2025-04-02 ジョージア大学
ジョージア大学(UGA)の研究者たちは、博物館に収蔵された約3,000点の蝶の標本を分析し、寄生虫Ophryocystis elektroscirrha(OE)の世界的な分布を追跡しました。この寄生虫は蝶の成長や飛行能力を妨げ、特にオオカバマダラ(モナーク)に深刻な影響を与えることが知られています。調査の結果、1909年に遡る標本からも感染が確認され、これまで報告されていなかったジャマイカ産のオオカバマダラからも初めてOEの感染が検出されました。感染はアメリカ大陸、ヨーロッパ、アジア、アフリカ、オセアニアと広範囲にわたりますが、主にDanaus属の5種(オオカバマダラ、クイーン、プレーンタイガー、レッサーワンダラー、ジャマイカンモナーク)に限定されていました。この研究は、博物館の標本が病原体の歴史的な分布や進化を理解する上で重要な資源であることを示しています。
<関連情報>
- https://news.uga.edu/museum-collections-reveal-worldwide-spread-of-butterfly-disease/
- https://resjournals.onlinelibrary.wiley.com/doi/10.1111/een.13426
オオカバマダラに寄生するOphryocystisの世界的な分布が博物館のコレクションから明らかになった Museum collections reveal a global range of Ophryocystis parasites in Danaus butterflies
Maria L. Müller-Theissen, Paola Barriga, Katie Yan, Nicole L. Gottdenker, Sonia M. Altizer
Ecological Entomology Published: 06 February 2025
DOI:https://doi.org/10.1111/een.13426
Abstract
- Understanding the host range, patterns and consequences of parasite infection is essential for detecting and responding to parasite-mediated insect declines. The debilitating protozoan Ophryocystis elektroscirrha (OE; Neogregarinorida: Ophryocystidae) was identified as a parasite of monarch (Danaus plexippus) and queen (D. gilippus) butterflies in the late 1960s in Florida, USA. Recently, similar parasites were documented in other Danaus species, but their occurrence among the diverse clade of milkweed butterflies (Nymphalidae: Danainae) remains unexplored.
- This study used museum collections to systematically investigate the host range and global occurrence of OE and similar Ophryocystis parasites in milkweed butterflies. We examined 2727 museum specimens from 86 countries/areas, spanning 61 milkweed butterfly species across 10 genera, to document parasitism.
- Our findings revealed that, among milkweed butterflies, Ophryocystis parasites were confined to hosts in the genus Danaus and were widespread across five continents. Positive specimens dated back to 1909. Lesser wanderers (D. petilia) exhibited the highest percentage of positive specimens (16%), followed by monarchs (12%), plain tigers (D. chrysippus, 11%) and queens (4%). We also present the first documented infections in Jamaican monarchs (D. cleophile, 4%). The patterns of parasite variation in size reflected the relatedness of their host species but not their size.
- Overall, this research underscores the value of museum collections for investigating geographic and temporal host–parasite associations and provides foundational ecological data on the relationships between Ophryocystis parasites and their milkweed butterfly hosts.
