An integrated approach to the control of Lycoriella solani (Diptera:Sciaridae) during production of the cultivated mushroom (Agaricus bisporus)

Individual and combined effects of light‐trapping, biological and chemical control on Lycoriella solani (Winnertz) populations in experimental mushroom production cubicles were examined. During three weeks following the introduction of recorded numbers of adult L solani into experimental cubicles, light‐traps caught a maximum 74% of flies initially released. However, light‐trapping stimulated adult fly activity and immature stages in the growing substrate throughout the experiment. Consequently, no yield improvements, independently or in combination with biological control agents, were recorded. Incorporation of diazinon (25 mg AI kg⁻¹) to compost following pasteurisation did not significantly reduce subsequent emergence of adult sciarids. Additional drench application of diflubenzuron (1 g AI m⁻²) to the casing layer reduced the number of immature sciarids during the first cropping period by 99% (P < 0.001). However, inclusion of chemical insecticides reduced the mushroom yield during this period by 14% (P < 0.001). Introduction of the predatory mite Hypoaspis miles (Berlese) to the compost during its colonisation by mycelium of Agaricus bisporus (Lange) reduced emergence of adult sciarids by 87% (P < 0.05). Later introduction of H miles at the beginning of the case‐run period was less effective. Application of the parasitic nematode, Steinernema feltiae (Filipjev (=S bibionis Bovien, after Poinar, 1990)) to the compost during its colonisation by mycelium of A bisporus had no immediate effect on sciarid emergence and provided only limited reduction at later crop stages. Similar application immediately after casing reduced sciarid emergence at first flush by 82% (P < 0.05). Irrespective of application time, a formulation of Bacillus thuringiensis (Berliner) var israeliensis had no significant effect on sciarid emergence or mushroom yields at any production stage. © Crown copyright 2000. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.     

Effect of compost and casing treatments of insecticides against the sciarid Bradysia ocellaris (Diptera: Sciaridae) and on the total yield of cultivated mushrooms,Agaricus bisporus

BACKGROUND: Bradysia ocellaris (Comstock) is one of the major pests of cultivated mushrooms, Agaricus bisporus (Lange) Imbach. The feeding of sciarid fly larvae causes damage to the cultivation substrates, compost and casing. A comparative study of insecticidal treatments incorporated into compost and casing against B. ocellaris was conducted during 2003–2004. Treatments with an organophosphate, diazinon, a pyrazole, fipronil, and an insect growth regulator (IGR), triflumuron, were incorporated into casing. Another IGR, cyromazine, was incorporated into compost. Insecticidal incorporation into compost and casing has been associated with reductions in mushroom yield. Therefore, the effect of these insecticidal treatments on the overall yield was evaluated. RESULTS: A combined treatment, incorporation of cyromazine at 10 mg kg^?1 into compost and of triflumuron at 20 mg kg^?1 into casing, provided 100% control against B. ocellaris. There was no apparent reduction in yield as a result of incorporation of the tested chemicals into either compost or casing. CONCLUSION: The results obtained from this study suggest that incorporation of insecticides into both compost and casing is required to control a moderate to high pressure of insect pests. There were no significant yield reductions as a result of the incorporation of pesticides in the Australian mushroom‐growing system. Copyright © 2009 Society of Chemical Industry     

Control of the mushroom phorid fly, Megaselia halterata (Wood), with plant extracts

