Formosan Entomologist (2002) 22, 279-290

Ching-Chin Chien and Shiu-Chih Ku (2002)
Intraspecific competition of two species of parasitoids (Hymenoptera: Eulophidae) of Liriomyza trifolii (Diptera: Agromyzidae)
Formosan Entomologist 22 (3), 279-290
Abstract: Hemiptarsenus varicornis (Girault) and Neochrysocharis formosa (Westwood) are the two dominant indigenous parasitoids of Liriomyza trifolii (Burgess) on Gerbera jamesonii Bolues ex Hook. f. in Taiwan. The modes of host killing by female wasp are parasitism and host-feeding. The ratio of oviposition to host-feeding regardless of female wasp density ranged 0.6-0.8:1 and 1.9-2.7:1 for H. varicornis and N. formosa, respectively. However, its density significantly affected superparasitism and the total host utilization rate. The optimal wasp:host ratios for propagation of H. varicornis and N. formosa were 1:20 and 1:15, respectively. When 15 female wasps of H. varicornis or 20 female wasps of N. formosa were provided with 300 third-instar larvae of L. trifolii in an acrylic cylinder (25 x 20 cm) at 25°C, the total host utilization rates and superparasitism rates after 24 hours were 90.7% and 6.4%, and 98.6% and 11.1%, respectively. There were 109 and 205 adult progeny which emerged after 11.1 and 14.4 days, respectively.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Ching-Chin Chien

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Liriomyza trifolii		Taiwan
Closterocerus formosus (parasitoid)	Liriomyza trifolii		Taiwan
Hemiptarsenus varicornis (parasitoid)	Liriomyza trifolii		Taiwan