Flowers, Bats, and Human Activity: Why Have Butterflies and Moths Become Able to Eat "Leaves on the Ground"? The Evolution Driven by "Gene Hijacking"

Flowers, Bats, and Human Activity: Why Have Butterflies and Moths Become Able to Eat "Leaves on the Ground"? The Evolution Driven by "Gene Hijacking"

Butterflies and Moths. Butterflies fluttering around flower beds during the day are popular, while moths drawn to lights at night tend to be avoided—this image might cast a slight shadow even in the world of research. In fact, these "Lepidoptera" are an extraordinarily diverse and large group among animals, with an enormous number of known species. Moreover, they are not just "pretty." Their larvae (caterpillars) consume large amounts of plant leaves, and the adults play a role in the ecosystem's cycle through pollen, nectar, and tree sap. They are also an important food source for many predators like birds and bats. In other words, understanding Lepidoptera is akin to conducting a "health check of nature."


A review that consolidates the "current state" of Lepidoptera research, organized by researchers from multiple institutions, was published in Nature Reviews Biodiversity in February 2026. The key point is simple: "Butterflies and moths seem well-studied, but there is still much unknown, even basic information necessary for understanding evolution and conservation." This "unexpected gap" is the most important message of this article.


1) On a 300-million-year scale, the main players aren't just "flowers"

The article emphasizes the incredibly long history of Lepidoptera. Lepidoptera are often discussed in comparison with their close relatives, the Trichoptera (known for their aquatic larvae that build cases). The "great transition" from living near water to terrestrial herbivory might have been the starting point for the prosperity of Lepidoptera. However, this brings up a point that cannot be fully explained by the traditional evolutionary mechanisms of mutation and natural selection alone.


The article introduces the possibility that "horizontal gene transfer" from fungi and bacteria might have contributed to their ability to digest plant tissues and process toxic substances. Recent studies, supported by genomic comparisons, suggest that some gene groups related to digestion and detoxification might be derived from bacteria and fungi. This acts as a "subtle but effective" evolutionary booster.


Furthermore, major environmental events such as the appearance of flowers, changes in pollinators, and the emergence of bats dominating the night sky have successively altered the form and behavior of Lepidoptera. For example, the "arms race" with bats might have led moths to develop auditory organs capable of detecting ultrasound—such stories highlight the excitement that erupts when fragments of research connect.


2) More than "what is known," "what is unknown" has been visualized

The value of this review lies not just in organizing knowledge but in drawing a "map of the unexplored."


For example, due to the sheer size of the Lepidoptera group, there are still unresolved parts of their phylogenetic relationships (how closely related they are to each other). Particularly in large groups with many species (known as Ditrysia), there are unclear areas in higher classification relationships. For researchers, phylogeny is a "measure for comparison," so ambiguity here makes it difficult to prioritize evolutionary discussions and conservation efforts.


Another complication is the bias in research subjects. While large and conspicuous butterflies and moths are well-studied, small moths (commonly known as micromoths) tend to be underrepresented in classification and genomics. Although diversity hotspots are concentrated in the tropics, research efforts have been skewed towards temperate regions—this "discrepancy" is also clearly stated.


3) The genomic era changes the "next steps" in conservation

However, it's not all gloomy. The article introduces efforts to collect genomes on a global scale, which are accelerating Lepidoptera research. Large projects like the European initiative to decode Lepidoptera genomes (Project Psyche) and the grand plan to encompass eukaryotic genomes (Earth BioGenome Project) are driving forces in filling "knowledge gaps."


What is the benefit of having more genomes? It's not just about having a larger "catalog of genes." It increases the potential to read information directly linked to conservation plans, such as the history of speciation, traces of adaptation, population connectivity (whether they are fragmented), and the risk of local extinction. In other words, genomes can transform conservation from "retrospective records" to "proactive predictions."


4) Reasons to hurry: It's not just the "numbers" that are decreasing

The sense of crisis repeatedly emphasized by the review and article is the recent decline in Lepidoptera. As their numbers decrease, the impact on pollination and food webs cascades. Moreover, the fact that the decline is strongly visible in relatively well-studied "conspicuous butterflies" is itself ominous. When visible indicators drop, more serious issues may be occurring in less visible areas.


The review suggests that conservation efforts should not just focus on creating protected areas but also emphasize creating, restoring, and managing habitats with a focus on "connectivity" and "quality." Preparing corridors for movement and landscapes with multiple environmental conditions under the assumption of changing climate and land use—this approach expands insect conservation from "points" to "areas."


Reactions on Social Media (Perceived "Reception")

This review was a topic where the dissemination from the researcher community side could be relatively clearly observed.

  • Academic journal accounts announce it as a "new review"
    The official account of Nature Reviews Biodiversity posted an announcement about the review's publication. Initially, it spreads as "release information" to the specialized community.

  • The author explains "what kind of review it is" in a short thread style
    One of the authors summarizes the pillars covered by the review (evolutionary history, diversification, genomics, global diversity patterns, conservation). On social media, "what can be read (a map of highlights)" tends to be more welcomed than "the abstract of the paper."

  • Reader reactions to general articles tend to polarize into "trivia-like surprise" and "sense of crisis"
    The article on Phys.org is structured to heavily introduce "surprising facts" such as the large feeding volume of larvae and the diverse diet of adults, while landing on the topic of decline and conservation in the latter half. When spread on social media, this coexistence of "Wow!" and "Uh-oh..." tends to occur.

  • An increase in posts touching on "research bias" is possible
    Since the review explicitly states biases like "small moths are underrepresented" and "tropics are underrepresented," it can easily fit into the context of sharing "where the gaps are" among researchers and nature observers. It could also serve as a trigger for shifting conservation topics from "protecting favorite insects" to "filling data gaps."


Summary: The "Points of Interest" in This Topic

Butterflies and moths embody both glamour and subtlety. However, within ecosystems, they are pollinators, herbivores, prey for predators, and "sensors" sensitive to changes in climate and land use.


The reality that this review confronts is that "even famous creatures lack foundational knowledge." And the key to filling these gaps lies in genomic projects, while simultaneously facing a time constraint due to their current decline.


Updating the "butterflies and moths we think we know" from both research and conservation perspectives—this review serves as the current map for that purpose.


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