We used a citrus seedling dipping method to evaluate pesticide toxicity toward pink citrus rust mite, Aculops pelekassi (Keifer), collected in Shizuoka Prefecture from three citrus orchards that had different pesticide use histories. Mancozeb and bifenazate were determined to be less effective against the three populations (correction density index >11), whereas lepimectin, milbemectin, lufenuron, amitraz, acequinocyl, pyridaben, tolfenpyrad, spiromesifen, fluazinam, and quinoxaline were highly effective (correction density index <2). In addition, the toxicity of pesticides not registered for use against the mite was evaluated in one population. Ethiprole, spinosad, pyrifluquinazon, hexythiazox, buprofezin, spirotetramat, cyenopyrafen, cyflumetofen, cyantraniliprole, flubendiamide, and mepanipyrim were determined to be highly effective (correction density index <2). When applying chemical control measures to A. pelekassi, however, care should be taken regarding the type and application timing of these effective pesticides, because some of them have serious harmful effects on natural enemies.

For biological control of aphids in greenhouses using “banker-plant” strategies, we compared the population growth of the bird cherry-oat aphid Rhopalosiphum padi (L.) on different gramineous grasses under different soil moisture conditions as follows. Experiment 1: eight species, including oat Avena sativa L. ‘Hayoat’, wheat Triticum aestivum L. ‘Satonosora’, barley Hordeum vulgare L. ‘Temairazu’, and rye Secale cereale L. ‘007’, were planted in three soil moistures (pF = 1.8, 2.0, and 2.2) in the commercial greenhouses of sweet pepper. Experiment 2: to clarify the effect of soil moisture on the population growth of aphids, the same grasses as above were planted under different soil moisture conditions (pF = 1.8 and 2.3) in experimental small greenhouses. The numbers of aphids were compared among the host plants and soil moisture conditions in both experiments. In the commercial greenhouses in Experiment 1, soil moisture significantly affected the number of aphids. However, soil moisture did not significantly affect the number of aphids in Experiment 2. Thus, we could not explain the differences in the population growth of aphids by soil moisture. The species of grass significantly affected the population growth of the aphids, suggesting oat, wheat, and rye were useful host plants for “banker-plant” strategies.

The red necked longhorn beetle (Aromia bungii), globally known as an insect pest damaging Rosaceae, was found in Osaka Prefecture in 2015. The occurrence pattern was examined of the species on their host trees (Rosaceae) in Osaka Prefecture between 2015 and 2017. The number of damaged trees increased over years and some trees seemed to have died due to the feeding of the long horn beetles.

More damages were observed in ornamental cherry trees with larger trunk (in perimeters at the root). When compared among similarly damaged trees of different size, larger trees were found less vulnerable and smaller ones tended to wither easily.

The highest damage position of each tree was measured, and in most trees, the positions were lower than 2 m above the ground. Also, they were higher in those trees with longer period of damage.

In order to develop the control measure of siso mosaic disease, whose causal pathogen is perilla mosaic virus transmitted by siso rust mite (Shevtchenkella sp.), we investigated occurrence of the mites on the perilla plants through two years and the frequency of disease occurrences on each branch of the perilla.

The first occurrence of siso rust mites appeared on perilla of self-sown seedlings from April to June. After that, siso rust mites appeared on other perilla in the next field. Three months after, siso rust mites appeared on perilla planted in greenhouse about 50 meters distant from that. The number of siso rust mites peaked from July to October in each field. The disease occurred and rapidly expanded from July to September, along with the occurrence of vector mites in each field. Therefore, this implies that the mites invaded from outside field into greenhouse and transmitted the disease despite of low density of the mites.

The frequency of disease occurrences in each perilla branch rapidly increased at 40 days after the viruliferous mites were released, but decreased 69 and 96 days later. We observed that the symptoms were disappeared on one of newly grown branches from the diseased branch, and some of those restored mosaic symptoms later. Accordingly, apparently healthy branch which has been infected can transmit the disease.

Overall, it is important to remove infected perilla in and outside of the greenhouses which can be potential sources of the disease, and to control the vector mites before their massive occurrence.

