The Outbreak of the European Spruce Sawfly in Canada and Some Important Features of Its Bionomics

Migration of terrestrial arthropods in relation to habitat

We challenge the oft-repeated claim that the beetles (Coleoptera) are the most species-rich order of animals. Instead, we assert that another order of insects, the Hymenoptera, is more speciose, due in large part to the massively diverse but relatively poorly known parasitoid wasps. The idea that the beetles have more species than other orders is primarily based on their respective collection histories and the relative availability of taxonomic resources, which both disfavor parasitoid wasps. Though it is unreasonable to directly compare numbers of described species in each order, the ecology of parasitic wasps—specifically, their intimate interactions with their hosts—allows for estimation of relative richness. We present a simple logical model that shows how the specialization of many parasitic wasps on their hosts suggests few scenarios in which there would be more beetle species than parasitic wasp species. We couple this model with an accounting of what we call the “genus-specific parasitoid–host ratio” from four well-studied genera of insect hosts, a metric by which to generate extremely conservative estimates of the average number of parasitic wasp species attacking a given beetle or other insect host species. Synthesis of our model with data from real host systems suggests that the Hymenoptera may have 2.5–3.2× more species than the Coleoptera. While there are more described species of beetles than all other animals, the Hymenoptera are almost certainly the larger order.

/pdf/quantifying-the-unquantifiable-why-hymenoptera-not-18qrs8y48s.pdf

Quantifying the unquantifiable: why Hymenoptera, not Coleoptera, is the most speciose animal order

http://science.sciencemag.org/content/sci/179/4078/1090.full.pdf

Diprionid Sawflies: Polymorphism and Speciation: Changes in diapause and choice of food plants led to new evolutionary units

Invertebrates constitute about 80% of the known animal species in the world, so it is not surprising to find that they harbor large numbers of a wide range of virus types. Unfortunately, our present knowledge of viruses that are pathogenic to invertebrates is largely centered on those reported from the class Insecta, but even here the available information is often fragmentary. However, this is more a reflection of the scarcity of virologists working in this field than of any intrinsic difficulty in studying the particular viruses (Tinsley and Melnick, 1974). It is encouraging that in recent years reports have appeared on virus diseases of invertebrates other than insects and mites. Very little work has been done to characterize such viruses, and some of the reports must be regarded with caution until the viral nature of the causative agent has been fully established, including the infectivity of the isolated viruses to uninfected members of the recorded host.

The Outbreak of the European Spruce Sawfly in Canada and Some Important Features of Its Bionomics

Citations

Migration of terrestrial arthropods in relation to habitat

Quantifying the unquantifiable: why Hymenoptera, not Coleoptera, is the most speciose animal order

Diprionid Sawflies: Polymorphism and Speciation: Changes in diapause and choice of food plants led to new evolutionary units

Viruses of Invertebrates

A Basis for a General System of Insect Migration and Dispersal by Flight

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