FINE STRUCTURE OF THE PROTHORACIC MYCANGIUM, A CHAMBER FOR THE CULTURE OF SYMBIOTIC FUNGI, IN THE SOUTHERN PINE BEETLE, DENDROCTONUS FRONTALIS

by | Jun 15, 2022 | 1971-1980 Publications

Abstract

The ultrastructure of the prothoracic mycangium of female Dendroctonus frontalis is examined. The mycangium consists of a cuticular invagination within which symbiotic fungi are cultured by the pine beetle and transported to new host trees. Secretions from two types of gland cells pass into the mycangial lumen. The plasma membrane of type-1 cells is invaginated to form an enclosed extracellular cavity. The secretory product passes into the cavity, then through fine cylindrical channels into an end apparatus and finally via an efferent cuticular ductule to the lumen of the mycangium. Secretion of the type-2 cells is released into a cavity just beneath the mycangial cuticle. The cuticle over this cavity is quite thin (0-2μ), consisting mostly of inner epicuticle riddled with irregular canals through which the secretion reaches the lumen. Beneath the patches of porous cuticle are ribs (up to 10μ, in thickness) which flank the cavities and presumably provide structural support for the porous secretory zones.

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HAPP, GM, CM HAPP, and SJ BARRAS. 1971. “FINE STRUCTURE OF PROTHORACIC MYCANGIUM, A CHAMBER FOR CULTURE OF SYMBIOTIC FUNGI, IN SOUTHERN PINE BEETLE, DENDROCTONUS-FRONTALIS.” Tissue & Cell3 (2): 295-+. https://doi.org/10.1016/S0040-8166(71)80024-1.

Standardized Within-Tree Sampling for Populations of Dendroctonus frontalis

by | Jun 15, 2022 | 1971-1980 Publications

Abstract

The objective of this study was to evaluate the applicability of procedures for sampling and estimating within-tree populations of Dendroctonus frontalis in North Carolina. The procedures developed under epidemic conditions in Texas were applied to declining populations in North Carolina. Despite the differences in total population numbers, the within-tree distributions of all D. frontalis life stages were similar for both states. Infested surface area estimates using tree geometry tables developed from the Texas data base were satisfactory for North Carolina. Hence the “tree geometry proportional density function” procedures for estimating total within-tree life stages are applicable in 2 widely separated regions of D. frontalis‘ range and under extremely different population sizes.

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HAIN, FP, WT MCCLELLAND, DN POPE, PE PULLEY, JL FOLTZ, and RN COULSON. 1978. “STANDARDIZED WITHIN-TREE SAMPLING FOR POPULATIONS OF DENDROCTONUS-FRONTALIS (COLEOPTERA-SCOLYTIDAE).” Environmental Entomology7 (1): 157–64. https://doi.org/10.1093/ee/7.1.157.

Relative Abundance and Seasonal Distribution of the Major Hymenopterous Parasites of the Southern Pine Beetle, Dendroctonus frontalis Zimmermann, on Loblolly Pine

by | Jun 15, 2022 | 1971-1980 Publications

Abstract

Relative abundance and seasonal occurrence of hymenopterous parasites of the southern pine beetle (Dendroctonus frontalis Zimm.) were studied in loblolly pine (Pinus taeda L.) stands located in southeastern and western Louisiana. The 6 most abundant parasites were: Roptrocerus eccoptogastri (Ratz.)-65% of total complex, Coeloides pissodis (Ash.)-l0%, Dendrosoter sulcatus Mues.-8%, Spathius pallidus Ash.-7%, Heydenia unica (Cook and Davis)-7%, and Dinotiscus (=Cecidostiba) dendroctoni (Ash.)-3%. Parasite abundance
peaked between Apr.-June and remained at low levels from Dec. to Mar. Parasite populations within trees differed little between areas of opposing site conditions and geographic location. The relationship between host and parasite populations and bark thickness of loblolly pine,
host egg gallery length (number of beetle eggs) and site differences at 2 ecologically different areas were also investigated. Bark thickness significantly affected populations of the parasitic species that oviposit through the bark but did not influence populations of R. eccoptogastri 

