Aprostocetus sp females produced progeny throughout their lifetime and lived

Aprostocetus sp. females produced progeny throughout their lifetime and lived an average of 20.7 ± 8.2 d.
Aprostocetus sp. larvae fed externally on N. lugens eggs for 5 d until pupation. Many N. lugens eggs were consumed by each larval parasitoid (number of host eggs consumed was not recorded), so Aprostocetus sp. larvae showed predatory behavior. This characteristic of Aprostocetus sp. larvae in the current study agreed with Jacas et al. (2005) who reported that Aprostocetus vaquitarum Wolcott (Hymenoptera: Eulophidae) was a predator of Diaprepes abbreviates (Linnaeus) (Coleoptera: Curculionidae). Aprostocetus sp. was a predator, like other AZD8931 cost of this genus. One adult female of Aprostocetus sp. can produce an average of 74.7 ± 33 offspring during her lifetime. These results suggest improved efficiency in the control of N. lugens. The numbers of larval instars were not investigated, but Lee et al. (2010) and Llácer et al. (2005) reported that tetrastichine Eulophidae display 3–4 larval instars.
Male adults of Aprostocetus sp. emerged (14.8 ± 1.3 d) before female adults (15.4 ± 1.3 d) in common with other parasitoids and this is presumably an advantage for mating immediately following female emergence (Macdonald and Caveney, 2004).
Aprostocetus sp. is an egg parasitoid of N. lugens. Previous reports about this parasitoid did not mention the Brown planthopper as a host. Pathak and Khan (1994) and Gurr et al. (2011) reported that Ootetrastichus and Tetrastichus were egg parasitoids of N. lugens and Sogatella furcellata (Horvoth) (Hemiptera: Delphacidae) and distributed in many countries including Thailand. Vungsilabutr et al. (2002) and Sriratanasak et al. (2007) reported that Tetrastichus spp. (Eulophidae) was an important ectoparasitoid that consumed N. lugens eggs. Furthermore, Nacro and Nénon (2009) and Heinrichs and Barrion (2004) reported that Aprostocetus procerae Risbec (Hymenoptera: Eulophidae) was a solitary pupal parasitoid of the rice gall midge, Orseolia oryzivora Harris and Gagné (Diptera: Cecidomyiidae). Sriratanasak et al. (2007) also reported that Aprostocetus sp. attacked pupae of the rice gall midge, Orseolia orysae (Wood–Mason) (Diptera: Cecidomyiidae).
The number of parasitized eggs or eggs that were consumed by Aprostocetus sp. were not counted in the current study, so this should be investigated because it would assist in forecasting mortality of the Brown planthopper, N. lugens in paddy fields.
The identification of the parasitoid, Aprostocetus sp. was provided by Dr. Charuwat Taekul, a taxonomist from the Entomology & Zoology Group, Plant Protection Research and Development Office, Department of Agriculture, Ministry of Agriculture and Cooperative, Bangkok, Thailand. Voucher specimens were deposited at National Biological Control Research Center, Kasetsart University, Bangkok, Thailand.

Conflict of interest statement

Acknowledgements

Introduction
From the first reported in vitro oyster fertilization in 1879 to the appearance of modern production hatcheries, hatchery practices have seen more than one hundred years of development (Helm et al., 2004). Today, knowledge about oyster reproduction and rearing techniques has improved greatly. Hatcheries successfully achieve controlled development of spat from fertilization to post-larvae for many oyster species. Induced spawning and gamete striping or sacrification are commonly used for obtaining gametes in oyster hatcheries as using stripped gametes is the most practical method for producing triploid oysters because the time of fertilization can be easily controlled (Allen Jr. and Bushek, 1992). Although “strip” spawning is the recommended method for obtaining gametes, it was found that there was much greater variability in the speed of egg development in “stripped” eggs than in those obtained from natural spawning (Allen Jr. and Bushek, 1992). This technique is an alternative practice in fully mature oysters in cases where induced spawning is ineffective.