Evaluation of Trap Crops and the Presence of the Predator Nabis americoferus for the Management of the Tarnished Plant Bug in Strawberries

Abstract

The polyphagous tarnished plant bug (TPB), Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), inflicts substantial damage to strawberries and to several other valuable crops, impacting both yield quantity and quality. Effective control strategies are crucial to mitigate these losses. This study aimed to elucidate TPB host preferences and reproductive behaviours under various integrated pest management approaches. Experimental arenas with strawberry plants included treatments involving the predator Nabis americoferus (Carayon) (Hemiptera: Nabidae) and trap crops. In each arena, 30 adult TPBs were exposed to different configurations: (i) three strawberry plants, (ii) three strawberry plants with predators, (iii) one strawberry plant alongside two trap crop plants (buckwheat and canola), and (iv) one strawberry plant with the two trap crops and predators. TPB distribution among the arena, plant species and plant sites (flower, stem and adaxial and abaxial leaves) were monitored over 72 h. One week later, adults were removed and the number of emerged first instar nymphs (L1) was recorded three times postexperiment. The results indicate a preference shift in TPB behaviour influenced by plant diversity and predator presence. TPBs exhibited a reduced presence on strawberries when trap crops were introduced, with canola as a preferred plant. This preference for canola was supported by higher TPB offspring counts. Conversely, buckwheat, although less preferred, contributed to diluting TPB populations across plant species. The introduction of N. americoferus showed dual effects: While reducing TPB oviposition on canola, it increased TPB presence on strawberries, highlighting the importance of nonconsumptive effects (NCEs) of predators in agroecosystems. Nonetheless, the combination of canola as a trap crop and N. americoferus as a predator effectively reduces TPB presence on strawberry flowers, essential for fruit development. This approach shows promise when integrated with other strategies, such as vacuuming and pheromone-enhanced coloured traps.