Systemic Insecticide Injections for Control of Cone and Seed Insects in Loblolly Pine Seed Orchards—2 Year Results

Three systemic insecticide treatments, emamectin benzoate alone, imidacloprid alone, and a combination of emamectin benzoate and thiamethoxam, were injected one or two times into loblolly pine,Pinus taeda L., during a 2 yr period in a seed orchard in east Texas. Single injections of treatments containing emamectin benzoate reduced coneworm (Dioryctria spp.) damage by 94–97% during the study period. A second injection after 1 yr did not improve protection. Imidacloprid also significantly reduced coneworm damage in 1999, but not in 2000. Significant reductions in damage from pine seed bugs (Tetyra bipunctata Say andLeptoglossus corculus Herrich-Schaffer) and an increase in the number of full seeds per cone resulted from imidacloprid and thiamethoxam treatments and to a lesser extent from emamectin benzoate. Yearly injections of imidacloprid or thiamethoxam were required to maintain protection against seed bugs. The best overall treatment, two injections of emamectin benzoate plus thiamethoxam, reduced cone and seed losses from insects by 86%. South. J. Appl. For. 26(3):146–152.

Recommendations for control of cone and seed insect pests of black spruce, Picea mariana (Mill.) B.S.P., with insecticides

Foliar sprays of dimethoate (1.25 g AI per tree) and permethrin (0.028 g AI per tree), applied to run-off one week prior to female flower bud flush, significantly reduced flower abortion, cone grazing, and shoot grazing caused by spruce budworm, Choristoneura fumiferna (Clem.), larvae as well as damage by the spruce cone maggot, Strobilomyia appalachensis (Michelsen). Treatment with Bacillus thuringiensis var. kurstaki (B.t.) (0.012 B.U.I, per tree) resulted in moderate protection from grazing damage to female flowers and cones as compared to treatment with dimethoate and permethrin. Systemic applications of acephate also reduced damage by spruce budworm larvae and the spruce cone maggot: fall and early spring applications were equal in efficacy, and the label rate (0.875 g acephate/3.2 cm dbh) provided similar protection to the half-label dose. Key words: Insecticides, black spruce, efficacy, recommendations, cone and seed insects

CONESYS: A Data Collection, Database, and Decision Support System for Making Insect Pest Management Decisions in Seed Orchards

This paper provides an overview of CONESYS, a computer software package designed to assist seed orchard managers to collect, process, and store information about the quality and quantity of seed orchard crops. CONESYS also contains a database on cone and seed insects, registered pest control products and their efficacy, and a decision support program that determines the costs and benefits of various pest management options. North. J. Appl. For. 15(3):154-157.

A Southwide Test of Bifenthrin (Capture®) for Cone and Seed Insect Control in Seed Orchards

In 1991, a Southwide study to evaluate the efficacy of bifenthrin (Capture®) for cone and seed insect control was established in six loblolly pine (Pinus taeda L.) and three slash pine (P. elliottii Engelm.) seed orchards. A control (no treatment), Capture® (bifenthrin), and Guthion® (azinphosmethyl) treatments were established in each seed orchard. Five aerial sprays were used to apply the insecticides during the growing season. At each spray Guthion® was applied at 3 lb ai/ac. Capture® was applied at 0.2 lb ai/ac for the first spray and 0.1 lb ai/ac for the other four sprays. Under the conditions of this study, Capture® was as effective in controlling cone and seed insects as the standard operational Guthion® treatment. Insecticide treatment resulted in a 42% and 17% increase in the number of sound seeds produced per conelet for loblolly and slash pine, respectively. Local need registration (24C) exists in several states, and seed orchard managers can currently use Capture® in Alabama, Arkansas, Georgia, Louisiana, Mississippi, Oklahoma, South Carolina and Tennessee. Seed orchard managers in other southern states need to determine if a 24C label is available in their state prior to useage. South. J. Appl. For. 18(1):72-75.

Evaluation of Aerial Applications of Acephate and Other Insecticides for Control of Cone and Seed Insects in Southern Pine Seed Orchards2

Acephate was evaluated for control of cone and seed insects in southern pine seed orchards from 1980 to 1985. Insecticides compared with acephate during this study were azinphosmethyl, fenvalerate, malathion, and the bacterium Bacillus thuringiensis. Insecticides were applied aerially, by hydraulic sprayers, and by airblast sprayers. Experiments were conducted in loblolly pine seed orchards in Florida and North Carolina and in two slash pine seed orchards in Florida. Control of coneworms, Dioryctria spp., slash pine flower thrips, Gnophothrips fuscus (Morgan), and two seed bugs, the leaffooted pine seed bug, Leptoglossus corculus (Say), and the shieldbacked pine seed bug, Tetyra bipunctata (Herrich-Schäffer) was evaluated. Frost damage and a serious infection of southern cone rust, Cronartium strobilinum (Arth.) Hedgc, and Hahn, caused significant flower and conelet losses and may have obscured differences between treatment effects during some years. All of the insecticide treatments were equally effective in controlling coneworms. The percentages of trees infested with pine tortoise scale, Toumeyella parvicornis (Cockerell), and the striped pine scale, T. pini (King), and the numbers of scale insects per branch after five applications of insecticide, differed significantly for acephate and fenvalerate treatments.

1- AND 2-YEAR DORMANCY OF THE DOUGLAS-FIR CONE MOTH, BARBARA COLFAXANA KFT. (LEPIDOPTERA: OLETHREUTIDAE): POSSIBLE RELATION TO INDIVIDUAL WEIGHTS

Many cone and seed insects exhibit a dormancy in which the individuals may undergo a diapause that lasts 1, 2, or more winters and the proportion of 1-year diapause (1YD) and 2-year diapause (2YD) varies from year to year (Hedlin et al. 1980). Thus, segregating the two diapause types carries a practical importance for forecasting the attacking adult population in a given year. Based primarily on teleological reasoning it has been argued that insects committed to a longer dormancy may have higher weights with metabolites to sustain survival for a longer period. Individual weights have been examined with the hope of separating 1YD from 2YD individuals.

PHYTOPHAGOUS INSECT COMPLEX ASSOCIATED WITH CONES OF WHITE FIR, ABIES CONCOLOR (GORD. AND GLEND.) LINDL., AND ITS IMPACT ON SEED PRODUCTION

White fir cones were sampled for insect damage from wild stands in California and Nevada during 1984–1986. Insects were recovered from cones and seed damage was partitioned by insect species. The important phytophagous insects were separated into guilds: the cone- and seed-mining guild, Dioryctria abietivorella Groté, Eucosma prob. siskiyouana (Kearfoot), Cydia prob. bracteatana (Fernald), Barbara sp.; the seed-feeding guild, Megastigmus pinus Parfitt, M. rafni Hoffmeyer, Earomyia abietum McAlpine; and the scale- and bract-feeding guild, Asynapta hopkinsi Felt, Dasineura prob. abiesemia Foote, Resseliella conicola (Foote), Strobilomyia abietis (Huckett). Total damage by insects varied by year and site, reaching a maximum of 47% in 1986 on one site and a minimum of 12.5% in 1984 on another. Abortion and incomplete development also were major factors in the production of sound seed. Populations of white fir cone and seed insects varied with cone crop but also were affected by the occurrence of cone crops on alternate hosts. During most years, the seed-mining guild insects were the major cause of seed damage.