Feeding behaviour and performance of different populations of the black currant‐lettuce aphid, Nasonovia ribisnigri, on resistant and susceptible lettuce

Abstract

When crops are bred for resistance to herbivores, these herbivores are under strong selection pressure to overcome this resistance, which may result in the emergence of virulent biotypes. This is a growing problem for crop species attacked by aphids. The Nr‐gene in lettuce confers near‐complete resistance against the black currant‐lettuce aphid, Nasonovia ribisnigri (Mosely) (Hemiptera: Aphididae). Since 2007, populations of N. ribisnigri have been reported in several locations in Europe to infest resistant lettuce varieties that possess the Nr‐gene. The objective of this study was to analyse the behaviour and level of virulence of several N. ribisnigri populations observed to have colonized Nr‐locus‐containing lettuce lines. We analysed the stylet penetration and feeding behaviour, and the performance of these N. ribisnigri populations on resistant and susceptible lettuce lines. Large variation in the degree of virulence to the Nr‐locus‐containing lettuce lines was found among populations of the Nr:1 biotype. The German population was highly virulent on the Nr‐containing resistant lettuce lines, and showed similar feeding behaviour and performance on both the susceptible and resistant lettuces. The French population from Paris was the second most virulent, though reproduction on the resistant lines was reduced. The French population from Perpignan and a population from Belgium, however, showed reduced performance and feeding rate on the resistant compared to the susceptible lettuces. The lettuce background in which the Nr‐gene is expressed influences the level of resistance to the various Nr:1 aphid populations, because the performance and feeding behaviour differed between the aphids on the cultivars (romaine lettuce) compared to the near‐isogenic lines (butterhead/iceberg lettuce). This study also shows that being able to feed on a plant not automatically implies that a population can successfully develop on that plant, because aphids showed phloem ingestion during the 8‐h recording period on resistant lettuce, but were not able to survive and reproduce on the same lettuce line.

Rearing history affects behaviour and performance of two virulent Nasonovia ribisnigri populations on two lettuce cultivars

“…Ten Broeke et al. () also suggested loss of virulence for Nr:1 Be after being reared on the susceptible cultivar Fatima, after which survival was significantly lower on a resistant than on a susceptible lettuce cultivar. Loss of virulence was also stated by Michel et al.…”

“…For details about the origin of these populations, see ten Broeke et al. (). The Nr:1 populations were reared on Nr:0‐susceptible Terlana and Nr:0‐resistant Corbana, for 2 months prior to the experiment (i.e., 5–6 generations), creating two separate colonies per Nr:1 population reared on different lettuce cultivars.…”

“…An Nr:1 population from Germany performed equally well on resistant and susceptible lettuce and did not seem to be affected by the Nr ‐resistance (ten Broeke et al., ). In a previous study, it was shown that there is large variation in virulence among populations of N. ribisnigri ; however, it remains unclear what caused this variation (ten Broeke et al., ). A possible cause mentioned was the loss of virulence of certain populations during the rearing period on susceptible lettuce plants that lack the Nr gene.…”

Struggle to survive: aphid—plant relationships under low-light stress. A case of Acyrthosiphon pisum (Harris) and Pisum sativum L.

“…For all experiments involving aphids, one to seven days old adult apterous females of A. pisum were collected from the stock culture. According to ten Broeke et al (2013), the use of aphids of random ages gives a clear view of the behavior of adult aphids within a population. (Janoudi and Poff 1990).…”

Antibiosis resistance against larval cabbage root fly, Delia radicum, in wild Brassica-species

“…to the lettuce aphid, Nasanovia ribisnigri (Mosely 1841) (Homoptera: Aphididae) was found economically and environmentally effective in controlling this pest (McCreight 2008). The resistance conferred by the Nr-locus resulted in reduced performance and feeding rate of aphids (Eenink and Dieleman 1983;ten Broeke et al 2013). To find host plant resistance, natural variation among wild relatives of crop species can provide good sources (Broekgaarden et al 2011).…”