THE SOUTHWESTERN NATURALIST 28(1):95-123 FEBRUARY 18, 1983 NOTES ADDITIONAL RECORDS OF BLACK-FOOTED FERRETS IN WYOMING.-Black-footed ferrets (Mustela nigripes) have been observed infrequently in Wyoming. Clark (Northwest Sci., 54:47-54, 1980) listed 148 black-footed ferret sight records in the state from 1851-1977, with 23 veri- fied by specimens. Twenty-one ferrets were reported from the eastern half of the state and two from northwestern (Park County) Wyoming. No specimens have been reported from southwestern counties. I acquired six additional specimens of this species while conducting statewide searches for black-footed ferrets on 245 white-tailed prairie dog (Cynomys leucurus) towns in 1978 and 1979. Three black-footed ferret skulls were found in south central Wyoming (Carbon County), 28-31 km NE Rawlins, and represent new records from within the reported range in Wyoming. Three addi- tional skulls (one from a 87-ha prairie dog town, 48 km south of Kemmerer, T16N, R118W, SW'4 Sec. 11; one from a 327-ha town, T16N, R118W, SEMSec. 12; and one from a 415-ha town, T16N, R117W, NW4 Sec. 7) constitute the only verified records of the black-footed ferret for southwestern (Uinta County) Wyoming. Repeated searches of locations where skulls were found plus adjacent towns in these areas, revealed no sign of present ferret occupation. Specimens were deposited in the U.S. Fish and Wildlife Service Biological Surveys Museum in Fort Collins, Colorado. I thank the Wyoming State Office of the Bureau of Land Management for funding and the many people who helped conduct these searches. Thanks also to R. Finley, who identified the specimens. R. Cannon and F. Knopf reviewed this paper.-STEPHEN J. MARTIN, Denver Wildl. Res. Ctr., U.S. Fish & Wildlife Service, 1300 Blue Spruce Drive, Fort Collins, CO 80524. SOUTHWESTERN PINE TIP MOTH: NOTES ON LARVAL DESCENT BEHAVIOR, PRE- DATORS, AND ASSOCIATED SHOOT BORER IN NORTHERN ARIZONA.-The southwest- ern pine tip month, Rhyacionia neomexicana (Dyar) (Lepidoptera: Tortricidae, Olethreutinae), infests young ponderosa pine, Pinus ponderosa Laws., in the central and southern Rockies, midw- estern Plains, and the Southwest. Details of its life history, habits, parasites and predators were described by Jennings (Annals Entomol. Soc. Amer. 68:596-606, 1975). Some additional informa- tion was obtained in July 1975, when students and faculty from Chadron State College, Chadron, Nebraska, observed the southwestern pine tip moth at the Loop Burn (elevation ca. 2300 m), Che- velon Ranger District, Apache-Sitgreaves National Forest, ca. 72 km SW of Winslow, Arizona. These observations centered on descent behavior, predators (and potential predators), and asso- ciates of R. neomexicana larvae. Mature larvae of the southwestern pine tip moth leave the shoots in July and August and des- cend tree boles to pupate. Once outside the shoots, descending larvae are susceptible and vulnera- ble to attack by a variety of predators, including ants, spiders and lizards (Jennings, 1975; Toliver and Jennings, Southwestern Nat. 20:1-11, 1975). Using the technique for collecting larvae described by Jennings and Stelzer (USDA Forest Ser- vice Res. Note RM-380, 4 p., 1979), a sand-filled plastic foam cup was placed directly below an infested shoot on each of 15 trees. Starting at 2000 on 16 July, and continuing at 3-hour intervals thereafter for 24 hours, cups were inspected for larvae. All larvae found in the cups were removed at each sampling period. Larvae were collected only at the 0500 sampling time, 17 July, with 8 larvae taken from 4 cups. No further observations were made this date. To determine the time of larval descent more precisely, detailed observations were undertaken on the same trees on 18 July. Observation periods were set for four consecutive 1-hour intervals, starting at 0300 and concluding at 0600. On 18 July, 5 and 4 larvae were recovered at 0400 and 0500 observation periods, respectively. Larvae were captured from only 6 (40%)of the 15 prepared trees, with a maximum of 2 larvae per cup. However, in addition to larvae removed from cups, several larvae were observed descending tree boles on nearby nonsampled trees. All observed larvae had descended to the base of their host trees by 0700. Larval descent by R. neomexicana occurred primarily in the early moring hours, before full day- light and before high daytime temperatures. Such behavior may have survival value by avoidance 96 The Southwestern Naturalist vol. 28, no. 1 TABLE 1.