Host plant selection by the pollen beetle Meligethes aeneus

Abstract

A simple bioassay is described for the response of Meligethes aeneus F. (Coleoptera: Nitidulidae) to different plants and plant parts. Assays with non‐hibernated beetles showed that (1) cruciferous buds and stamens were greatly preferred to petals and leaves; (2) stamens were most preferred when the quantity of mature pollen was at maximum; (3) anthers were preferred to filaments; (4) stamens from five different spring cultivars of Brassica napus were preferred at significantly different degrees; (5) stamens from four B. campestris cultivars were preferred to B. napus cv. Gulliver, but only when the preferences per mm2 were compared; (6) stamens from B. carinata and Sinapis alba were preferred to stamens from B. napus and B. campestris; (7) stamens from Compositae (Cirsium arvense, Leontodon nudicaulis, Sonchus arvensis and Taraxacum sp., Vulgaria group) were much less preferred than B. napus stamens (Cruciferae), but more preferred than stamens from Rosa pimpinellifolia (Rosaceae), whereas stamens from Papaver dubium (Papaveraceae) were not preferred to B. napus leaves; (8) chemical stimuli, including odours, were the most important stimuli in the bioassays. The use of equal crude areas for comparisons is briefly discussed. RÉSUMÉ Le choix de plantes‐hôtes de méligèthe des crucifères Une méthode simple et rapide, est signalée pour l'épreuve de la réponse de Meligethes aeneus vis‐à‐vis des plantes différentes et des organs différents de plantes. Des épreuves avec des insectes non‐hibernés ont indiqué que (1) des étamines et des boutons sont beaucoup plus préférées que les pétales et les feuilles; (2) la préférence des étamines est au maximum en même temps que le nombre de pollens mûrs; (3) des filaments (sans pollens) sont moins préférés que les anthères; (4) les préférences des étamines de cinq variétés différentes de Brassica napus diffèrent significativement; (5) les préférences des étamines de quatre variétés de B. campestris surmontent celle de B. napus var. Gulliver, mais seulement quand les préférences par mm2 sont comparées; (6) les préférences des étamines de B. carinata et Sinapsis alba dépassent celles de B. napus et B. campestris; (7) des étamines de Compositae (Cirsium arvense, Leontodon nudicaulis, Sonchus arvensis et Taraxacum sp., group de Vulgaria) sont beaucoup moins préférées que des étamines de B. napus (Cruciferae), et plus préférées que celles de Rosa pimpinellifolia (Rosaceae), tandis que les étamines de Papaver dubium (Papaveraceae) ne sont pas préférées à les feuilles de B. napus; (8) des stimuli chimiques, les odeurs incluses, étaient les stimuli les plus importants dans les épreuves. La nécessité d'appliquer des étendues standardisées dans les comparaisons est brièvement discutée.

The role of pollen odour in the attraction of pollen beetles to oilseed rape flowers

“…However, the difference could also be qualitative, due to chemical differences between the volatiles emitted by anthers and the rest of the flower, as observed in other species (Dobson et al, 1990). Charpentier (1985) tested the relative attractiveness of different oilseed rape plant parts to pollen beetles and found that the beetles could discriminate between them, preferring anthers over leaves, filaments, petals, and buds. Although visual and tactile cues were not removed from his bioassay, Charpentier proposed that the odour of anthers was particularly important in this attraction, and his work supports the possibility that chemical differences between the anthers and other floral parts of oilseed rape exist and that these are detectable by the pollen beetle.…”

Potential for oilseed rape resistance in pollen beetle control

“…However, a number of studies have compared life history traits of adults and larvae of this pest among different brassicaceous species Charpentier 1985;Borg and Ekbom 1996;Ekbom and Borg 1996;Hopkins andEkbom 1996, 1999;Ekbom 1998;Hopkins et al 1998;Billqvist and Ekbom 2001;Bartlet et al 2004;Cook et al 2007;Veromann et al 2012Veromann et al , 2014Kovács et al 2013;Kaasik et al 2014a, b). These results are summarized in Fig.…”

Semiochemical-based alternatives to synthetic toxicant insecticides for pollen beetle management

“…At this stage, other chemical stimuli (surface and/or inner tissue semiochemicals) gained from close inspection of the plant become more important. Indeed, Charpentier (1985) found differences between host-plant feeding preferences of pollen beetles and concluded that chemical stimuli were the most important. Hervé et al (2014) studied these stimuli by comparing six OSR genotypes for pollen beetle feeding preference, and identified possible phagostimulant/deterrent compounds in the bud perianth (the tissue that has to be pierced to access the food source) and in anthers (the tissue containing the food source).…”

“…In laboratory tests, pollen beetles have been found to be attracted to volatiles from OSR in the bud stage (Evans and AllenWilliams 1994;Cook et al 2007c;Jönsson and Anderson 2007), at the flowering stage (Evans and Allen-Williams 1994;Cook et al 2002Cook et al , 2006b, to floral volatiles from the OSR flower or part of the flower (Charpentier 1985;Byers 1992;Cook et al 2002), as well as to pollen odour (Cook et al 2002). The chemical basis for this attraction has been tested in the laboratory using electrophysiological studies and the most active compounds include 2-phenylethyl-, 3-butenyl-and 4-pentenyl-isothiocyanate, phenlyacetaldehyde and indole (Cook et al 2007c).…”