砂漠のゴミムシダマシ（Ironclad beetle）

昨年５月のBug Fairにて購入した砂漠の甲虫４匹の内、一匹がついに先月死亡。カブトムシやクワガタに比べて実に長生き。ジッとしていることが多かったけれど時折トコトコといった感じで歩く姿は面白かった。子供が興味を持つのも納得。餌は小麦とか人参とかをたまに与え水もたまに霧吹きする程度。夜になっても特に飛ぼうとする様子もないしいたって静かな甲虫。学名については今年のBug Fairで知り合ったDouglas Copelandさんの本「Beetles of California's Impreial Sand Dunes」を手がかりに調べたところ学名はCryptoglossa Verrucosa。通称はDeath-feigning beetleとかIronclad beetle。コウチュウ目 （Coleoptera）のゴミムシダマシ科（Tenebrionidae）のDarlkling Beetleに分類される。塵虫騙あるいは芥虫騙。

Roger Tory Peterson Field Guidesによれば、Darlkling Beetleは１３００種類おり甲虫のなかでも５番目に大きいグループ。米国では西部に生息とあった。

飼育方法についてはBRINE QUEENさんという海洋生物学を研究されている方が詳しいようで、この虫の産卵行動や卵の撮影に成功している。麦１に対し砂３の割合で幼虫飼育を試みている様子だがその後については不明。

（貼付け開始）

She is still laying eggs however, so I remain somewhat hopeful. I've got a second small tank set up with a 1: 3 mixture of oats and sand and am transferring half of her eggs into that tank. Other mealworms (often used for feeding) are raised on oats, so I am hoping that a high concentration of possible food will help the process.

（貼付け終わり）

拡大してあらためて見ると上翅のデザインは南部鉄瓶のようで美しい。アリゾナ州立大学のHADLEY助教授がこの虫の研究をされていたようで、このデザインは砂漠で生き抜くための有効な機能である様子。

（貼付け開始）

Wax Secretion and Color Phases of the Desert Tenebrionid Beetle Cryptoglossaverrucosa (LeConte)

NEIL F. HADLEY ¹

¹ Department of Zoology, Arizona State University, Tempe 85281

The desert beetle Cryptoglossa verrucosa(LeConte) exhibits distinct color phases that range from light blue to jet black when subjected to extremes of low and high humidity, respectively. The color phases are created by "wax filaments" that spread from the tips of miniature tubercles that cover the cuticlesurface. The meshwork that accumulates at low humidity reduces transcuticular water loss and may lower the rate at which body temperature rises under a radiation load by increasing reflectance.

Submitted on November 17, 1978

（貼付け終わり）

他にも、GREGORY A. AHEARNというやはりアリゾナ州立大学・動物学部の研究者がこの虫の水分保全機能について研究されていた様子。

（貼付け開始）

THE CONTROL OF WATER LOSS IN DESERT TENEBRIONID BEETLES

SUMMARY

1. Total water loss in tenebrionid beetles was composed of transpiratory losses from the cuticle and spiracles, water associated with defaecation, and water from the release of defensive quinone droplets or oral fluids.

2. Freshly killed specimens of E. armata, C. muricata and C. verrucosa had higher transpiration rates over long and short exposures than did living animals of the same species. These results may reflect the cessation of active water retention by cuticular and spiracular regulation in dead animals.

3. Cuticular transpiration, although low in absolute rate, was a greater source of water loss than respiratory transpiration in E. armata, C. muricata and C. verrucosa at temperatures from 25 to 42-5 ｡C and at 0% R.H., suggesting that spiracular control of water loss was of considerable importance in maintaining water balance.

4. A marked increase in respiratory transpiration over previous low rates was observed at 40 ｡C for E. armata and at 42-5 ｡C for C. muricata and C. verrucosa, and indicated a temperature-induced breakdown in spiracular water regulation due to increased respiratory activities. In contrast, cuticular transpiration maintained a linear rate of increase over the temperature range investigated.

5. A direct relationship existed between oxygen consumption and estimated respiratory transpiration for E. armata from 25 to 40 ｡C and at 0 % R.H.

6. Evidence for the presence of discontinous respiration and unidirectional tracheal air flow in E. armata was presented.

7. Cuticular transition temperatures were measured for E. armata (40 ｡C), C. muricata (47*5 ｡C), and C. verrucosa (50 ｡C) with results showing that the autumn species {E. armata) possessed a lower cuticular breakdown point than either of the two summer species.

8. Much of the success of tenebrionid beetles in desert habitats is due to the development of highly impermeable cuticles and well regulated spiracular control mechanisms for reducing the loss of body water.

（貼付け終わり）