Many coconut producing countries in Asia are facing a serious infestation of Opisina arenosella (Lepidoptera: Oecophoridae) or commonly called the coconut black-headed caterpillar. Recently, the pest has been detected in the coconut (Cocos nucifera) planting area in Pahang, Malaysia. Thus, an initiative to manage the pest by using parasitoids has been started with a study on the effects of diet on survival, longevity and reproduction of naturally occurred parasitoid known as Trichospilus pupivorus (Hymenoptera: Eulophidae). The aim of this study was to identify suitable concentrations of honey that can be used in developing its rearing technique. Two independent experiments were conducted, i.e., a) survival and longevity study; and b) reproduction study. In each study, different honey concentrations were tested on ten (eight replications) and one (five replications) female parasitoids respectively. 30% honey concentrations resulted in high survival rate of the adult during early life with relatively prolonged longevity up to 6.0±0.19 days and significantly produced the highest number of progenies (105.4±0.81). The lowest survival rate was given by 60% honey and significant longevity up to 6.5±0.33 days with no progenies. Further studies on other plausible factors affecting the reproduction and fitness of progenies should also be investigated to ensure efficient rearing techniques.

Coconut black-headed caterpillar (Opisina arenosella) or BHC is one of the main coconut palm defoliators in many Asian countries, including Malaysia, where it was discovered in 2017. Since then, an effort has been made to manage the pest by the use of larval parasitoids, started with a study on the effects of sucrose diet on reproduction, longevity and parasitism of a naturally occurring parasitoid known as Bracon brevicornis (Hymenoptera: Braconidae). The aim of this study was to determine the optimal sucrose concentration for improving its rearing technique. Two experiments were conducted, i.e., a) reproductive performance study; and b) longevity study. In each study, different sucrose concentrations were tested on mated females in five (5) replications. Feeding on 20% sucrose concentration resulted in significantly (P<0.05) highest fecundity (82.4 ± 0.9), hatchability (100%), pupation, fertility (82.7%) and longest reproductive period (12.8 ± 0.3 days) of B. brevicornis among treatments. Meanwhile, 40% sucrose was able to prolong its adults' lifespan (20.6 days). Adults fed on 20% sucrose had the highest parasitism (33.4±0.6 host larvae), despite the fact that 30% sucrose had no statistically significant difference. Thus, this study suggested that 20% sucrose could be suitable to increase fertility and parasitism by B. brevicornis. However, additional research on its effect on behaviours is necessary to acquire a better knowledge of its efficiency in the field.