Adelphocoris Lineolatus Research Articles

Assessment of Damage Caused by Tarnished Plant Bug and Alfalfa Plant Bug (Hemiptera: Miridae) on Alfalfa Grown for Forage in Wisconsin

Relative damage to alfalfa due to feeding by the tarnished plant bug, Lygus Lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), and the alfalfa plant bug, Adelphocoris Lineolatus (Goeze) (Hemiptera: Miridae), was assessed with alfalfa plants grown in field cages. Feeding by adults and nymphs of both species reduced dry weight and length of stems in established stands (at least 1 yr old) of alfalfa, but feeding had no consistent effect on percentage of crude protein. However, feeding by caged adult plant bugs caused a reduction in length of stem and biomass in newly seeded alfalfa and an increase in percentage of crude protein. Sprays applied at various stages of alfalfa development and plant bug population densities failed to show that either species reduced yield or quality during this 2-yr study.

Effect of Swathing Alfalfa for Hay on Insect Dispersal

Alfalfa ( Medicago sativa L.) is often grown for seed in fieldsadjacent to fields of alfalfa grown for hay in southern Alberta. Swathing of the hay fields could cause pest and predatory insects to disperse into the adjoining seed fields, resulting in damage to the latter. To determine the potential of such movement occurring, populations of pest and predatory insects were compared before and after two cuts of alfalfa. At sites where the seed field was separated from the hay field by barriers such as farm field roads and irrigation ditches, no dispersal was detected. However, at sites where the seed field was immediately adjacent to the hay field, dispersal of insects out of hay fields into adjacent seed fields occurred, varying with the cut (first or second) and insect species. Dispersing insect pests were Lygus spp., the alfalfa plant bug, Adelphocoris lineolatus (Goeze), and the pea aphid, Acyrthosiphon pisum (Harris); dispersing predatory insects were the minute pirate bug, Orius tristicolor White, and the western damsel bug, Nabts alternatus Parshley. Cutting alfalfa hay fields caused insects to disperse if there were no physical barriers to their movement.

Early and Late-Season Insecticide Applications in Seed Alfalfa: Impact on Pest Species and Yield2

Alfalfa is grown for seed on approximately 9,500 ha in Alberta, Canada. Pest insects, such as Lygus spp. and the alfalfa plant bug, Adelphocoris lineolatus (Goeze), (Heteroptera: Miridae) can reduce seed yield if they are not controlled. However, little is known of the damage caused by these pest insects during late seed formation and development. Field studies were conducted during 1983 and 1986 to determine the effect of early- and late-season applications of the insecticides trichlorfon and phosmet alone and combined on Lygus spp., alfalfa plant bug and seed yield of alfalfa. Effects were dependent on the time of application, year, and insect species. Lygus spp. densities for late-season trichlorfon treatments were significantly (P < 0.05) lower than the control. Trichlorfon and phosmet had no effect on densities of alfalfa plant bugs in 1983, but some late-season trichlorfon treatments did reduce plant bug densities in 1986. Seed yields in plots receiving late-season trichlorfon were generally greater than in the control in both years.

Effect of Swathing and Clear-Cutting Alfalfa on Insect Populations in Southern Alberta

Swathing alfalfa ( Medicago sativa L.) for hay greatly reduced the populations of several pest insects and their insect predators for 2 and often for 4 wk after swathing in southern Alberta. Clear-cutting alfalfa reduced pest and predator insects usually for 3-4 wk, but the predator populations recovered rapidly in some fields. The pest insects were Hypera postica (Gyllenhal), Acyrthosiphon pisum (Harris), Lygus spp., Adelphocoris lineolatus (Goeze), and Sitona scissifrons Say. Predators were Aeolothrips fasciatus (L.), Nabls alternatus Parshley, Orius tristicolor White, and Coccinellidae. There was a difference in insect populations among fields because of management of the alfalfa during the growing season. These results have led to the recommendation for southern Alberta that, if pea aphid populations are high and the alfalfa is near the 10% bloom stage, the crop should be cut rather than treated with an insecticide.

