Agriculture

Research Publications In Field Crop Entomology -  2006

Summarized by: John Gavloski, Entomologist,  Manitoba Agriculture, Food and Rural Initiatives, Carman, Manitoba.

The following provides a summary of peer-reviewed research publications from 2006 relating to field crop entomology. Publications are grouped by commodity, with more general research categorized at the end of this document. Highlights from the research are noted and occasionally I have provided some of my own comments regarding applications of the research. Although the list may not be complete, articles were selected based on their relevance to farmers and agronomists in Manitoba.

Canola

Emergence of overwintered and new generation adults of the crucifer flea beetle, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae) Crop Protection. Vol. 25, Issue 1. January 2006. pp 23-30 B.J. Ulmer and L.M. Dosdall

Location of primary researchers / study site: University of Alberta, Edmonton

Highlights: Peak emergence occurred near the end of May, as mean ground temperature reached 15ºC. The highest number of flea beetles recorded from a single 1 m2 emergence cage was 3,736. Significantly more flea beetles emerged from sheltered locations than from open habitats; sheltered areas were predominantly shelterbelts and yard sites of Caragana and poplar trees.

Dissemination of Beauveria bassiana by Honey Bees (Hymenoptera: Apidae) for Control of Tarnished Plant Bug (Hemiptera: Miridae) on Canola M. S. Al Mazra'awi; J. L. Shipp; A. B. Broadbent; P. G. Kevan Environmental Entomology, Vol. 35, No. 6, December 2006. pp 1569-1577 Location of primary researchers / study site: Ontario: Harrow, London and Guelph.

Highlights: Bees effectively vectored the fungus from the hive to the crop. The fungus was recovered on 47-83% of lygus bugs recovered.

My comments: Although the rates of control from this fungus were lower than could be expected with insecticides, if biological insecticides are eventually registered for the control of insects in canola, this could prove to be an added benefit to locating beehives near canola fields.

Pollinators provide economic incentive to preserve natural land in agroecosystems Agriculture, Ecosystems and Environment. Volume 116. Issues 3-4. September 2006. pp 289-292 Lora A. Morandin and Mark L. Winston Location of primary researchers / study site: Simon Fraser University, British Columbia

Highlights: Bee abundance was greatest in canola fields that had uncultivated land within 750 m of field edge, and seed set was greater in fields with higher bee abundance. A cost-benefit model that estimates the profit of canola agroecosystems with different proportions of uncultivated land found that profit could be maximized with 30% of land uncultivated within 750 m of field edges.

My comments: This demonstrates that leaving some uncultivated land on farms may have economic benefits beyond providing refuge for wildlife.

Effects of Fall and Spring Seeding Date and Other Agronomic Factors on Infestations of Root Maggots, Delia spp. (Diptera: Anthomyiidae), in Canola L. M. Dosdall; G. W. Clayton; K. N. Harker; J. T. O'Donovan; F. C. Stevenson Journal of Economic Entomology, Vol. 99, No. 5, October 2006 pp 1665-1674. Location of primary researchers / study site: Alberta: Vegreville, Fort Saskatchewan, Lacombe and Beaverlodge.

Highlights: Root maggot damage declined with an increase in seeding rate for plots seeded in May but not in fall or April. Seeding date has no significant effect on root maggot damage.

Size doesn’t matter: The effects of seed size and seeding rate on injury by root maggots (Delia spp., Diptera: Anthomyiidae) to canola (Brassica rapa L. and B. napus L.) J J Soroka, R H Elliott Canadian Journal of Plant Science. Vol. 86, No. 3, July 2006. pp 907-909. Location of primary researchers / study site: Saskatchewan: Saskatoon and Melfort 

Highlights: Seed size had no effect on feeding level by root maggots feeding on canola.