We examined the effects against the grape ripe rot (Glomerella cingulata (Stoneman) Spaulding & H. Schrenk (anamorph: Corretotrichum groeosporioides Penzig & Saccardo)), by spraying several fungicides including non-QoI (Quinone outside Inhibitors) fungicides and QoI fungicides. The cultivar of berries used in this experiment were “Kyoho” (Vitis vinifera L. × Vitis labrusca L. cv. Kyohou), and we sprayed fungicides in June to July, when the pathogen scatters most spores.

In 2015, 2016 and 2017, we sprayed each fungicides two times to the grape trees, leaves, and fruits at the immature fruits stage and influence on the fruits bloom by the fungicides were researched. And in 2016 and 2017, we measured the number of berries which infected by the grape ripe rot in the mature stage. As a result, in our experiments, the most effective fungicide is azoxystrobin (Amistar 10 flowable; Syngenta Japan, Inc.), followed by pyraclostrobin-boscalid (Naria WDG; BASF Japan, Inc.), captan (Orthocide 80; Arysta Life Science, Inc.), and penthiopyrad (Affet flowable; Mitsui Chemicals Agro, Inc.) in order.

Additionally, we also examined the influence of each fungicides to the berries in the mature stage. As a result, the bloom leaching appeared after pyraclostrobin-boscalid sprayed when berries were as large as the size of soybeans. However, 2016 and 2017, bloom leaching did not occur after spraying when berries size were as large as adsuki beans.

A investigation revealed that Neoseiulus californicus is the dominant species among the natural enemies of citrus red mite Panonychus citri in mandarin orange orchards in Shizuoka prefecture. In conventionally managed orchards, routine herbicide spraying suppresses habitats of phytoseiids. It has indicated that habitat management in orchards is important to conserve Phytoseiid mites for control of spider mites. Then, we compared the occurrence of N. californicus in orchards covered with rat’s tail fescue Vulpia myuros with that in orchards with bare soil in 2004 and 2005. We collected N. californicus from spikes of rat’s tail fescue in late April and from citrus trees after death of the fescue in May, but 1 to 5 weeks later in the bare-soil orchards. The peak density of the citrus red mite during the summer in the fescue orchards was 11% to 59% of that in the bare-soil orchards. In autumn and winter, we collected a few female adults of N. californicus from rat’s tail fescue. The provision of additional rat’s tail fescue may stabilize the occurrence of N. californicus in mandarin orange orchards in spring.

We investigated the use of soil alkalization with converter slag to control allium white rot (caused by Sclerotium cepivorum Berkeley) of Welsh onion (Allium fistulosum L.) planted in severely infested fields. The application of converter slag over the entire surface of experimental plots before planting significantly decreased the rate of heavily diseased plants at harvest both with (from 74.7% to 16.7%) and without (from 82.0% to 50.7%) preliminary soil disinfection. The alleviation of white rot was still evident to an extent in the next year without additional application. The application of a lower rate of converter slag into planting trenches decreased the rate of heavily diseased plants by almost the same amount as surface application in two independent trials. These results demonstrate the possibility of converter slag application before planting to alleviate the severity of allium white rot.

The aphid-controlling effect of flightless Harmonia axyridis and Aphidius colemani was examined for eggplants, which insectary plants were intercropped with and alternative diet for H. axyridis was supplied on, in a commercial greenhouse in Osaka Prefecture, Japan. By releasing H. axyridis larvae (second and third instar) and A. colemani adults thrice and twice, respectively, onto eggplants intercropped with sweet alyssum Lobularia maritima and with the provision of brine shrimp (Artemia sp.) eggs, density of the green peach aphid Myzus persicae was maintained low for approximately three months (late April–late July).

Mosaic diseases and wilt are caused by viral infections, and cause loss of cucumber yield. It is a serious problem for cucumber cultivation in Japan. In Osaka prefecture, the main virus type detected in cucumber plants with the disease symptoms was Zucchini yellow mosaic virus (ZYMV). Greenhouse shade treatment reduced the temperature differences between sunny and cloudy or rainy days and occurrence of wilt symptoms caused upon ZYMV inoculation. The result supported the hypothesis that wilting caused by viral infection was probably induced by drastic changes in temperature from cloudy or rainy days to clear sunny days. The combined use of CUBIO ZY-02 (ZYMV vaccine) and greenhouse shading prevented the reduction in cucumber yield, due to ZYMV infection, from the nursery stage.

