Pest Of Vegetable Crops Research Articles

A note on the detection of the carrot weevil in Nova Scotia

The carrot weevil, Listronotus oregonensis [Coleoptera: Curculionidae], is a significant pest of vegetable crops in northeastern North America. However, the species had not been previously detected in Atlantic Canada. In 1985,1986, and 1988, attempts to detect this pest in Nova Scotia were unsuccessful. In 1992, in one of three carrot (Daucus carota) fields monitored using thigmotactic wooden-plate traps baited with fresh carrots, six individuals were captured during the spring migration of the inseetfrom overwintering sites into a carrot field near Great Village, Nova Scotia.

Toxicity of chemicals commonly used in Indonesian vegetable crops to Liriomyza huidobrensis populations and the Indonesian parasitoids Hemiptarsenus varicornis, Opius sp., and Gronotoma micromorpha, as well as the Australian parasitoids Hemiptarsenus varicornis and Diglyphus isaea.

Liriomyza huidobrensis (Blanchard) and Liriomyza sativae (Blanchard) are important pests of vegetable crops in Indonesia and are likely to spread to neighboring countries. Three pesticides (dimehypo, abamectin, and cyromazine) are currently used to control these pests, but there is little information on their effectiveness against field populations and on their impact on parasitoids controlling Liriomyza species. The toxicity of these chemicals to L. huidobrensis and three common parasitoids (Hemiptarsenus varicornis Gerault, Opius sp., and Gronotoma micromorpha Perkins) was therefore evaluated in Indonesia with mortality laboratory assays. All three chemicals were effective against larvae of three populations of L. huidobrensis with different histories of chemical exposure. Dimehypo caused mortality in adult Opius sp., G. micromorpha, and H. varicornis, whereas abamectin was toxic only at concentrations substantially higher than the field rate. Cyromazine did not influence survival of the parasitoids. A commonly used fungicide, mancozeb, had no impact on parasitoid mortality. Trials were repeated with a strain of H. varicornis from Australia and a different parasitoid (Diglyphus isaea) recently found in Australia. Neither parasitoid was influenced by mancozeb or cyromazine. Abamectin applied at field rates caused some mortality among the adults of both species, but was less toxic than chlorpyrifos. Abamectin produced lower LC50s against Australian H. varicornis than against Indonesian H. varicornis. These results suggest that cyromazine can be incorporated into Liriomyza control programs in Indonesia that conserve parasitoids, whereas dimehypo and abamectin need to be used cautiously. Local Australian parasitoids should help control L. huidobrensis as long as only cyromazine and nontoxic fungicides are applied.

Fusarium Fruit Rot of Greenhouse Sweet Peppers in Canada.

In the summer of 2001, a fruit rot of orange sweet peppers (Capsicum annum L. cv. Sympathy MZ) was observed in commercial greenhouses in British Columbia, Canada. According to the grower's estimate, approximately 40% of fruits in the commercial greenhouse were severely affected in the year 2001 and approximately 10% in 2002. The disease appeared on mature fruits at harvest time, and affected fruits are considered as culls. The disease appeared as discolored soft patches or necrotic spots predominantly at the calyx end and occasionally, anywhere on the mature fruit at harvest time. Seeds and the surrounding area inside the fruits were covered with fungal growth and orange-pink spore masses. Five fungal isolations were made from the lesions. Infected tissues from the edge of lesions were surface sterilized in 1% sodium hypochlorite for 2 min, blotted dry on sterile filter paper, and cultured on potato dextrose agar (PDA). Plates were incubated at 22°C for 7 days. Single spore fungal colonies isolated from the tissues yielded Fusarium sp. Only one fungal species was consistently isolated from affected pepper fruits. Morphology of the fungus was consistent with Fusarium subglutinans (Wollenweber & Reinking) Nelson et al. according to Keith Seifert of Eastern Cereal and Oilseed Research Centre, Ottawa, Canada. Molecular tests are being developed to confirm the identification of the fungus. To confirm pathogenicity, 10 flowers and developing fruits of sweet pepper cv. Sympathy MZ grown in a greenhouse were inoculated with the pathogen. For inoculation, 20 μl of spore suspension of the fungus (concentration 106 spores/ml) was drop-inoculated on the wounded and unwounded surfaces of fruits. To inoculate flowers, a spore suspension was drop-inoculated in the middle of flowers without any wounding. Controls were treated with 20 μl of sterile water. The experiment was repeated once. Approximately 80% of inoculated fruits and flowers developed symptoms on fruits similar to naturally infected fruits at maturity. Fruits from control plants did not develop any disease. On PDA, a Fusarium species identical to the original one was recovered from all inoculated infected fruits. A preliminary study showed that this pathogen does not infect other greenhouse crops such as tomato, cucumber, or lettuce. Sweet pepper stem and fruit rot caused by Fusarium solan has been reported previously (1) but there is no report of fruit rot caused by a Fusarium subglutinans-like species on greenhouse sweet peppers. Reference: (1) J. G. Menzies and W. R. Jarvis. Fusarium stem and fruit rot. Pages 333-334 in: Diseases and Pests of Vegetable Crops in Canada. R. J. Howard et al. eds. The Canadian Phytopathological Society and Entomological Society of Canada, 1994.