Using Degree-Day and Logistic Models to Predict Emergence Patterns and Seasonal Flights of the Cabbage Maggot and Seed Corn Maggot (Diptera: Anthomyiidae) in Canola Jim S. Broatch; Lloyd M. Dosdall; George W. Clayton; K. Neil Harker; Rong-Cai Yang Environmental Entomology, Vol. 35, No. 5, October 2006. pp 1166-1177. Location of primary researchers / study site: Lacombe, Alberta

Highlights: In western Canada, maximum flight activity of seed corn maggot will occur in early June, about 2 weeks before that of the cabbage maggot. Primary damage to canola taproots  by larvae of the cabbage maggot seems to precede invasion by seed corn maggot, which causes secondary damage. 

Diamondback moth–host plant interactions: Implications for pest management M. Sarfraz, L.M. Dosdall and B.A. Keddie

Crop Protection. Vol. 25, Issue 7. July 2006. pp 625-639. Location of primary researchers / study site: University of Alberta, Edmonton.

Highlights: In this review article, the authors present information on certain biochemical and morphological characteristics that have been investigated to promote resistance to diamondback moth in cruciferous crops.

Note: Although cabbage seedpod weevil has not been detected in Manitoba to date, the following publications may still be of interest to farmers and agronomists concerned with this insect in canola.

Spring Emergence Biology of the Cabbage Seedpod Weevil (Coleoptera: Curculionidae) B. J. Ulmer; L. M. Dosdall Annals of the Entomological Society of America, Vol. 99, No. 1, January 2006 pp 64-69. Location of primary researchers / study site: Research conducted near Lethbridge, Alberta.

Highlights: Peak emergence of cabbage seedpod weevil occurred as mean ground temperature (5 cm in depth) reached 15ºC. Significantly more weevils emerged from sheltered  and intermediately sheltered locations than from open grassy habitats; sheltered areas were predominantly shelterbelts and yard sites of caragana and poplar trees. Significantly more males than females emerged early in the season, although during peak emergence there was no difference in sex ratio; and after peak emergence, significantly more females than males emerged.

Glucosinolate profile and oviposition behavior in relation to the susceptibilities of Brassicaceae to the cabbage seedpod weevil. B.J. Ulmer and L.M. Dosdall. Entomologia Experimentalis et Applicata. Volume 121. Issue. 3. December 2006. pp 203-213. Location of primary researchers / study site: University of Alberta, Edmonton

Highlights: Feeding, egg laying preference and behavior, and larval development of the cabbage seedpod weevil were investigated on eight Brassicaceae species that differed in their glucosinolate profiles. The least preferred host plants for feeding and egg laying were Sinapis alba lines, while the Brassica carinata lines were most preferred. Larval development occurred most rapidly on Brassica rapa, and lowest on S. alba. Females explored pods of S. alba and B. nigra, but rarely laid eggs on these species.

Sunflowers

Effects of Honey Bee (Hymenoptera: Apidae) Foraging on Seed Set in Self-fertile Sunflowers (Helianthus annuus L.) Gloria Degrandi-Hoffman; Mona Chambers Environmental Entomology, Vol. 35, No. 4, August 2006 pp.1103-1108. Location of primary researchers / study site: Arizona

Highlights: A majority of self-fertile sunflower cultivars had significantly greater seed set when capitula were exposed to bees compared with when they were not. The weight of seeds from open-pollinated capitula was greater than from those where bees were excluded. Under high temperature conditions some cultivars set four times more seed on open-pollinated capitula compared to those that were bagged. Foraging activity and cross-pollination by bees might mitigate reductions in seed set caused by high temperatures.

My comments: This reinforces the message we have been trying to extend to sunflower growers, and agronomists scouting sunflowers, that the activity of bees can have real economic value to sunflowers. Thus decisions on whether and how to treat flowering sunflowers to control pest insects need to be made very carefully. If economic thresholds for pests are exceeded, it is in the economic interest of sunflower growers to minimize harm to bees.

