Extrafloral Nectar of Bottle Gourd: Synthesis and Role of Carbohydrates as a Dietary Supplement for Nesidiocoris tenuis Reuter (Heteroptera: Miridae)

Plants can provide natural enemies with alternative food resources that enhance their performance in addition to prey consumption. Extrafloral nectaries attract beneficial insects by supplying nectar in exchange for pest suppression, although other arthropods may also benefit. This study aimed to characterize the extrafloral nectar composition of bottle gourd, Lagenaria siceraria (Molina) Standley (Cucurbitaceae), a host plant of Nesidiocoris tenuis Reuter (Hemiptera: Miridae), and to evaluate the effects of its carbohydrate profile on key biological parameters of this predator. Extrafloral nectar was chemically characterized for carbohydrate and amino acid composition, and laboratory bioassays were conducted to assess the effects of a sugar solution of the extrafloral nectar carbohydrate profile when provided with two factitious food sources, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs and Artemia sp. (Anostraca: Artemiidae) cysts. Female egg production, nymphal development and food source consumption were evaluated. Chemical analysis revealed that bottle gourd extrafloral nectar consisted primarily of glucose, fructose, sucrose and melezitose, while serine was the dominant amino acid. Four essential amino acids were also detected. Sugar supplementation did not affect nymphal development rate but significantly reduced factitious food consumption. Significant differences in egg production were observed among feeding regimes. Sugar supplementation did not affect egg production when E. kuehniella eggs were provided, but significantly increased egg production when Artemia cysts were used as food source. These results indicate that extrafloral nectar carbohydrates can function as effective supplementary nutritional resources for N. tenuis, particularly when lower-quality factitious food sources are used. These findings enhance our understanding of plant–predator nutritional interactions and suggest that extrafloral nectar-derived components warrant further evaluation for incorporation into mass rearing protocols.