BACKGROUND: The most serious insect pest problems affecting the cultivation of mushroom [Agaricus bisporus (Lange) Imbach] in Turkey are mushroom flies (sciarids, cecids and phorids). Mushroom phorid fly, Megaselia halterata (Wood), is the most common insect pest species during April‐October. The aim of this study was to evaluate the potential for eight botanical materials (two commercial neem‐based products and six hot‐water plant extracts) to control M. halterata populations in three successive growing periods. RESULTS: Treatment efficacy was evaluated by assessing adult emergence and sporophore damage rates compared with that of a standard insecticide, chlorpyrifos‐ethyl (positive control). All plant extracts caused significant reductions in the mean number of emerging adults and sporophore damage rates compared with the water‐treated control (negative control). Reduction in adult emergence in both neem treatments, Neemazal and Greeneem oil, was greater than that in the positive control. While Neemazal and Origanum onites L. extract had significantly lower sporophore damage rates than the positive control, there were no significant differences between the chlorpyrifos‐ethyl, Greeneem oil and Pimpinella anisum L. extract treatments. CONCLUSION: The results suggest that both neem products and hot‐water extracts of O. onites and P. anisum may be potential alternatives to conventional pesticides for the control of mushroom phorid fly. Copyright © 2008 Society of Chemical Industry     

Residues of carbofuran and 2,3-dihydro-3-hydroxy- 2,2-dimethylbenzofuran-7-yl methylcarbamate in the mushroom,agaricus bisporus,cultivated in casing soils treated with the insecticide

Residues of carbofuran ( 1 ) and 2,3-dihydro-3-hydroxy-2,2-dimethylbenzofuran-7-yl methylcarbamate ( 2 ) in and on mushrooms, cultivated on casing soils containing added carbofuran granular insecticide, were determined. The quantitative estimations in cleaned mushroom extracts were done on thin-layer plates using a cholinesterase inhibition method. Samples were analysed, which had been harvested at different times from cultures, to which different amounts of carbofuran were added. Residues in washed and unwashed mushroom samples were compared. Residues did not exceed 0.5 mg (carbofuran) kg^?1 and 0.25 mg (compound 2 ) kg^?1 for fresh unwashed mushrooms grown on casing soil treated with carbofuran granules 1 g (a.i.) m^?2.     

Surface contact toxicity and synergism of several insecticides against different stages of the tropical bed bug, Cimex hemipterus (Hemiptera: Cimicidae)

BACKGROUND: Five formulated insecticides (lambda‐cyhalothrin at 10 mg m^?2, bifenthrin at 50 mg m^?2, fipronil at 10 mg m^?2, fenitrothion at 50 mg m^?2, imidacloprid at 5 mg m^?2) and one active ingredient (DDT at 500 mg m^?2) were evaluated using a surface contact method against early and late instars and adults of two strains of the tropical bed bug, Cimex hemipterus (F.). Synergism of lambda‐cyhalothrin and fipronil using piperonyl butoxide (PBO) was also assessed. RESULTS: The order of susceptibility of different stages of bed bugs was as follows: early stage ? lambda‐cyhalothrin > bifenthrin = imidacloprid > fipronil > fenitrothion > DDT; late stage—lambda‐cyhalothrin > bifenthrin > fenitrothion > imidacloprid > fipronil > DDT; adult—lambda‐cyhalothrin > imidacloprid > bifenthrin > fenitrothion > fipronil > DDT. The late instars exhibited significantly higher LT₅₀ among the life stages. The addition of PBO to fipronil increased the susceptibility of the insects. CONCLUSIONS: Lambda‐cyhalothrin, bifenthrin, fenitrothion and fipronil at the recommended application rates were effective against C. hemipterus. Although imidacloprid demonstrated good initial response against C. hemipterus, the insects showed substantial recovery 72 h post‐treatment. The late instars (fourth and fifth instars) should be used as the model for toxicological evaluation. Copyright © 2011 Society of Chemical Industry     

The toxicity of cyromazine to Chironomus zealandicus (chironomidae) and Deleatidium sp. (leptophlebiidae)