Intercropping sunflower in organic vegetables to augment bird predators of arthropods Gregory A. Jones and Kathryn E. Sieving Agriculture, Ecosystems and Environment. Volume 117. Issues 2-3. November 2006. pp 171-177. Location of primary researchers / study site: University of Florida

Highlights: Cropped areas with sunflower treatments of one or two rows per 0.4 ha exhibited significantly greater mean abundance of insectivorous birds than did control plots, across a variety of crops. The addition of sunflower intercrops proved to be an effective habitat modification for augmenting avian insectivore numbers and insect-foraging time in organic vegetables.

Small Grain Cereals

Resistance to Hessian fly (Diptera: Cecidomyiidae) in a Canadian spring wheat cultivar I.L. Wise, R.J. Lamb, R.I.H. McKenzie, J.W. Whistlecraft The Canadian Entomologist. Vol. 138, No. 5, Sept./Oct. 2006. pp 638-646. Location of primary researchers / study site: Winnipeg, Manitoba and London, Ontario

Highlights: The spring wheat cultivar “Superb” has partial antibiosis and tolerance to Hessian fly, which is sufficient to reduce losses by 65% in comparison with a susceptible cultivar such as “AC Barrie”.

Corn

Impact of Trap Design, Windbreaks, and Weather on Captures of European Corn Borer (Lepidoptera: Crambidae) in Pheromone-Baited Traps Brendon J. Reardon; Douglas V. Sumerford; Thomas W. Sappington Journal of Economic Entomology, Vol. 99, No. 6, December 2006. pp.2002-2009. Location of primary researchers / study site: Iowa State University

Highlights: Trap design affected trap catch. Under strong (>14 kph) or moderate (7<14 kph) wind speeds, traps located leeward of windbreaks captured the most moths; when wind speeds were light (<7 kph), traps not associated with windbreaks caught the most moths. The higher the nightly mean air temperature the more moths would be caught in the traps.

My comments: Whenever pheromone-baited traps are used to monitor insects, we need to consider that environmental factors, as well as landscape factors, will affect trap catches.

Effects of Living Mulches on Predator Abundance and Sentinel Prey in a Corn-Soybean-Forage Rotation J. R. Prasifka; N. P. Schmidt; K. A. Kohler; M. E. O'neal; R. L. Hellmich; J. W. Singer Environmental Entomology, Vol. 35, No. 5, October 2006 pp.1423-1431. Location of primary researchers / study site: Iowa State University

Highlights: Living mulches are cover crops grown concurrently within main crops, usually for their benefits to weed control and soil quality. Compared with a no-mulch control, the presence of alfalfa and kura clover mulches in corn and soybean increased the abundance of ground-dwelling predators, and consumption of European corn borer pupae used as sentinel prey.

Soybeans

Characterization of Antibiosis and Antixenosis to the Soybean Aphid (Hemiptera: Aphididae) in Several Soybean Genotypes John Diaz-Montano; John C. Reese; William T. Schapaugh; Leslie R. Campbell. Journal of Economic Entomology, Vol. 99, No. 5, October 2006 pp.1884-1889. Location of primary researchers / study site: Kansas State University

Highlights: Reproduction of the soybean aphid was compared on 240 soybean entries. Eleven entries has fewer nymphs produced compared to the susceptible checks; of these 11 entries nine showed a moderate antibiotic effect to soybean aphids, and the other two entries showed not only a strong antibiotic effect but were also less preferred.

Sex Pheromone of the Soybean Aphid, Aphis glycines Matsumura, and Its Potential Use in Semiochemical-Based Control Junwei Zhu; Aijun Zhang; Kye-chung Park; Tom Baker; Brian Lang; Russell Jurenka; John J. Obrycki; William R. Graves; J. A. Pickett; D. Smiley; Kamlesh R. Chauhan; Jerome A. Klun Environmental Entomology, Vol. 35, No. 2, April 2006 pp.249-257 Location of primary researchers / study site: Iowa  

Highlights: In autumn, soybean aphids start producing winged females that search for their overwintering host plant, the common buckthorn. These winged females then produce pheromone-emitting wingless female offspring that attract male aphids. This study reports the chemical identification of the soybean aphid sex pheromone.

