Megalomus

Rambur, 1842

brown lacewings

Species Guides

Megalomus is a of brown lacewings (Neuroptera: Hemerobiidae) comprising more than 40 described distributed across northern and central Europe, with some species extending into North America. The genus includes the Bordered Brown Lacewing (M. hirtus), the only Megalomus species recorded in the UK and a conservation priority in Scotland. Species in this genus are small, typically around 1 cm in length, with distinctive wing venation including a notably broad costal space and multiple branching radial .

Pronunciation

How to pronounce Megalomus: /mɛˈɡæləməs/

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Identification

Members of Megalomus can be distinguished from other brown lacewing by the broad costal space on the forewings and the presence of at least six (often 5-7) branching radial originating from the humeral vein. The Bordered Brown Lacewing (M. hirtus), the only UK representative, is small (~1 cm), brown, and inconspicuous, requiring careful examination to separate from other brown lacewing in the field.

Habitat

In the UK, M. hirtus is strongly associated with rocky exposed slopes, rocky hillsides, undercliffs, and rocky outcrops where wood sage (Teucrium scorodonia) grows in nutrient-poor, thin-soil conditions. In continental Europe, some Megalomus have been recorded from hazels (Corylus spp.) and other plant species.

Distribution

Widely distributed across northern and central Europe. In the UK, restricted to Scotland with confirmed sites at Holyrood Park (Edinburgh) and multiple coastal locations in Aberdeenshire from Stonehaven to Portlethen, including Skatie Shore, Perthumie Bay, Doonie Point, Craigeven Bay, Muchalls, and Portlethen Village. Historic record from St. Cyrus (1935, not refound). North American records include Vermont (USA) and Sweden.

Seasonality

of M. hirtus active from late May to mid-August, with peak activity in June-July; timing may vary with local climate conditions.

Diet

Associated with aphids and other soft-bodied insects on plants.

Host Associations

wood sage - and foraging substrateTeucrium scorodonia; primary UK for M. hirtus
hazels - and foraging substrateCorylus spp.; European records, not UK

Life Cycle

Larval stage lasts up to four years. When ready to pupate, larvae overwinter in cocoons and emerge as the following year. Females lay individually on undersides of leaves.

Behavior

spend most of the day deep within vegetation and are reluctant to move even when disturbed.

Human Relevance

M. hirtus is included on the Scottish Biodiversity List as a priority due to its highly restricted UK distribution. Subject of targeted conservation through the Species on the Edge programme (2023-2027), involving surveys, ecological research, and citizen science initiatives including the '200 Hours for Lacewings' campaign. Rediscovered at Holyrood Park in 2019 after last record in 1982, prompting renewed conservation interest.

Similar Taxa

Other Hemerobiidae generaMegalomus distinguished by broad costal space and multiple branching radial ; other brown lacewings typically have narrower costal spaces and fewer radial veins.
Green lacewings (Chrysopidae)Superficially similar but green lacewings are usually green or yellow-green with golden , whereas Megalomus are brown with different wing venation.