Multiplex Detection of Criniviruses Associated with Epidemics of a Yellowing Disease of Tomato in Greece.

Since 1997, a yellowing disease has been observed in greenhouse tomato (Lycopersicon escu-lentum). By 2001, the disease was widespread, including open field tomato crops, and in most cases its incidence was 80 to 90% or even 100%. Epidemics in glasshouses were mainly associated with high populations of the whitefly Trialeurodes vaporariorum and Bemisia tabaci, the major whitefly pests in vegetable crops in Greece. The main leaf symptoms were severe yellowing, rolling, and brittleness. Samples from symptomatic plants were analyzed by polymerase chain reaction (PCR) and shown to be infected with Tomato infectious chlorosis virus (TICV) and Tomato chlorosis virus (ToCV) (family Closteroviridae, genus Crinivirus). TICV was found in 164 of 183 symptomatic samples, while ToCV was less representative (25/183). Sequence comparisons of the amplified 229-bp and 466-bp products revealed 99 and 100% identity with the reported sequences of TICV and ToCV, respectively. A reverse transcription (RT) multiplex PCR assay using a simple sample preparation procedure was developed to allow rapid, specific, and simultaneous detection of both ToCV and TICV sequences in two steps. The method involves a one-tube RT-PCR step in which the combination of primers amplifies part of the heat shock protein to homologue gene of both ToCV and TICV, followed by a multiplex nested PCR amplification. This is the first report of TICV and ToCV in Greece and, as far as we know, the first report of TICV in Europe.

Effect of cover crops and tillage system on symphylan (Symphlya: Scutigerella immaculata, Newport) and Pergamasus quisquiliarum Canestrini (Acari: Mesostigmata) populations, and other soil organisms in agricultural soils

The garden symphylan ( Scutigerella immaculata: Newport) is a common myriapod soil pest of vegetable crops in the Pacific Northwest and other regions of the US. Symphylans consume germinating seeds, plant roots, and above-ground plant parts in contact with the soil. Factors regulating symphylan populations in agricultural soil systems are poorly understood, particularly the effects of farming practices such as cover cropping and reduced-tillage. Cover crops were planted in the fall of 1994 through 1996 and either incorporated into the soil in the spring with tillage or killed with glyphosate and the residue left on the soil surface. Fewer symphylans were recovered with Berlese funnels from soil under cereal cover crops than soil in mustard cover crops, regardless of tillage system. Fewer symphylans were recovered from soil under the spring oat cover crop than soil under the barley cover crop. Eliminating spring tillage may have increased symphylan populations but the effect of reduced tillage on symphylan populations was less important than cover cropping. Predaceous mites were more abundant in soil under large amounts of cover crop residue but these predators were not correlated with lower populations of symphylans. Spring tillage dramatically reduced populations of Pergamasus quisquiliarum, a known predator of symphylans. Cover crops increased both the ratio of predaceous mites to symphylans and the total population of potential prey, thereby, reducing the capacity of predaceous mites to regulate symphylan populations.