Influence of Potassium Fertility on Soybean Aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), Population Dynamics at a Field and Regional Scale Scott W. Myers; Claudio Gratton Environmental Entomology, Vol. 35, No. 2, April 2006 pp.219-227. Location of primary researchers / study site: University of Wisconsin

Highlights: Populations of soybean aphids had significantly higher peak abundance and rate of increase in the low potassium treatment compared with medium and high potassium treatments.

Suppression of Population Growth of the Soybean Aphid, Aphis glycines Matsumura, by Predators: The Identification of a Key Predator and the Effects of Prey Dispersion, Predator Abundance, and Temperature Nicolas Desneux; Robert J. O'neil; Ho Jung S. Yoo. Environmental Entomology, Vol. 35, No. 5, October 2006 pp.1342-1349. Location of primary researchers / study site: Purdue University, Indiana.

Highlights: Orius insidiosus, a species of minute pirate bug, can be one of the more abundant predators feeding on soybean aphids. When soybean aphids are distributed in a clumped manner, increases in O. insidiosis resulted in lower aphid growth rates.

Defensive Response of Soybean Aphid (Hemiptera: Aphididae) to Predation by Insidious Flower Bug (Hemiptera: Anthocoridae) Casey D. Butler; Robert J. O'Neil Annals of the Entomological Society of America, Vol. 99, No. 2, March 2006 pp.317-320 Location of primary researchers / study site: Purdue University, Indiana.

Highlights: The mouthparts of some minute pirate bugs, Orius insidiosus, which had been fed soybean aphids, were covered with a substance excreted from the cornicles of attacked aphids. The cornicle exudate was capable of causing death because of molting failure and starvation. First instar minute pirate bugs were most severely affected. The exudate from the cornicles does not seem to compromise the survival of the soybean aphids. The exudate also seems to contain an alarm pheromone.

Stored Grains

Effect of Pisum sativum fractions on the mortality and progeny production of nine stored-grain beetles Paul G. Fields Journal of Stored Products Research. Vol. 42, Issue 1. 2006. pp 86-96. Location of primary researchers / study site: Winnipeg, Manitoba

Highlights: The toxicity of yellow field pea fractions (either protein, fibre or starch), when mixed with wheat kernels or wheat flour, was tested against several insects that feed on stored grain. The protein treatment was more toxic than the fiber, which was more toxic than the starch. The insecticidal activity of pea fractions decreased after treated wheat kernels were held at 30ºC, 70% r.h. for 8 months.

Simple technique to increase the sensitivity of probe traps in detecting Cryptolestes ferrugineus (Coleoptera: Laemophloeidae) in stored wheat S. Mohan, S.S. Sivakumar, S.R. Venkatesh, G.S.V. Raghavan. The Canadian Entomologist. Vol. 138, No. 5, Sept./Oct. 2006. pp 733-735. Location of primary researchers / study site: McGill University, Quebec.

Highlights: Probe traps in wheat treated with protein-enriched pea flour caught more rusty grain beetles than traps placed in untreated wheat.

Economic Thresholds

Integrating Biological and Chemical Controls in Decision Making: European Corn Borer (Lepidoptera: Crambidae) Control in Sweet Corn as an Example Fred R. Musser; Jan P. Nyrop; Anthony M. Shelton. Journal of Economic Entomology, Vol. 99, No. 5, October 2006 pp.1538-1549. Location of primary researchers / study site: Mississippi State University, and Cornell University, NY

Highlights: Current economic thresholds do not consider the role of natural enemies in regulating pest populations. Considering the potential impact of natural enemies would lead to dynamic economic thresholds that vary for different insecticides based on the level of natural enemy activity remaining after the insecticide application.

