苯醚威作用于不等单蚤的组织学研究（蚤目：蚤科）

目的通过研究苯醚威对不等单蚤的早3龄幼虫和未吸血新羽化成虫的组织学变化,探讨其灭蚤机制,为鼠疫媒介蚤种的防治提供基础资料。方法用微量点滴法将苯醚威施药于不等单蚤早3龄幼虫和未吸血新羽化成虫,采用组织学、显微摄影及统计学方法观察组织变化。结果经苯醚威作用后,不等单蚤早3龄幼虫的表皮增厚,卵巢芽先增大后缩小,睾丸芽缩小,中肠上皮细胞萎缩;不等单蚤未吸血新羽化成虫的睾丸塞消失快,唾液腺细胞破坏,中肠上皮细胞萎缩。结论（1）苯醚威通过于扰不等单蚤幼虫的变态,引起幼虫表皮、生殖芽和中肠上皮细胞异常改变,未能发育为成虫而死亡。（2）苯醚威可加速不等单蚤新羽化雄性成虫的睾丸塞吸收。（3）苯醚威可破坏不等单蚤新羽化成虫的唾液腺细胞,并引起中肠上皮细胞萎缩。     

Local abundance of Ixodes scapularis in forests: Effects of environmental moisture,vegetation characteristics,and host abundance

Ixodes scapularis is the primary vector of Lyme disease spirochetes in eastern and central North America, and local densities of this tick can affect human disease risk. We sampled larvae and nymphs from sites in Massachusetts and Wisconsin, USA, using flag/drag devices and by collecting ticks from hosts, and measured environmental variables to evaluate the environmental factors that affect local distribution and abundance of I. scapularis. Our sites were all forested areas with known I. scapularis populations. Environmental variables included those associated with weather (e.g., temperature and relative humidity), vegetation characteristics (at canopy, shrub, and ground levels), and host abundance (small and medium-sized mammals and reptiles). The numbers of larvae on animals at a given site and season showed a logarithmic relationship to the numbers in flag/drag samples, suggesting limitation in the numbers on host animals. The numbers of nymphs on animals showed no relationship to the numbers in flag/drag samples. These results suggest that only a small proportion of larvae and nymphs found hosts because in neither stage did the numbers of host-seeking ticks decline with increased numbers on hosts. Canopy cover was predictive of larval and nymphal numbers in flag/drag samples, but not of numbers on hosts. Numbers of small and medium-sized mammal hosts the previous year were generally not predictive of the current year’s tick numbers, except that mouse abundance predicted log numbers of nymphs on all hosts the following year. Some measures of larval abundance were predictive of nymphal numbers the following year. The mean number of larvae per mouse was well predicted by measures of overall larval abundance (based on flag/drag samples and samples from all hosts), and some environmental factors contributed significantly to the model. In contrast, the mean numbers of nymphs per mouse were not well predicted by environmental variables, only by overall nymphal abundance on hosts. Therefore, larvae respond differently than nymphs to environmental factors. Furthermore, flag/drag samples provide different information about nymphal numbers than do samples from hosts. Flag/drag samples can provide information about human risk of acquiring nymph-borne pathogens because they provide information on the densities of ticks that might encounter humans, but to understand the epizootiology of tick-borne agents both flag/drag and host infestation data are needed.     

Strain difference in sensitivity to 3,4-dichloroaniline and insect growth regulator, fenoxycarb, in Daphnia magna

Acute and reproductive toxicity tests were conducted on seven strains of Daphnia magna from six laboratories in five countries. 3,4-Dichloroaniline (DCA) and fenoxycarb were used as test chemicals. Acute toxicity tests revealed that estimated EC(50) (50% effective concentration) values for DCA varied by a factor of 2.1 among strains (310-640 microg/L), whereas the EC(50) values for fenoxycarb varied by a factor of 4 (210-860 microg/L). EC(50) values for reproductive toxicity tests with DCA ranged from 5.9 to 38 microg/L among strains. Fenoxycarb exposure induced the production of male neonates in all the strains used in the present study. Estimated EC(50) values for the induction of male offspring were highly variable among strains: sensitivity to fenoxycarb differed by a factor of approximately 23 overall (0.45-10 microg/L). The present pre-validation tests suggest that induction of male sex in neonates by a juvenile hormone analog is universal among genetically different strains. Decreased total numbers of neonates at increased concentrations of fenoxycarb as well as other juvenoids may, however, obscure the incidence of male neonates production in the 21-day reproduction tests due to the low statistical power.     

