The leaf beetle Labidostomis lusitanica (Coleoptera: Chrysomelidae) as an Iberian pistachio pest: projecting risky areas

Can Pheromones Contribute to Phylogenetic Hypotheses? A Case Study of Chrysomelidae

Pheromones mediate species-level communication in the search for mates, nesting, and feeding sites. Although the role of pheromones has long been discussed by various authors, their existence was not proven until the mid-twentieth century when the first sex pheromone was identified. From this finding, much has been speculated about whether this communication mechanism has acted as a regulatory agent in the process of speciation, competition, and sexual selection since it acts as an intraspecific barrier. Chrysomelidae is one of the major Phytophaga lineages, with approximately 40,000 species. Due to this immense diversity the internal relationships remain unstable when analyzed only with morphological data, consequently recent efforts have been directed to molecular analyses to establish clarity for the relationships and found their respective monophyly. Therefore, our goals are twofold 1) to synthesize the current literature on Chrysomelidae sex pheromones and 2) to test whether Chrysomelidae sex pheromones and their chemical structures could be used in phylogenetic analysis for the group. The results show that, although this is the first analysis in Chrysomelidae to use pheromones as a phylogenetic character, much can be observed in agreement with previous analyses, thus confirming that pheromones, when known in their entirety within lineages, can be used as characters in phylogenetic analyses, bringing elucidation to the relationships and evolution of organisms.

Chemical Communication in Insects: New Advances in Integrated Pest Management Strategies

Chemical communication plays a pivotal role in many insect behaviors, including food-seeking, recruitment, the recognition of congeners, reproduction, alarm, territorial marking, and survival [...].

Laboratory Evidence of 2-Isobutyl-3-methoxypyrazine as a Male-Released Aggregative Cue in Labidostomis lusitanica (Germar) (Coleoptera: Chrysomelidae)

In spite of its incidence on pistachio trees, the chemical ecology of Labidostomis lusitanica (Germar) (Coleoptera: Chrysomelidae) has been neglected so far. In this work, we provide the first evidence of a biologically active male-specific compound that may be promoting field aggregation. Headspace collections through solid-phase microextraction from feral males and females reported the presence of 2-isobutyl-3-methoxypyrazine exclusively in males. Electroantennographic recordings revealed that males and females responded in a dose-dependent manner to increasing stimuli of 2-isobutyl-3-methoxypyrazine, with females overall displaying a higher response than males. In dual-choice tests, both males and females showed a significant preference for the compound in comparison to a pure air stimulus. In light of these results, the possible role of 2-isobutyl-3-methoxypyrazine as an aggregation cue in L. lusitanica is discussed.

The Paths of the Galls: Differences in the Ecology and Distribution of Two European Oak Gall Wasps Andricus dentimitratus and Andricus pictus

Andricus dentimitratus (Rejtõ, 1887) and Andricus pictus (Hartig, 1856) are two European gall wasps (Hymenoptera, Cynipidae) that induce galls on species of Quercus. The distribution and ecological niches of these species have not been studied in detail, though they are known to have a different distribution pattern in the Iberian Peninsula in Europe. To investigate this difference and its potential relationship with climate and host species distribution, we analysed the potential distribution of both species in the Iberian Peninsula using six algorithms and a consensus model based on 600 iterations for each species. We compared the models obtained for each species with the distribution of their host Quercus species. The results show that A. dentimitratus and A. pictus have a complementary distribution delimited by the Ebro valley, with A. dentimitratus occurring northeast of the valley and A. pictus southwest. The observed distribution patterns might be due to differences in the climatic requirements of each species or to the distribution of their host species given that A. dentimitratus is specific to Q. humilis and Q. cerris (except in the northeastern Iberian Peninsula) and A. pictus, to marcescent Mediterranean oaks (Q. faginea and Q. pyrenaica) and Q. suber. We propose two hypotheses to explain the nonoverlapping distribution of the two gall wasp species in the Iberian Peninsula: in the first scenario, A. dentimitratus arrived to the to the Iberian Peninsula from the eastern Palearctic by way of Europe and A. pictus, from the north coast of Africa; in the second, their distribution is a result of their speciation in different glacial refugia: A. dentimitratus in the Italian Peninsula and A. pictus in the Iberian Peninsula.

Risk Assessment of the Worldwide Expansion and Outbreak of Massicus raddei (Blessig) (Coleoptera: Cerambycidae) Based on Host Plant and Climatic Factors

Massicus raddei (Blessig) is a serious trunk borer of oak species, currently widespread only in eastern Asia. A better understanding of the invasive potential of this borer across other distribution-free areas is further needed to prevent its invasion and outbreaks. In this study, we mapped the current distribution of M. raddei, two susceptible hosts (Quercus mongolia and Q. liaotungensis) and all 11 host species of this borer, and then modeled their potential distributions. We comprehensively compared the current distributions and potential invasion ranges among M. raddei, susceptible hosts and all hosts to select areas at risk for the establishment of this borer. MaxEnt model predictions revealed that (1) the central and eastern US, a small area of central and western Europe, western Georgia, and central Argentina had suitable climates for M. raddei. Such highly suitable areas for this borer overlapped considerably with the current plantation and potential distributions of its hosts. Consequently, susceptible hosts and climate suitability together create the highest risk for M. raddei establishment and outbreaks, throughout central and eastern America, a small area of central Europe, western Norway and western Georgia, and (2) the broad host suitability across six continents creates a situation favorable for the colonization of this borer, further extending the spatial scale of possible infestation by M. raddei worldwide.