Reticulitermes (Isoptera : Rhinotermitidae) in Arizona: Multiple cuticular hydrocarbon phenotypes indicate additional taxa

摘要

Current taxonomic and biogeographical information on Reticulitermes in the United States suggests the only species found in Arizona is Reticulitennes tibialis Banks. Reticulitermes occurs naturally throughout Arizona with the exception of much of the Sonoran and Colorado deserts. Collections of Reticulitermes from disparate locations in Arizona and neighboring states were made to characterize their cuticular hydrocarbons for taxonomic purposes. We identified five phenotypes based on cuticular hydrocarbon mixtures of worker termites. The predominant hydrocarbons in AZ-A have 25 and 27 carbons in the parent chain, including 5,17-dimeC27. The late-eluting compounds are composed primarily of dienes, trienes, a homologous series of internally branched mono- and dimethylalkanes, and 5,17-dimethylalkanes. AZ-B differs from AZ-A by lacking the late-eluting dienes and trienes and by producing smaller amounts of hydrocarbons with 27 carbons in the parent chain. The cuticular hydrocarbons in AZ-C are composed primarily of olefins; C29:1 is the most abundant, and, with C27:1, C31:2, and C33:2, predominates the hydrocarbon mixture. This phenotype also has a homologous series of 5,17-dimethylalkanes from C27 to C43. AZ-D is distinguished by the absence of any 5-methylalkanes, 5,17-dimethylalkanes, or late-eluting dienes or trienes. The hydrocarbon mixture of AZ-D most closely resembles that of Reticulitennes hesperus Banks from northern California. NM-A can be distinguished from the other phenotypes by the significant amounts of the hydrocarbons coeluting in two peaks: C27 + C27:3 and 7-, 9-, 11-, 13-meC27 + C27:2. AZ-A was not common; the few samples we collected were all at the higher elevations, from 2,000 to 2,250 m, in northern Arizona. AZ-B was the most common and was found throughout the state from Fairbank (approximate to 1,300m) to Jacob Lake (approximate to 2,600 m). This phenotype also was found in eastern Nevada and southern Utah. AZ-C was sympatric with AZ-B over most of the distribution of the latter regions but was elevationally allopatric in southern Arizona. AZ-C occurred at high elevations (> 1,500 m) on the desert islands of southeastern Arizona, such as the Santa Catalina, Santa Rita, Chiricalma, and Pinaleno mountains, whereas AZ-B occurred at lower elevations (< 1,250 m), usually associated with a riparian area. AZ-D was collected only once in northern Arizona near Jacob Lake, AZ (approximate to 1,800 m) but also on Mt. Charleston in southern Nevada. NM-A was collected near jemez Springs and Chaco Canyon, NM, as well as in the vicinity of Moab, UT. Additional data from morphology, behavior and/or DNA may confirm that these phenotypes represent distinct species as it has with California Reticuliternies.