Life table and biological characteristics of Macrolophus pygmaeus when feeding on Myzus persicae and Trialeurodes vaporariorum

AbstractThe life table and biological characteristics of the predatory bug Macrolophus pygmaeus Rambur (Hemiptera: Miridae) were studied when the bugs were fed with Myzus persicae (Sulzer) (Homoptera: Aphididae) feeding on eggplant and with Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae) feeding on tomato plants. The tests were done at five temperatures between 15 and 30 °C, using a L16:D8 photoperiod and 65 ± 5% r.h. Most eggs (range 85 to 90%) hatched at 15 and 20 °C. Incubation period was shortest at 27.5 °C (8.45 and 8.38 days on eggplant and tomato, respectively). Preoviposition was also shortest at 27.5 °C (5.10 and 4.75 days on eggplant and tomato, respectively) whereas fecundity was highest at 20 °C (213.90 and 228.25 eggs on eggplant and tomato, respectively). Maximum longevity of females was at 15 °C (122.40 and 129.35 days on eggplant and tomato, respectively). Mean generation time was longest at 15 °C on both host plants (122.75 and 124.64 days, respectively). The intrinsic rate of increase of M. pygmaeus was highest at 27.5 °C with similar values on eggplant (0.0981 day−1) and tomato (0.1040 day−1). Doubling time was shortest at 27.5 °C (7.06 and 6.67 days on eggplant and tomato, respectively) and, also, finite rate of increase was highest at 27.5 °C (1.1031 and 1.1096 on eggplant and tomato, respectively). The results show that the predator M. pygmaeus develops well on the aphid M. persicae or on the whitefly T. vaporariorum, both of which are important pests of vegetable crops. This predator is also well adapted to the temperatures that occur both in greenhouses and in the open field in the Mediterranean region. Compared to other natural enemies of whiteflies, such as Encarsia formosa Gahan (Hymenoptera: Aphelinidae), Macrolophus pygmaeus can increase at relatively low temperatures.

Spatial Mapping of Adult Corn Earworm and European Corn Borer Populations in New Jersey

In 1998, Rutgers Cooperative Extension (RCE) and the Grant F. Walton Center for Remote Sensing and Spatial Analysis (CRSSA) at Rutgers University began a joint program to use global positioning system (GPS) and geographic information systems (GIS) technologies to map the spatial distribution of corn earworm (Helicoverpa zea Boddie (Lepidoptera:Noctuidae)) and European corn borer (Ostrinia nubilalis Hübner (Lepidoptera:Pyralidae)). In 1999 the Rutgers Cooperative Extension Vegetable Integrated Pest Management (IPM) Program operated a network of 81 blacklight insect survey traps in New Jersey. These 15 W blacklight traps were used to monitor adult populations of vegetable crop pests including corn earworm and European corn borer. All blacklight trap sites were mapped using a hand held GPS unit. Average daily corn borer population data were imported into a GIS software package, and then linked to corresponding mapped locations throughout New Jersey. State wide spatial distributions of adult corn earworm and European corn borer population data were imported into a GIS software package, and then linked to corresponding mapped locations throughout New Jersey. State wide spatial distributions of adult corn earworm and European corn borer populations were produced weekly, and distributed via extension newsletters and web sites to augment the current RCE IPM outreach program.

Incidence and Control of Insect Pests of Vegetable Crops on Jos Plateau, Northern Nigeria

A study on the insects associated with green beans, okra, peas and cabbages was carried out at Vom and Riyom Agricultural Stations in Jos, Nigeria from October, 1980 to April; 1984. During the study period, a wide range of insects were found in association with green beans and okra plants. Sericothrips occipitalis, Empoasca spp., Aphis craccivora, Zonocerus variegatus and Bemisia tabaci were found on pea, green beans and okra plants while Myzus persicae and Brevicoryne brassicae were common on cabbage plants. Early infestation of okra and cabbage by Podagrica spp. and Brevicoryne brassicae respectively within the first three weeks after sowing, resulted in poor plant performance and low yield. Insecticide treatments reduced insect population on the treated plants and enhanced yield. In this study, insecticide treatments and the treatment of using ordinary water to hand wash aphids from cabbage plants bi-weekly, reduced aphid population on plants and increased crop yield. The number of insects on different experimental plants treated with Dichlorvos at 500, 750 and 1000g a.i/ha; pennethrin at 12.5g a.i/ha; deltamethrin at 7.5, 10.5, 12.5 and 17.5g a.i/ha, cypennethrin at 12.5g a.i/ha; carbofuran 3g at 100g a.i/ha was less than those on untreated plants.

