Selection of Cassida spp. from southern Africa for the biological control of Chrysanthemoides monilifera in Australia

Four species of tortoise beetle (Chrysomelidae, Cassidinae) (Cassida spatiosa Spaeth and three undescribed Cassida species, labelled 1. 2 and 3) from South Africa, were assessed as potential biological control agents against Chrysanthemoides monilifera monilifera (L.) T. Norl. and C. m. rotundata (DC.) T. Norl. These southern African plants are important weeds of conservation areas in Australia. In South Africa, Cassida spatiosa was found feeding on C monilifera subcanescens (DC.) T. Norl., Cassida sp. 1 on Chrysanthemoides monilifera pisifera (L.) T. Norl. and C m. monilifera, Cassida sp. 2 on C m. pisifera and Chrysanthemoides incana (Burm.f.) T. Norl. and Cassida sp. 3 on C. m. rotundata. The life cycle of each species was completed in about three months on the leaves of the host. Cassida species 1, 2 and 3 were tested against eight species of plant and only fed and completed development on Chrysanthemoides species and the related species. Calendula officinalis L. Cassida species 1 and 3 showed no preference between Calendula officinalis and Chrysanthemoides species for oviposition. Cassida species 3 was selected for further assessment as a biological control agent based on match to the host subspecies and target climate in Australia.     

Semi disposable reactor biosensors for detecting carbamate pesticides in water

Two flow-injection biosensor systems using semi disposable enzyme reactor have been developed to determine carbamate pesticides in water samples. Acetylcholinesterase was immobilized on silica gel by covalent binding. pH and conductivity electrodes were used to detect the ionic change of the sample solution due to hydrolysis of acetylcholine. Carbamate pesticides inhibited acetylcholinesterase and the decrease in the enzyme activity was used to determine these pesticides. Parameters influencing the performance of the systems were optimized to be used in the inhibition procedure. Carbofuran and carbaryl were used to test these systems. Detection limits for the potentiometric and conductimetric systems were both at 10% inhibition corresponding to 0.02 and 0.3 ppm of carbofuran and carbaryl, respectively. Both systems also provided the same linear ranges, 0.02-8.0 ppm for carbofuran, and 0.3-10 ppm for carbaryl. The analysis of pesticides was done a few times before the reactor was disposed. Percentages of inhibition obtained from different reactors were reproducible, therefore, no recalibration was necessary when changing the reactor. The biosensors were used to analyze carbaryl in water samples from six wells in a vegetable growing area. Both systems could detect the presence of carbaryl in the samples and provided good recoveries of the added carbaryl, i.e., 80-106% for the potentiometric system and 75-105% for the conductimetric system. The presence of carbaryl in water samples analyzed by the biosensors was confirmed by gas chromatography-mass spectrometric system. These biosensors do not require any sample preconcentration and are suitable for detecting pesticides in real water samples.     

Effect of pesticides on Colpoclypeus florus (Hymenoptera: Eulophidae) and Trichogramma platneri (Hymenoptera: Trichogrammatidae), parasitoids of leafrollers in Washington.

Pesticides were evaluated for their effect on two parasitoid species, Colpoclypeus flouts and Trichogramma platneri, that are potential biological control agents of leafrollers in apple orchards. Organophosphate and carbamate insecticides were highly toxic to both parasitoids in topical applications, but foliar residues of some products were nontoxic after 7 d. At reduced rates, topically applied pyrethroids were low in toxicity to C. florus were highly toxic to T. platneri, and foliar residues were nontoxic after about 7 d. Imidacloprid and abamectin were highly toxic when applied topically to both parasitoids but were not toxic as 1-d-old residues. Insect growth regulators did not cause mortality either as topical applications or residues; however, diflubenzuron caused severe sublethal effects, completely blocking the production of C. florus offspring. Biorational pesticides, such as soap, oil, and B. thuringiensis products, caused no toxicity to C. florus but had a direct impact on T. platneri as topical applications through physical immobilization. The potential to integrate different pesticides with biological control of leafrollers and the need for a step-wise approach to evaluate the impact of pesticides against natural enemies is discussed.     

