• Korean journal of applied entomology
• /
• v.51 no.4
• /
• pp.343-348
• /
• 2012

Developmental period, mummification, pupal mortality, and sex ratio of Korean strain of Aphelinus varipes F$\ddot{o}$rster parasitizing the green peach aphid, Myzus persicae were studied at 20, 25, 30, and $35^{\circ}C$ in controlled climate cabinets. The plastic container with a leaf disc of sweet pepper (Capsicum annuum L.) was used as experimental units. Green peach aphids at different developmental stages were reared in four different temperatures and presented to A. varipes for 12 hours. A female adult of A. varipes was allowed to parasitize for 12 hours in each plastic petri dish. The periods from egg to adult of A. varipes were 18.3 days, 14.7 days, 10.4 days, and 9.3 days at $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$, respectively. The pupal mortalities of A. varipes were 0%, 1.5%, 2.8%, and 10.2% at $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$, respectively. The mummifications of A. varipes were significantly different in all developmental stages of the aphid. The mummification of A. varipes parasitizing green peach aphid was the highest at 1st and 2nd in $20^{\circ}C$ and $25^{\circ}C$, but the highest at 3rd (84.4-85.0%) in $30^{\circ}C$ and $35^{\circ}C$. The host feedings of A. varipes were $20^{\circ}C$ (12.5%), $25^{\circ}C$ (17.3%), $30^{\circ}C$ (16%), and $35^{\circ}C$ (10.9%), respectively. The sex ratios of A. varipes female were $20^{\circ}C$ (49%), $25^{\circ}C$ (46%), $30^{\circ}C$ (69%), and $35^{\circ}C$ (60%), respectively.

• Korean journal of applied entomology
• /
• v.51 no.4
• /
• pp.397-403
• /
• 2012

This study compared the Aphelinus varipes and Aphelinus asychis in terms of how they parasitized the cotton aphid, Aphis gossypii and green peach aphid, Myzus persicae. Host-feeding, parasitism, emergence, the proportion of females and development time were all studied at 15, 20, 25 and $30^{\circ}C$ in controlled climate cabinets. When A. gossypii were provided for the two aphid parasitoids, the number of aphids killed by host-feeding for A. varipes (5.4 and 9.7 aphids) at $15^{\circ}C$ and $25^{\circ}C$ was higher than those for A. asychis (2.0 and 2.9 aphids). At $15^{\circ}C$ and $30^{\circ}C$, the parasitized A. gossypii were higher in A. varipes (11.1 and 21 aphids) than in A. asychis (7 and 12.3 aphids). The emergence rate was also significantly different between A. varipes (83.3%) and A. asychis (69.4%). The proportion of females was higher for A. asychis (75.2 and 73.9%) than for A. varipes (19.5 and 48.6%) at $15^{\circ}C$ and $30^{\circ}C$, respectively. No significant differences were found in development time between the two parasitoids. When M. persicae were provided for the two parasitoid species, the host-feeding number and the emergence rate of two parasitoids were not different at all four temperatures. The M. persicae were more highly parasitized by A. varipes (12.1 and 17.1 aphids) than by A. asychis (6.1, 10 aphids) at 20 and $25^{\circ}C$. The proportion of females for A. varipes (65.3 and 90.0%) was higher than that for A. asychis (34.4 and 78.8%) at $15^{\circ}C$ and $25^{\circ}C$. The development time from oviposition to the adult emergence of A. varipes (19.9 d) was significantly longer than that of A. asychis (16.5 d) at $20^{\circ}C$. Development times decreased with increasing temperature for both in two parasitoid species.