Voles,shrews and red squirrels as sources of tick blood meals and tick-borne pathogens on an island in southwestern Finland

Molecular identification of the previous blood meal source of a questing tick (Acari: Ixodidae) from blood meal fragments was proposed a few decades ago. Following this, several blood meal assays have been developed and published, but none of them have been taken into widespread use. Recently, novel retrotransposon-based qPCR assays designed for detecting blood meal fragments of North American host species were published. We wanted to assess their function with host species present in Finland.Questing ticks were collected by cloth dragging in August-September 2021 from an island in southwestern Finland. DNA was extracted from Ixodes ricinus nymphs (n=438) and qPCR assays applied to identify larval blood meal sources (voles, shrews and red squirrels) and screen for several tick-borne human pathogens and other microbes with pathogenic potential [Borrelia spp. (including specific assays for Borrelia afzelii, Borrelia garinii, Borrelia valaisiana), Anaplasma phagocytophilum, Babesia spp., Rickettsia spp., and Neoehrlichia mikurensis].The probability of a nymph having fed as larva on either a vole, shrew or red squirrel was 0.34 (0.30 – 0.38; 95% confidence interval). Bacteria of the genus Borrelia were the most common pathogens detected, with host-specific probabilities of carrying Borrelia of 0.30 (0.18 – 0.44) for nymphs that had fed on voles, 0.23 (0.14 – 0.35) for nymphs that had fed on shrews, and 0.42 (0.28 – 0.58) for nymphs that had fed on red squirrels. Other microbes were rarely acquired from these hosts, apart from N. mikurensis from voles.This study highlights that shrews and red squirrels may equal voles as blood meal sources for I. ricinus larvae. Overall, variation in proportions of blood meals provided by these animals may be high across even proximate study areas. All studied host species appeared to be important sources for particularly Borrelia afzelii, and voles also for N. mikurensis.     

A spatially-explicit model of acarological risk of exposure to Borrelia burgdorferi-infected Ixodes pacificus nymphs in northwestern California based on woodland type,temperature, and water vapor

In the far-western United States, the nymphal stage of the western black-legged tick, Ixodes pacificus, has been implicated as the primary vector to humans of Borrelia burgdorferi sensu stricto (hereinafter referred to as B. burgdorferi), the causative agent of Lyme borreliosis in North America. In the present study, we sought to determine if infection prevalence with B. burgdorferi in I. pacificus nymphs and the density of infected nymphs differ between dense-woodland types within Mendocino County, California, and to develop and evaluate a spatially-explicit model for density of infected nymphs in dense woodlands within this high-incidence area for Lyme borreliosis. In total, 4.9% (264) of 5431 I. pacificus nymphs tested for the presence of B. burgdorferi were infected. Among the 78 sampling sites, infection prevalence ranged from 0% to 22% and density of infected nymphs from 0 to 2.04 per 100 m². Infection prevalence was highest in woodlands dominated by hardwoods (6.2%) and lowest for redwood (1.9%) and coastal pine (0%). Density of infected nymphs also was higher in hardwood-dominated woodlands than in conifer-dominated ones that included redwood or pine. Our spatial risk model, which yielded an overall accuracy of 85%, indicated that warmer areas with less variation between maximum and minimum monthly water vapor in the air were more likely to include woodlands with elevated acarological risk of exposure to infected nymphs. We found that 37% of dense woodlands in the county were predicted to pose an elevated risk of exposure to infected nymphs, and that 94% of the dense-woodland areas that were predicted to harbor elevated densities of infected nymphs were located on privately-owned land.     

First isolation of Borrelia lusitaniae DNA from green lizards (Lacerta viridis) and Ixodes ricinus ticks in the Czech Republic

This study aimed to reveal whether green lizards (Lacerta viridis), common hosts of tick larvae and nymphs, might be involved in the transmission cycle of Borrelia burgdorferi sensu lato in the Czech Republic. Green lizards were sampled in two areas at the Tiché Údolí Nature Reserve (site A: 50.1482 N, 14.3669E; site B: 50.1476 N, 14.3745 E), Central Bohemian Region, Czech Republic. The skin biopsy specimens and attached ticks (if any) were collected from 52 captured lizards. Also, questing ticks from both areas were collected by flagging. The touchdown polymerase chain reaction and gel electrophoresis revealed Borrelia lusitaniae in three lizard tissue samples. Most lizards (19/30, 63%) had at least one Borrelia positive tick. Borrelia lusitaniae formed 92% (34/37) and 59% (17/29) of all borreliae detected in larvae and nymphs, respectively. Borrelia lusitaniae (6/10, 60%) was also the major pathogen in questing nymphs from site B. At site A, 13% (2/16) of questing nymphs were positive for B. lusitaniae. Based on our data, it can be assumed that B. lusitaniae is a common pathogen at lizard sites in the Czech Republic, and further research to prove this hypothesis is therefore highly recommended. As lizards often inhabit urban areas, the data presented may also contribute to raising awareness of the possible spread and risk of Borrelia infection.     