Pesticide Residues

Ambient air concentrations of pesticides used in potato cultivation in Prince Edward Island, Canada. L.M.White, E. William, G. Julian, C. Garron and L. Martin. Pest Management Science. Volume 62. Number 2. February 2006. pp. 126-136. Location of primary researchers / study site: Environment Canada (Nova Scotia and New Brunswick) and Ecosystem Research (Nova Scotia). Samples taken on P.E.I.

Highlights: Ambient air concentrations of nine pesticides used in potato cultivation were investigated on Prince Edward Island in 1998 and 1999 by collecting samples at potato farm sites and one non-agricultural site. The fungicide chlorothalonil was detected in every sample. The ubiquitous presence in air of relatively high concentrations of chlorothalonil in agricultural areas on Prince Edward Island is likely related to its repeated use on potato farms where fungicides account for 80-90% of pesticides applied. Eight of the nine pesticides were detected at farm sites in 1998. Five pesticides were detected at the Summerside farm in 1999, but only two fungicides (chlorothalonil and metalaxyl) were used locally, while the presence of metribuzin, ą-endosulfan and methamidophos in air was not associated with local application. Evidence of pesticide drift was observed for chlorothalonil, ą-endosulfan and methamidophos, and these pesticides were identified as being of high concern in terms of potential wildlife exposure on the Island.

Beneficial Insects And Insecticides

A Survey of Pesticide Residues in Pollen Loads Collected by Honey Bees in France Marie-Pierre Chauzat; Jean-Paul Faucon; Anne-Claire Martel; Julie Lachaize; Nicolas Cougoule; Michel Aubert. Journal of Economic Entomology, Vol. 99, No. 2, April 2006 pp.253-262. Location of primary researchers / study site: France

Highlights: This study in France demonstrated the presence of a wide range of pesticides in pollen loads collected by honey bees. These pesticides were found at various concentrations from trace amounts to hundreds of micrograms per kilogram.

My comments: Often it is just the kill of bees foraging in the crop that is of immediate concern when crops that are flowering are sprayed with insecticides. But even if the bees survive the insecticide application, pesticide residues can be brought back to the hive through the pollen and nectar the bees collect. Where possible and practical it is preferred that pesticides are not applied to crops in flower.

Ground Beetle (Coleoptera: Carabidae) Assemblages in Organic, No-Till, and Chisel-Till Cropping Systems in Maryland Sean Clark; Katalin Szlavecz; Michel A. Cavigelli; Foster Purrington. Environmental Entomology, Vol. 35, No. 5, October 2006 pp.1304-1312. Location of primary researchers / study site: Maryland

Highlights: In 2002, ground beetle relative abundance, species richness, and species diversity were greater in the organic than in the chisel-till system. Similar trends were found in 2001, but no significant differences were found in these measurements. Relatively few differences were found between the no-till and chisel-till systems.

Growth and Survival of Monarch Butterflies (Lepidoptera: Danaidae) After Exposure to Permethrin Barrier Treatments K. S. Oberhauser; S. J. Brinda; S. Weaver; R. D. Moon; S. A. Manweiler; N. Read. Environmental Entomology, Vol. 35, No. 6, December 2006 pp.1626-1634. Location of primary researchers / study site: Minnesota

Highlights: Monarch butterfly larvae and adults are likely to be killed if exposed to residues of permethrin after barrier treatments for mosquito control. Extent of mortality will depend, among other things, on the proportion of host plants that are treated in a given area.

General Entomology

Effect of temperature and soil on the control of a wireworm, Agriotes obscurus L. (Coleoptera: Elateridae) by flooding Crop Protection. Volume 25, Issue 9. September 2006. pp 1057-1061. W.G. van Herk and R.S. Vernon. Location of primary researchers / study site: British Columbia

Highlights:  Wireworms submerged at high temperatures died more quickly than those submerged at low temperatures, and wireworms in flooded Delta soil died more quickly than those in flooded Agassiz soil.

