No abstract

Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) is an omnivorous generalist predator which is augmentatively released and conserved for control of whiteflies (Hemiptera: Aleyrodidae) and Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in tomato crops. Eggs of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) are often provided as factitious prey to improve the establishment of N. tenuis after its release. We first tested different amounts of E. kuehniella eggs per plant to optimize N. tenuis establishment and then investigated whether the amount of eggs that optimized N. tenuis establishment might be reduced by adding sugars (hydrocapsules filled with 0.5 m sucrose) under walk‐in cage and commercial greenhouse conditions. These experiments demonstrated that the addition of sugar to the diet of N. tenuis could half the amount of E. kuehniella eggs required to establish N. tenuis. Under greenhouse conditions, the progeny of N. tenuis per plant did not differ significantly between E. kuehniella alone or the half amount of E. kuehniella plus hydrocapsules. These results demonstrated that the sugar could partially substitute for E. kuehniella eggs improve establishment of N. tenuis and suggest that natural sugars such as nectar and honeydew might also beneficial.

Pest populations at climate change conditions can reach higher densities than forecasted according to its demographic parameters. Natural pest regulation provided by natural enemies depends on environmental conditions, is species-specific and is affected by interspecific interactions. Local extinctions may occur more frequently in a warmer future. Spider mite natural regulation can be seriously disrupted in a climate change scenario. Pest outbreaks may be increasingly more frequent in a warmer future.

Zoophytophagous mirids (Hemiptera: Miridae) are one of the most studied and successful group of natural enemies used as biological control agents in horticultural crops. When prey is scarce, some species, such as Nesidiocoris tenuis (Reuter) may damage plant tissue by increasing feeding on vegetative and reproductive organs. Despite the importance of mirids, the provision of a sugar source as an alternative or complement to plant feeding has never been addressed to reduce mirid phytophagy. Here we analyzed the nutritional status and phytophagy of N. tenuis in the presence of tomato plants with and without sugar dispensers. Our study demonstrated how nymphs and adults obtained carbohydrates when fed on tomato plants. Phytophagy was reduced more than two-fold with the provision of sugar dispensers. Both nymphs and adults contained higher carbohydrate levels when they had access to plants with sugar dispensers than without. Nymphs, which are generally responsible for more serious plant damage, had a higher content of carbohydrates than adults independently of the diet provided. Our findings contribute not only to improve the use of zoophytophagous predators as biological control agents, but also to understand the nutritional ecology of the Miridae, a group with a very diverse diet.