Cultural and Chemical Control Strategies for Three Plant Bug (Heteroptera: Miridae) Pests of Birdsfoot Trefoil in Northern Wisconsin

Several cultural and chemical control methods were evaluated for reducing population levels of the plant bugs Adelphocoris lineolatus (Goeze), Lygus Lineolaris (Palisot de Beauvois), and Plagiognathus chrysanthemi (Wolff) in birdsfoot trefoil ( Lotus corniculatus L.) grown in northern Wisconsin. In insecticide efficacy trials, all insecticides (malathion, dimethoate, trichlorfon, and fluvalinate) significantly reduced populations of plant bugs. Fluvalinate was slightly less effective than the other insecticides, particularly against L. Lineolaris . Insecticides applied in June provided a longer period of control (before adult plant bugs dispersed into the sprayed areas) than did applications made in July. Spring burning of the previous fall’s trefoil regrowth also significantly reduced populations of plant bugs but was slightly less effective than insecticide applications. Removal of plant material following seed harvest during late summer did not provide significant control of plant bugs for the following year.

Damage Potentials of Three Plant Bug (Hemiptera: Heteroptera: Miridae) Species to Birdsfoot Trefoil Grown for Seed in Wisconsin

Field cage feeding studies were conducted on birds foot trefoil, Lotus corniculatus L., in northern Wisconsin during 1986 to identify and quantify plant damage inflicted by three plant bug species: Adelphocoris lineolatus (Goeze), the alfalfa plant bug; Lygus lineolaris (Palisot de Beauvois), the tarnished plant bug; and Plagiognathus chrysanthemi (Wolff). Three experiments were conducted with each species caged separately (with trefoil stems) at one, two, or three individuals per cage during bud/flower and pod stages of plant development. Nymphs and adults of all three species commonly fed on or near the buds and flowers, resulting in a chlorotic appearance and shedding of these reproductive parts. Other types of damage included stem growth suppression, puckering and cupping of leaves, leaf margin necrosis, and shriveling of seeds. Nymphs of A. lineolatus, L. lineolaris , and P. chrysanthemi caused 82-99%, 63-91%, and 43-45% bud death compared with the check after being caged on the trefoil stems for 5 d. When caged for 6 d adults of A. lineolatus, L. lineolaris , and P. chrysanthemi caused 63-95%, 62-82%, and 43-53% bud death compared with the check. A. lineolatus adults caused shriveling of 49-68% of the developing trefoil seeds when caged for 13 d. Survival of nymphs was 37-60%, 45-70%, and 27-60% for A. lineolatus, L. lineolaris , and P. chrysanthemi on bud/flower-stage trefoil. Survival of adults was 60-70%, 80-90%, and 53-80% for A. lineolatus, L. lineolaris , and P. chrysanthemi on bud/flower-stage trefoil, and 68-82%, 47-49%, and 13-31 % on pod-stage trefoil. On a perinsect basis, A. lineolatus was most destructive to birds foot trefoil, followed by L. lineolaris , then P. chrysanthemi .

Effect of Spring Burning on Insects in Seed Alfalfa Fields

Burning of alfalfa (Medicago sativa (L.)) stubble in the spring reduced some pest insect populations in the year of the burn. Effects of the burn were dependent on the insect species and whether the alfalfa was burned before growth or at 20-25 cm of growth. Alfalfa plant bug (Adelphocoris lineolatus (Goeze)) populations were decreased by both burn treatments during the year of the burn. Lygus bug (Lygus spp.) populations were decreased for the year of the burn in plots burned before growth, but were not decreased when alfalfa was burned at 20-25 cm. Alfalfa weevil (Hypera postica (Gyllenhal)) and pea aphid (Acyrthosiphon pisum (Harris)) populations were reduced for the first year only when alfalfa was burned at 20-25 cm of growth. Burning had no effect on beneficial insect species in either year when alfalfa was burned before growth; however, burning at 20-25 cm of growth reduced populations of ladybird beetles for the first year and spiders for both years. Pirate bug (Orius tristicolor White) counts were correlated to lygus bug counts during most years. Overall, correlations between predator and prey insect counts were not consistent over years and burn treatments.