The toxicity of cyromazine and a commercial formulation, ‘Vetrazin’®, to Chironomus zealandicus (thummi) Hudson and Deleatidium sp. was investigated. Under acute test conditions, the LC₅₀ values for each species were quite comparable. For C. zealandicus, the value varied according to instar, 100–400 mg litre^?1 for second- and third-instar to 1000–10000 mg litre^?1 for older fourth-instars. For the one size class of Deleatidium tested (c.10 mm long), the value was 300–400 mg litre^?1. High control mortalities of C. zealandicus limit that species' usefulness as an acute bioassay candidate. Under chronic test conditions, cyromazine showed a high toxicity to eggs or early-instar larvae of C. zealandicus. The maximum acceptable toxicant concentration for cyromazine against C. zealandicus was approximately 17.5 μg litre^?1. The possibility of water contamination at this level is discussed. Whole-of-life chronic tests with C. zealandicus indicated that the most susceptible stage was in the egg or soon after larval emergence. These results highlight the dangers of using short-term acute toxicity results to formulate environmental exposure limits for modern pesticides that do not have dysfunction of the nervous system as their mode of action.     

Compatibility of spinosad with predaceous mites (Acari) used to control Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)

BACKGROUND: Spinosad is a biopesticide widely used for control of Frankliniella occidentalis (Pergande). It is reported to be non‐toxic to several predatory mite species used for the biological control of thrips. Predatory mites Typhlodromips montdorensis (Schicha), Neoseiulus cucumeris (Oudemans) and Hypoaspis miles (Berlese) have been used for control of F. occidentalis. This study investigated the impact of direct and residual toxicity of spinosad on F. occidentalis and predatory mites. The repellency of spinosad residues to these predatory mites was also investigated. RESULTS: Direct contact to spinosad effectively reduced the number of F. occidentalis adults and larvae, causing > 96% mortality. Spinosad residues aged 2–96 h were also toxic to F. occidentalis. Direct exposure to spinosad resulted in > 90% mortality of all three mite species. Thresholds for the residual toxicity (contact) of spinosad (LT₂₅) were estimated as 4.2, 3.2 and 5.8 days for T. montdorensis, N. cucumeris and H. miles respectively. When mites were simultaneously exposed to spinosad residues and fed spinosad‐intoxicated thrips larvae, toxicity increased. Residual thresholds were re‐estimated as 5.4, 3.9 and 6.1 days for T. montdorensis, N. cucumeris and H. miles respectively. Residues aged 2–48 h repelled T. montdorensis and H. miles, and residues aged 2–24 h repelled N. cucumeris. CONCLUSION: Predatory mites can be safely released 6 days after spinosad is applied for the management of F. occidentalis. Copyright © 2011 Society of Chemical Industry     

Managing earthworm casts (Oligochaeta: Lumbricidae) in turfgrass using a natural byproduct of tea oil (Camellia sp.) manufacture

BACKGROUND: Earthworm casts are a worldwide problem on golf courses and sports fields when they disrupt the playability, aesthetics and maintenance of closely mowed playing surfaces. Currently, no pesticides are labeled for earthworms in the United States. Tea seed pellets (TSPs), a saponin‐rich byproduct of Camellia oleifera Abel oil manufacture, were tested for expelling earthworms and reducing casts on creeping bentgrass turf. The fate of expelled worms, methods for removing them and impacts on pest and beneficial arthropods were also evaluated. RESULTS: Application of TSPs at 2.93 kg 100 m^?2, followed by irrigation, quickly expelled earthworms from the soil. A single application reduced casts by 80–95% for at least 5 weeks. Mowing or sweeping removed expelled earthworms from putting green surfaces. Most expelled earthworms burrowed down when transferred to untreated turf, but few survived. Bioassay‐guided fractionation confirmed the vermicidal activity results from a mix of saponins. TSPs did not reduce the abundance of beneficial soil arthropods, nor did they control black cutworms or white grubs in treated turf. CONCLUSION: TSPs are an effective botanical vermicide that could be useful for selectively managing earthworm casts on closely mowed turfgrass. They might also be used to suppress earthworms in grassy strips alongside runways to reduce bird strike hazard at airports. Copyright © 2009 Society of Chemical Industry     

