The airborne organic particles derived from indigenous dipole instrument (Stanford Radioscience Laboratory field organisms were relatively few at Arrival Heights and Lake ill 2) mounted on a wooden post 2.5 meters above the Vanda, still fewer at McMurdo, and absent at South Pole ground. During periods of blowing snow and dust, the Station. The particles in this group identified so far are from electric field gradient was + 500 to + 2,500 volts per meter. algae, fungi, lichens, a moss, and a very small . In those intervals the Tauber traps with earthed covers col- Two categories of introduced organic particles caught by the lected two or more times as much snow and dust as the ones air samples greatly outweigh the numbers of native particles: with insulated covers. During periods of falling snow, the first, (a) cells and tissue fragments of conifer wood, most electric field gradient was -1,000 to -1,500 volts per meter. In abundant and pervasive; second, (b) clothing fibers, both those intervals the insulated traps collected more, and in natural and synthetic. The wood cells undoubtedly are some instances almost twice as much, snow and dust as the derived from the wooden packing cases at camps and experi- traps with earthed covers. mental sites. Snow samples collected at South Pole Station Dispersal of diaspores and minute organisms by wind over contained incompletely burned diesel fuel residue and small snow and ice has long been recognized in the polar regions. quantities of mineral grains as well as conifer wood cells and The relationships to electric fields shown here suggest that, clothing fibers, all presumably introduced by station activity. during periods of blowing snow and/or dust, greater numbers The results suggest the usefulness of air and snow sampling of airborne particles would tend to be deposited on wet (i.e., for monitoring releases of airborne particles into the local en- earthed) soil or rock surfaces. This principle may be of basic vironment. significance in processes of diaspore (i.e., viable reproductive The Tauber traps were modified by coating surfaces particle) lodgment and germination. The principle also may around the aperture with conductive carbon paint. All these apply to differential accumulation of fine material and traps were exposed in pairs, one earthed, the other not organic sediments on diversified terrain in cold or dry cli- (although earthing in the snow at South Pole is probably in- mates. effective). At the McMurdo sampling site, the Cosmic Ray This research was supported by National Science Founda- Laboratory, the electric fields were measured by a rotating tion grant DPP 77-00202 to the University of Michigan.

Physiological basis of low Station area (64°S.640 W.), Belgica antarctica and Cryptopygus antarctica, two distinct mechanisms of adaptation have been temperature tolerance in antarctic identified. Belgica larvae are freezing-tolerant during the austral sum- mer and are capable of elaborating an array of cryoprotectant compounds. This species is the first identified to endure freezing in a non-overwintering state. Ambient larvae pro- JOHN G. BAUST,JOHN S. EDWARDS, 2 and ROBERT BROWN I duce a cryoprotectant profile containing erythritol, glucose, Department of Biology sucrose, and trehalose. Adults are freezing-susceptible and University of Houston contain only trace amounts of protective agents (figure 1). Houston, Texas 77004 The identification of erythritol, a plant sugar derivative, has not been made or associated with cryoprotective function in Department of Zoology other species. University of Washington Preliminary evidence (figure 2) suggests that, at tem- Seattle, Washington 98195 peratures below 0°C, cryoprotectant accumulation is tem- perature dependent and independent of nutrient (carbon) source. Cryoprotectants include in increasing order of con- centration: glycerol, erythritol, fructose, and glucose. At 0°C The strategies of low temperature tolerance utilized by the triggers become biphasic. Temperature induces shifts in various species of terrestrial insects has been studied by carbohydrate metabolism such that glycerol is built up. relatively few investigators. Cold hardiness, especially freez- Simultaneously, dietary carbon sources cause accumulations ing tolerance, is most frequently correlated with the presence of other protective sugars and/or polyhydric alcohols. A of cryoprotective compounds (Baust and Morrissey, 1977). glycerol diet results in increased fructose levels, an eryrhritol Salt (1959), Somme (1964, 1965), Asahina (1966), Baust diet in erythritol increases, a glucose diet in nonpatterned (1972), and Miller and Smith (1975) have described a variety profiles, and a sucrose diet in a profile similar to the -5°C of single-type cryoprotectant systems that utilize low molecu- profile. It would be speculative to proceed with discussions of lar weight polyhydric alcohols as antifreeze agents. Other evi- intermediary metabolism beyond this point. However, the dence now suggests that many species rely on mixed-type Belgica data suggest a number of exciting prospects for con- cryoprotectants that are sequentially synthesized upon cold tinued study: exposure (Mansingh and Smallman, 1972; Morrissey and 1. Erythritol metabolism and its apparent conversion to Baust, 1976). glycerol imply that an undescribed metabolic pathway exists. Following a first season of study (December 1977 and 2. The mechanism (site) of influence by the dicotomous January 1978) of two antarctic species resident to the Palmer triggers is unknown.

164 ANTARCTIC JOURNAL 0° 10° 200

M I prasiola 1-51.7 11 1 • 5 I 248.9 6 I- IUIII0 3-47.6 — 6.7 4 C 3 4 I- 1, 5-30.2 U I–L 2 311174 6 4 7— ? 2 0 0 0 03 >- 22 Cr 22 52 U

E C4

I-. 1 Z I,- U I-. 0 3 F S 3 F S X ? 0. 46T 4 6 R D 0 Figure 1. Cryoprotectant profiles for ambient Beigica antarc- tica and a primary food source, Prisioia crispa. (Abscissa C key: 3-glycerol, 4-erythrltol, F-fructose, 6-glucose, S-sucrose, T-trehaiose, R-ribose, X=xylose, D?-unidentified disac- charides.)