Pesticide Susceptibility of Two Coccinellids (Stethorus punctum picipes and Harmonia axyridis) Important in Biological Control of Mites and Aphids in Washington Hops

The susceptibility of Stethorus punctum picipes (Casey) and Harmonia axyridis Pallas larvae to pesticides used or with potential for use in Washington hops, was examined in laboratory bioassays. All pesticides tested except the miticide, hexythiazox, the insecticides, chlorpyrifos and pirimicarb, and the fungicide, mycobutanil, produced 100% mortality in S. punctum picipes at concentrations equivalent to field rates. The insecticides, pirimicarb, endosulfan, and thiamethoxam were least toxic to H. axyridis. Bifenthrin, diazinon, dimethoate, methomyl, carbaryl, malathion, phosmet, imidacloprid, and chlorpyrifos were highly toxic. The miticides, abamectin and fenpyroximate were highly toxic, milbemectin was moderately toxic but all other miticides tested were non-toxic. All fungicides had low toxicity. Selection and use of pesticides compatible with natural enemies and conservation biological control in Washington hop production is discussed.     

Determination of organophosphate and carbamate pesticides in spiked samples of tap water and fruit juices by a biosensor with photothermal detection.

The determination of organophosphate (paraoxon, chlorpyrifos, diazinon) and carbamate (carbaryl, carbofuran) pesticides in spiked drinking water and fruit juices was carried out using a photothermal biosensor. The biosensor consists of a cartridge containing immobilised enzyme acetylcholinesterase (AChE) placed in a flow-injection analysis (FIA) manifold and a photothermal detector based on thermal lens spectrometry. With this approach, 0.2 ng/ml of paraoxon can be detected in less than 15 min. Limits of detection for other organophosphate (chlorpyrifos, diazinon) and carbamate (carbaryl, carbofuran) pesticides varied, depending on their antiacetylcholinesterase (AntiAChE) toxicity, from 1 ng/ml to 4 microg/ml. The biosensor was used for the direct detection of pesticides in spiked tap water and fruit juices without any pretreatment steps. In these cases, the LOD3sigma of 1.5, 2.8 and 4 ng/ml paraoxon in tap water, orange juice and apple juice were obtained, respectively.     

Chemical control of stem nematode, Ditylenchus dipsaci, in field beans (Vicia faba)

‘Giant race’ stem nematode (Ditylenchus dipsaci) was well controlled in spring beans (Vicia faba) by up to 5 kg aldicarb or carbofuran ha^-1 applied to the seed furrows at sowing. Carbofuran was rather more effective in the clay loam soil used than was aldicarb. The best treatments almost eliminated injury to the stems and nematode infestation in the harvested seed. Similarly applied, oxamyl and fenamiphos were less effective and phorate, dimethoate and disulfoton were ineffective. Applying part of the dosage of an effective nematicide to the seed furrows and part along the plant rows mid-season was no more effective and was sometimes less effective than applying the whole dose to the seed furrows. Treating the plant rows mid-season with aldicarb or phoxim sometimes enhanced control but thiabendazole applied thus did not. Seed furrow applications of aldicarb or carbofuran were much less effective in controlling the nematodes in winter beans and seed dressings were less effective than seed furrow treatments. In one experiment, in plots in which aldicarb or oxamyl had been applied to the seed furrows, phoxim or thiabendazole applied over the rows of plants, enhanced nematode control. In two other experiments, thiabendazole was ineffective when applied in this way or when applied as a combined soil and plant treatment.     