Mobilities of organic compounds in reconstituted cuticular wax of barley leaves: Determination of diffusion coefficients

Isolated cuticular wax, obtained from barley leaves, was mixed with ¹⁴Clabelled organic chemicals including aromatic pesticides and long-chain linear alkanes, alcohols and acids. These mixtures were reconstituted from the melt and labelled chemicals were desorbed from the wax by immersing the wax samples in aqueous phospholipid suspensions. Diffusion coefficients (D) of radiolabelled test compounds in the wax were derived from desorption kinetics. Diffusion coefficients ranged from 10^?17 to 10^?22 m² s^?1 and decreased rapidly with increasing molar volumes of solutes. However, size selectivity of D was much more pronounced with the linear, long-chain molecules than with the aromatic compounds. It is argued that the two different groups of chemicals (compounds occurring naturally in cuticular waxes vs pesticide molecules) were trapped in different fractions of wax during crystallization from the melt. The normal long-chain aliphatic compounds appear to be incorporated into the crystalline fraction of the wax, while the cyclic pesticide molecules are confined to the solid amorphous regions. Our data indicate that constituents of cuticular waxes are not immobile. In fact, relatively small linear aliphatic molecules have mobilities that do not differ too much from those of cyclic pesticides. However, the pronounced size selectivity of diffusivities of long-chain aliphatic compounds causes a rapid decrease in D with increasing chain length. The value of D of hexadecanoic acid was 3.81 × 10^?18 m² s^?1 while that of dotriacontane was only 4.07 × 10^?22 m² s^?1. Thus, increasing the carbon number by a factor of two resulted in a decrease in mobility by almost four orders of magnitude. Diffusivities of selected pesticide molecules in reconstituted wax were compared with permeances measured using intact barley leaves and were found to be in satisfactory agreement.     

Threshold level and seed production of velvetleaf (Abutilon theophrasti Medicus) in maize

Four tests were carried out in 1980 and 1981 to determine: (a) the economic threshold density of Abutilon theophrasti Medicus (velvetleaf) in maize, and (b) seed production with varying densities of infestation, both in the presence and in the absence of maize. The infestation was artificially created, and the density of the weed ranged from 0 to 80 plants m^?2. The economic threshold, calculated using the Cousens (1987) model, varied between 0?3 plants m^?2 and 2?4 plants m^?2, depending on the variables considered. The presence of maize reduced the seed-rain of A. theophrasti by 50%. This seed-rain reached its maximum level at 20–30 plants m^?2 in maize, and at 30–35 plants m^?2 in weed monoculture. However, with only 4–5 plants m^?2 in competition with maize, A. theophrasti produced 8–10 thousand seeds m^?2. The usefulness of threshold density in weed management is debatable when one considers the ecological characteristics of the A. theophrasti seed, and the great capacity of seed production of this weed.     

Field trial measuring the compatibility of methoxyfenozide and flonicamid with Orius laevigatus Fieber (Hemiptera: Anthocoridae) and Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) in a commercial pepper greenhouse

BACKGROUND: Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) and Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) are among the most serious pests of sweet peppers in greenhouses. Chemical control is difficult because of their high reproductive rates and insecticide resistance, and seasonal inoculative releases of Orius laevigatus (Fieber) and Amblyseius swirskii (Athias‐Henriot) are commonly used to reduce their populations. As chemical treatments are often needed in the crop against other pests, the side effects of methoxyfenozide (an insect growth regulator against lepidopteran pests) and flonicamid (a selective feeding inhibitor against sucking insects) were studied in both beneficial organisms in a commercial greenhouse. RESULTS: Orius laevigatus and A. swirskii were released at commercial rates (4–5 and 100 m^?2), and a strong establishment and a very homogeneous distribution were reached. One pesticide treatment with the maximum field recommended concentration of methoxyfenozide and flonicamid (96 and 100 mg AI L^?1) was done when they were well established, and their population levels were not affected either immediately or up to 30 days after treatment. CONCLUSION: The results are indicative of no impact of methoxyfenozide and flonicamid on the two natural enemies in the field, and both can be considered as potential alternatives to be included in IPM programmes in sweet pepper. Copyright © 2011 Society of Chemical Industry     

Interference of Sinapis arvensis L. and Chenopodium album L. in spring rapeseed (Brassica napus L.)