Aluminum accumulation in a lotic mayfly at low pH--a laboratory study

The authors experimentally studied the occurrence of aluminum (Al) accumulation in nymphs of the mayfly Heptagenia sulphurea at low pH (4.5). Nymphs were exposed to two Al concentrations (0.2 and 2 mg inorganic Al liter-1), and two exposure times (2 and 4 weeks), the longer time period also including a molting phase. The major part of the Al was deposited on/in the exuviae of the nymphs, as Al determination in nymphs showed a 70% decrease in Al content after molting. When nymphs were exposed for two instar periods, with a molt in between. Al content almost doubled (2.34 mg Al g-1 dry wt) compared with that of a one-instar treatment (1.24 mg Al g-1 dry wt). This indicated that Al also accumulated within the mayfly nymphs. Determination of Al in emerged adults confirmed that most of the metal was deposited externally on the nymphs. No clear indications of Al accumulation were found in this short-term experiment. The implications for food-web accumulation of Al are that internally accumulated Al may be transferred to terrestrial predators by mayflies and other aquatic insects that leave their final exuvium in the water. However, aquatic insects that make their final molt in the terrestrial environment, and thereby bring adsorbed Al out of the water are more likely vectors.     

Effect of sedimentary cadmium on the behavior of a burrowing mayfly (Ephemeroptera, Hexagenia limbata)

Behavioral responses of aquatic invertebrates can serve as precocious indicators of adverse effects caused by metals. We conducted experiments to determine if the behavior of nymphs of the burrowing mayfly Hexagenia limbara (Ephemeroptera) was modified by the presence of cadmium (Cd) in sediments. We first exposed H. limbata to concentrations of sedimentary Cd found in lakes subject to smelter emissions (20 microg/g dry wt). We then compared the burrowing activity of control and Cd-contaminated nymphs by means of radiographs. We also studied the time allotted by nymphs to various activities (irrigation, walking, burrowing/feeding, cleaning, and turning) as determined from films taken using an infrared video camera. The results obtained suggest no significant difference in the burrowing activity of control versus Cd-contaminated individuals. Furthermore, the time spent in various behavioral activities was similar between control and Cd-contaminated nymphs. Given these results, we conclude that Cd has no effect on the behavior of H. limbata for the range of Cd concentrations that we measured in nymphs.     

转基因技术及骨髓间充质干细胞在骨缺损修复中的应用与展望

骨髓间充质干细胞（bone mesenchymal stem cells,BMSCs）是一类存在骨髓内的非造血干细胞,具有较强的增殖功能及多向分化潜能.在一些细胞因子的诱导下可以向成骨系细胞、内皮细胞、成纤维系细胞、成软骨系细胞等方向分化,近年来已成为生物学和医学的研究热点.而转基因技术是一项目前较为热门的生物科技技术.本文简要介绍了不同基因如骨形态发生蛋白（bone morphogenetic protein,BMP）、血管内皮细胞生长因子（vascular endothelial growth factor,VEGF）、软骨源性形态发生蛋白1（cartilage-derived morphogenetic protein 1,CDMP-1）、碱性成纤维细胞生长因子（basic fibroblast growth factor,bFGF）、成骨生长肽（osteogenic growth peptide,OGP）等通过转染后对BMSCs增殖、分化的影响及其在骨缺损修复中的应用.     

Teratogenesis of the horseshoe crab by alpha-lipoic amide (6,8-thioctic amide) in marketed vitamin tablets

Some marketed vitamin tablets induce defects and fusion of body segments and appendages in the developing horseshoe crab. alpha-Lipoic amide may be responsible for the induction, and the other vitamins are probably not directly responsible. alpha-Lipoic acid also induces the same malformations. It is presumed that alpha-lipoic amide and alpha-lipoic acid inhibit thioldisulphide exchange and this inhibition disturbs the morphogenetic movement. As a result, the monsters may be induced by treatment with vitamin tablets.     