Impact of the biological control agent Mesoclanis polana (Tephritidae) on bitou bush (Chrysanthemoides monilifera subsp. rotundata) in eastern Australia

The seed fly Mesoclanis polana (Diptera: Tephritidae) was released in Australia in 1996. Its impact on seed production of bitou bush (Chrysanthemoides monilifera subsp. rotundata) was monitored at eight sites along the New South Wales coast from 1996 to 2004. Peak flowerhead production occurred in autumn (March to May); therefore, samples collected in May of each year were used to compare abundance and impact of M. polana across sites and between years. Latitude had a significant effect on abundance and impact of M. polana. By May 2004, 99.6% of flowerheads at the five most northern sites contained at least one egg, while 64% of flowerheads from the two most southern sites contained at least one egg. In May 2004, mean numbers of M. polana eggs per flowerhead were between 13 and 17 at four of the six northern sites and below two at the two southern sites. In May 2004, average seed destruction by M. polana was 58% at the four most northern sites and 11% at the two most southern sites. The highest level of seed destruction recorded was 86% at Kingscliff in May 2003. Percentage seed destruction in May provided a reasonable estimate of seed destruction for the whole year. Parasitoids were found throughout the range of M. polana in Australia. Their attack rate on M. polana was less than 10% at all sites, except at the two most northern sites where parasitism of up to 27% was recorded. Parasitism results are compared with predictions made following an earlier study. The release of Mesoclanis magnipalpis, a species suited to cooler environments, is recommended for the southern range of C. monilifera subsp. rotundata.     

High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health

Background

Recent declines in honey bees for crop pollination threaten fruit, nut, vegetable and seed production in the United States. A broad survey of pesticide residues was conducted on samples from migratory and other beekeepers across 23 states, one Canadian province and several agricultural cropping systems during the 2007–08 growing seasons.

Methodology/Principal Findings

We have used LC/MS-MS and GC/MS to analyze bees and hive matrices for pesticide residues utilizing a modified QuEChERS method. We have found 121 different pesticides and metabolites within 887 wax, pollen, bee and associated hive samples. Almost 60% of the 259 wax and 350 pollen samples contained at least one systemic pesticide, and over 47% had both in-hive acaricides fluvalinate and coumaphos, and chlorothalonil, a widely-used fungicide. In bee pollen were found chlorothalonil at levels up to 99 ppm and the insecticides aldicarb, carbaryl, chlorpyrifos and imidacloprid, fungicides boscalid, captan and myclobutanil, and herbicide pendimethalin at 1 ppm levels. Almost all comb and foundation wax samples (98%) were contaminated with up to 204 and 94 ppm, respectively, of fluvalinate and coumaphos, and lower amounts of amitraz degradates and chlorothalonil, with an average of 6 pesticide detections per sample and a high of 39. There were fewer pesticides found in adults and brood except for those linked with bee kills by permethrin (20 ppm) and fipronil (3.1 ppm).

Conclusions/Significance

The 98 pesticides and metabolites detected in mixtures up to 214 ppm in bee pollen alone represents a remarkably high level for toxicants in the brood and adult food of this primary pollinator. This represents over half of the maximum individual pesticide incidences ever reported for apiaries. While exposure to many of these neurotoxicants elicits acute and sublethal reductions in honey bee fitness, the effects of these materials in combinations and their direct association with CCD or declining bee health remains to be determined.     

Sister-chromatid exchanges in human lymphocytes induced by dimethoate, omethoate, deltamethrin, benomyl and their mixture.

Dimethoate and omethoate, two common organophosphorus insecticides, induced a dose-related increase in the frequency of sister-chromatid exchanges (SCEs) in human lymphocytes in vitro (P of the regression lines less than 0.01). Two other common pesticides, the pyrethroid insecticide deltamethrin and the systemic fungicide benomyl, induced a modest increase in SCEs which bordered on statistical significance (P = 0.053 and 0.055, respectively). Mixtures of the four pesticides at total concentrations of 41.5 and 83 micrograms/ml (composed of 43% dimethoate, 43% omethoate, 12% deltamethrin and 1.2% benomyl) induced a dose-dependent increase in SCEs (P less than 0.01). The effects of these mixtures of pesticides were variable using lymphocytes from different individuals, although these differences did not attain statistical significance. Moreover, low concentrations of the four pesticides that did not increase SCEs significantly when tested alone, were positive for SCE induction when tested as a mixture. The experiments show that sub-threshold doses of pesticides may increase SCEs when present in a mixture.     