Control of Alfalfa and Tarnished Plant Bugs in Birdsfoot Trefoil, 1985

Abstract Plots were located at Badger and Roseau, MN in Roseau County. Plots were 25 ft × 50 ft, replicated 4 times, and arranged in a randomized complete block design. Applications were made at the onset of bloom (14 Jun) using a ground sprayer with a 12 ft boom. Application pressure was 50 psi with hollowcone nozzles and 25 gal total material per acre. Plan: bug counts were taken from 20 pendulum sweeps per plot. Numbers of nymphs and adults were totaled without regard to age or species.

Alfalfa Insect Control in Nebraska, 1986

Abstract This test was conducted at the University of Nebraska Agric. Res. & Develop. Center, Mead, NE in a second-year stand of ‘Ranger’ alfalfa. Plots were 9 x 15 ft, arranged in a randomized complete block design replicated 4 times. A single application of 6 insecticides at various rates, was made on 12 May ‘86. Insecticides were applied with a C02 activated pressure sprayer calibrated to deliver 12.5 gal/acre at 20 psi and equipped with a 5.5 foot boom. Each plot was sampled 3 times, 1, 2, and 3 weeks post-treatment, by taking 5 sweeps per plot with a 15-inch dia insect net. Pre-treatment counts, made on the day of treatment in the border area surrounding the plots, averaged 61.1 alfalfa weevil larvae, 49.2 pea aphids, 0.7 potato leafhopper adults, and 0.7 alfalfa plant bug adults per 5 sweeps.

Effects of Lygus borealis Kelton (Hemiptera: Miridae) and Adelphocoris lineolatus (Goeze) (Hemiptera: Miridae) Feeding on Sainfoin Seed Production

There was a highly significant negative linear correlation between seed production of sainfoin, Onobrychis viciifolia Scop., and population densities of Lygus borealis Kelton and Adelphocoris lineolatus (Goeze) during and after blooming. Insect population densities were reduced by applications of carbofuran at 0.28, 0.56, and 0.84 kg (AI)/ha during blossoming. Seed production was significantly increased by treatments of carbofuran during and after blooming.

Inexpensive Female-Baited Trap for the Tarnished Plant Bug (Hemiptera: Miridae)

A trap for Lygus lineolaris (Palisot de Beauvois) that uses live virgin female L. lineolaris as bait was developed. The adult females maintained viability and attractiveness in the field for at least 2 weeks without special attention. Males of Adelphocoris lineolatus (Goeze) and Stenotus binotatus (F.) were also captured in traps baited with L. lineolaris females.

Heteropterous insects collected by light traps in Edirne (Turkey).

This study deals with Heteropterous insects collected by light traps settled in the experimental fields of Plant Production Institute, Edirne, during 1978-1981. By this method, 128 species of 12 families of Heteroptera have been encountered. Sigara nigrolineata (Fieb.) (Corixidae); Perithrecus gracilicornis (Put.), P. angus­ ticoIlis (R.Sb.) (Lygaeidae); Exolygus pratensis (L.), E. rugulspennis (Popp.) , Adel­ phocoris lineolatus (Gz.) and Trigonotylus ruficornis (G.) (Miridae) have been found as the most abundant species.

Plant Bug (Heteroptera: Miridae) Damage to First-Crop Alfalfa in South Dakota1

Populations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), the pale legume bug, Lygus elisus Van Duzee, and the alfalfa plant bug, Adelphacoris lineolatus (Goeze), on first-crop alfalfa influenced hay quality and yields over two growing seasons at Brookings, S.D. Significant suppression of these species of plant bugs increased hay yields, total digestible nutrients, and digestible protein yields per ha in these tests.

