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

1989 ◽  
Vol 121 (8) ◽  
pp. 699-708 ◽  
Author(s):  
Patrick J. Shea
Keyword(s):  
Phytophagous Insects ◽  
Phytophagous Insect ◽  
Feeding Guild ◽  
Seed Damage ◽  
Dioryctria Abietivorella ◽  
White Fir ◽  
Cone And Seed Insects ◽  
Major Factors ◽  
Total Damage ◽  
Seed Insects

AbstractWhite 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.

CONE AND SEED INSECTS IN DOUGLAS-FIR, PSEUDOTSUGA MENZIESII (MIRB.) FRANCO, SEED ORCHARDS IN THE WESTERN UNITED STATES: DISTRIBUTION AND RELATIVE IMPACT

1985 ◽  
Vol 117 (10) ◽  
pp. 1223-1230 ◽  
Author(s):  
T.D. Schowalter ◽  
M.I. Haverty ◽  
T.W. Koerber
Keyword(s):  
Pseudotsuga Menziesii ◽  
Gall Midge ◽  
Douglas Fir ◽  
Western United States ◽  
Seed Orchards ◽  
Or Management ◽  
Dioryctria Abietivorella ◽  
Explained Variation ◽  
Cone And Seed Insects ◽  
Seed Insects

AbstractDouglas-fir cones were collected from 17 seed orchards in California, Oregon, and Washington in the fall of 1983. Cones were completely dissected and seed losses ascribed to the Douglas-fir cone gall midge (Contarinia oregonensis (Foote)), the Douglas-fir seed chalcid (Megastigmus spermotrophus (Wachtl)), the Douglas-fir cone moth (Barbara colfaxiana (Kearfott)), and the fir coneworm (Dioryctria abietivorella (Groté)). There appear to be great differences between orchards, but overall C. oregonensis and M. spermotrophus collectively destroyed approximately 70% of the filled seed. Physiographic province significantly (P<0.05) explained variation in damage by all insect species between seed orchards. In general, damage by all species increased from northern provinces to southern mountainous provinces. Damage by C. oregonensis and B. colfaxiana appeared to be related to land use or management factors, as well.

scholarly journals The relationship between resource abundance and insect herbivory on islands

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256183
Author(s):  
Bora Shin ◽  
Jae-Young Lee ◽  
Nang-Hee Kim ◽  
Sei-Woong Choi
Keyword(s):  
Plant Species ◽  
Forest Cover ◽  
Food Resource ◽  
Phytophagous Insects ◽  
Feeding Guild ◽  
Resource Abundance ◽  
Variable Effect ◽  
The Relationship ◽  
External Feeding ◽  
Number Of Plant Species

We examined the relationship between resource abundance and the feeding activity of phytophagous insects on three common island plants. The aim was to investigate the correlation between phytophagous insects’ abundance and availability of food and island geography. We collected 30,835 leaves from three tree species groups (Mallotus japonicus, Prunus species, and Quercus species) on 18 islands in southwest Korea. The number of plant resources for herbivores varied: the number of leaves per shoot was the highest in Mallotus, leaf weight and the water content per leaf was significantly lower in Quercus species. External feeding was higher for Prunus and Quercus species, whereas the internal feeding type was significantly higher for Quercus species. Geography (area and distance), elevation and food resource (elevation, number of plant species, and the forest cover rate) had a variable effect on phytophagous insects feeding activities: distance and the number of plant species were more explainable to the external feeding guild. In contrast, area and forest cover were more to the internal feeding guild.

Insects Affecting Seed Production in Red Pine: Part I Conophthorus resinosae Hopk. (Coleoptera: Scolytidae)

1956 ◽  
Vol 88 (10) ◽  
pp. 599-608 ◽  
Author(s):  
L. A. Lyons
Keyword(s):  
Seed Production ◽  
Pacific Coast ◽  
Large Numbers ◽  
The Pacific ◽  
Future Success ◽  
Loblolly Pines ◽  
Unfavourable Weather ◽  
Cone And Seed Insects ◽  
Seed Crops ◽  
Seed Insects

Natural and artificial reforestation, which basically depend on an abundance of sound seed, are adversely affected when insects destroy large numbers of cones, seeds, and cone-bearing shoots. Other factors, such as unfavourable weather, incomplete seed development, and damage by birds and mammals also reduce seed production, but they are rarely of such widespread importance as insects, whose damage often results in the failure of seed crops over large areas. Cone and seed insects sometimes restrict the natural regeneration of trees for a few years at a time, as, for example, in conifers on the Pacific coast (16), loblolly pines in Virginia (13), and oak in Michigan (5), but they become particularly important when the seeds they destroy are required for use in artificial reforestation. The future success of much reforestation, which is inclining more and more toward the use of seed obtained from trees cultivated especially for that purpose, may largely depend on a thorough understanding of cone and seed insects and their effect on seed production.

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

1992 ◽  
Vol 27 (2) ◽  
pp. 172-184
Author(s):  
Carl W. Fatzinger ◽  
Harry O. Yates ◽  
Larry R. Barber
Keyword(s):  
Loblolly Pine ◽  
Frost Damage ◽  
Slash Pine ◽  
Scale Insects ◽  
Southern Pine ◽  
Seed Orchards ◽  
Flower Thrips ◽  
Bacterium Bacillus ◽  
Cone And Seed Insects ◽  
Seed Insects

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.

scholarly journals Species of Phytophagous Insects Associated with Strawberries in Latvia

2013 ◽  
Vol 67 (2) ◽  
pp. 124-129
Author(s):  
Valentīna Petrova ◽  
Līga Jankevica ◽  
Ineta Samsone
Keyword(s):  
Sampling Methods ◽  
Insect Species ◽  
Phytophagous Insects ◽  
Phytophagous Insect ◽  
Pitfall Trapping ◽  
Insect Fauna ◽  
Number Of Species ◽  
Leaf Sampling

The aim of the present study was to describe the phytophagous insect fauna of strawberries in Latvia. This study was carried out in 2000-2004 on strawberry plantations in Tukums, Rîga, Dobele, and Limbaþi districts. Insects were collected from strawberry fields by pitfall trapping, sweep netting and leaf sampling methods. A total of 137 insect species belonging to seven orders and 41 families were identified to species. Of the phytophagous insects, the order Orthoptera was represented by one species, other orders by a larger number of species: Hymenoptera (3), Diptera (16), Lepidoptera (20), Thysanoptera (21), Hemiptera (39), and Coleoptera (37). Of the recorded insects, 48 species have a status of general strawberry pests.

