Tri-Trophic Level Impact of Host Plant Linamarin and Lotaustralin on Tetranychus urticae and Its Predator Phytoseiulus persimilis

Abstract

The impact of linamarin and lotaustralin content in the leaves of lima beans, Phaseolus lunatus L., on the second and third trophic levels was studied in the two-spotted spider mite, Tetranychus urticae (Koch), and its predator Phytoseiulus persimilis Athias-Henriot. The content of linamarin was higher in terminal trifoliate leaves (435.5 ppm) than in primary leaves (142.1 ppm) of Henderson bush lima beans. However, linamarin concentrations were reversed at the second trophic level showing higher concentrations in spider mites feeding on primary leaves (429.8 ppm) than those feeding on terminal trifoliate leaves (298.2 ppm). Concentrations of linamarin in the predatory mites were 18.4 and 71.9 ppm when feeding on spider mites grown on primary and terminal leaves, respectively. The concentration of lotaustralin in primary lima bean leaves was 103.12 ppm, and in spider mites feeding on these leaves was 175.0 ppm. Lotaustralin was absent in lima bean terminal trifoliate leaves and in mites feeding on these leaves. Fecundity of spider mites feeding on lima bean leaves (primary or trifoliate) was not significantly different from mites feeding on red bean, Phaseolus vulgaris L., primary leaves. However, the progeny sex ratio (in females per male) of spider mites feeding on lima bean leaves was significantly lower than progeny of spider mites feeding on red bean leaves (control). Fecundity and progeny sex ratio of P. persimilis were both significantly affected by the concentration of linamarin present in the prey. Changes in concentration of linamarin in living tissue across the three trophic levels are discussed.

Lima bean–lady beetle interactions: spider mite mediates sublethal effects of its host plant on growth and development of its predator

“…The two-spotted spider mite feeds less on lima bean (Henderson cultivar) than on red kidney bean, possibly due to the presence of linamarin and other cyanogenic glycosides in lima bean than in red kidney bean. Although this herbivore is adapted to feeding on lima bean and is able to process cyanogenic glycosides (e.g., linamarin), the progeny sex ratio becomes male biased when restricted to feeding on Henderson lima bean (Rojas and Morales-Ramos 2010). The observation that the Henderson rather than the Fordhook cultivar expressed high linamarin content corroborates with the high content of this molecule in the second and third trophic levels.…”

“…Determining linamarin content in plant foliage, spider mite, and predator Detailed procedures of sample preparation are reported elsewhere (Rojas and Morales-Ramos 2010). We dried random samples of plant tissue from un-infested primary, secondary, and tertiary leaves of Henderson and Fordhook cultivars in an Isotemp vacuum oven (Model 282A, Fisher Sci.)…”

“…The cyanogenic glycoside content can vary considerably between the different varieties (cultivars) of lima bean (Ballhorn et al 2005). Linamarin and lotaustralin (at a much lower concentration) occur in Henderson lima bean foliage; spider mites ingest linamarin, and to a lesser extent lotaustralin, as they feed on the nutrients inside cells within the leaf epidermis (Rojas and Morales-Ramos 2010). This can have sublethal effects on spider mites.…”

“…This can have sublethal effects on spider mites. For example, Rojas and Morales-Ramos (2010) showed that T. urticae produced fewer female progeny when reared on Henderson lima bean in comparison with red kidney bean, Phaseolus vulgaris L. Neither linamarin nor lotaustralin was present at detectable levels in red kidney bean foliage. Additionally, a predatory mite, Phytoseiulus persimilis Athias-Henriot, experienced a decline in fecundity and production of female progeny when consuming spider mites treated with linamarin (Rojas and Morales-Ramos 2010).…”

Mother-Offspring Relations: Prey Quality and Maternal Size Affect Egg Size of an Acariphagous Lady Beetle in Culture

“…At the time, we did not think it was necessary to record their size, since our previous research clearly showed that prey quality altered the growth and development of S. punctillum immatures; smaller immatures resulted from feeding on low-quality rather than high-quality prey [27]. The concentration of linamarin, a cyanogenic glycoside purportedly used by the plant in defending itself against herbivory, is much greater in Henderson than in Fordhook lima beans [30]. Linamarin reduces the amount of nutrients (including soluble protein) that T. urticae can extract from lima bean foliage, resulting in prey of lower quality for S. punctillum, reducing growth rate and body size, but not fecundity or longevity [27].…”