ECONOMIC IMPORTANCE OF INSECTS ON REGROWTHS OF ESTABLISHED ALFALFA FIELDS IN ONTARIO

AbstractDamage caused by Empoasca fabae (Harris) and Philaenus spumarius (L.), caged on second and third alfalfa harvests, was additive. Numbers of E. fabae were linearly correlated negatively with plant height, leaf area, and percentage protein, and positively with percentage chlorosis. Perceptible stunting and yellowing occurred with mean infestations per stem of 0.09 E. fabae and 0.6 P. spumarius nymphs. P. spumarius adults reduced plant height only at infestations of 0.3/stem, while 0.6 nymph/stem also reduced dry weight. E. fabae reduced protein at 0.11/stem and dry weight and leaf area at higher populations of 0.17/stem. None of these parameters was affected on subsequent regrowths. Lygus lineolaris (P. de B.) could not be maintained on pre-bloom alfalfa and was not considered a pest. Adelphocoris lineolatus (Goeze) reduced protein at levels of 0.01 bug/stem and dry weight at 0.06 bug/stem but results were confounded by high mortality. Field populations of all these species were reduced by the second cutting but redeveloped on the regrowth. Although applications of dimethoate (200 g AI/ha) and dimethoate (200 g AI/ha) plus endosulphan (280 g AI/ha) were effective in reducing populations of E. fabae, Acyrthosiphon pisum (Harris), A. lineolatus, and Hypera postica (Gyllenhal), insecticides were cost-effective on only one field. This field had 1.9 E. fabae/sweep and a 3% loss in protein resulted. Plant height, density, dry weight, protein content, and overwintering survival were not significantly affected at harvest in other fields. With the exception of E. fabae, the sum of the maximum field populations, each expressed as a fraction of its threshold, did not reach 50% of an economic threshold.

Damage by the Tarnished Plant Bug and Alfalfa Plant Bug (Heteroptera: Miridae) to Asparagus1

Tip die-back symptoms are common in asparagus and could be the result of feeding by tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) or the alfalfa plant bug, Adelphocoris lineolatus (Goeze). Various levels of adults of each species were caged on greenhouse plants for 1 week and removed and the plants were observed for symptoms of tip die-back. Plants were sacrificed 2 months later and evaluated for fern growth and fern and root dry weights. Both tarnished plant bugs and alfalfa plant bugs were capable of causing tip die-back symptoms in asparagus. Although the possibility of long-term damage cannot be ruled out, plants apparently recovered readily from damage. Moderate levels of damage can apparently be tolerated, even by young plants, and the economic injury level for mature plants is probably quite high.

Insect Control on Seedling Alfalfa by Cultivars and Soil and Foliar Insecticides1

AbstractControl of insects on seedling alfalfa (Medicago sativa L.) is often desirable for stand establishment and forage production. The objective of these studies was to determine the use of cultivars and soil and foliar insecticides in controlling insects on seedling alfalfa. Three field studies were conducted on the use of preplant soil application of carbofuran (2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl methylcarbamate) in spring seedings on a Typic Arguidoll soil. The studies also included foliar application of carbofuran alone and in combination with soil application, and cultivars that varied, in resistance to insect species. Insecticide was applied at 1.1 kg a.i./ha.Neither soil nor foliar insecticide application increased forage yield, protein and carotene concentration of seedling alfalfa. Potato leafhopper [Empoasca fabae (Harris)], pea aphid [Acyrthosiphon pisum (Harris)], spotted alfalfa aphid [Therioaphis maculata (Buckton)], and plant bugs [Lygus lineolaris (Beauv.)] and [Adelphocoris lineolatus (Goeze)] were controlled by carbofuran.The pea aphid resistance of ‘Arc,’ ‘Baker,’ and ‘Perry’ and spotted alfalfa aphid resistance of Baker were effective in controlling aphid populations. ‘Buffalo,’ susceptible to potato leafhopper, pea aphid, and spotted alfalfa aphid, was lower than Arc, Baker, and Perry in forage yield, protein and carotene concentrations.No residual effects of soil insecticide application prior to seeding were apparent on insect numbers in the second and third cuttings.

