EVALUATION OF THE RE-EMERGENCE PROCESS OF PARENT ADULT DENDROCTONUS FRONTALIS (COLEOPTERA: SCOLYTIDAE)

Abstract

Can. Ent. 110: 471-473 (1978) Xenoborus Reuter is synonymized with Tropidosteptes Uhler. Tropidostepres brooksi n. sp. is described from Saskatchewan, Manitoba, Ontario, and Quebec. The species was collected on Fraxinus spp. Reuter (1908) described Neoborus commissuralis and proposed the subgenus Xenoborus for it. Soon after (1909) he transferred commissuralis to Tropidosteptes Uhler (1 878) and described petitti and plagifer under that genus. Van Duzee (1 9 16a, b ) raised Xenoborus to generic status and transferred commissuralis and plagifer to it respectively. Knight (1917) transferred petitti to Xenoborus and described X. neglectus. Later (1927Later ( , 1929 he added chinaonthi and selectus to it. Xenoborus has retained generic status to the present day.Slater (1950) studied genital structures of Neoborus Distant (1884), Tropidosteptes, and Xenoborus and suggested that the three genera were congeneric. Carvalho (1954) synonymized Neoborus with Tropidosteptes. Kelton (1959) studied the male genital structures of Tropidosteptes, Xenoborus, and Neoborella Knight (1925) and also suggested that the three genera were congeneric. Further studies of the species included in those genera show that Tropidosteptes and Xenoborus are congeneric but Neoborella may be retained as a distinct genus.In addition to the similar structures of the male and female genitalia, species of Tropidosteptes and Xenoborus are also similar in shape and appearance, and all have similar type of habitat. The species are rather large, generally over 5.0 mm in length, elongate and subparallel. The frons are smooth or punctate but not transversely grooved or striate. All are confined to deciduous trees and mostly to Fraxinus spp. The character of the carinate lateral margins of the pronotum used to separate them into two genera is weak and inconsistent. Species in both genera have carinate, partly carinate, or rounded pronotal margins.Although the male genital structures and puncturation on the pronotum in species of Neoborella show a close relationship to those of Tropidosteptes and Xenoborus, species of Neoborella are easily separated from the others by the distinctly grooved and striate frons. They also differ in size and shape. Species of Neoborella are rather small, less than 5.0 mm in length, and oval or oblong in shape. So far as is known species of Neoborella are confined to dwarf mistletoe growing on conifers.Herewith Xenoborus Reuter is synonymized with Tropidosteptes Uhler, and Neoborella Knight is retained as a distinct genus. A new species belonging to Tropidosteptes is described, and illustrated.

Parasite and Predator Component of Within-Tree Southern Pine Beetle (Coleoptera: Scolytidae) Mortality

“…Each successfully emerged brood adult is capable of colonizing and producing offspring in more than one host tree (Cooper and Stephen 1978;Coulson et al 1978). Once successfully attacked, the infested tree will die.…”

How to fight against southern pine beetle epidemics: An insurance approach

“…Particularly, the long‐distance migration is evidenced by Borden () and Hedden and Billings (). It is found that the SPB population density follows spatiotemporal patterns during each stage of SPB life history, that is, colonization (Fargo et al., ), reemergence (Coulson et al., ), survivorship (Coulson et al., ), and emergence (Coulson, Pulley, Foltz, Martin, & Kelley, ). In addition, research on broadscale SPB risks also found spatiotemporal patterns of probabilities of SPB outbreaks (e.g., Gumpertz, Wu, and Pye, ; Pye et al., ; Zhu et al., ).…”

Synchrony's double edge: transient dynamics and the Allee effect in stage structured populations

“…With realistic parameter sets, the number of hosts attacked has the greatest effect on generational overlap by setting the upper limit on adult lifespan. Field observations suggest that attacks by re-emerged adults are integral to sustaining infestation growth (Coulson et al 1978;Coulson 1980), but Thatcher & Pickard (1964) noted that SPB do not produce more than two broods in nature. We allowed model adults to lay a maximum of two sequential broods and manipulated the probability of re-emergence and betweenhost survival to test the effect of adult mortality on population continuity.…”