Micromalthus debilis LeConte (1878 ), has one of the most bizarre life cycles of any metazoan. Reproduction is typically by thelytokous, viviparous, larviform females, but there is also a rare arrhenotokous phase. The active first‐instar (triungulin) larva develops into a legless, feeding (cerambycoid) larva. This form either pupates, leading to a diploid adult female, or develops into any of three subsequent types of reproductive paedogenetic forms: (1) a thelytokous female that produces triungulins via viviparity; (2) an arrhenotokous female that produces a single egg that develops into the short‐legged (curculionoid) larva, eventually devouring its mother and becoming a haploid adult male; or (3) an amphitokous female that can follow either of the two above reproductive pathways. We speculate that Micromalthus is dependent on maternally transmitted bacteria for the ability to digest rotting wood, and that these bacteria are senescent in males, causing males to be obligately cannibalistic. Obligate male cannibalism, in turn, would have dramatically increased the cost of males, and have created a strong selective advantage for cyclic thelytoky and the other features of the Micromalthus life cycle that minimize the role of the male.

The 12 genera of Pilipalpinae are classified on the basis of characters of larvae and adults. Three new genera and six new species are here described: Malagaethes, gen. nov. (type species M. lawrencei, sp. nov.); Ranomafana, gen. nov. (type species R. steineri, sp. nov.); Binburrum, gen. nov. (type species Techmessa ruficollis Champion); Binburrum angusticollis, sp. nov.; Binburrum concavifrons, sp. nov.; Cycloderus immaculicollis, sp. nov. and Cycloderus hirsutus, sp. nov. The following new synonymies of specific names are proposed (with valid names given first): Paromarteon constans Lea, 1917 = Eucistela cyanea Carter, 1922; Paromarteon mutabile Blackburn, 1897 = Paromarteon mutabile var. nigripenne Lea, 1920; Temnopalpus bicolor Blackburn, 1888 = Temnopalpus tricolor Lea, 1920; Pilipalpus dasytoides Fairmaire, 1876 = Copobaenus maculicollis Pic, 1942 and Pilipalpus danvini Abdullah, 19646; Exocalopus pectinatus Broun, 1893 = Exocalopus antennalis Broun, 1903. The following subspecies have been elevated to species rank: Paromarteon apicale Lea, Paromarteon fasciatum Lea and Paromarteon parvum Lea. Phylogenetic analysis of 30 structural characters of larvae and adults yielded the following set of incompletely resolved relationships among genera of Pilipalpinae: (((Paromarteon + ((Temnopalpus + Malagaethes) + Pilipalpus + (Ranomafana + (Incollogenius + ((Exocalopus + (Binburrum + (Cycloderus + Morpholycus)) + Techmessodes) + Techmessa))))). The data set contained much homoplasy and several reversals. The historical geographical relationships inferred from the reconstructed phylogeny were compared with geological evidence for the break-up of Pangaea and Gondwanaland. The ancestral stock of Pilipalpinae was widespread on Gondwanaland, and differentiated through its fragmentation. Remnant relict genera persisted on Madagascar, New Zealand, southern South America (Magellanica), and Australia. Brooks Parsimony Analysis was conducted on the data resulting in the following area relationships: (Holarctic + (Madagascar + (New Zealand + (Australia + Chile)))). This agrees generally with accepted geological evidence and is considered support for they hypothesised phylogeny. A single clade (Temnopalpus + Malagaethes) was in disagreement (homoplasous) with the area cladogram, indicating possible incongruence in the data. The area relationships of other Southern Hemisphere groups were compared with Pilipalpinae.

The classification of the nine world species of Pytho Latreille is reviewed by study of adult, larval, and pupal stages. Keys are provided for separation of species in these three life stages. Taxonomic changes (senior synonym in brackets) include synonymy of P. fallax Seidlitz 1916 [= P. niger Kirby 1837]; P. americanus Kirby 1837 [= P. planus (Olivier 1795)]; P. deplanatus Mannerheim 1843 is transferred from a junior subjective synonym of P. depressus (Linnaeus 1767) to a junior subjective synonym of P. planus (Olivier 1795). Lectotype designations are provided for the following: P. seidlitzi Blair 1925; P. nivalis Lewis 1888; P. niger Kirby 1837; P. fallax Seidlitz 1916; P. abieticola J. Sahlberg 1875; and P. americanus Kirby 1837. Eight larval stage, and 12 adult stage characters were selected for cladistic analysis. Lacking out-group material, pupal characters were not analysed. Character states were polarized using a generalized out-group composed of the three other genera of Pythinae (all monobasic). Phylogenetic analysis based on these 18 characters suggests four monophyletic species-groups: P. seidlitzi group (P. seidlitzi Blair — North America); P. kolwensis group (P. strictus LeConte – North America, P. kolwensis C. Sahlberg —Fennoscandia and the U.S.S.R., P. nivalis Lewis — Japan); P. niger group (P. niger Kirby — North America, P. abieticola J. Sahlberg — Europe, P. jezoensis Kôno — Japan); P. depressus group [P. planus (Olivier, 1795) — North America, P. depressus (Linnaeus, 1767) — Europe and the U.S.S.R.]. Larval stage synapomorphies are relatively more important in defining the species-groups than are those of the adult stage. The ancestor of Pythidae may have been associated with Coniferae as early as the Jurassic. The common ancestor of Northern Hemisphere Pythinae became isolated upon Laurasia once separation from Gondwanaland occurred near the end of the Jurassic. Two of the species-groups have similar disjunctions in North America, Europe, and Japan. The relatively eastern distributions of the North American member of each suggests that the ancestor of each species-group was Euramerican, and underwent vicariance with the opening of the North Atlantic in the Middle Cretaceous. The present distribution of both species-groups is thought to have been caused by the same vicariant event. The ancestor of the P. depressus group, which is presently circumboreal, was probably widespread and could have been Asiamerican in distribution. In the middle to late Tertiary, evidence suggests that Beringia was covered with coniferous forest, and the ancestor of the P. depressus group probably extended across this land bridge. Final separation between any North American and European/Asian species occurred in the Late Miocene or Pliocene, when a cooling climate made possible the evolution of treeless tundra in the north.

Waidelotus hoffeinsorum gen. et sp. nov. is described from Eocene Baltic amber and assigned to Waidelotinae subfam. nov. within family Pyrochroidae (Coleoptera). The new subfamily differs from the other subfamilies by the following combination of features: penultimate tarsomere of all tarsi deeply bilobed, antepenultimate tarsomere of each pro- and mesothoracic tarsus slightly bilobed, antepenultimate tarsomere of metathoracic tarsi slightly widened apically; pronotum laterally margined in basal half; eyes emarginate; pretarsal claws appendiculate; prosternal intercoxal process incompletely separating prothoracic coxae; pronotum with fine posterior submarginal groove; head without distinct constriction behind eyes; posterior pronotal pits absent; and elytral pubescence homogenous. It is the only authentic species of Pyrochroidae (Coleoptera) from Baltic amber, pending final placement of Palaeopyrochroa crowsoni Abdullah, 1965. Additionally, the available data on stratigraphy of amber-bearing strata on the Sambian peninsula, and the age and location of Eocene amberiferous forests are discussed. A middle Eocene (mostly Bartonian) age is interpreted for the extinct Central European resin-producing forests resulting in the Sambian amber deposits.

Citation: Pollock DA (2008) Review of the Canadian Eustrophinae (Coleoptera, Tetratomidae). In: Majka CG, Klimaszewski J (Eds) Biodiversity, Biosystematics, and Ecology of Canadian Coleoptera. ZooKeys 2: 261-290.