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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.

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Biological control programmes involving Ooencyrtus pityocampae Mercet (Hymenoptera: Encyrtidae) have proved effective at reducing the damage caused by the pine processionary Thaumetopoea pityocampa Denis & Schifferm€ uller (Lepidoptera: Thaumatopoeidae). In this study, the biological variables that influence the parasitism of O. pityocampae on the new laboratory host Philosamia ricini Danovan (Lepidoptera: Saturniidae) have been investigated. Laboratory experiments were conducted under the conditions of 25 AE 1°C, 65 AE 5% R.H (relative humidity) and a photoperiod of 16 : 8 h (L : D = light : dark). The host egg age and parasitoid age are often regarded as being key factors influencing the emergence rate of O. pityocampae. The optimal age of host eggs for parasitization was 1-2 days, and the emergence rate was highest with 5-day-old female parasitoids. Thus, our results define the optimal conditions for the effective and economic rearing of parasitoids as follows: one 5-day-old female parasitoid per 50 (1-2)-day-old host eggs. The development time of O. pityocampae ranged between 19.5 and 22.6 days. Parasitoids that were exposed to bio-honey survived 10.5 times longer than those that did not receive supplemental food. O. pityocampae was reared for more than nine generations on the eggs of P. ricini. Consequently, P. ricini has been found as a suitable new laboratory host for the mass rearing of O. pityocampae for the use of biological control programmes against T. pityocampa in future.

The brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae) originates from Asia and has recently disseminated to America and Europe, where it is considered as an invasive pest of various crops. Developing biological control strategies is necessary, and egg parasitoids are among the best candidates. In this context, the objective of this study was to evaluate the fitness of the egg parasitoid Ooencyrtus pityocampae Mercet (Hymenoptera: Encyrtidae) reared on H. halys eggs, under laboratory conditions. We specifically investigated the impact of host age, host density and length of exposure on O. pityocampae life history traits. Host age × host density and host age × length of exposure affected the performance of O. pityocampae. The optimal emergence rate of the parasitoid was obtained from one-day-old H. halys eggs and 3 days of exposure. The parasitoid embryonic development ranged from 17.1 to 18.3 days. The mean longevity of O. pityocampae was 44.1 days. This species reproduces by thelytokous parthenogenesis and the female parasitoid produced an average of 42.6 progeny during their lifespan. Pre-oviposition, oviposition and post-oviposition periods were 1.9 days, 18.8 days and 24.8 days, respectively. These results suggest that H. halys is a suitable host for O. pityocampae, and may help for the development of a pest-management strategy against H. halys.