Alfalfa Insect Control, 1981

Abstract Applications of registered and experimental insecticides were applied to second cutting alfalfa on the ISU Dairy Research Farm, Ames, IA. All treatments were applied to 4.7 x 12.2 m plots arranged in a randomized complete block design and replicated 3 times. Materials were broadcast using a back-pack sprayer equipped with Teejet 65015 tips at 30 psi pressure and 30 gal/acre. All treatments were applied on Jul 18. Treatments were evaluated by taking ten 180° sweeps using a 38.1 cm dia sweep net. Samples were taken pre-treatment and 1, 3 and 6 days post-treatment. Samples were bagged, returned to the laboratory where garden webworm, green cloverworm and alfalfa plant bug numbers were recorded.

Lygus Bugs: Crop Resistance and Physiological Nature of Feeding Injury

Plant bugs of the family Miridae are serious pests of seed, fruit, and nursery crops throughout the world. The genus Lygus Hahn has at least 9 species of major importance to agriculture in North America, Europe, and Asia (Kelton 1975). The bulk of this review will deal with these species, but where appropriate, reference will be made to the following additional species in the family Miridae: alfalfa plant bug, Adelophocoris lineolatus (Goeze); cotton fleahopper, Pseudatomoscelis seriatus (Reuter); Lygocoris pabulinus (L.), and Taylorilygus vosseleri Poppius. Whenever possible, papers dealing with crop resistance relationships of lygus bugs and related mirids are used for discussion.

Quantitative Estimation of Alfalfa Insect Populations by Removal Sweeping 1

Insect populations were estimated from the reduction in catches in successive sweep samples taken from the same area. A model is provided which assumes that the probability of collecting an insect may change with successive samples. This model seems superior to previous models which assume a constant probability for capture. Population estimates are compared with results of D-Vac samples. Removal sweeping provided good estimates of Lygus lineolaris (Palisot de Beauvois), Adelphocoris lineolatus (Goeze), Empoasca fabae (Harris), Macrosteles fascifrons (Stal), Nabis sp., grasshoppers, and Hippodamia convergens Guerin-Meneville larvae. H. convergens adults were reasonably estimated in one experiment but overestimated in another case due to immigration during sampling. Estimates for Orius insidiosus (Say), Hypera postica (Gyllenhal) larvae, and Aphidius sp. were unsatisfactory. General considerations involved in obtaining optimum estimates are discussed.

Combining Ability Effects for Resistance to Four Insects in Selected Alfalfa Clones1

Diallel cross progenies, including reciprocals, of six alfalfa (Medicago sativa L.) clones that differed in miridinduced leaf malformation and aphid resistance were studied to obtain estimates of combining ability effect for characters associated with resistance to the spotted alfalfa aphid (SAA), Therioaphis maculata Buckton; the peaaphid (PA), Acyrthosiphon pisum Harris; and two mirids: the alfalfa plant bug (APB), Adelphocoris lineolatus Goeze, and the tarnished plant bug (TPB), Lygus lineolaris Beauv. The responses to mirid feeding were measured in the field with controlled APB and TPB infestations under cages. Aphid tests were conducted on seedlings in the greenhouse. The hypothesis that the same genetic system controlled feeding by APB and TPB was supported by the absence of significant genotype ✕ mirid species interactions. Forage yield and stem length were reduced 5 and 20%, respectively, whereas percentages of dry matter were unchanged and protein percentages increased 4% due to mirid infestation. Resistance to mirid‐induced forage yield reduction and stunting was not found. Leaf malformation, a symptom of mirid feeding, appeared to be a highly heritable trait, but was not correlated with forage yield reduction, stunting, forage quality, or aphid resistance. General combining ability effects were far more important than specific combining ability effects among single crosses for forage yield, stem length, and leaf malformation under mirid infestation, and for PA and SAA resistance.