Purification and characterization of the N-methylcarbamate hydrolase from Pseudomonas strain CRL-OK.

A unique cytosolic enzyme that hydrolyzes the carbamate linkage of the insecticide carbaryl (1-naphthyl N-methylcarbamate) was purified from extracts of Pseudomonas sp. strain CRL-OK. Substrates of the hydrolase include the N-methylcarbamate pesticides carbofuran and aldicarb but not the phenylcarbamate isopropyl m-chlorocarbanilate, the thiocarbamate S-ethyl N,N-dipropylthiocarbamate, or the dimethylcarbamate o-nitrophenyldimethylcarbamate.     

Purification and characterization of the N-methylcarbamate hydrolase from Pseudomonas strain CRL-OK.

A unique cytosolic enzyme that hydrolyzes the carbamate linkage of the insecticide carbaryl (1-naphthyl N-methylcarbamate) was purified from extracts of Pseudomonas sp. strain CRL-OK. Substrates of the hydrolase include the N-methylcarbamate pesticides carbofuran and aldicarb but not the phenylcarbamate isopropyl m-chlorocarbanilate, the thiocarbamate S-ethyl N,N-dipropylthiocarbamate, or the dimethylcarbamate o-nitrophenyldimethylcarbamate.     

Effects of pirimicarb, dimethoate and benomyl on natural enemies of cereal aphids in winter wheat

The insecticides, pirimicarb and dimethoate are commonly applied to cereal crops in the UK and when this study was begun the fungicide benomyl was also regularly used. The effects of these chemicals on natural enemies of cereal aphids were examined in replicated plots of winter wheat. Benomyl did not affect any of the groups examined but it was applied early in the season (April/May) when most natural enemies were few or absent from the crop. Numbers of carabid beetles, staphylinid beetles and spiders, sampled using pitfall traps and a vacuum net sampler, were all reduced by dimethoate but not by pirimicarb, although these effects were only detected by pitfall traps when the small plots were surrounded by polyethylene barriers to prevent inter-plot movements. Parasitic Hymenoptera were decreased by both insecticides, partly due to direct toxicity and partly to host removal. Data on the aphid predators, Coccinellidae, Syrphidae and Chrysopidae were inconclusive because there were very few in the crop due to the scarcity of aphids. Ways in which pesticides can affect natural enemy populations other than by direct mortality and the dangers associated with routine, prophylactic pesticide applications are discussed.     

Seed characteristics and regeneration of some species in invaded coastal communities

The seed production, germination and regeneration characteristics of two native species (Acacia longifolia var. sophorae and Banksia integrifolia) and two invasive subspecies (Chrysanthemoides monilifera ssp. monilifera and ssp. rotundata) were compared. C. monilifera ssp. rotundata was similar in seed characteristics and regeneration to B. integrifolia in that: (1) seed production was over an extended period each year; (2) seed longevity was low (0–2% viable after burial for 3 years), but increased with depth of burial; and (3) regeneration from 26 to 28% of mature plants occurred after fire. By contrast, C. monilifera ssp. monilifera was similar to A. Iongifolia var. sophorae in that; (1) seed production was over a short period each year; (2) of the total buried, 6–13% of seeds were viable after 3 years, and again numbers increased with depth of burial (percentages of missing seeds of A. longifolia were high but all remaining seeds were viable after 3 years); and (3) regeneration after fire occurred only from seed, hence their seed longevity is an important factor for long-term survival. However, growth habit and niche occupation by ssp. rotundata is similar to that of A. longifolia and the above differences may contribute to the observed displacement of the native by the invasive species. The distribution of the two invasive subspecies is at present largely in separate areas in Australia and it is predicted this situation will continue because of their differing climatic preferences, morphology and regeneration from fire.     

