170 JOURNAL OF THE LEPIDOPTERISTS' SOCIETY

Heterocampa subrotata (Harvey) . 3 July 1971, 5 miles south­ east Ethel. Host: Celtis mississippiensis (hackberry). Hymenia perspectalia (Huebner) PYRAUSTIDAE. 28 August 1971, 2 miles south­ east Ethel. Host: Amaranthus hybridus (pigweed). Hysoropha hormos (Huebner) NOCTUIDAE. 19 August 1970, 5 miles southeast Ethel. Host: Diospyros virginian a (persimmon). Parasites: Meteorus sp. BRACONIDAE. Loxostege sp. PYRAUSTIDAE. 27, 28 August 1971, 2 miles southeast Ethel. Host: Amaranthus hybridus (pigweed). Parasites: Cremnops haematodes (Brulle) BRACONIDAE; Nemorilla pyste (Walker) TACHINIDAE. Mineola indigenella (Zeller) PHYCITIDAE. 1-3 August 1971, 4 miles southeast Ethel. Host: Crataegus viridis. Parasites: Eusisyropa boarmiae (Coq.), Eusisyropa virillis (Aldrich & Webber) TACHINIDAE. Olene leucophaea (Abbot & Smith) LIPARIDAE. 2 October 1970, 6 miles south St. Charles. Host: Liquidamber styraciflua (sweet gum). Phaecasiophora niveiguttana (Grote) OLETHREUTIDAE. 1 August 1971, 2 miles southeast Ethel. Host: Sassafras sp. (sassafras). Parasites: Macrocentrus ancy­ livorus Roh. BRACONIDAE. Polychrosis sp. OLETHREUTIDAE. 4 August 1971, 2 miles north St. Charles. Host: Amaranthus hybridus (pigweed). Parasites: Agathis annulipes (Cress.) BRACONIDAE. Psilocorsis cmyae Clarke OECOPHORIDAE. 23 August 1970, 3 miles east Ethel. Host: Carya sp. (hickory). Psilocorsis quercicella (Clemens) OECOPHORIDAE. 4 August 1971, 4 miles southeast Ethel. Host: Quercus sp. (oak). Parasites: Temelucha grapholithae (Cush.) ICHNEUMONIDAE. Scythris trivinctella (Zeller) SCYTHRIDAE. 2 October 1970, 3 miles southeast Ethel. Host: Amaranthus hybl'idus (pigweed). Parasites: Nemorilla pyste (Walker) T ACHINIDAE. Stegasta bosqueella (Chambers) GELECHIIDAE. 18-24 July 1971, 5 miles southeast Ethel. Host: Cassia fasiculata. Xenolechia "Telphusa" sp. group GELECHIIDAE. 2 August 1969, 2 miles south St. Charles. Host: Salix sp. (willow). Thanks are due Mr. Raymond McMasters for his cooperation in allowing use of the White River National Wildlife Refuge; Drs. Ed Smith and Patricia Coons for plant determinations; Drs. Paul Marsh, R. W. Carlson, C. W. Sabrosky, and B. D. Burks for detemlination of parasites; and Drs. R. W. Hodges and Ed Todd for determination of . This article is published with the approval of the Director, Arkansas Agricultural Experiment Station.

RICHARD L. BROWN AND ROBERT T. ALLEN, Entomology Department, University of Arkansas, Fayetteville, Arkansas 72701.

A NOTE ON FREEZE-DRYING CATERPILLARS At the request of Dr. Richard B. Dominick this small amount of information is offered to anyone interested in freeze-drying caterpillars without purchasing any materials whatsoever. In the summer of 1971 several saturniid caterpillars (mainly Hyalophora species and hybrids) were frozen alive with the original intention of keeping a small larval collection in the freezer permanently. On adding more speci­ mens to the box in the spring of 1973, the 1971 ones were observed to be very light in weight. They were taken out, and no changes have been observed for VOLUME 28, NUMBER 2 171 months thereafter. Some wrinkling of the skin had occurred in the freezer, but the colors were excellent, including tubercles. The fact that the kitchen freezer used was self-defrosting apparently answers the question of where the moisture went. It seems that had a well-ventilated box been used, the same results could have been achieved in several months instead of two years.

RICHARD S. PEIGLER, 303 Shannon Drive, Greenville, South Carolina 29607.

FREEZE-DRYING AND VACUUM DEHYDRATION: INSTRUMENTATION Some time ago I repOlted on the process of freeze-drying and vacuum dehydra­ tion for the preservation of immatures (Dominick 1972, J. Lepid. Soc. 26: 69-79 ) . Since then, experience has led to some modification of procedure and equipment. These recommendations form the substance of this article. It is assumed that the reader has before him the previous report (of which a few reprints are still avail­ able), for this article will proceed point by point on that basis. The pump oil should be changed regularly, otherwise the efficiency of the pump may be seriously impaired. An oil change is recommended after every 20 hrs. of operation, so a disconnect coupling (an "0" type ring) is desirable. Such disconnect couplings will also be found useful for anyone desiring to constmct a mobile field unit. The inside diameter of the tubing is of no great consequence in the system described. However, % in. tubing is recommended over ~ in., for two minor reasons: first, a slightly more efficient pull-down time will result, and second, the larger diameter is a bit easier for the amateur to flare or solder. Next, it is advantageous to lower the temperature of the freezer below the _7 0 C (20 0 F) previously recommended, since opening the freezer door can quite e~sily raise the temperature to above freezing. By removing the taped end of the thermostat from the ice-making compartment and gently bending it out of the way into the rear of the larger compartment. the temperature of the whole unit may be lowered to between -12 to _150 C (10 to 50 F), while the ice-making compart­ ment goes down to about _24 0 C (_15 0 F). The resulting increase in drying time is not sufficient to be of practical concern. This lower temperature, in fact, is theoretically more suitable for the preservation of integrity of the cells. Previously the suggestion was made that Duco or similar cement would help preserve the integrity of the permanent joints. The suggestion is erroneous, for proper flaring alone guarantees the adequacy of sealing. If the flare (or soldering) is not properly made, no amount of posthumous treatment will help. As for killing the , I have largely abandoned the method of very quick deep freezing, which often agitates the larva so much that presentation of a lifelike attitude becomes difficult. It also influences the cellular integrity by destmctive crystal formation. Slow freezing in the main compartment in general seems best. In case an undesirable attitude prevails, correction should be made as soon as possible, before the larva is frozen through. Try to avoid thawing a frozen specimen, for this has undesirable effects on some of the color pigments. Try to manipulate the larva when it is just cold enough to be dormant, but before cellular freezing. Frank R. Hedges, Houston, Texas, suggests that contact with the ambient air after any degree of freezing might change some of the chemically activated color pigments, and my own experience tends to bear this out. In such a case the larva may be put straight away into a cold desiccator and left to freeze to death, applying vacuum only when thoroughly frozen. One may have to sacrifice a lifelike posture in favor of coloration. More experimentation is needed. Other methods of killing are