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GOYER, RA, and CK FINGER. 1980. “RELATIVE ABUNDANCE AND SEASONAL DISTRIBUTION OF THE MAJOR HYMENOPTEROUS PARASITES OF THE SOUTHERN PINE-BEETLE, DENDROCTONUS-FRONTALIS ZIMMERMANN (COLEOPTERA, SCOLYTIDAE), ON LOBLOLLY-PINE.” Environmental Entomology9 (1): 97–100. https://doi.org/10.1093/ee/9.1.97.

Attack and Survival of Dendroctonus frontalis In Relation to Weather During Three Years in East Texas

by | Jun 15, 2022 | 1971-1980 Publications

Abstract

The seasonal trends of Dendroctonus frontalis Zimmermann attack on, and survival in, pines were studied. Estimates of beetles attacking, egg gallery length, 3rd and 4th instars, pupae, and beetles emerging were obtained for a total 113 loblolly pines, Pinus taeda L. The estimates were used to calculate the percentages of each of the following: eggs that survived to become 3rd and 4th instars, SE; 3rd and 4th instars that survived to become pupae, SL; pupae that survived to emerge as beetles, SP; and, eggs that survived to emerge as beetles, SO. The sizes and seasonal trends of SE, SL, SP, and SO changed during the 3-yr period studied. SE, SL, SP, and SO all decreased during the summer, but SL decreased most predictably. Trends in SO followed the trends in SL most closely. Indices of temperature and rainfall were calculated from the daily records of weather stations. Only SL and SO were associated with temperature and rainfall indices. The most useful indices in regression equations describing SL and SO were day-degree accumulation, DD, and the proportion of the infestation period when 0.6 cm or more of rain fell per day, PR. Increases in DD and PR were associated with decreases in SL and SO. It is suggested that DD and PR were the most useful indices because they measure both the size and the duration of temperature or rainfall.

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GAGNE, JA, RN COULSON, JL FOLTZ, TL WAGNER, and LJ EDSON. 1980. “ATTACK AND SURVIVAL OF DENDROCTONUS-FRONTALIS (COLEOPTERA, SCOLYTIDAE) IN RELATION TO WEATHER DURING 3 YEARS IN EAST TEXAS.” Environmental Entomology9 (2): 222–29. https://doi.org/10.1093/ee/9.2.222.

Correlation of Southern Pine Beetle Attack Density, Oviposition, and Generation Survival with Host Tree Characteristics and Preceeding Beetle Life Stages Within the Host

by | Jun 15, 2022 | 1971-1980 Publications

Abstract

Correlations between host characteristics of loblolly pine (Pinus taeda L.) and population parameters for the southern pine beetle (Dendroctonus frontalis Zimm.) were investigated. Beetle variables studied were attacking adult density (AITKD), density of eggs laid per female (EGFEM), and generation survival (GENS). Three sets of independent variables were analyzed for each dependent variable. Stepwise regression analysis identified the best model for each dependent variable for each set of independent variables considered.

With one exception the diam of the host was found to be the only physical characteristic correlated with the D. frontalis variables. When the AITKD and EGFEM variables were added to host variables in analysis of EGFEM and GENS, respectively, they became the best
correlated variables. Addition of the date of peak attack to the models showed no Iinear effect of season.

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FARGO, WS, RN COULSON, JA GAGNE, and JL FOLTZ. 1979. “CORRELATION OF SOUTHERN PINE-BEETLE [DENDROCTONUS-FRONTALIS ZIMM (COLEOPTERA, SCOLYTIDAE)] ATTACK DENSITY, OVIPOSITION, AND GENERATION SURVIVAL WITH HOST TREE CHARACTERISTICS AND PRECEEDING BEETLE LIFE STAGES WITHIN THE HOST.” Environmental Entomology8 (4): 624–28. https://doi.org/10.1093/ee/8.4.624.