Should we help maggots and caterpillars?

Episode Summary

Executive Summary: This episode argues that many overlooked insects—especially hoverflies, midges, larvae, and caterpillars—are essential to ecosystems and food production. Through garden encounters and expert interviews, it shows that pollination supports most plants and many crops, and that valuing insects means protecting them across their life cycles, not just as adults.

Main Topics: Why bees and butterflies get all the attention (Priority: 5/5): Experts explain that familiar, visible, daytime insects are easier for humans to notice and appreciate, while many equally important species remain hidden by habitat, behavior, or timing. Hoverflies as underappreciated pollinators (Priority: 5/5): The program explores hoverflies’ biology, how to identify them, and how their larvae can act as predators or decomposers while adults pollinate flowers. Commercial use of hoverflies in agriculture (Priority: 4/5): A Spanish company mass-rears hoverflies for greenhouse and farm pollination, showing that lesser-known insects can directly improve yields and support food production. Midges and cocoa pollination (Priority: 5/5): The episode highlights tiny midges as likely key pollinators of cocoa, illustrating how an insect many people dislike may be vital to chocolate production. Hand pollination research in Ghana (Priority: 5/5): Researchers tested how much pollination affects cocoa yield and found that natural insect pollination may be insufficient in some areas, with measurable gains from intervention. Caterpillars, larvae, and habitat tolerance (Priority: 4/5): The final section stresses that gardeners should value larval stages and even tolerate plants like nettles because they support future butterflies and other insects.

Key Arguments: Bees and butterflies are important, but many less visible insects are also crucial pollinators and ecosystem workers. Human bias toward conspicuous, daytime insects creates a blind spot for nocturnal, camouflaged, or ground-level species. Hoverflies deserve more recognition because they pollinate flowers and can also be used as biological control agents against aphids. Mass-reared hoverflies can have real agricultural impact, including substantial yield gains on crops such as avocados. Cocoa production depends on tiny insects, likely midges, and in some regions natural pollination may be too low for the trees’ potential. Hand pollination experiments showed cocoa yields can rise when pollination is increased, implying current insect pollination is limiting. Protecting insect biodiversity means protecting habitats and food plants for larvae, not just admiring adult butterflies and bees. Gardens function best as ecosystems; dead wood, soil, nettles, and weeds can all support insect life stages.

Data Points: Number of ladybird larvae purchased: 250 - Producer Marnie bought 250 ladybird larvae for the studio demonstration. Minimum purchase size for larvae: 200 - She could not buy fewer than 200 larvae. Plant dependence on animals/insects for pollination: 80–90% - Experts said roughly 80–90% of plants rely on insects or animals for pollination to some degree. Crop dependence on pollination: about one-third - About one-third of all crops eaten by humans depend on pollination. Hoverfly species reared commercially: 2 of 6,000 species - Polyfly focuses on just two hoverfly species out of roughly 6,000 known species. Annual hoverflies bred by company: in excess of 1 billion per year - Polyfly mass-rears hoverflies for agricultural pollination. Avocado yield increase: over doubled - Polyfly reported cases where hoverflies more than doubled avocado yields on some farms. Cocoa yield increase from hand pollination: 20% - A study in Ghana found hand pollination increased cocoa yields by 20%.

Pivotal Quotes: "We need to count every single one we find, because if we leave even one here." — Alex Lathbridge: Opening studio scene as the team tries to contain the escaped ladybird larvae. "Out of sight, out of mind, but just as important." — Nicholas Barfer: Explaining why many pollinators are overlooked compared with visible bees and butterflies. "It is a very good thing in a garden to see holes in your leaves. You want that to happen." — Caitlin Johnstone: On the ecological value of larval feeding and the importance of supporting insect life stages.

Implications: Listeners are encouraged to rethink “pests” and favor insect-friendly gardening and farming. Protecting native plants, nettles, dead wood, and diverse habitats can support pollinators, improve yields, and sustain biodiversity.