The tarnished plant bug, Lygus lineolaris, is a major strawberry pest. Only marginally effective control methods exist to manage this pest. Various predators attack L. lineolaris, but their potential is overlooked. In this study, we explore the potential of two omnivorous predators of the tarnished plant bug: the damsel bug, Nabis americoferus, and the minute pirate bug, Orius insidiosus. Firstly, the predation rate of these predators was measured in laboratory tests. Secondly, their potential release rates and release periods were determined in the field using strawberry plants. The results show that N. americoferus feeds on all nymphal stages and adults of the tarnished plant bug, while O. insidiosus attacks only smaller nymphs (up to the N2 stage). In the field, all tested densities of N. americoferus (0.25, 0.5, and 0.75 individual/plant) reduced the population of the tarnished plant bug for several weeks compared with the control treatment, but the effect of O. insidiosus alone was marginal. Additionally, for all the release periods tested, Nabis americoferus was efficient in reducing the pest population. These results demonstrate the potential of N. americoferus to control the tarnished plant bug in strawberry fields. We discuss the possible application of these results for establishing an effective and economically viable biological control strategy.
Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), a true omnivorous insect, poses a significant threat to agriculture in the Neartic region. Understanding the feeding behavior of L. lineolaris is crucial for developing integrated pest management strategies. This study aimed to evaluate the effects of different diets on the fitness of L. lineolaris, with a focus on the diet source, feeding regime (phytophagy, zoophagy, and phytozoophagy), and number of diet items. The experimental design in the laboratory investigated the impacts of strawberry, canola and buckwheat flowers, as well as spider mites and aphids to explore relationships found in a conventional strawberry field. Results reveal that diet source, feeding regime, and the number of diet items influence L. lineolaris performance (i.e., survivorship rate, developmental time, and adult weight and length). Improvements in fitness are indicated by higher nymphal survival, shorter developmental time, and larger adults. Immature stages of L. lineolaris show improved fitness when provided with diets rich in canola compared to strawberry flowers and spider mites. Furthermore, the inclusion of multiple diet items in phytozoophagous regimes enhances insect performance. The findings emphasize the significance of understanding L. lineolaris’ nutritional requirements and the biodiversity of target ecosystems for modeling energy flows and designing effective IPM strategies against this pest. This research contributes to the knowledge base for biological control programs targeting L. lineolaris in agricultural systems.
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.
Lygus lineolaris is a highly polyphagous pest that impacts key crops such as strawberries, making an understanding of its feeding behavior critical for developing effective management strategies. Using metataxonomy, this study examined the dietary breadth of L. lineolaris in a commercial strawberry field in Quebec, revealing an extensive and diverse omnivorous diet. The multiprimer approach, combined with validation samples, ensured high taxonomic resolution and accuracy. We expanded the documented list of L. lineolaris host taxa to 475, including 441 plants and 34 prey species, with 51 taxa unique to this research, comprising eight new plant hosts and five prey species. Molecular evidence confirmed active ingestion, underscoring its omnivorous behavior with a predominantly herbivorous tendency. Notably, 70% of individuals fed exclusively on plants, 20% exhibited omnivory, and only 4% were strictly zoophagous. To quantify the level of phytozoophagy in omnivorous species, we propose a novel coefficient of omnivory (CO), calculated as CO = P /( P + Z), where P and Z represent the number of individuals with molecular evidence of phytophagy and zoophagy, respectively. With a CO of 0.833 (95% CI: 0.77–0.90), L. lineolaris demonstrates a strong bias toward plant feeding. Diet composition varied seasonally and between sexes, with females showing increased zoophagy during reproductive periods. These findings highlight L. lineolaris 's dietary flexibility and resilience, providing critical insights into its feeding ecology and food web interactions to inform targeted integrated pest management strategies tailored to its omnivorous nature.