Host-tree Geometric Models for Use in Southern Pine Beetle 1 Population Studies 2

1976 ◽  
Vol 5 (4) ◽  
pp. 714-719 ◽  
Author(s):  
John L. Foltz ◽  
Adil M. Mayyasi ◽  
Robert N. Coulson ◽  
P. E. Pulley ◽  
William C. Martin
Keyword(s):  
Population Studies ◽  
Host Tree ◽  
Southern Pine Beetle ◽  
Southern Pine ◽  
Geometric Models ◽  
Pine Beetle

MITES PHORETIC ON THE SOUTHERN PINE BEETLE: WHEN AND WHERE THEY ATTACH

1978 ◽  
Vol 110 (5) ◽  
pp. 557-558 ◽  
Author(s):  
L. M. Roton
Keyword(s):  
Dendroctonus Frontalis ◽  
Host Tree ◽  
Southern Pine Beetle ◽  
Southern Pine ◽  
Outer Bark ◽  
Host Trees ◽  
Pine Beetle ◽  
Three Stages ◽  
Southern Pine Beetles ◽  
Pine Beetles

Southern pine beetles, Dendroctonus frontalis Zimmerman, often carry mites as they emerge from host trees. At least 14 species of mites are phoretic (Moser and Roton 1971). But for D. frontalis, it is not clearly known where in the host tree and at what stage of the beetle's development the mites attach themselves. After the beetle larvae construct oval feeding cells, they develop in three stages: pupa, callow adults, and brood adults (Fig. 1). In trees with thick bark, the larvae bore into the outer bark from within, construct pupal cells, and pupate. But in trees with thin bark, the larvae pupate directly in the larval cells next to the xylem. Thus, the larval galleries in either case are in the living phloem adjacent to the sapwood.

scholarly journals Contrasting Competitor and Predator Responses to a Short-Lived Southern Pine Beetle Outbreak: A Case Study

2020 ◽  
Author(s):  
Stephen R Clarke ◽  
Jessica Hartshorn
Keyword(s):  
Natural Enemy ◽  
Bark Beetles ◽  
Southern Pine Beetle ◽  
National Forest ◽  
Population Fluctuations ◽  
Thanasimus Dubius ◽  
Southern Pine ◽  
Widespread Application ◽  
Pine Beetle

Abstract The southern pine beetle (SPB) Dendroctonus frontalis Zimmermann, is the most important insect pest of pines in the southeastern United States, with outbreaks often resulting in thousands of hectares of pine mortality. Natural enemies and competitors have been cited as significant regulators of SPB populations and, therefore, outbreaks. A recent outbreak on the Homochitto National Forest (NF) in Mississippi provided an opportunity to undertake a case study comparing population fluctuations of SPB, its major predator Thanasimus dubius, and its competitors, Ips bark beetles. Trap catches of all three were tracked through the course of the outbreak on the Homochitto NF as well as in two other forests with low or no SPB activity. The number of predators collected initially increased on the Homochitto NF in response to the SPB outbreak, but their impact on reducing infestation numbers was unclear. Numbers of Ips trapped were similar across all three forests, indicating that other factors were regulating SPB populations. The outbreak only lasted a single year, and its brevity likely limited the availability of host resources for natural enemy and competitor populations. Additional studies are warranted to explore the mechanisms affecting the extent and duration of SPB outbreaks, such as active forest management. Study Implications: The widespread application of cut-and-leave treatments during a short duration southern pine beetle (SPB) outbreak on the Homochitto National Forest did not result in immediate increased collections of Ips bark beetles, competitors of SPB. Similar population trends of Ips bark beetles in areas with and without SPB infestations suggest that other factors, such as climate, regulate population numbers. Low numbers of the main SPB predator, Thanasimus dubius, immediately preceded an outbreak, and trap collections increased after outbreak onset, reaffirming the importance of this natural enemy in SPB population fluctuations.

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