Acanthocephala (Melapodiessa) thomasi (Uhler)

Packauskas, Richard J., Sites, Robert W., Taylor, Steven J., Bundy, Scott, Bradshaw, Jeffrey D. & Mitchell, Paula Levin, 2011, Review of Acanthocephala (Hemiptera: Heteroptera: Coreidae) of America north of Mexico with a key to species, Zootaxa 2835, pp. 30-40 : 37-38

Acanthocephala (Melapodiessa) thomasi (Uhler)

( Figs. 4 , 7, 8 , 14 )

Metapodius thomasii (sic) Uhler, 1872, U. S. Geol. Geogr. Surv. Terr. 5: 399. Acanthocephala granulosa: Distant, 1881 , Biol. Centr.-Am., Rhyn., 1: 120. Acanthocephala thomasi: Barber, 1926 , J. N. Y. Ent. Soc. 34: 209.

Diagnosis. Length: 24–31 mm. This species can be recognized by the angles of the pronotum, which are only slightly extended laterally. The metatibial expansions are broadly dilated for most of their length, ending abruptly near the apex.

Distribution. AZ, CA, NM, TX ( Mexico [Chihuahua City])

Discussion. Almost all biological information for this species comes from Jones (1993) as part of his study of the Pentatomoidea and Coreidae of Arizona and includes host plants, habitats, and field life history. The specific collecting sites are listed in Jones' paper so are not given here.

Jones (1993) found adults from May to September, with mating pairs observed in July and August. Eggs and early instars (i.e., 1sts –2nds) were found in August, and late instars (i.e., 3rds–5ths) from July into September. From these data, it is difficult to determine whether this coreid is uni- or bivoltine. However, appearance of mating adults in July, followed by eggs in August, and nymphs from July into September suggest the completion of a spring generation and beginning of a summer generation in July. CSB here reports that adults have been collected in New Mexico from April through October, thus close to that for Arizona noted above.

Jones (1993) listed several host plants but did not report feeding. However, field data strongly suggest the bugs were feeding at the time of capture. Host plants discussed were Agave palmeri Engelmann (Palmer's century plant), Agave schottii Engelmann (shin dagger), Baccharis sarothroides A. Gray (desertbroom), Fraxinus pennsylvanica Marsh ssp. velutina Torrey (red ash), Prosopis velutina Wooton (velvet mesquite), and Yucca elata Engelmann (soaptree yucca ). Accompanying life history observations are as follows: (1) Agave palmeri : adults were found on flower buds and green seed pods, nymphs and adults on leaves, fruiting stalks, and green fruits; (2) Agave schottii : nymphs and adults were found on fruiting stalks; (3) Baccharis sarothroides : adults, including mating pairs, eggs, and third and fourth instars were found on this host plant. Adults generally were on the lower parts of the main stems. Eggs were deposited singly on different plants; (4) Fraxinus pennsylvanica ssp. velutina : third–fifth instars and adults were found on a single small tree; (5) Prosopis velutina : three adults and one third instar were found (no additional information provided); and (6) Yucca elata : third–fifth instars and mating adults were found on flowers and fruits. CSB notes several records from New Mexico on Yucca baccata Torrey (banana yucca ) (nymphs and adults, feeding observed) and Agave ( agave ) (adults); and on Yucca (Spanish bayonet), Prosopis , and Verbascum thapsus (1 adult /plant). Jones (1993) also collected three adults at UV light.

Palmer (1987) conducted a survey of the phytophagous insect fauna associated with Baccharis halimifolia and B. neglecta in Louisiana, Texas, and northern Mexico. He reported A. thomasi as a rare ectophagous species on B. neglecta without a specific location but apparently this was observed in Texas (see Jones 1993). Waring and Smith (1987) reported occasional specimens of Acanthocephala sp. on Agave palmeri near Tucson, Arizona. As Jones (1993) reported only A. thomasi on this host plant in Arizona, it strongly suggests that Waring and Smith (1987) also collected this species. A. thomasi also may be the species involved in Gentry's (1972) paper in which he referred (p. 104) to damage of Agave palmeri as "large pustulate scars, probably made by the large, sap-sucking bugs of the family Coreidae observed on the plants" in nearby Sonora, Mexico.

Figures

FIGURES 1 – 4. Habitus photographs of male Acanthocephala spp. 1. A. declivus. 2. A. femorata. 3. A. terminalis. 4. A. thomasi.

FIGURES 5 – 12. Hind tibiae of Acanthocephala, male and female respectively. 5 – 6, A. declivis. 7 – 8, A. thomasi. 9 – 10, A. terminalis. 11 – 12, A. femorata.

FIGURES 13 – 14. Humeral angles of Acanthocephala, posterior view. 13. A. declivis. 14. A. thomasi.