A new substitute host and its effects on some biological properties ofOoencyrtus kuvanae

Abstract

Lymantia dispar (L.) (Lepidoptera: Lymantriidae), commonly known as the gypsy moth, is a serious forest pest, and beneficial insects are particularly important for reducing its population numbers. Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyrtidae) is an arrhenotokous, solitary egg parasitoid of L. dispar. In this study, we evaluated a new substitute host, Philosamia ricini (Danovan) (Lepidoptera: Saturniidae) for O. kuvanae. We investigated some of the biological effects of O. kuvanae on P. ricini eggs. In this context, the importance of the age of the female parasitoid (1, 3 or 5 days old), host age (1-2 and 3-4 days old) and host number (40, 60 and 80 host eggs) were examined under laboratory conditions (25 ± 1 °C, 65 ± 5% relative humidity and a 16 : 8 h photoperiod [light : dark]). The highest rate of offspring production (89.90%) occurred with 40 (1-2-day-old) host eggs and 5-day-old females. The mean developmental period ranged from 16.5 ± 0.08 days to 18.7 ± 0.08 days. The mean lifespan of the parasitoid was 51.10 ± 1.1 (n = 60) days with bio-honey and 3.92 ± 0.14 (n = 60) days without food. The mean fecundity was 68.88 ± 3.22 offspring/female. Peak adult emergence occurred between 2 and 9 days. The mean oviposition and mean post-oviposition periods of the female parasitoid were 22.76 ± 1.37 days and 13.64 ± 1.40 days, respectively. O. kuvanae was reared for more than ten generations on the eggs of P. ricini. Based on our findings, P. ricini can be used to rear O. kuvanae for the biological control of L. dispar.

Occurrence, Seasonal Abundance, and Superparasitism of Ooencyrtus kuvanae (Hymenoptera: Encyrtidae) as an Egg Parasitoid of the Spotted Lanternfly (Lycorma delicatula) in North America

“…In the laboratory at 22 ± 1 • C, 40% ± 5% relative humidity, and a photoperiod of 16:8 (light/dark) h, adult emergence occurred between 22 April and 2 May in 2016, with peak emergence on days 3, 8, and 11, respectively (Figure 2). Similar peak emergence between day 2 and day 9 was also observed for this parasitoid on its substitute host P. ricini when reared at 25 ± 1 • C, 65% ± 5% relative humidity, and a photoperiod of 16:8 (light/dark) in laboratory incubation [58]. A development time from egg to adult of 21 days at 25 • C was recorded on gypsy moths [24], compared to a developmental period of 16.5-18.7 days at the same temperature on P. ricini [58].…”

“…Similar peak emergence between day 2 and day 9 was also observed for this parasitoid on its substitute host P. ricini when reared at 25 ± 1 • C, 65% ± 5% relative humidity, and a photoperiod of 16:8 (light/dark) in laboratory incubation [58]. A development time from egg to adult of 21 days at 25 • C was recorded on gypsy moths [24], compared to a developmental period of 16.5-18.7 days at the same temperature on P. ricini [58]. Differences in host species and incubation temperatures could explain the discrepancies between different studies.…”

Biocontrol characteristics of the fruit fly pupal parasitoid Trichopria drosophilae (Hymenoptera: Diapriidae) emerging from different hosts

“…Parasitoids reared in substitute hosts would help to increase the availability of biocontrol agents 20 – 22 . It has also been proven that large parasitoids of the same species have longer life spans, and large females produce approximately twice as many eggs as small females 18 .…”

Performance of Ooencyrtus kuvanae (Hymenoptera: Encyrtidae) on two host species, Halyomorpha halys and Philosamia ricini

“…Finally, we were determined the parasitism rate, emergence rate, development time, sex ratio and adult longevity (with honey as well as without food). The fecundity experiment was conducted according to Tunca et al (2017). Thirteen single mated female parasitoids…”

“…The study was conducted at the INRA-PACA Mediterranean Forest and Entomology Unit, Laboratory of Biological Control located in Antibes, France. The laboratory conditions were 25 ± 1°C, 60 ± 5% RH and a photoperiod of 18:6 hr L:D. A three-year-old laboratory colony of O. kuvanae (~60th generation) was used in the experiment and reared according to the method described by Tunca et al (2017).…”