I tested the toxicity of insecticides against the adults, eggs, and hatchlings of pea blue, Lampides boeticus (Linnaeus), on the peas of summer seeding cultures. I examined the insecticides’ effects in preventing the first instar larvae from eating into the pea pods. Seven insecticides showed high effectiveness against the adults. In particular, pyrethroids (etofenprox, permethrin, tau-fluvalinate, and tralomethrin) showed rapid effects. The spraying of any of these insecticides on a wide area might prevent the laying of eggs. Additionally, 10 insecticides showed high effectiveness against the eggs and hatching larvae. The insecticides that showed the ovicidal effect included emamectin, spinosad, etofenprox, and acetamiprid, which are also effective against hatching larvae. The spraying of any of these insecticides flower buds might have a stable controlling effect. Ten insecticides were shown to be effective in preventing the first instar larvae from eating into snow pea pods. Cartap, malathion, etofenprox, permethrin and tau-fluvalinate showed no feeding traces on the pea pod surfaces. This finding suggests that it would be most practical to use these insecticides when the snow peas bear pea pods.

Conditions for effective anaerobic soil disinfection (ASD) using sugar-containing diatomite and dried molasses were investigated. In the laboratory, ASD using diatomite and dried molasses (1% [w/w]) were more effective for disinfection of Ralstonia solanacearum compared with use of the control molasses. At 20–50°C, oxidation-reduction potential of soil after ASD decreased with increasing temperature. In addition, R. solanacearum population in soil decreased to a level below the detection limit at 30°C when sugar-containing diatomite was used and no R. solanacearum were detected from untreated soil after 14 days incubation at 40 and 50°C. During soil disinfection in the summer greenhouse in Wakayama prefecture, soil temperature at 30 cm depths was maintained above 40°C for 12 days. Soil temperature at 40 cm depth was maintained above 40°C or did not reach 40°C depending on the field. From the above, in the shallower layer than 30 cm underground, R. solanacearum population is assumed to decrease due to the high soil temperature. On the other hand, in the deep layer than about 30–40 cm underground, it is expected that R. solanacearum population decrease due to ASD caused by eluted component of sugar-containing diatomite and dried molasses.

Ceratocystis canker is one of the most serious diseases of figs, Ficus carica, in Japan. Some fungicides, such as triflumizole WP (T) and thiophanate-methyl WP (TM), have been drenched monthly to control the disease. However, these fungicides are not applied during harvest season because of registration restrictions, and losses of soil drench during harvest season were feared. We evaluated effectiveness of control with soil drenches of the newly registered tebuconazole WP (TE), which can be used up to the day before harvest. We planted fig cuttings in the soil contaminated with Ceratocystis ficicola, causal agent of Ceratocystis canker. Treatments were as follows: 1) control, 2) existing treatment (T and TM drenched bimonthly from April to October, except for the harvest period from August to October), 3) existing treatment plus TE at harvest (TE drenched monthly from August to October). Cumulative death rates of plants in each treatment were evaluated for 3 years. More than half of the plants died in the control, and less than half of plants died in the existing treatment. On the contrary, no plants died in the existing treatment plus TE. These results suggest that existing treatment plus TE possess high control effect against the disease.

We investigated the effect of various plants on the population density of Plasmodiophora brassicae, which causes clubroot disease in crucifers. The amount of P. brassicae in soil samples was measured using quantitative real-time PCR (qPCR). The impact of the plants used in this study was generally small under both greenhouse and field conditions. P. brassicae does not cause clubroot disease in leaf radish (ha-daikon), but is known to be able to proliferate in the root hairs of the plant. The qPCR could also detect an increased density of P. brassicae in soil where leaf radishes were grown.

The effects of utilization of agricultural mulch sheets against brown rot on Citrus unshiu were examined in this study. This disease is caused by Phytophthora palmivora and P. nicotianae which were observed during two cultural seasons from 2016 to 2017. The difference in the number of diseased fruits in mulching cultivation areas and open cultivation areas was surveyed. As a result, it was revealed that utilization of agricultural mulch sheets is effective to control the disease.