Interference of Sinapis arvensis L. (wild mustard) and Chenopodium album L. (lamb's-quarters) in spring rapeseed (Brassica napus L.) was studied under field conditions in 1983 and 1984. Both weed species interfered with rapeseed early in the growing season, causing significant reductions in rapeseed dry weight by June of each year. Sinapis arvensis caused greater rapeseed grain yield reductions than did C. album. With weed densities of 20–80 plants m^?2, rapeseed grain yield reductions ranged from 19 to 77% with S. arvensis but only 20 to 25% with C. album. Rapeseed yield reductions caused by mixtures of both weed species ranged from being less than to being equal to the sum of reductions caused by each weed alone, depending on the weed density and year of study. Both weed species were prolific seed producers capable of returning large quantities of seed to the soil. With weed densities ranging from 10–80 plants m^?2, S. arvensis produced 5700–30 100 seeds m^?2 while C. album produced 3100–63 600 seeds m^?2.     

Seed production by an arable weed community

After cultivation in early April of a sandy loam soil with 9500 apparently viable seeds/m² in 0–10 cm, 295 seedlings/m² emerged of which about half survived to maturity in July. Seeds were dispersed from mid-June to November and 136,460/m² were returned to the soil, representing a 14-fold increase in the seed bank. Application of soil-acting herbicides reduced the numbers of weeds and the total seed output, but that of tolerant species was increased. Maximum numbers of seeds were 59,980/m² for Chenopodium album, 39,430/m² for Sleltaria media and 37,580/m² for Veronica persica.     

Distribution and activity of spray deposits in an oak canopy following aerial application of diluted and undiluted formulations of Bacillus thuringiensis Berliner against the gypsy moth,Lymantria dispar L. (Lepidoptera: Lymantriidae)

The distribution and biological activity of spray deposits resulting from aerial applications of diluted and undiluted Bacillus thuringiensis, ‘Dipel 64AF’ against the gypsy moth, Lymantria dispar L., were examined in oak stands in south-eastern Ontario, Canada. The sprays were applied by fixed-wing aircraft equipped with four ‘Micronair AU4000’ atomizers. Application of diluted formulation at 30 BIU ha^?1 in 6.0–6.4 litre generally resulted in a higher droplet density (10–28 cm ^?2 leaf) than application of undiluted product at the same dosage rate in 1.8 litre ha^?1 (4–10 cm ^?2). However, spray deposits of undiluted product with a volume median diameter (D_v.5) of 90–130 μm caused as much mortality of gypsy moth larvae in bioassays of sprayed foliage as deposits of diluted product with a D_v.5 of 150–350 μm despite a two- to three-fold reduction in droplet density. Our data suggest that by using fine spray atomization, undiluted application of these formulations can offer the same efficacy against gypsy moth as coarsely atomized sprays of diluted product.     

Efficacy of Vapam fumigant against clubroot (Plasmodiophora brassicae) of canola

Clubroot, caused by Plasmodiophora brassicae, has become a serious threat to canola (Brassica napus) production in western Canada. Experiments were conducted under greenhouse and field conditions to assess the effect of Vapam fumigant (dithiocarbamate; sodium N‐methyldithiocarbamate) on primary and secondary infection by P. brassicae, clubroot severity, and growth parameters in canola. Preliminary trials showed a 12–16‐fold reduction in primary and secondary infection and clubroot severity at all of the Vapam application rates (0·4–1·6 mL L^?1 soil) assessed. Vapam was also found to be effective in reducing clubroot severity and improving seed yield of canola under field conditions. Application of Vapam at soil moisture levels in the range of 10–30% (v:v) had a large effect on both disease severity and infection rates and plant growth parameters. The results suggest that Vapam can effectively reduce clubroot severity and may be useful for the treatment of transplant propagation beds in brassica vegetable production, and for the containment of small, localized clubroot infestations in commercial canola crops.     

