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Dynastes neptunus
Rare large beetle from South American highlands. Second largest after Hercules. Jet-black body with long horn is stunning.
Dynastes neptunus, the Neptune beetle, inhabits high-altitude cloud forests of the Andes in Colombia, Ecuador, and Peru, at elevations roughly between 1,000 and 2,500 meters. It is one of the largest rhinoceros beetles, with males reaching total lengths of 80–150 mm, ranking second only to the Hercules beetle in maximum size. Males bear a long thoracic horn and shorter cephalic horn, with a striking glossy jet-black body coloration. As a highland species, it requires strict low-temperature management at 17–22°C; warmer conditions are detrimental to both adults and larvae. The larval stage spans 2–3 years—exceptionally long for a rhinoceros beetle—and demands large quantities of high-quality fermented substrate. Females lay eggs in fermented substrate, and breeding is moderately challenging. Adults live 6–12 months. While requiring experienced husbandry, the Neptune beetle's jet-black form and impressive proportions make it one of the most revered species in the collecting world.
Origin
high-altitude Andean cloud forests of Colombia, Ecuador, and Peru
Lifespan
Adult 6-12 months, larva 2-3 years
Size
Up to 150mm
Temperature
20〜28℃
Humidity
60〜80%
Beetle jelly (adult), fermented substrate (larva)
Captive record (♂)
157.3 mm
Record source: BE-KUWA 2025年度版(ネプチューン 飼育157.3mm 滝沢元美 2018、全長=角込み)
Notable localities
細く長い胸角・頭角を持つアンデス産オオカブト。記録は角を含む全長。飼育レコードは BE-KUWA(むし社)のコンテストで毎年更新される。産地・累代(CBF/WF/WD)・サイズで個体価値が大きく変動する。
Generation codes
Sources: BE-KUWA 認定飼育レコード(むし社、2025年度版)
Edited & verified by: br-choku editorial team
The taxonomic, regulatory, and husbandry data on this page are compiled and verified against the authoritative primary sources below.
Accepted name: Dynastes neptunus (Quensel, 1805)
Synonyms: Dynastes neptunus rouchei Nagai, 2005, Geotrupes neptunus Quensel, 1805, Scarabaeus jupiter Buquet, 1840
Authority databases: GBIF
Nomenclature follows global taxonomic authority databases.
Plant Protection Act: コガネムシ上科(カブトムシ・クワガタムシ・ハナムグリ等)の生きた個体を輸入する際は、外来生物法に基づき輸出国政府機関等が発行する種類名証明書の添付が必要(輸入港は成田・中部・関西・福岡・鹿児島の各空港に限定)。本種自体は特定外来生物ではなく、証明書の添付により輸入可能。
Sources: 環境省 外来生物法「コガネムシ上科に含まれる生きた昆虫を輸入される方へ」 / CITES 附属書(checklist.cites.org)
Regulations may change. Always verify the latest information with the relevant authorities.
Find listings for this species
17-22°C (cool temperature essential)
2-3 years — very long
Rare in trade and expensive
Wine cooler temperature management essential
Highland species — Japanese summer is biggest threat
Advanced. This is an advanced-level species. It requires specialized equipment and advanced husbandry skills with precise environmental control.
The ideal temperature for Neptune Beetle is 20〜28℃. Recommended humidity is 60〜80%. Avoid sudden temperature changes and maintain a stable environment.
The average lifespan of Neptune Beetle is Adult 6-12 months, larva 2-3 years. With proper care and nutrition, they can live a long and healthy life.
Neptune Beetle typically reaches Up to 150mm as an adult. Size may vary depending on care conditions and individual genetics.
Neptune Beetle feeds on: Beetle jelly (adult), fermented substrate (larva). Aim for a balanced diet with appropriate feeding frequency.
The price of Neptune Beetle varies significantly depending on morph, size, and lineage. Check our market price page for the latest pricing information.
Last updated: June 23, 2026