We demonstrated a method for the quick discrimination of live and dead sclerotia of the allium white rot pathogen (Sclerotium cepivorum Berkeley) by vital staining with fluorescein diacetate (FDA) hydrolysis. Surface-sterilized sclerotia were cracked by forceps and placed on a water agar plate. Within 20–30 min after the application of 1.25–10 ppm FDA, bright green fluorescence was observed from within and around the sclerotia under blue light (480 nm ). Water agar (background) and autoclaved (dead) sclerotia emitted negligible fluorescence with 10 ppm FDA. Inhibition of sclerotial germination by cyanamide did not affect fluorescence. FDA application did not suppress germination and growth of sclerotia. This method can be used to assess the viability of sclerotia quickly.

To estimate the influence of harvest timing on the severity of allium white rot (caused by Sclerotium cepivorum Berkeley) of Welsh onion (Allium fistulosum L.), we compared the severity of white rot during 5 cropping periods. The rate of plant death was significantly lower during the 2 earlier cropping periods (15 June–24 Nov., 30 June–16 Dec.) than during the 3 later periods (15 Jul.–14 Jan., 5 Aug.–28 Jan., 19 Aug.–28 Jan.). The results indicate that earlier cropping allowing harvest in December can avoid severe damage by white rot because of the shorter cool soil period (daily average <15°C).

We investigated the efficiencies of several treatments to control clubroot disease caused by Plasmodiophora brassicae on ‘Tennoji-kabura’ turnip (Brassica campestris L. ‘Tennoji-kabura’), a traditional vegetable in Osaka, Japan. Growing ‘Tanabe-daikon’ (Japanese radish) for 1.5 months as a decoy plant reduced the gall formation as is in the case of growing leafy daikon breeding line CR-1. Dolomite-converter slag raised the soil pH from 6.8 to 7.5, and remarkably suppressed the gall formation in ‘Tennoji-kabura’. A commercial seaweed fertilizer did not yield a significant effect.

Wild soybean consumption by nine species of coleopteran adults and two species of Trachyinae larvae was investigated for the environmental assessment of Bt soybean. The leaf area eaten by the coleopteran adults per day was 1158, 915, 599, 30, 22, and 6 mm² for Mimela splendens, Anomala rufocuprea, Epicauta gorhami, Medythia nigrobilineata, Trachys reitteri, and Pagria ussuriensis, respectively. The total area eaten by the Trachyinae larvae was 200 and 599 mm² for T. reitteri and T. auricollis, respectively.

The control effects of 14 insecticides on the diamondback moth, Plutella xylostella (Linnaeus), collected from Komatsuna, Brassica rapa L.var. perviridis, in Wakayama City, were investigated at 3rd instar larvae using the leaf-dipping method. Spinetoram, spinosad, emamectin benzoate, and two BT-insecticides exhibited high insecticidal activity. Flufenoxuron, chromafenozide, cypermethrin, chlorantraniliprole, and flubendiamide had low efficacity. Lepimectin showed relatively low efficacy on the 4th day after treatment, but all individuals died later. Mortality rates associated with lepimectin, pyridalyl, metaflumizone, and chlorfenapyr in the Nagusa population were lower than these in the Kasei population.

The efficacy of insecticides against adults of the Hawaiian flower thrips, Thrips hawaiiensis (Morgan), and larvae of the garden pea leafminer, Chromatomyia horticola (Goureau), on the garden pea (snap pea), Pisum sativum L., was evaluated under laboratory conditions. Seven insectides (cartap, chlorfenapyr, clothianidin, emamectin, phenthoate, imidacloprid, and spinetoram) were effective against T. hawaiiensis adults and three insecticides (chlorantraniliprole, imidacloprid, and spinetoram) were effective against C. horticola larvae.

We examined the nymphal development of the fruit-piercing stink bug, Glaucias subpunctatus, a pest of citrus and pears, on mature capsules of the Chinese tallow-tree, Triadica sebifera, considered to be an alternative host plant. The rearing experiment revealed that all nymphs after the second instar stage developed and survived to adulthood, but a large proportion of the second instar nymphs died, considered to be due to sucking failure. The marked mortality of the second instars may be due to the hard seed coat of T. sebifera. In conclusion, T. sebifera may be an alternative host plant after the successful passage of second instars on immature capsules of T. sebifera, or on Cryptomeria japonica or Chamaecyparis obtuse, conventionally viewed as the host plants.