Fine-scale tissue distribution of cadmium, inorganic mercury, and methylmercury in nymphs of the burrowing mayfly Hexagenia rigida studied by whole-body autoradiography

The distribution of inorganic 109Cd(II), inorganic 203Hg(II), and [203Hg] methylmercury (MeHg) in nymphs of the burrowing mayfly Hexagenia rigida after exposure via water and sediments was studied. To better understand the mechanisms underlying the fate of Cd, Hg, and MeHg in this animal and to identify target organs, autoradiography of whole-body cryosections was used to obtain a detailed view of the distribution of the radiolabels. The gut and exoskeleton were the only structures labeled in nymphs exposed to Cd via water or sediments. After exposure to inorganic Hg via water, the Malpighian tubules exhibited a very high labeling, indicating that these organs may be a target for Hg toxicity. The distribution of Hg after exposure via sediments was similar, though the labeling of Malpighian tubules was less intense. Distribution of MeHg strongly differed between treatment groups. Nymphs were rather uniformly labeled after exposure via water, whereas in those exposed to MeHg in sediments, the intense labeling of all internal tissues contrasted with the very low labeling of the hemolymph, indicating that the translocation rate of the absorbed MeHg was faster in the latter group. This may be related to the complexation of MeHg by small thiol ligands in the gut as a result of the digestion process.     

Deer management generally reduces densities of nymphal Ixodes scapularis,but not prevalence of infection with Borrelia burgdorferi sensu stricto

Human Lyme disease–primarily caused by the bacterium Borrelia burgdorferi sensu stricto (s.s.) in North America–is the most common vector-borne disease in the United States. Research on risk mitigation strategies during the last three decades has emphasized methods to reduce densities of the primary vector in eastern North America, the blacklegged tick (Ixodes scapularis). Controlling white-tailed deer populations has been considered a potential method for reducing tick densities, as white-tailed deer are important hosts for blacklegged tick reproduction. However, the feasibility and efficacy of white-tailed deer management to impact acarological risk of encountering infected ticks (namely, density of host-seeking infected nymphs; DIN) is unclear. We investigated the effect of white-tailed deer density and management on the density of host-seeking nymphs and B. burgdorferi s.s. infection prevalence using surveillance data from eight national parks and park regions in the eastern United States from 2014–2022. We found that deer density was significantly positively correlated with the density of nymphs (nymph density increased by 49% with a 1 standard deviation increase in deer density) but was not strongly correlated with the prevalence of B. burgdorferi s.s. infection in nymphal ticks. Further, while white-tailed deer reduction efforts were followed by a decrease in the density of I. scapularis nymphs in parks, deer removal had variable effects on B. burgdorferi s.s. infection prevalence, with some parks experiencing slight declines and others slight increases in prevalence. Our findings suggest that managing white-tailed deer densities alone may not be effective in reducing DIN in all situations but may be a useful tool when implemented in integrated management regimes.     

Triatoma brasiliensis Neiva, 1911 (Hemiptera, Reduviidae): observations on dynamics of feeding behavior in an artificial ecotope

In order to study the behavior of triatomine bugs under artificial ecotopic conditions, an experimental, double-walled poultry coop was built. Its inside walls were made of sun-dried clay blocks which could be broken apart for better access to the insects hiding in their crevices. The coop was subdivided into two main areas of different sizes using wire netting and a wall made of perforated bricks. The chickens, the only food source available for the triatomines, were kept in the larger, rectangular area, further subdivided diagonally. The triatomines were released in the smaller area and were allowed to migrate to the larger one though the holes in the bricks. Information about migration, survival, and hiding places of fourth-stage nymphs of Triatoma brasiliensis was thus gathered. At 30-day intervals, over a period of six months, the inner walls of the house were taken apart and inspected. The nymphs were marked with different colors according to the month and place of capture. It was found that 88.5% of the nymphs were captured near the roost and found engorged. After having taken their first blood meal, they would remain in the vicinity of their food source. The results obtained are considered epidemiologically relevant, and particularly so as pertaining to the control of the vectors of Chagas disease.     

铝盐在水溶液中的水解和聚合反应对铝致大鼠发育毒性的影响

目的;探讨铝盐在水中发生的化学反应对铝发育毒性的影响。方法：用全胚胎培养方法比较新配和存放11．5个月的Al2(SO4)3溶液对大鼠胚胎生长发育和器官形态分化的抑制效应。结果;二种受试溶液均表现出一定的胚胎毒性和致畸性,但与新配溶液相比,存放溶液的毒性明显降低。在同一浓度下,给予存放溶液的大鼠其反映胚胎生长发育的各项指标和反映器官形态分化的Brown总评分,以及畸形胚胎发生率和胚胎死亡均明显低于新溶液,其中胚胎死亡率下降幅度更大。结论：存放的Al2(SO4)3溶液因子Al^3 与水分子发生络合反应使Al^3 的存在状态发生改变,使其对大鼠的发育毒性减弱。     

Is there an advantage to including the nucleoprotein in a rabies glycoprotein subunit vaccine?

