. Adult emergence was lower at 13°C and 34°C than at 18 and 25°C. The highest fertility (mean - SE) (50.37 - 2.32 adult female^-1) and progeny production (44.03 - 2.02 adult female^-1) was recorded at 25°C for T. evanescens. Sex ratio was biased towards female at all temperatures in T. bournieri and T. chilonis. At all temperatures tested, T. sp. nr. mwanzai produced more males than females. For all species tested, favourable parasitism was between 18 and 25°C. The results from this study will be useful for mass rearing purposes as well as for future field release programmes.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Sherif A. Hassan, Callistus K.P.O. Ogol, Claus P.W. Zebitz, Johann U. Baumgärtner, Juan-Carlos Monje

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
rearing/culturing/mass production

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Helicoverpa armigera		Kenya
	Plutella xylostella		Kenya
Trichogramma chilonis (parasitoid)
Trichogramma evanescens (parasitoid)			Germany
Trichogramma bournieri (parasitoid)			Kenya