Effects of selected pesticides used against glasshouse tomato pests on colony growth and conidial germination of Paecilomyces fumosoroseus

Two isolates of a potential biological control agent, Paecilomyces fumosoroseus, for greenhouse whitefly, Trialeurodes vaporariorum, on tomato in greenhouses were tested for their compatibility with five fungicides (captan, dichlofluanid, iprodione, benomyl, and carbendazim) and six insecticides (malathion, carbaryl, primicarb, pymetrozine, cypermethrin, and deltamethrine) which are used on glasshouse tomato. Conidial germinations after 24 h and radial growths after 14 days of inoculation were determined in the presence of each pesticide at three concentrations (recommended rate, 0.1 and 10 times of the recommended rate by its manufacturer) and resultant variations were evaluated. Our results suggest that the tested pesticides, especially the fungicides, have potential to interfere with the success of P. fumosoroseus if they are to be employed together. The recommended concentration rate of primicarb and pymetrozine, and the lower concentrations of cypermethrin and deltamethrin were less hazardous than the others.     

Pre-release impact assessment of two stem-boring weevils proposed as biological control agents for Alliaria petiolata

Experimental studies can be useful tools to test plant responses to herbivory and to quantify the impact of potential biological control agents prior to their release. We evaluated the per-capita effect of Ceutorhynchus alliariae and C. roberti, two stem-boring weevils currently being investigated as potential biological control agents for garlic mustard, Alliaria petiolata, in North America. Weevils were released at three different densities in individual and mixed-species treatments onto potted plants of A. petiolata. Damage by C. roberti alone and by both weevils combined caused an increase in the numbers of inflorescences produced per plant. Although plants could compensate for low levels of damage, moderate to high levels of damage by both C. alliariae and C. roberti, individually and in combination, caused a decrease in plant height and a reduction in seed output per plant. The damage inflicted by both weevil species is similar so the overall impact of both species combined can be predicted by summing the impact of each species alone. Provided they are sufficiently host specific, both weevils could be released as biocontrol agents. Because reduced seed production is necessary to suppress A. petiolata populations, both species have the potential to contribute to control of A. petiolata in North America.     

Status of coastal dune communities invaded by Chrysanthemoides monilifera

It has often been assumed that the introduced species Chrysanthemoides monilifera is displacing native species in invaded coastal communities in Australia but no direct evidence has been presented that this displacement is occurring and, if so, to what extent. At an invaded site near Moruya, New South Wales, we found strong negative correlations between the presence (measured as cover, frequency or volume of shrub) of C. monilifera and Acacia longifolia, the hitherto dominant native species, and of C. monilifera and Lomandra longifolia. The negative correlations are partly accounted for by differences in the amounts of each species on different zones on the dune, but the negative correlations remain even within these zones. Also a comparison with uninvaded sites indicates that C. monilifera is displacing A. longifolia from the fore-dune and mid-dune but is having less effect in the swale. In addition, there is a trend towards reduced seed production of A. longifolia when growing in proximity to C. monilifera. There is no significant difference in the presence of L. longifolia in the uninvaded and invaded sites. In invaded sites, significantly fewer C. monilifera seedlings occur in the presence of L. longifolia. Thus it appears that the observed negative associations arise from different causes. Chrysanthemoides monilifera is displacing the structurally similar, and previously dominant A. longifolia, while the tussock-forming L. longifolia is locally hindering the invasion.     

Genetic and phenotypic diversity of carbofuran-degrading bacteria isolated from agricultural soils

Thirty-seven carbofuran-degrading bacteria were isolated from agricultural soils, and their genetic and phenotypic characteristics were investigated. The isolates were able to utilize carbofuran as a sole source of carbon and energy. Analysis of the 16S rRNA gene sequence indicated that the isolates were related to members of the genera Rhodococcus, Sphingomonas, and Sphingobium, including new types of carbofuran-degrading bacteria, Bosea and Microbacterium. Among the 37 isolates, 15 different chromosomal DNA patterns were obtained by polymerase chain reaction (PCR) amplification of repetitive extragenic palindromic (REP) sequences. Five of the 15 representative isolates were able to degrade carbofuran phenol, fenoxycarb, and carbaryl, in addition to carbofuran. Ten of the 15 representative isolates had 1 to 8 plasmids. Among the 10 plasmid-containing isolates, plasmid-cured strains were obtained from 5 strains. The cured strains could not degrade carbofuran and other pesticides anymore, suggesting that the carbofuran degradative genes were on the plasmid DNAs in these strains. When analyzed with PCR amplification and dot-blot hybridization using the primers targeting for the previously reported carbofuran hydrolase gene (mcd), all of the isolates did not show any positive signals, suggesting that their carbofuran hydrolase genes had no significant sequence homology with the mcd gene.     

