1,4-benzoquinone attracts males of Rhizotrogus vernus Germ

The Addition of a Pheromone to a Floral Lure Increases Catches of Females of the Click Beetle Agriotes ustulatus (Schaller) (Coleoptera: Elateridae)

Agriotes ustulatus is an economically important click beetle in Europe. A female-produced pheromone, (E,E)-farnesyl acetate, has been identified and is used for monitoring and detecting males. More recently, a floral lure targeting females with modest, but significant, activity has been described. Based on preliminary data, we hypothesized, that similar to the effects on the congeneric A. brevis, addition of the pheromone to the floral lure should improve female A. ustulatus catches. Also, as click beetles have been reported to respond to white light, we studied possible interactions between visual and chemical cues. In field trials, the addition of the synthetic pheromone to the floral lure resulted in a dramatic increase in the number of females trapped, whereas male catches remained unaffected and equal to those in traps baited with pheromone only. A white visual cue did not influence trap catches. Maximum catches of both sexes of A. ustulatus can be achieved using the pheromone and the floral lure inside the same trap. Furthermore, the compounds can be formulated in a single polyethylene bag dispenser, making handling of the trap easier. Due to a much larger proportion of females in the catch, this improved trap may be a promising tool for semiochemical-based, environmentally sound agricultural practice against this important pest.

Identification of the aggregation-sex pheromone of Plagionotus arcuatus ssp. arcuatus (Coleoptera: Cerambycidae) from two geographically separated European populations

Plagionotus arcuatus ssp. arcuatus (L.) is a common saproxylic cerambycid beetle in most parts of Europe, and is designated as an occasional pest of oak wood that is stored outside during the summer months. In an effort to identify attractants that can be used for monitoring this species, we collected headspace samples from adult beetles and conducted field bioassays with the resulting compounds as potential aggregation-sex pheromone components for this species. Three compounds, (R)-3-hydroxyhexan-2-one, (R)-3-hydroxyoctan-2-one, and (R)-3-hydroxydecan-2-one, were consistently present in relatively large quantities in headspace extracts from male P. arcuatus populations in both Hungary and Sweden, regardless of the adsorbent media (activated charcoal or Porapak™ Q) used to sample beetle odors, or the type of solvent (hexane, diethyl ether, or dichloromethane) used to elute trapped volatiles from the collectors. None of the hydroxyketone and related compounds were detected in corresponding extracts from females. In field bioassays in both countries, the blend of the C₆ and C₁₀ compounds, and the ternary blend both attracted significantly more beetles than the control, while other combinations or single compounds were not significantly attractive. Males and females showed similar patterns of responses to treatments. Our results demonstrate that (R)-3-hydroxyhexan-2-one and (R)-3-hydroxydecan-2-one constitute a male-produced aggregation-sex pheromone of P. arcuatus, whereas the role of (R)-3-hydroxyoctan-2-one remains unclear. Lures with the pheromone could be developed for monitoring of P. arcuatus populations as an indicator of fresh oak wood resources.

Semiochemistry of the Scarabaeoidea

The superfamily Scarabaeoidea comprises a large and diverse monophyletic group. Members share ancestral characteristics, but often exhibit considerable differences in their ecology, physiology, or mating strategies. A large number of species are regarded as pests of crop or amenity plants, while others are beneficial to humans and even may be extremely rare as a result of anthropogenic activities. A significant number of chemical ecology-based studies have been conducted with the Scarabaeoidea in order to characterize semiochemicals influencing their behavior, such as pheromones and plant-derived allelochemicals. These may be used either to control or preserve populations of the beetles, depending upon pest or beneficial status. This paper is a review of the role and identity of the semiochemicals of the Scarabaeoidea, with comments on possible future research and applied opportunities in the field of chemical ecology.

Quinone mixture as attractant for necrophagous dung beetles specialized on dead millipedes

2-Methyl-1,4-benzoquinone (toluquinone) and 2-methoxy-3-methyl-1,4-benzoquinone are the most common components of defensive secretions of juliform millipedes (Diplopoda: Juliformia). A natural and a synthetic millipede-defensive secretion composed of these two substances attract dung beetles of a few Onthophagus species (Coleoptera: Scarabaeidae) that feed mainly on freshly dead millipedes. This olfactory mechanism and adaptation to the toxic effects of quinones enables them to be the first and exclusive users of this resource.