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Aim Lepidoptera is a highly diverse, predominantly herbivorous insect order, with species transported to outside their native range largely facilitated by the global trade of plants and plant‐based goods. Analogous to island disharmony, we examine invasion disharmony, where species filtering during invasions increases systematic compositional differences between native and non‐native species assemblages, and test whether some families are more successful at establishing in non‐native regions than others. Location Hawaii, North America, Galapagos, Europe, South Africa, South Korea, Japan, Nansei Islands, Ogasawara Islands, Australia, New Zealand. Taxon Lepidoptera. Methods We compared numbers of non‐native, unintentionally introduced Lepidoptera species with the land area of 11 regions worldwide. Differences among native and non‐native assemblages in the distribution of species among families were investigated using ordination analysis. We tested whether invasion disharmony is explained by propagule pressure (proxied by species richness in border interceptions) and if families were associated with specific trade commodities. Results In total, 741 non‐native Lepidoptera species, accounting for 0.47% of the global diversity of lepidopterans, are established in at least one of the 11 regions. Crambidae, Pyralidae, Tineidae and Gracillariidae were particularly successful invaders, whereas the two most species‐rich families, Erebidae and Geometridae, were under‐represented among non‐native Lepidoptera. Much of the variation in species numbers in the native, and less so in the non‐native assemblages could be attributed to land area. Although native assemblages were similar among nearby regions, non‐native assemblages were not, suggesting geography had little effect on invasion disharmony. Comparison of established with intercepted species revealed that macromoth families were generally under‐represented in establishments, whereas several micromoth families were under‐represented in interceptions. This discrepancy may relate to greater detectability of larger species or high propagule pressure via associations with specific invasion pathways. Main conclusions Invasion disharmony in Lepidoptera appears to be driven by processes unrelated to the success of native assemblages. While native assemblages developed through long‐term evolutionary radiation, the composition of non‐native assemblages is driven by differential invasion pathways and traits affecting the establishment of founder populations that vary among families.

Genomic conflicts arising during reproduction might play an important role in shaping the striking diversity of reproductive strategies across life. Among these is paternal genome elimination (PGE), a form of haplodiploidy which has independently evolved several times in arthropods. PGE males are diploid but transmit maternally inherited chromosomes only, whereas paternal homologues are excluded from sperm. Mothers thereby effectively monopolize the parentage of sons, at the cost of the father's reproductive success. This creates striking conflict between the sexes that could result in a co‐evolutionary arms race between paternal and maternal genomes over gene transmission, yet empirical evidence that such an arms race indeed takes place under PGE is scarce. This study addresses this by testing whether PGE is complete when paternal genotypes are exposed to divergent maternal backgrounds in intraspecific and hybrid crosses of the citrus mealybug, Planococcus citri, and the closely related Planococcus ficus. We determined whether males can transmit genetic information through their sons by tracking inheritance of two traits in a three‐generation pedigree: microsatellite markers and sex‐specific pheromone preferences. Our results suggest leakages of single paternal chromosomes through males occurring at a low frequency, but we find no evidence for transmission of paternal pheromone preferences from fathers to sons. The absence of differences between hybrid and intraspecific crosses in leakage rate of paternal alleles suggests that a co‐evolutionary arms race cannot be demonstrated on this evolutionary timescale, but we conclude that there is scope for intragenomic conflict between parental genomes in mealybugs. Finally, we discuss how these paternal escapes can occur and what these findings may reveal about the evolutionary dynamics of this bizarre genetic system.