Bug FAQNorthern Masked Chafer
Cyclocephala borealis · Order: Coleoptera · Family: Scarabaeidae
Source: Wikipedia
Adults are 11 to 14 mm long, 6 to 7 mm wide, dull yellow-brown with darker head markings and hairy wing covers. Larvae feed on plant roots near the soil surface and can cause damage to lawns and grain fields, with the worst injury in early fall and spring. Adults emerge in mid-June, larvae grow to about 22 to 25 mm, pupate for roughly 17 days, and the cycle repeats each year.
Source: Wikipedia
Size
Adults measure 11 to 14 mm in length and 6 to 7 mm in width.
Source: Wikipedia
What it eats
Larvae eat plant roots and other material near the soil surface. Adult beetles do not feed.
Source: Wikipedia
Life cycle
Adults emerge starting in mid-June. New larvae are about 4.5 mm long and can grow rapidly to 22 to 25 mm as third-instar larvae under good conditions. The 17 mm pupa matures in about 17 days, changing from creamy white to reddish-brown.
Source: Wikipedia
Lookalikes
Their larvae look the same as those of Cyclocephala immaculata, which can mate with them.
Source: Wikipedia
Where it is found in the US
Recorded in 24 of 51 states and DC. Most records: Ohio, Pennsylvania, Kentucky, Texas, Indiana, Maryland, New Jersey, Connecticut.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What plants do northern masked chafers damage?
Their larvae damage turf and cereal crops, especially in early fall and spring.
Source: Wikipedia
How big are the larvae when they mature?
Mature third-instar larvae can reach 22 to 25 mm in length.
Source: Wikipedia
Can I tell the larvae apart from those of other beetles?
The larvae are indistinguishable from those of Cyclocephala immaculata.
Source: Wikipedia
Same family (Scarabaeidae)
Japanese BeetlePopillia japonicaDamages trees, gardens or crops
Common Green June BeetleCotinis nitidaDamages trees, gardens or crops
Phyllophaga crinitaPhyllophaga crinitaDamages trees, gardens or crops
European Rose ChaferCetonia aurata
Mediterranean Spotted ChaferOxythyrea funestaDamages trees, gardens or crops
Oriental BeetleExomala orientalisDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Cyclocephala_borealis
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-24.