Effect of Different Honey Concentrations on Survival, Longevity and Reproduction of Trichospilus pupivorus (Hymenoptera: Eulophidae), a Parasitoid of Coconut Black-Headed Caterpillar, Opisina arenosella (Lepidoptera: Oecophoridae)

Nor Ahya Mahadi,Mazidah Mat,Tajul Ariffin Aziz Yusof

doi:10.5539/jas.v12n10p57

Abstract

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&plusmn;0.19 days and significantly produced the highest number of progenies (105.4&plusmn;0.81). The lowest survival rate was given by 60% honey and significant longevity up to 6.5&plusmn;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.

Highlights

Coconut (Cocos nucifera) which is known as the tree of life is one of the most important commodities in Malaysia with total production of 527,729 metric tonne in 2019 (DOA Malaysia, 2019, p. 20) and has been listed as one of the new wealth resources for the country
The survival curves of T. pupivorus adults were significantly different between the diets (χ2 = 65.97; df = 6; P < 0.0001)
Results revealed that the high survival rate of the parasitoid was recorded for 30% honey followed by 50%, 20%, 40%, 10% and 60% honey (Table 1 and Figure 1) when compared with distilled water

Summary

Introduction

Coconut (Cocos nucifera) which is known as the tree of life is one of the most important commodities in Malaysia with total production of 527,729 metric tonne in 2019 (DOA Malaysia, 2019, p. 20) and has been listed as one of the new wealth resources for the country. This positive trend has caused problems of coconut insect pest infestations which later induced yield reduction. Opisina arenosella (Lepidoptera: Oecophoridae) or commonly called the coconut black-headed caterpillar is a harmful defoliator of coconut in many coconut producing countries including India, Sri Lanka (Kumara, 2015), Bangladesh (APPPC, 1987), Pakistan, Myanmar (EPPO, 2014), China (Baoqian et al, 2016; Jin et al, 2018), Thailand (DOA Thailand, 2017) and Malaysia (Nor Ahya et al, 2018). This pest found infesting other crops such as oil palm, jackfruit, cashew (Shameer et al, 2017), date palm, and numerous types of ornamental palms (Murthy & Jalai, 2003). Due to its prolonged larval stage that consists of 7 (male) and 8 (female) larval instars (Kumar, 2002), it could cause up to 45.4% of crop loss on infested palms in jas.ccsenet.org

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