D3138: Does fitness drive Lygus lineolaris feeding choices?

The omnivorous Tarnished plant bug (TPB), Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), behaves both as a pest and predator in strawberry fields. Its feeding choices can be driven for sensorial preferences, avoiding competition or predation risk, resource scarcity, or fulfilling nutrient requirements.

The objective was to assess the impact of different nutrient compounds on TPB fitness. For this purpose, several omnivorous sources were offered to TPB from the beginning of N2 until the adult stage. The development time, survival rate, sex, weight, and size of adults were evaluated. To assess the potential of canola and buckwheat as trap crops and to evaluate aphids and spider mites as potential preys in strawberry fields, these nutritional sources were offered alone and combined.

Results showed five days of difference in developmental time between the different food resources offered. Additionally, adults were larger and heavier when the developmental time was shorter, highlighting an improvement in fitness. Phytozoophagous mixtures tended to improve TPB fitness, especially when canola, and secondly, aphids, were offered. With a development time greater than 17 days, and a mortality greater than 50%, spider mites and strawberry flowers represented low quality food resources.

Overall, this study reveals the nutritional prerequisites of TPB and suggests that TPB feeding choices may not only be driven for fitness improvement.
Furthermore, this information may help to build a theoretical framework to predict the behavior of mirids according to their degree of phyto-zoophagy and, therefore, help reduce their impact as pests.