Sexing and Rearing the Black Turpentine Beetle (Coleoptera: Scolytidae)

Abstract

Dendroctonus terebrans (Olivier) adults may be accurately sexed by means of the seventh abdominal tergite. Stridulation sound and stridulation movement are useful especially in field observations but not completely accurate because some male beetles do not stridulate and some females do.Laboratory rearing is accomplished by the introduction of parent beetles to fresh pine bolts. Development takes ca. 78 days at 23 °C ± 2 °C or ca. 1302 degree days of effective temperature.

Sexing live mountain pine beetles Dendroctonus ponderosae: refinement of a behavioral method for Dendroctonus spp.

“…The only consistently 100% accurate method of sex determination via secondary characters for Dendroctonus spp. This morphological character is highly accurate (Lyon, 1958;Jantz & Johnsey, 1964;Godbee & Franklin, 1978), but can pose challenges when working with live insects (Tate & Bedard, 1967). This plectrum is used for stridulation by males but absent in females.…”

“…requires examination of adults for the presence of a highly sclerotized plectrum on the seventh abdominal tergite (Lyon, 1958;Safranyik & Carroll, 2006). Squeezing the abdomen or manipulating its position with a metal probe under a dissecting microscope (McCambridge, 1962) can extend handling times and result in harm to the insect (Godbee & Franklin, 1978). This morphological character is highly accurate (Lyon, 1958;Jantz & Johnsey, 1964;Godbee & Franklin, 1978), but can pose challenges when working with live insects (Tate & Bedard, 1967).…”

“…Up to 92% accuracy has been achieved in identifying female black turpentine beetles [Dendroctonus terebrans (Olivier)] based on females being silent (43%) or producing a low-pitch rasping sound (57%), with error occurring due to silent males (Godbee & Franklin, 1978). Inaccuracies most frequently result from some males remaining silent and not due to females chirping (Tate & Bedard, 1967;Godbee & Franklin, 1978). For the western pine beetle (Dendroctonus brevicomis LeConte), 85-90% of males and <1% of females stridulate (Tate & Bedard, 1967).…”

“…This method has been used most successfully in the native elm bark beetle, Hylurgopinus rufipes (Eichhoff), with accuracies of 99.5% (Lyons, 1982). (Tate & Bedard, 1967;Godbee & Franklin, 1978). However, observation of stridulatory movements is less accurate than listening for audible chirps in other Dendroctonus spp.…”

“…This plectrum is used for stridulation by males but absent in females. This morphological character is highly accurate (Lyon, 1958;Jantz & Johnsey, 1964;Godbee & Franklin, 1978), but can pose challenges when working with live insects (Tate & Bedard, 1967). For example, female mountain pine beetles (Dendroctonus ponderosae Hopkins) tend to draw their abdomens tight against the elytra when prodded.…”