We estimated the density of shoot blight from Pestalotiopsis longiseta and rolled leaves produced by Adoxophyes honmai or Homona magnanima in tea fields using a direct counting method based on aerial photography from a multirotor-type drone. We used a DJI Phantom 4 to conduct aerial photography of shoot blight and rolled leaves. We then counted the densities of both the diseased and rolled leaves in-situ. We examined the aerial photographs on a LCD, and identified and counted the densities of both the diseased and rolled leaves. The relationship between the densities of shoot blight counted using the LCD and in-situ was R² = 0.69 and 0.76, respectively. The accuracy of estimation using the LCD was about 80%. These results suggested that estimation of the density of shoot blight based on aerial photography was effective. For the rolled leaves, the accuracy of counting using an LCD increased to about 60% from <40%, after comparing to the first count.

We examined the effect of 13 pesticides by using the kidney bean leaf-dipping method on the 1st instar larvae, 3rd-4th instar larvae, and adults of Q-biotype Bemisia tabaci (Gennadius) collected from three major tomato-growing districts in Aichi Prefecture. The effects of the pesticides on Q-biotype were almost the same as previously reported, whereas those of pyridaben WP and tolfenpyrad WP were lower. In addition, the appropriate timing for applying the pesticides in forcing culture, the main tomato cultivation method in Aichi prefecture, is discussed based on our study results.

We investigated the ability of phytoseiid mites in intercropped barley to suppress onion thrips (Thrips tabaci Lindeman) on Welsh onion in the laboratory. Ten adult females of T. tabaci were released into a cage containing Welsh onion seedlings planted in a pot and intercropped with barley transplanted from a Welsh onion field. For comparison, insecticide-treated barley and soil from the Welsh onion field were tested. At 20 days after release, the number of T. tabaci was lowest (significantly) in the untreated barley, but there was no change in the treated barley. Phytoseiid mites (mainly Gynaeseius liturivorus (Ehara)) were observed only in untreated barley.

Control effects of etoxazole spraying were investigated for cotton aphid, Aphis gossypii Glover and potato aphid, Macrosiphum euphorbiae (Thomas) on strawberry. Densities of both aphid species were suppressed 3–14 days after spraying. Results show that etoxazole is effective to control aphids on strawberry.

Toxicities of 21 insecticides for Tetranychus kanzawai Kishida collected from a strawberry field in Nara Prefecture were investigated. Corrected mortality rates of these insecticides, except malathion, were almost 100%. Chemical control of T. kanzawai was inferred as possible by spraying these insecticides.

Toxicities of insecticides for adult females of Tetranychus urticae Koch collected from five chrysanthemum fields in Nara Prefecture were investigated. The corrected mortality rates of bifenazate were 100% in all populations. The rates of acequinocyl and abamectin were higher than 80% in three and four populations, respectively. No significant decrease of susceptibility was found. The rates of milbemectin and emamectin benzoate were lower than 50% in one or two fields, respectively. The rates of cyenopyrafen, pyflubumide-fenpyroxymate, spinetoram were lower than 28.4% in all fields.

The first generation of crawlers of arrowhead scale Unaspis yanonensis (Kuwana) occur in citrus orchards from early May to late July. Insecticide application is generally carried out to control U. yanonensis during the peak days of larval occurrence in June. We demonstrated that a high synergistic effect in controlling U. yanonensis was observed with the combined application of petroleum oil (9.7 g/L) and buprofezin (0.2 g/L) at the adult stage in late April. However, independent application of each insecticide during this time was less effective in controlling U. yanonensis.

Seven insecticides were treated against cotton ballworm larvae with kidney bean leaves. Two days after treatment, all insecticides were found to have high toxicity at commercial and 1/10 of this concentrations. It was thought that chemical control of cotton ballworm can be accomplished using rotation spray of these insecticides.

For two western flower thrips (WFT) populations collected from chrysanthemum fields in Nara prefecture, toxicities of seven insecticides were investigated. Fipronil was most effective in terms of corrected mortality, followed by prothiofos and chlorfenapyr. Tolfenpyrad, thiocyclam and abamectin were less effective in terms of corrected mortality but leaf damages were scarce. Spinosad was less effective in terms of corrected mortality and leaf damage. These result suggest that WFT populations on chrysanthemum in Nara prefecture developed resistance to spinosad.