Analysis of grasshopper (Orthoptera: Acrididae) population surveys in Saskatchewan: 1972–2004 O. Olfert, D. Giffen, S. Hartley. The Canadian Entomologist. Vol. 138, No. 5, Sept./Oct. 2006  pp 875-887. Location of primary researchers / study site: Saskatchewan

Highlights: Eco-districts most at risk of crop damage by grasshoppers within each of the four major Eco-regions of Saskatchewan were identified. Risk was highest in five eco-districts of the Mixed Grasslands Eco-region.

Post-dispersal weed seed predation by invertebrates in conventional and low-external-input crop rotation systems Megan E. O’Rourke, Andrew H. Heggenstaller, Matt Liebman and Marlin E. Rice Agriculture, Ecosystems and Environment. Vol. 113. Issues 1-4. April 2006. pp 280-288. Location of primary researchers / study site: Iowa

Highlights: Crop type, rather than management practices within a specific crop, had the greatest influence on the activity-density of invertebrates that feed on weed seeds. The most abundant consumer of weed seeds was Gryllus pennsylvanicus, a common field cricket.  Invertebrates consumed less than 30% of seeds in July, early-August and early-October, but as much as 80-90% of seeds in late-August and September in corn and soybeans in the study.

The Economic Value of Ecological Services Provided by Insects. John E. Losey and Mace Vaughan.

BioScience. Volume 56, Issue 4. April 2006. pp 311-323. Location of primary researchers / study site: Cornell University, NY.

Highlights: The ecological services provided by “wild” insects, not including services from domesticated or mass-reared insect species, were estimated. The four insect services for which estimates were provided include dung burial, pest control, pollination, and wildlife nutrition. Estimations of each of these services were based on projections of losses that would accrue if insects were not functioning at their current level. The annual value of these ecological services in the United States was estimated to be $57 billion. In addition to the value of ecological services by wild insects estimated here, other potentially important services that insects provide could not be quantified, including suppression of weeds and exotic herbivorous species, facilitation of dead plant and animal decomposition, and improvement of the soil.

My comments: Attempts to quantify the benefits of insects can serve many purposes. In agriculture, it is important to realize that although we often focus on insects that can potentially be pests, there are many species of insects on every farm that are producing valuable services. When pest insects get to levels where control is determined to be economical, it may be in the best economic interest of farmers, where practical, to consider management strategies that minimize harm to those insects providing beneficial services on the farm.  

Climate And Insects

Impact of climate change on potential distributions and relative abundances of Oulema melanopus, Meligethes viridescens and Ceutorhynchus obstrictus in Canada O. Olfert and R.M. Weiss. Agriculture, Ecosystems and Environment. Volume 113. Issues 1-4. April 2006. pp 295-301. Location of primary researchers / study site: Analysis performed at Saskatoon, Saskatchewan.

Highlights: The models that were developed indicate that cabbage seedpod weevil, cereal leaf beetle, and pollen beetles would all have increased ranges and relative abundances for temperature increases between 1 and 7ºC. Risks associated with these species will likely become more intense, both in terms of severity in regions where these species presently occur and in terms of their ability to become established in areas they do not occur.

Effects of High and Fluctuating Temperatures on Myzus persicae (Hemiptera: Aphididae)  J. A. Davis; E. B. Radcliffe; D. W. Ragsdale. Environmental Entomology, Vol. 35, No. 6, December 2006 pp.1461-1468. Location of primary researchers / study site: Minnesota and North Dakota.

Highlights: Optimum temperature for green peach aphid population growth was 26.7ºC. The lower and upper development thresholds were 6.5 and 37.3ºC respectively. Under optimal conditions, population doubling time was 1.95 d. In midwestern North America, green peach aphid would benefit from an increase in mean summer temperature (20ºC) of 2.5-3.5ºC.