Flow-injection determination of carbaryl and carbofuran based on KMnO(4)-Na(2)SO(3) chemiluminescence detection.

A flow-injection method is described for the determination of carbaryl and carbofuran. It was found that a strong chemiluminescence (CL) signal was generated when these pesticides were mixed with Na(2)SO(3) and KMnO(4) in acidic medium. Under the optimum experimental conditions, the enhanced CL intensity was linear, with the concentrations in the range 0.1-2.0 microg/mL (r(2) = 0.9996 and 0.9993, n = 6) with relative standard deviation (n = 4) in the range 1.0-2.3%. The limits of detection (3sigma blank) were 10 and 50 ng/mL, respectively, with a sample throughput of 180/h. The proposed method was applied to determine carbaryl and carbofuran in freshwaters with satisfactory results. Most metal and non-metal ions and some pesticides, such as carbophenothion and aldicarb, do not interfere with the determination. Dinoseb, diazinon and malathion calibration graphs (in the range 0.2-2.0 microg/mL, r(2) = 0.9966-0.9988, n = 6) were also established with relative standard deviations (n = 4) in the range 1.2-2.0% with limits of detection (3sigma blank) in the range 100-300 ng/mL.     

Establishment and rapid spread of the bitou seed fly, Mesoclanis polana Munro (Diptera: Tephritidae), in eastern Australia

The establishment and spread of the seed fly Mesoclanis polana Munro, an introduced biological control agent for Chrysanthemoides monilifera (L.) Norlindh, is described. From an initial release of 124 adult flies in August 1996, the species occupied virtually the entire range of bitou bush by October 1998, from Rainbow Beach in the north to Tathra in the south, a distance of over 1200 km. Early data on abundance are provided.     

Crop protection by seed coating

Providence of sufficient and healthy food for increasing human population clears the importance of notice to increasing crop production in company with environmental loss reduction. Growth and yield of every plant with sexual reproduction, depends on germination & emergence of sown seeds. Seed is a small alive plant that its biological function is protection and nutrition of embryo. Biological, chemical and physiological characteristics of seed, affect on plant performance & its resistance to undesirable environmental conditions, and even on its total yield. So attention to seed and try to increase its performance is so important. One of the factors that cause reduction in germination percentage and seedling establishment, is seed disease. It's possible to control these diseases by treating the seed before planting it. Coating the seed with pesticides, is one of the ways to gain this goal. Seed coating is a technique in which several material as fertilizers, nutritional elements, moisture attractive or repulsive agents, plant growth regulators, rhizobium inocolum, chemical & pesticide etc, add to seed by adhesive agents and cause to increase seed performance and germination. Seed coating, leads to increase benefits in seed industry, because seeds can use all of their genetic vigor. This technique is used for seeds of many garden plants, valuable crops (such as corn, sunflower, canola, alfalfa,...) and some of the grasses. In this technique that was first used in coating cereal seeds in 1930, a thin and permeable layer of pesticide is stuck on seed surface and prevent damage of seedborn pathogens. This layer is melted or splited after absorption of moisture and suitable temperature by seed, and let the radical to exit the seed. In this approach materials are used accurately with seed, evaporation & leakage of pesticide and also adverse effects of some pesticides on seeds are diminished, and these factors cause to increase the accuracy and performance of pesticide, decrease their consumption, environmental pollution and costs. This technique in new and there is a few information about it. So after searching and studying about this technique this paper is written to introduce it and its applications in crop protection.