The species composition and seasonal occurrence of phytoseiid mites on weeds around the eggplant field were investigated by collecting the weeds from April 2016 to March 2017 in Osaka Prefecture, Japan. The phytoseiid mites were extracted from the collected weeds using Tullgren funnels provided with a light bulb. Totally, 288 adult females were sampled, and 12 native and 1 non-native species were identified. The predominant species was Scapulaseius okinawanus (Ehara), accounting for 49.7% of the total number of identified adult females. The second most abundant species was Neoseiulus barkeri (Hughes) (16.3%), followed by Amblyseius tsugawai Ehara (14.2%) and Neoseiulus koyamanus (Ehara and Yokogawa) (7.3%). The four species are all native. Scapulaseius okinawanus was abundant from May to July and in November, and N. barkeri was captured exclusively in September.

The species composition of lepidopteran insects feeding on Japanese pear blossoms was investigated in Kyotango City, Kyoto Prefecture, from late March to late April in 2017. Pasiphila rectangulata (Linnaeus), Archips nigricaudanus (Walsingham), and Ptycholoma lecheana circumclusana (Christoph) were found from early to mid-April. It was reported for the first time that A. nigricaudanus feeds on the blossoms. Pa. rectangulata was predominant of the three species.

In Osaka prefecture, we investigated the species composition of thrips captured from leaves and flowers on cultivated Chrysanthemum morifolium. As results, Thrips nigropilosus was the dominant species on the leaves. But on the flowers, species composition of thrips diversified and dominant species were changed by fields and months. The results suggested that the species composition of thrips depends on the parts of the C. morifolium plant.

Susceptibility of beet armyworm Spodoptera exigua (Hübner) from watermelon to insecticides in Wakayama was determined in the 2nd instar larvae using the leaf dipping method. Spinetoram, spinosad, lepimectin, emamectin, and chlorfenapyr were effective on the 1st day after treatment, whereas pyridalyl and chromafenozide were effective on the 5th day after treatment. Toxicities of emamectin, pyridalyl, and chromafenozide in the Inami population were lower than those in the Gobo population.

Euzophera batangensis Caradja and Synanthedon tenuis (Butler) cause serious damages in persimmon stems. I examine the causes of death in overwinter larvae. In the persimmon trees, dead larvae with white fungi were found frequently. In raring test, although two parasite wasps emerged from E. batangensis larvae, no parasite insects emerged from S. tenuis larvae. Dead larvae with white fungi were found in both species under raring condition. Hatch ratio of E. batangensis was lower than S. tenuis. The difference of parasitism between two stem pests correspond to the tendency of actual specie that injures persimmon stems in spring season.

Enclosing with a red insect-proof net and defuse-reflection mulch sheets were set up in an open fig orchards in Osaka Prefecture in 2017. The dominant thrips species found on the sticky color traps were Thrips tabaci Lindeman from late May to early June and Frankliniella intonsa (Trybom) from mid-June to mid-July. Thrips hawaiiensis (Morgan) was dominant inside fig fruits. The use of these materials effectively prevented thrips from immigrating into the fig orchards, reducing population numbers and infestation of figs. We recommend placing these materials by the middle of May.

We investigated the method for measuring the adhesion amount of medicine sprayed on crops.

Potassium solution as an indicator was sprayed on strawberries, and potassium attached to phylloplane was washed while shaking and collected in a vial. Next, the recovered potassium was measured with an atomic absorption spectrophotometer. When comparing distilled water, 0.025 mol/L hydrochloric acid, and 0.25-N hydrochloric acid, 0.025 mol/L hydrochloric acid was most suitable for potassium recovery. Moreover, since the potassium present in strawberry juice may interfere with the measurement, it is critical that we use leaves that are not scratched.

If we use the insecticide clothianidin or fipronil in a seedling growing box, we can apply the insecticide just before rice planting (hereinafter, termed as “rice planting treatment”) or after seeding and before the seed is covered by soil (hereinafter, termed as “rice seeding treatment”). With the rice seeding treatment, the clothianidin level in plants at the rice-planting stage was 18.4 mg/kg, which was the highest value, and the level rapidly decreased thereafter. With the rice planting treatment, the clothianidin level increased to 1.53 mg/kg 1 day after rice planting and decreased thereafter. The difference in the levels between both treatments at 28 days from the rice planting was small. The fipronil level with rice seeding treatment was higher than that with the rice planting treatment at the rice-planting stage. But there were little differences in the fipronil levels between both treatments after 1 day from rice planting and thereafter.