The Role of Host Selection in the Ecology of Phytophagous Insects

1953 ◽  
Vol 85 (8) ◽  
pp. 276-282 ◽  
Author(s):  
A. J. Thorsteinson
Keyword(s):  
Host Plant ◽  
Host Selection ◽  
Host Plants ◽  
Host Plant Selection ◽  
Phytophagous Insects ◽  
Phytophagous Insect ◽  
Ecological Significance ◽  
Plant Selection ◽  
Suitable Host

It is a commonplace entomological observation that each phytophagous insect is restricted in its feeding to a small fraction only of the plant species that grow in any area. This phenomenon is generally referred to as “host selection”. The ecological significance of host plant selection among insects is manifest principally in an effect on the geographical distribution of insect species since phytophagous insects can occur only where suitable host plants are available.

CONE AND SEED INSECTS OF TAMARACK, LARIX LARICINA (DU ROI) K. KOCH, AND ATTEMPTS TO CONTROL DAMAGE USING CHEMICAL INSECTICIDES

1986 ◽  
Vol 118 (6) ◽  
pp. 589-596 ◽  
Author(s):  
P.A. Amirault ◽  
N. Rae Brown
Keyword(s):  
New Brunswick ◽  
Choristoneura Fumiferana ◽  
Larix Laricina ◽  
Insect Damage ◽  
Weekly Basis ◽  
Breast Height ◽  
Growing Seasons ◽  
Protection Trees ◽  
Cone And Seed Insects ◽  
Seed Insects

AbstractAn investigation of the insects that damage cones (megasporangiate strobili) and seeds of tamarack [Larix laricina (Du Roi) K. Koch] in New Brunswick was undertaken. During two growing seasons (1982 and 1983) cones were removed from natural and planted stands of tamarack on a weekly basis. These cones were dissected, the nature and amount of insect damage recorded, and insect habits documented. Efforts were made to rear to adults any destructive insects encountered in order to identify them and to isolate parasites. Insects destroyed from 24.6 to 88.0% of the seed produced in the stands under study. Larvae of the spruce budworm [Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae)] and the cone maggot [Lasiomma viarium (Huckett) (Diptera: Anthomyiidae)] were responsible for most of the damage. Among insects that caused lesser amounts of damage were a cone midge [Resseliella sp. (Diptera: Cecidomyiidae)], a seed chalcid [Megastigmus sp. (Hymenoptera: Torymidae)], and various lepidopterous larvae. Applications of the insecticides carbofuran and dimethoate reduced the amount of insect damage. Carbofuran applied at the rate of 13.5 g active ingredient per centimetre of diameter at breast height provided the best protection. Trees treated in this manner had 37.0% of their seeds destroyed by insects as opposed to 74.2% on control trees.

DISPERSAL OF CONE AND SEED INSECTS TO AN ISOLATED DOUGLAS-FIR TREE IN WESTERN OREGON

1984 ◽  
Vol 116 (10) ◽  
pp. 1437-1438 ◽  
Author(s):  
T. D. Schowalter
Keyword(s):  
Pacific Northwest ◽  
Gall Midge ◽  
Douglas Fir ◽  
Control Measures ◽  
Host Trees ◽  
The Pacific ◽  
Major Species ◽  
Insect Populations ◽  
Cone And Seed Insects ◽  
Seed Insects

Cone and seed insects frequently cause severe losses to Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seed production in the Pacific Northwest (Hedlin et al. 1981; Ruth 1980). Two of the major species west of the Cascades are the Douglas-fir cone gall midge (Contarinia oregonensis Foote (Diptera: Cecidomyiidae)) and the Douglas-fir seed chalcid (Megastigmus spermotrophus Wachtl. (Hymenoptera: Torymidae)). These two species are host specific on Douglas fir and exhibit an extended diapause in which more than 50% of each year's cohort may remain in diapause under host trees for 1 or more years (Annila 1982; Hedlin 1961; Hedlin et al. 1981; Johnson 1962). The economic and biological costs of chemical control have supported recommendation of alternative control measures, particularly (1) establishing seed orchards some distance from sources of coneand seed-insect populations, and (2) removing all cones and burning litter as a means of reducing such populations (Hedlin et al. 1981; Ruth 1980). The success of these two options depends on the dispersal strategies of cone and seed insects (Johnson 1962), but information on dispersal has been lacking. The purpose of this study was to obtain such information.

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

2002 ◽  
Vol 26 (3) ◽  
pp. 146-152 ◽  
Author(s):  
Donald M. Grosman ◽  
William W. Upton ◽  
Frank A. McCook ◽  
Ronald F. Billings
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Seed Orchard ◽  
Systemic Insecticide ◽  
East Texas ◽  
Emamectin Benzoate ◽  
Seed Orchards ◽  
Pinus Taeda L ◽  
Cone And Seed Insects ◽  
Seed Insects

Abstract 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.

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