Formosan Entomologist (2004) 24, 91-105
Ching-Chin Chien, Shu-Chen Chang and Shiu-Chih Ku (2004)
Influence of temperature on both population increase and host-killing capability of Hemiptarsenus varicornis (Hymenoptera: Eulophidae)
Formosan Entomologist 24 (2), 91-105
Abstract: The ifluence of temperature on both population increase and host-killing capability of Hemiptarsenus varicornis (Girault) was studied at 10, 15, 20, 25, 30, and 35°C. H. varicornis completed their development between 15 and 35°C. In this temperature range, its survival rate and development period from egg to adult was 90.9-96.3% and 7.0-54.0 days, respectively. But its hatch rate was 0% at 10°C. A lower developmental threshold was estimated to be 11.97°C for development from egg to adult. H. varicornis required 16, 46, 9, 81, and 152°C-days, respectively, to complete the egg, larval, prepupal, pupal, and egg to adult stages. When 40-50 third-instar larvae of Liriomyza trifolii (Burgess) were provided daily for a pair of H. varicornis between 15-35°C at 5°C intervals, the relationship between temperature and the total number of hosts killed formed a quadratic regression. Accordingly, the maximum number of hosts killed was estimated to be 372 at 25.4°C; However, when wasps reared at 25°C during the immature stages were then transferred to 30 or 35°C after emergence, the parasitism and feeding tests showed total numbers of hosts killed of 611 and 651 larvae, respectively. The relationship between temperature and the ratio of number of lifetime host parasitized over lifetime host feeding fitted to a quadratic regression, as was the relationship between temperature and the female progeny ratio. The estimated maximum values of the former ratio and the latter one were 0.72:1 at 24.9°C and 0.71 at 23.8°C, respectively. At 25°C, the intrinsic rate of increase (r), net reproductive rate (Ro), and mean generation time (T) were 0.2337/day, 121 female wasps/female, and 20.52 days, respectively. When adults were fed daily with pure honey only between 15 and 35°C, the relationship between temperature and longevity of females or males showed a linear regression and the estimated maximum longevity of females and males was 38 and 36 days at 15°C, respectively. For those fed pure honey and provided with hosts, the relationship between temperature and longevity of females or males formed a quadratic regression, and the estimated maximum longevity of females and males was 19 days at 22.6°C and 13 days at 23.7°C, 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:
general biology - morphology - evolution
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Liriomyza trifolii | Taiwan | |||
| Hemiptarsenus varicornis (parasitoid) | Liriomyza trifolii | Taiwan |