Vegetable crop pests

Vegetable crop pests

Sub-chronic toxicity of methyl benzimidazole carbamate in rats.

Methyl benzimidazole carbamate (MBC) is a broad spectrum systemic fungicide effectively used against a wide variety of pests of vegetable crops and fruit orchards. On seed treatment MBC was found to be actively absorbed by the seedlings and transported to aerial parts. The residual activity of the chemical on various parts of vegetable and food crops was reported to vary from 3.5 to 6.3 ppm persisting from 15 days to 45 days in different parts of the plant. However, WHO has recommended the desirability of conducting short-term and long-term toxicity studies of this fungicide in mammals. Subsequent studies revealed its embryotoxic potential in rats and rabbits. This paper gives the results of sub-chronic administration of MBC in rats designed to assay the possible toxicity to vital organs like the haemopoetic system, liver and kidneys.

Photolysis of phoxim on glass and on tomato leaves.

Phoxlm (phenylglyoxylonltrile oxlme O,0-diethylphosphorothloate; volaton) is an organophosphorus insecticide with a broad spectrum of effectiveness as a contact and stomach poison (~K&RRIS 1970, HARRIS & SVEC 1970, JUDA & McE~ZN 1970, HOH~F/~ 1975). It Ims a short residual life in soil (HARRIS 1970, DRAGh~ 197V) and on forage corn and ~ass plants (BOWMAN & LEUCK 1971). Phoxim is widely used in Egypt to oontrol several vegetable crop pests. The ~9urpose of the present study was to investigate the effects of heat and light on the stability of this compound. Also, the decline of the lusecticide residue on and in treated tomato plants was investigated to determine the span of time v~Ich should lapse between spraylng and safe marketing of treated plants under local environmental couditlons.

Rational control of vegetable crop pests

Rational control of vegetable crop pests

Wireworm Control on Sweet Corn in Organic Soils

The southern potato wireworm, Conoderus falli Lane, and the corn wireworm, Melanotus communis (Gyllenhal), are important vegetable crop pests in organic soils of the Everglades. Sweet corn is one of the crops most susceptible to damage by either of these wireworms. The southern potato wireworm has developed resistance to chlorinated hydrocarbon insecticides in Florida (Workman 1963) and in South Carolina (Reid and Cuthbert 1956). However, it is usually adequately controlled by any one of several phosphatic insecticides. The corn wireworm has been the more difficult species to control in the organic soils of the Everglades. Soil insect control is usually more difficult in organic soils than in mineral soils. Wireworm control research in the Everglades was intensified in 1961 after many growers reported inadequate control with recommended practices. Several insecticides were compared. Insecticide baits were evaluated in applications made before planting sweet corn and in applications made after corn plants had emerged from the soil.

3.1. Control of Carrot Fly on Carrots in Kent, 193–64

Plant PathologyVolume 14, Issue s1 p. 14-15 3. THE CONTROL OF OTHER DIPTEROUS PESTS OF VEGETABLE CROPS 3.1. Control of Carrot Fly on Carrots in Kent, 193–64 G. J. Smith, G. J. Smith Rowhill Experimental Farm, Hextable, KentSearch for more papers by this author G. J. Smith, G. J. Smith Rowhill Experimental Farm, Hextable, KentSearch for more papers by this author First published: March 1965 https://doi.org/10.1111/j.1365-3059.1965.tb00947.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume14, Issues1March 1965Pages 14-15 RelatedInformation

DDT Against Some Pests of Vegetable Crops

DDT Against Some Pests of Vegetable Crops