Toxicity of chlordimeform and amitraz to the egyptian cotton leafworm (Spodoptera littoralis) and the tobacco budworm (Heliothis virescens)

The relative toxicity (μg a.i. g^?1 body wt) of the formamidine insecticide chlordimeform (CDM) and the triazapentadiene insecticide amitraz was examined in two species of noctuid moth Spodoptera littoralis and Heliothis virescens. When applied topically, there was an unexpected and marked difference in the toxicity of CDM base and its hydrochloride to adults of both species, the salt being appreciably more toxic. For H. virescens at least, this difference in toxicity could not be explained by differences in penetration. This trend was reversed for larval instars of S. littoralis; while there was relatively little difference in the toxicity of the base to adult and larval stages, the salt was at least 1000-fold more toxic to adults than to larvae. N¹-Demethylchlordimeform (DCDM) was the only metabolite of CDM to show biological activity against either species, but was much less toxic than the parent compound. Amitraz was far less toxic than either CDM or DCDM; like the CDM salt, it appeared to be more toxic to adult than larval stages of S. littoralis. Application of piperonyl butoxide significantly increased the toxicity of the CDM salt, DCDM and amitraz to adult H. virescens, the synergist being particularly effective with DCDM and amitraz. In contrast, piperonyl butoxide had no significant effect on the toxicity of DCDM, and slightly antagonised the toxicity of DCDM to fourth-instar larvae of S. littoralis.     

Evaluation of semiochemical toxicity to Aedes aegypti,Ae. albopictus and Anopheles quadrimaculatus (Diptera: Culicidae)

BACKGROUND: Mosquitoes are the most important vectors of human pathogens. Wide‐scale use of pesticides has led to the development of resistance to most common insecticide groups. The need to develop novel products that have a low impact on human health and the environment is well established. The toxicity of selected semiochemicals with molecular structures indicative of insecticidal activity was determined against adult Aedes aegypti (L.) and Anopheles quadrimaculatus (Say). The two most active insecticides against Ae. aegypti were also evaluated against Ae. albopictus (Skuse). RESULTS: Fifteen semiochemicals classified as terpenoid alcohols, ketones or carboxylic esters showed toxicity to both mosquito species. Geranyl acetone (LC₅₀ = 38.51 µg cm^?2) followed by citronellol (LC₅₀ = 48.55 µg cm^?2) were the most toxic compounds to Ae. aegypti, while geraniol and lavonax, with LC₅₀ values of 31.88 and 43.40 µg cm^?2, showed the highest toxicity to An. quadrimaculatus. Both geranyl acetone and citronellol were highly toxic to Ae. albopioctus. No semiochemical showed fumigation activity against either species. All semiochemicals persisted for less than 24 h when tested on filter paper. CONCLUSION: Quantification of LC₅₀ values of several semiochemicals against Ae. Aegypti, An. quadrimaculatus and Ae. albopioctus showed that semiochemicals not only modify insect behaviors but also hold potential as potent insecticides for mosquito control programs. Copyright © 2010 Society of Chemical Industry     

