Bioacoustics of Ammopelmatus eatoncanyon

Figs 1335–1348, Tables 3 , 19 Species #6, Weissman 2001a , p. 69. Mislabeled as from Santa Monica Mts in Weissman (2001a , p. 61), but this is the species that deploys, if rarely, an anal, defensive discharge. Distribution. (Fig. 1335). Known only from a narrow, linear area 7.3 km in length, on the southern side of the San Gabriel Mts , between Eaton Canyon Natural Area and Arcadia Wilderness Park, Los Angeles Co., California . Recognition characters. Medium-large size, medium fast drumming JC with SCD, 2n ♂ =25, frequently with purple areas on the lower sections of the abdomen. Separated ( Table 19 ) from the five other San Gabriel Mt JCs species by drum rate and DNA . Holotype . Male (in alcohol, Fig. 1336). California, Los Angeles Co ., Eaton Canyon Natural Area , 34.177131° -118.097064°, 292m , 25-ii-2001 (S01-10) DBW & VF Lee. R 01-121, R01-123, F1248. Molt to adult 10-x-2001 . Deposited CAS , Entomology type #20184. Measurements in mm: Body length 32.86, hind femur length 11.65, hind femur width 4.42. Fore leg tibia with 3 ventral spurs; middle leg tibia with 7 calcars, 2 ventral spurs; hind leg tibia (Fig. 1337) with 5 inner and 3 outer spines, 2 ventral spurs. Allotype . Female (in alcohol, Fig. 1338). California, Los Angeles Co ., Henninger Flats Natural Area , 34.193461° -118.090022°, 774m , 25-ii-2001 (S01-9) DBW & VF Lee. R 01-110. Molt to adult 30-ix-2001 . Deposited CAS , CASENT #9078746 . Measurements in mm: Body length 40.43, hind femur length 11.67, hind femur width 4.64. Fore leg tibia with 3 ventral spurs; middle leg tibia with 8 calcars, 2 ventral spurs; hind leg tibia (Fig. 1339) with 4 or 5 inner and 3 outer spines, 2 ventral spurs. Ovipositor Fig. 1340. Paratypes . ♂ 18 ♀ 48. CALIFORNIA , Los Angeles Co . , Holotype locality, 26-xii-1982 (S82-152) ♂ 1 ♀ 4; 23-xii-1983 (S83-164) ♂ 4 ♀ 9; 14-iii-1985 (S85-31) ♂ 1 ♀ 5; 18-x-1986 (S86-140) ♂ 3 ♀ 4; 25-ii-2001 (S01-10) ♂ 1 ♀ 10. Allotype locality, 25-ii-2001 (S01-9) ♂ 2 ♀ 13. Arcadia Wilderness Park, 34.176008° -118.019161°, 258m , 25-ii-2001 (S01-8) ♂ 2 ♀ 3. Pasadena, 1445 Coolidge Ave, 34.171090° -118.100786°, 266m , 9-xi-1998 (S98-133) G. Lockhard ♂ 1. Possible placement. An individual (F1036) from San Dimas, Bonelli Park , 34.0795° -117.8100°, 312m , I. Swift, 30-x-1998 (S98-107) ♂ 2 ♀ 1 & 22-i-1999 (S99-2A) ♂ 1, was recovered near both A. ballonadark and A. eatoncanyon . He drummed [R99-111] at 6.0 drums/s, at 18°C, and had a sex clarification drum. Given his inland location, some 29 km SE of the type locality, he is most consistent with A. eatoncanyon . Unfortunately, we lack a karyotype since A. ballonadark [2n ♂ =23] and A. eatoncanyon [2n ♂ =25], which are very similar, can be separated by chromosome count. Drum. Calling drums similar in both sexes except that males with a sex clarification drum ( SCD ). Male : Holotype R01-123 (Fig. 1341) with 45 drums over 8.0s (5.6 drums/s) at 19°C. Paratype R01-102, S01-9 (Fig. 1342) with 3 SCD, the longest of 9 drums over 1.1s (8.1 drums/s) at 19° C. Female : Allotype R01-110 (Fig. 1343) with 59 drums over 8.4s (7 drums/s) at 18°C . Individuals of both sexes, from paratype locality Wilderness Park (S01-8), were recorded at either 15°C and 18.5-19°C, so we also present those results: Male: R01-148 with 87 drums over 17.5s (5.0 drums/s); Female: R01- 143 with 93 and 317 drums over 19s (4.9 drums/s) and 63s (5.0 drums/s) respectively), both at 15°C. Male: R01- 132 (Fig. 1344) shows 57 drums over 7.5s (7.6 drums/s) at 19°C; Female: R01-114 (Fig. 1345) shows 69 drums over 9.3s (7.4 drums/s) at 18.5°C. Derivation of name. Named in reference to the holotype locality. Habitat. Holotype locality is mixed-shrub riparian while higher Henninger Flats area with pines, Rhus, Yucca , and grasses. Wilderness Park site is dry river bed bottom and flood plain area, with rocks and various shrubs. Life cycle and seasonal occurrence. Apparent 2-year typical life cycle. Variation. Of 45 individuals, all had 3 ventral fore leg tibial spurs;10 had 7 and 34 had 8 middle leg tibial calcars, all with 2 ventral spurs; 1 had 4 and 44 had 5 inner rear leg tibial spines, and 44 had 3 and 1 had 4 outer rear leg tibial spines, all with 2 ventral spurs. In general, rear leg inner tibial spine #1 is longer than #2 which is longer than #3. Head color varies from brown (Fig. 1338) to orange (Fig. 1336). DNA . Fig. 1323, p. 706. F0909 (S98-133, Pasadena); F1036 (S99-2A, Bonelli Park); (F1124 & F1125 (both type locality, S01-10); F1243 (S01-8, Wilderness Park ); F1244 (S01-9, Henninger Flats ); F1267 (S01-8, Wilderness Park ); F1275 (S01-8, Wilderness Park ) recovered in Group 25 Southern California #5, along with A. ballonadark (2n ♂ =23) and A. sp. #5. Karyotype. 2n ♂ =25. Three males examined and all consistent: Type locality Eaton Canyon T 01-16 ( Fig. 1346, S01-10); Arcadia Wilderness Park T 01-46 ( Fig. 1347, S01-8); and allotype locality Henninger Flats T01-47 ( Fig. 1348, S01-9) all with 5 metacentric or submetacentric autosomal pairs; 7 acrocentric or telocentric autosomal pairs; and 1 metacentric X chromosome . Discussion. We chose an allotype from a site ~ 2 km away, and ~ 470 m higher, than the holotype site because we had no photographs of live females from the holotype locality. Microsympatric at Eaton Canyon and Arcadia Wilderness Park with A. mahogani . In 1982, equal numbers of nymphs of both species were found, at the type locality, by turning over rocks along nature trails. In 2001, during a wet year, A. eatoncanyon more common than A. mahogani , although latter appears to prefer more shaded microhabitats. The type locality Eaton Canyon Nature Center was ravaged by the catastrophic Eaton Fire of January, 2025: https://www.latimes.com/travel/newsletter/2025-01-16/the-wild-eaton-canyon-nature-recovery-the-wild Group 26, Santa Monica Mts Group (Fig. 1349) This Group contains two species with identical morphology, ecology, and calling drums, and only differ in 2n ♂ = 23 in A. leei vs 2n ♂ = 25 in A. lakesherwood . SPECIES WRITE UPS: A. lakesherwood (p. 718) and A. leei (p. 725).