3. The role and significance of the noncarbohydrate in- termediates is unknown. 4. The fate of dietary carbon sources in ambient speci- mens is unknown. 6 5. The pivotal temperature concept appears to be a key in determining metabolic routes. Other factors complicate the wintering picture. First, both C l 2 4 adults and larvae have limited supercooling capabilities ( = supercooling points -5.3°C and -5.7°C). Therefore, early 2 freezing is ensured in larval specimens. Adults, however, represent a nonfeeding, short-lived reproductive stage (few days) and are sufficiently mobile to avoid subfreezing ex- 3 F S 3 F S posures by vertical migration (Baust and Edwards, in prepa- 46T 461 ration). Second, snowmelt, precipitation, and wind combine Figure 2. Cryoprotectant profiles for Beigica antarctica main- to present many terrestrial habitats with transient freshwater tained at fixed temperatures and on controlled diets. or saline conditions. Larvae survive well in distilled water (50 (Abscissa key: 3-glycerol, 4-erythritol, F-fructose, 6-glucose, percent survival after 9 days) or seawater (75 percent survival S-sucrose, T-trehalose.) after 4 days). Fifty percent seawater or less results in survivals that anaerobic conditions facilitate cryoprotectant accumula- equivalent to distilled water. The data suggest a remarkable tion (Conradi-Larsen and Somme, 1973a, 1973b). degree of euryhalinity and strong ion-regulating capacities at This project was supported by National Science Founda- near freezing temperatures. Third, Belgica are tolerant to 76-24205 to the University of Houston. The anaerobic conditions. Whether or not the decayed detritus tion grant oPt field team comprisedJohn G. Baust, Robert Brown, andJohn habitat containing larvae is anaerobic is unknown. However, S. Edwards. occasional bouts of anaerobiosis may be necessary. Larvae are capable of 90 percent survival after 6 days in an aqueous nitrogen environment. Preliminary electrophoretic evidence References (Baust and Edwards, in preparation) indicates that Belgzca is capable of anaerobiosis in that the frequency of appropriate transaminase and oxidase isozymes increases, suggesting a shift toward anaerobic metabolism. What effects, if any, the Asahina, E. 1966. Freezing and frost resistance in insects. In: latter two factors have on low temperature tolerance is Cryobiology (H. T. Meryman, ed.). Academic Press, New York, unknown. A number of authors have, however, demonstrated New York. pp. 451-484.

165 October 1978 Baust, J. G. 1972. Mechanisms of freezing protection- Pterostichus brevicornis. Nature, 236(68): 219-220. Baust, J. C., and J. S. Edwards. In preparation. Molecular basis of anaerobiosis in an antarctic insect. Baust, J. C., and R. Morrissey. 1977. Strategies of low temperature adaptation. Proceedings of the International Congress on En- tomology, 173-184. Conradi-Larsen, E., and L. Somme. 1973. Anaerobiosis in the over- wintering borealis. Nature, 245: 388-390. Conradi-Larsen, E., and L. Somme. 1973. The overwintering of Pelophia boreolis Payk. II Aerobic and anaerobic metabolism. NORSK Entomologisk Tidsskr!fi, 20: 325-332. Mansingh, L. A., and B. N. Smallman. 1972. Variations in -- ,?. -- polyhydric alcohol in relation to diapause and cold-hardiness in the larvae of Isia isabella. Journal of Insect Physiology, 18: 1565-1571. Miller, L. K., and J. S. Smith. 1975. Production of threitol and sor- M bitol by an insect: Association with freezing tolerance. Nature, 258: 519-520. Morrissey, R., and J. C. Baust. 1976. The ontogeny of cold tolerance in the gall fly, Eurosta Solidagensis. Journal of Insect Physiology, 22: 431-437. Figure 1. Langway Mt. An outcrop rich in mites. Salt, R. W. 1959. Role of glycerol in the cold hardening of Bracon cephi. Canadian Journal of Zoology, 37: 59-69. Somme, L. 1964. Effects glycerol on cold hardiness in insects. (wi- dian journal of Zoology, 42: 87-101. Somme, L. 1965. Further observations on glycerol and cold-hardiness in insects. Canadian journal of Zoo/og, 43: 764-770.

Terrestrial , Marie Byrd Land, Antarctica

R. W. STRANDTMANN

Department of Biological Sciences Texas Tech University Lubbock, Texas 79409 Figure 2. Scanning electron microscope photo of Nanorchestes sp. found on Cox Point.

The project objective was to determine the presence or ab- sence of terrestrial arthropods in Marie Byrd Land. None 4l - previously had been reported from that region of Antarctica. d The research quadrant was bounded by latitudes 740 to 76°S. and longitudes 132°30 to 140°W. The area is covered by deep snow, with widely scattered, relatively small, rocky outcrops (figure 1). I visited 32 exposures, some of them twice. r I made collections between 20 November and 14 Decem- ber 1977 as weather permitted (a total of 11 collecting days) I.. 4I using several research methods. One was to locate a likely 1I 41 I &è$i t: habitat (i.e., a moist substrate of coarse sand and pebbles with some evidence of plant life such as mosses, algae, fungi, lichens) and then to look for mites or insects on the indersur- face of pebbles. Indirect search methods included (1) putting a spoonful of moist sand and plants in a shallow dish and covering with water, and (2) putting algae mats, moss, and loose sand in a plastic jar and subsequently floating the mites or insects in the lab. All methods were successful in locating arthropods, but the last was most efficient. Figure 3. Scanning electron microscope photo shows setae and cuticular detail of Nanorchestes sp.

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