July 9, 2026
Lanceolated Chafer (Phyllophaga lanceolata)
(syn Melolontha lanceolata)
aka Brown Scarab Beetle, May (June) Beetle
The Lanceolated Chafer (Phyllophaga lanceolata) is a scarab beetle native to North America. In New Mexico (along with Colorado and Kansas) these chafers thrive in open, grassy ecosystems, including native shortgrass prairies, pastures, rangelands, and agricultural fields dominated by grasses like blue grama (Bouteloua gracilis) and others. It’s in these arid habitats that the larvae (grubs) are rarely considered major pests1. Unlike most Phyllophaga species, adults are diurnal (active during the day); females are flightless.
Adults – This small to medium-sized chunky beetle, is about 0.5 to 0.7 inches (13 to 17 mm) long; females are larger than males. Their hard wing/body cover (elytra) is brown with several darker brown/grayish longitudinal marks under a coat of white bristly hairs. Their segmented abdomens are mostly a smooth grayish/white; their thorax (pronotum) is heavily covered with long brown hairs. Because of their noticeably long, magenta-colored legs, they stand tall above the ground while walking. If picked up, their legs feel clingy and prickly. Adults live only 1 – 2 months, just long enough to grab a quick bite to eat, mate, and lay eggs.
Calling All Males!
The female Lanceolated Chafer produces and uses a unique sex pheromone, l-leucine methyl ester, to attract males! Because this pheromone acts as a highly-targeted sex attractant in the wild, she is able to communicate her readiness to mate and get a rapid response. As has been demonstrated in field trials, male chafers catching a whiff of her urgent communication can’t resist the call and come flying (read the true story of my eye-witness account in my post titled The Life and Times of the Lanceolated Chafer ). Research scientists (and I) whole-heartedly believe this pheromone contributes to the species’ reproductive success in its native range.
This was a unique discovery because the Lanceolated Chafer is the first scarab beetle ever identified to produce an amino acid-derived pheromone. (And there are over 35,000 species of scarab beetles in the world, making up one of the largest and most diverse insect families on Earth!) The pheromone is so effective at targeting male chafers that entomologists use it to monitor and manage populations of these beetles in agricultural crops and turfgrass.
And now a note about topic organization …..
As in all beetle species, it’s usually the adults that are encountered. And it was the adult stage of the Lanceolated Chafer that’s most obvious along the subdivision’s 2-track rockpile trail. That’s why information about the adults was placed first, even though it’s actually the final stage in the life cycle of the chafer. But it’s interesting to understand how all those adults came to be. So the following few sections tackle the highlights of the 1 – 3 year long larval stage, and pupal stage of their life cycle, which take place after egg laying and hatching. Afterall, the Lanceolated Chafer spends the longest parts of their lives underground. And then, for no particular reason, I’ll end with a section on entomology.
Larval Stage – Larvae (grubs) have a translucent white to cream-colored body and a light tan to brown hard and stiff (sclerotized) head capsule. Larvae have three pairs of well-developed legs. When at rest they do so in a C-shaped curve.
Larvae live for 1 – 3 years, primarily in the upper layers of the soil profile. To protect themselves from extremes in soil temperatures, both in summer and winter, they will burrow to depths ranging from 3 to 20 inches (7.6 to 50.8 cm), averaging 10.3 inches (26.2 cm). Larvae actually hibernate in the winter.
The three instar stages of larvae development, serves to progressively increase body size, head capsule width, and degree of sclerotization. At the end of each instar, larva take up excess air and/or water to swell their bodies. This extra pressure causes its old exoskeleton to split, allowing it to be shed (a process called ecdysis). Mature (third instar) larvae are 1.75 inches (45 mm) long with a nearly uniform body width.
Pupal Stage and Metamorphosis – When larvae are ready to move beyond the third instar, each individual builds a protective, earthen cell in the soil 8 to 12 inches (20 to 30 cm) deep where they will remain for the next 2 – 4 weeks while they undergo metamorphosis and and finally emerge as adult beetles.
Etymology
The genus, Phyllophaga, is a generic name that comes from two Greek words ….. phyllon which means “leaf,” and phagos which means “eater.” The specific epithet lanceolata comes from the Latin word lanceolatus, meaning lance-shaped, probably referring to the fine, lanceolate hair-like scales covering parts of the beetle’s body, such as the head (frons) and thorax (pronotum). The etymology of the word “chafer” comes from an Old English word meaning “gnawer,” referring to the beetle’s strong jaws.
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Hope you found this interesting!
As always, thanks for stopping by!
1 Larvae of Lanceolated chafers are considered serious pests in the humid central and eastern U.S. they cause extensive damage to agricultural crops like corn, timothy, potatoes, and various other plants in the grass (Gramineae), pea (Fabaceae), and sunflower (Asteraceae) families.
References
ageconsearch.unm.edu
Lunginbill Sr., P and Printer, H.R., 1953, May Beetles of the US
a curious nature 