Tarsonemid mite associates of Dendroctonus frontalis (Coleoptera : Scolytidae): Implications for the historical biogeography of D-frontalis

Seven species of mites (Acari: Tarsenomidae) were associated with two local outbreaks of the southern pine beetle, Dendroctonus frontalis Zimmerman, i n Chiapas, Mexico; three of these species were new records for Mexico and C entral America. The morphology and phoretic behavior of these mites differe d little between the western and southern populations from the United State s. One major difference was that the hyperphoretic ascospores of the southe rn pine beetle mycangial fungus, Ceratocystiopsis sp. (Ophiostomataceae), w ere common in sporothecae of Tarsonemus krantzi Smiley and Moser (Acari: Ta rsonemidae) and Tarsonemus ips Lindquist in Chiapas, Mexico, whereas the as cospores of the blue stain fungus, Ophiostoma minus (Hedgcock) H. and P. Sy dow (Ophiostomataceae), were rare; this situation in the southern United St ares is reversed. The paucity of behavioral and morphological differences b etween the two southern pine beetle populations and the relevant historical climatology suggest that the appearance of D. frontalis in the southern Un ited States may be a recent event.