Master Blister Beetle

Lytta magister · Order: Coleoptera · Family: Meloidae

Can bite. They can bite, but the bite is mild.

Source: Wikipedia

Master Blister Beetle
Photo: Ken-ichi Ueda, CC BY

The master blister beetle is 0.6 to 1.3 inches long and has a red head, legs and prothorax with black wing covers. They appear in large swarms in the Mojave and Colorado deserts during spring and the females lay eggs in desert soil; the larvae attack bee nests while adults feed on brittlebush flowers and leaves.

Source: Wikipedia

How to recognize it

The beetle shows a bright red head, legs and prothorax contrasted with black elytra.

Source: Wikipedia

Size

Adults measure between 16 and 33 mm (about 0.6 to 1.3 inches) in length.

Source: Wikipedia

Does it bite or sting?

Although not venomous, they are capable of biting.

Source: Wikipedia

What it eats

Larvae are insectivorous and mainly prey on bee nests. Adults feed on the flowers and leaves of brittlebush.

Source: Wikipedia

Life cycle

Females lay their eggs in holes dug in desert soil. The hatched larvae seek out bee nests for food.

Source: Wikipedia

When you see it

They are most abundant in spring, when they form large swarms in desert habitats.

Source: Wikipedia

Where it comes from

The species is native to the southwestern part of North America.

Source: Wikipedia

Where it is found in the US

Recorded in 7 of 51 states and DC. Most records: California, Arizona, Nevada, Utah, New Mexico, Idaho, Texas.

Darker = more records. Counts are museum and citizen-science records, not population size.

Source: GBIF

Status: native in North America. Source: iNaturalist

Months it is reported in the US

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Source: GBIF

More photos

Master Blister Beetle photo 3
Photo: unknown, CC0
Master Blister Beetle photo 4
Photo: Jonathan Bright, CC BY-SA
Master Blister Beetle photo 5
Photo: unknown, CC0
Master Blister Beetle photo 6
Photo: ayden, CC BY

Questions people ask

Can the master blister beetle bite people?

Yes, they can bite, but the bite is mild.

Source: Wikipedia

What do the larvae eat?

The larvae are insectivorous and mainly attack bee nests.

Source: Wikipedia

Where are master blister beetles found?

They appear in large numbers in the Mojave and Colorado Deserts, especially in spring.

Source: Wikipedia

What do adult master blister beetles feed on?

Adults feed on the flowers and leaves of brittlebush.

Source: Wikipedia

Same family (Meloidae)

Sources

  • Wikipedia: https://en.wikipedia.org/wiki/Lytta_magister

Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia

Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.

How this page works

This is one bug's fact sheet. The colored box at the top says whether it is dangerous. Sections below cover how to recognize it, whether it is a pest, and how to deal with it. The US map shows which states have records; tap a state to see other bugs there.

Every fact on Bug FAQ comes from a named source (university extension sites, government agencies, GBIF, iNaturalist, Wikipedia). The source is linked next to each section. If we have no source for something, we leave it out.