Control of Achillea millefolium L. (yarrow) by rotary cultivation and glyphosate

Various control strategies for Achillea millefolium L. (yarrow) were investigated in a dense stand of the weed at Lincoln College in 1977–1978. In early spring plots were either rotary cultivated or left undisturbed. In late spring, plots of both previous treatments were either left undisturbed, rotary cultivated or sprayed with glyphosate at 1·5 kg ha^?1. The whole experiment was rotary cultivated twice 1 week later and sown with Hordeum vulgure L. cv. Zephyr (barley) at 144 kg seed ha^?1. MCPA + dicamba at 0·9+0·15 kg ha^?1 was applied to half of each plot when the second node was detectable (Zadok 32). Rotary cultivation and glyphosate both substantially reduced the regrowth of A. millefolium but glyphosate reduced regrowth by a greater proportion when applied to undisturbed plants than when applied to plants regenerating after cultivation. Both gave a more than 95% reduction compared to the control (rotary cultivation only at sowing time) in the amount of A. millefolium present in the barley stubble in the autumn. MCPA + dicamba caused seedling mortality but did not affect the numbers of primary shoots from rhizome fragments. The grain yield of the barley increased from 2·91 t ha^?1 when A. millefolium was not controlled to 4·23 t ha^?1 with good control. The barley yield appeared to be restricted by competition from regenerating A. millefolium and by a nitrogen deficiency induced in some regimes by nitrogen immobilization in decaying rhizomes.     

Effects of different potato cultivars on life history and demographic parameters of Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae)

Potato tuber worm, Phothorimae operculella Zeller (Lepidoptera: Gelechiidae) is a common pest of potato which causes a heavy loss in yield either in fields or storage. The effect of six potato cultivars (Agria, Florida, Impala, Picasso, Satina, and Sprint) were evaluated on the life history, life table and demographic parameters of P.operculella under laboratory conditions, which could be appropriate indices in resistance and susceptibility evaluation of potato cultivars. The longest development time was on Picasso (28.76 ± 0.36d) cultivar. The male longevity ranged from 4.83 ± 0.44d on Sprint to 7.45 ± 0.60d on Picasso. Impala and Satina with 53.22 ± 7.78 and 28.74 ± 3.54 eggs/individual had the highest and the lowest net reproductive rates (R₀). The highest values for the intrinsic rate of increase (r_m) and finite rate of increase (λ) were on Impala (r_m: 0.119 day^?1, λ: 1.75 day^?1), and the lowest value was on Sprint (r_m: 0.090 day^?1, λ: 1.01 day^?1). The results indicated that Sprint was the most resistant cultivar for the feeding of P.operculella, which could be useful in the development of integrated pest management programs for this pest.     

Efficacy of UV‐C radiation to reduce seedborne anthracnose (Colletotrichum acutatum) from Andean lupin (Lupinus mutabilis)

The potential of UV‐C radiation of Andean lupin (Lupinus mutabilis) seeds to eradicate seedborne infections of anthracnose caused by Colletotrichum acutatum was investigated. UV‐C doses from 0 to 691.2 kJ m^?2 (resulting from 0 to 96 h of exposure time) on disease incidence reduction and germination on artificially and naturally infected seed were evaluated. The degree of incidence reduction and seed germination was dependent on the dose of UV‐C. The UV‐C doses of 86.4 kJ m^?2 and higher reduced incidence from 6% to 7% to undetectable levels, but these UV‐C doses also reduced seed germination. UV‐C can deleteriously affect physiological processes and overall growth. To assess its impact, L. mutabilis seeds irradiated with UV‐C doses of 57.6 and 86.4 kJ m^?2 were grown. Seedlings grown from noninfected seed and UV‐C treated seed showed an increased concentration of chlorophyll and protein contents, as well as an increase in the activation of defence enzymes peroxidase and catalase, in comparison with plants grown from infected seed. UV‐C doses resulted in seed emergence and seedling dry weight rates that were similar to the noninfected control or better than the fungicide control. Moreover, 57.6 kJ m^?2 reduced transmission of the pathogen from seed to the plantlets by 80%, while 86.4 kJ m^?2 apparently eradicated the pathogen, under greenhouse conditions. The use of UV‐C, first reported here, is advantageous for controlling anthracnose in lupin.