-Infestation rates of E. sonomana and R. neomexicana in a 100-tree sample of ponderosa pine, Chevelon, Arizona, 1975. R. neomexicana Present Absent Total E. sonomana Present 34 24 58 Absent 39 3 42 Total 73 27 100 of parasites and predators and a reduced danger of dessication. Few tip moth parasites and preda- tors are known to be active during early morning hours; parasite-predator activity increases with rising temperatures. Larvae were never observed descending tree boles during daylight hours when extensive observations were made over a period of 3-4 years (Jennings, 1975). The mechanism that triggers and ends larval descent is not known; however, it is likely to be temperature-light depend- ent. During the larval descent study, three types of predators were observed on the cups: several ant species, a spider, and a syrphid larva. Individuals of Formica lasioides Emery were observed attacking a tip moth larva in one cup and a crab spider, Misumenops coloradensis Gertsch, was also observed grasping a larva in another cup. The spider is usually found on forbs, seldom on trees (Jennings, Southwestern Nat. 16:201-207, 1971). The syrphid larva has not been identified. Several predator-prey tests were staged in the field to determine the acceptability of tip moth larvae to various predators and view the predation process. Two species of aphid-tending ants, Formica lasioides Emery and F. pallidefulva nitridiventris Emery, were the most effective in attacking and killing tip moth larvae. Both species had a similar sequence of attack behavior: (1) the ant repeatedly bit the larva; (2) the ant's anal opening was placed to the bitten areas, presuma- bly to deposit formic acid; (3) biting continued at different parts of the larva's body; (4) the larva was chewed until it was immobilized; (5) the ant descended the tree carrying the larva to a nest. Several other aphid-tending ants were observed during the staged tests, but most were smaller than the two Formica species and usually did not attack tip moth larvae. Other species of ants have previously been observed preying on larvae of R. neomexicana (Jennings, 1975). Another controlled predation test was carried out with a snakefly, Agulla arizonica (Banks). Male and female snakeflies were placed in separate clear, round, plastic containers (7.5 x 5 cm) 100- .* ? sonomana 90 - 70- 20 X \ e 60- p 40- /, ---\ u 30 - \ S..- /,,',/ \\ 20- V R.neomx/cona 10,-, %Both species I . present 30-90 90-160 160-240 240-300+ Tree height(centimeters) FIG. 1.-Percentage infestation by Rhyacionia neomexicana, Eucosma sonomana, and both spe- cies together, related to iree height, Chevelon, Arizona, 1975. February 1983 Notes 97 and tip moth larvae introduced into each container. Both sexes of this snakefly quickly located the introduced prey and promptly devoured it. The female A. arizonica partially devoured a second larva offered after the first larva had been consumed. Two additional species of snakeflies, A. bicolor (Albarda) and A. minuta (Banks), were also col- lected on foliage of young pine trees infested with the southwestern pine tip moth at Chevelon; however, no predation tests were conducted with either of these species. Young ponderosa pines are susceptible to concurrent infestation by both the southwestern pine tip moth and the western pine-shoot borer, Eucosma sonomana Kearfott. Stevens and Jennings (USDA Forest Service General Technical Report RM-45, 8 p. 1977) noted that even the same shoots are occasionally attacked by both species. To determine a percentage of trees concurrently attacked by both Eucosma and Rhyacionia, we examined shoots on 100 typically damaged trees within the central part of the 32 ha. burn. Host tree height was also measured to ascertain if there is a relationship between tree height and percentage infestation by either or both species. While lack of randomization of the sample is acknowledged, the sample reflects a typical and realistic situation. Infestation rates were 58% for E. sonomana and 73% for R. neomexicana (Table 1). The rate of dual infestation was 34%. The test of interaction between species indicates a significant (adjusted X2 = 12.8 P < .001) within-tree association of the two species. The shoot borer seems to prefer larger trees, while the tip moth prefers smaller ones (Fig. 1), prossibly indicating resource partitioning.-H. RANDYLAWSON, Biology Dept., Chadron State College, Chadron, NE 69337; LARRY A. YOST,Alliance High School, Alliance, NE 69301; and, DANIELT. JENNINGS,Rocky Mountain Forest and Range Experiment Station, Albuquerque, NM 87101. (Present address, Nor- theastern Forest Experiment Station, USDA Building, Univ. of Maine, Orono, ME 04469). GEMSBOK (ORYX GAZELLA) IN WHITE SANDS NATIONAL MONUMENT.-During 1969-73 and 1976-7 93 gemsbok, Oryx gazella, were introduced to White Sands Missile Range in the Tularosa Basin of New Mexico (Saiz, R. B., unpubl. report, Dept. Fisheries and Wildlife Biol., Colo. State Univ., 1975; Little, New Mexico Game and Fish Comm., pers. com.). They are now being hunted on permits. Following the penetration of White Sands National Monument by herds of gemsbok, we studied their numbers and activity between May and August 1980. While a few gemsbock have been seen in the dune field and along the Monument's south margin, we concen- trated on the western third of the Monument (portions of T17, 18 and 19S R53 and T18 and 19S R6E) where they are most common.