Factors Affecting Gallery Construction, Oviposition, and Reemergence of Dendroctonus frontalis1 in the Laboratory2

Forest Thinning Affects Reproduction in Pine Engravers (Coleoptera: Scolytidae) Breeding in Felled Lodgepole Pine Trees: Fig. 1.

“…In terms of temperature, our results are more consistent with laboratory studies that show increased reproductive rates with warmer temperatures. Females had longer galleries and laid more eggs at a higher egg density in thinned stands than in unthinned stands, just as seen in laboratory studies on the effects of increased temperature for other bark beetle species (Reid 1962, Amman 1972, Sahota and Thomson 1979, Wagner et al 1981, Wermelinger and Seifert 1999.…”

“…First, reduced tree density and canopy closure make thinned stands warmer than unthinned stands (Bartos and Amman 1989;Schmid et al 1991Schmid et al , 1992aSchmid et al , 1992b; Bartos and Booth 1994;Hindmarch and Reid 2001). Controlled lab experiments have shown that as temperature increases, female bark beetles extend their egg galleries farther (Reid 1962, Sahota and Thomson 1979, Wagner et al 1981, lay more eggs (Wagner et al 1981, Wermelinger andSeifert 1999), have higher egg densities (Amman 1972, Wagner et al 1981, and lay their Þrst egg earlier (Sahota and Thomson 1979). However, in a Þeld study, Villa-Castillo and Wagner (1996) found that increased temperature due to thinning resulted in shorter egg galleries and lower egg densities.…”

“…Large females, which typically have higher fat content than do small ones (Wagner et al 1981, Anderbrant 1988, extend their egg galleries farther (Clarke et al 1979, Wagner et al 1981 and lay more eggs (Amman 1972, Clarke et al 1979, Wagner et al 1981) than do small females.…”

Importance of Log Size on Host Selection and Reproductive Success of <I>Ips pini</I> (Coleoptera: Scolytidae) in Ponderosa Pine Slash of Northern Arizona and Western Montana

“…The importance of density in the population dynamics of bark beetles has been noted in a number of studies (Cole 1978, Wagner et al 1981, Botterweg 1983, Light et al 1983, Anderbrant et al 1985, Anderbrant and Schlyter 1989, Byers 1989, Kirkendall 1989. For example, host selection and attack behavior of a population may change with increased adult beetle density (Cole 1978, Gara et al 1999, Wallin and Raffa 2002.…”

“…However, because pine engraver exhibits spatial and temporal differences in activity (see U.S. Department of Agriculture Forest Service, Forest Health Protection Insect and Disease Conditions reports in References), generalized recommendations may not be adequate in preventing pine engraver population increases or in assisting managers in determining the most effective and efÞcient control method for their situation. Regional and temporal differences in activity levels, manifest as both differences in host selection and in reproductive success, may be due to changes in host quality (Atkins 1966, Byers 1989, Redmer et al 2001, Erbilgin et al 2002, beetle condition (Wagner et al 1981, Anderbrant et al 1985, Gast et al 1993, Wallin and Raffa 2000, intraspeciÞc interactions (Wagner et al 1981, Anderbrant et al 1985, Byers 1989, Reeve et al 1998, Wallin and Raffa 2002, interspeciÞc competition (Birch and Wood 1975, Light et al 1983, Hunt and Borden 1988, Poland and Borden 1998), predation (McCambridge and Knight 1972, Byers 1989, Reeve 1997, Erbilgin et al 2002 and abiotic factors such as wind, temperature, and precipitation (Sartwell 1970, Wagner et al 1981, Holsten and Werner 1990, VillaCastillo and Wagner 1996, Wermelinger and Seifert 1999.…”