The PV rabies (genotype 1) G and N proteins were produced by recombinant baculoviruses in insect cells. We tested the ability of recombinant antigens to synergistically induce an immune response and, particularly, to broaden the spectrum of Lyssavirus-neutralizing antibodies produced. Cell-free preparations of recombinant proteins caused an immune response. Recombinant rabies G protein (RRG) from infected cell extract or supernatant induced virus neutralizing antibodies (VNAb) against rabies (CVS virus (genotype 1) and in a less extent against European Bat Lyssavirus-1 (EBL-1:genotype 5) Recombinant rabies N protein (RRN) induced antibodies that reacted with the rabies virus ribonucleoprotein (RNP) and primed mice for both the production of VNAb induced by inactivated and purified rabies virus and the protection conferred by RNP. RRN also had an adjuvant effect on VNAb production induced by RRG when the two recombinant proteins were physically associated either encapsulated in liposomes or subjected to ultrasound treatment. However, there was no increase in production of VNAb directed against EBL-1 although classical vaccines (genotype 1) induce partial protection against this virus. thus, beside its adjuvant effect there is some doubt as to whether including rabies N protein in a rabies subunit vaccine containing the recombinant G protein would be advantageous.     

M2SR,a novel live influenza vaccine,protects mice and ferrets against highly pathogenic avian influenza

The emergence of highly pathogenic avian influenza H5N1 viruses has heightened global concern about the threat posed by pandemic influenza. To address the need for a highly effective universal influenza vaccine, we developed a novel M2-deficient single replication (M2SR) influenza vaccine virus and previously reported that it provided strong heterosubtypic protection against seasonal influenza viruses in mice. In the current study, we assessed M2SR induced protection against H5N1 influenza in mice and ferrets.Mice were intranasally inoculated with M2SR viruses containing the HA and NA from A/Vietnam/1203/2004 (M2SR H5N1) or A/California/07/2009 (M2SR H1N1). All M2SR vaccinated mice survived lethal challenge with influenza A/Vietnam/1203/2004 (H5N1), whereas 40% of mice vaccinated with recombinant H5 HA and none of the naïve controls survived. M2SR H5N1 provided sterile immunity, whereas low levels of virus were detected in the lungs of some M2SR H1N1 vaccinated mice. In contrast, recombinant H5 HA vaccinated mice and naïve controls showed systemic infection.M2SR H5N1 induced strong serum and mucosal antibody responses (IgG and IgA classes) against H5 HA, with high hemagglutination inhibition (HAI) titers. In contrast, while M2SR H1N1 elicited cross-reactive antibodies recognizing the H5 HA2 stalk region or the neuraminidase, no HAI activity against H5N1 virus was detected after M2SR H1N1 immunization.Both M2SR H5N1 and H1N1 also protected ferrets against lethal challenge with A/Vietnam/1203/2004. A prime–boost regimen provided optimal protection with no virus detected in the respiratory tract or brain after challenge. As in the mouse model, only the M2SR H5N1 vaccine induced HAI antibodies against the challenge virus in ferrets, while the M2SR H1N1 was able to provide protection without the induction of HAI antibodies.In summary, effective protection against highly pathogenic H5N1 influenza virus was provided by both homologous H5N1 M2SR and heterologous H1N1 M2SR demonstrating the cross-protective attributes of the M2SR platform.     

Landscape ecology of Lyme disease in a residential area of Westchester County, New York

The landscape ecology of Lyme disease was studied in 1989 on 67 residences in an endemic area of Armonk, Westchester County, a northern suburb of New York City. Four main habitat types were defined, and each property was surveyed for immature and adult lxodes dammini ticks; 98.6% of 1,790 ticks collected were I. dammini. Overall, 67.3% were collected from woods, 21.6% from ecotone (unmaintained edge), 9.1% from ornamental vegetation, and 2% from lawns. Larval ticks were concentrated in woods, but nymphs and adults were widely dispersed in all habitats. Tick abundance was positively correlated with property size. Larger properties (greater than or equal to 0.5 acre) were more likely to have woodlots and, hence, more ticks. Dark-field and direct fluorescent microscopic examination of tick midgut tissues revealed that 29.6% of nymphs and 49.7% of adults were infected with Borrelia burgdorferi. Infected nymphs and adults were found on 36% and 60% of properties, respectively. These data indicate that the abundance of ticks capable of transmitting Lyme disease spirochetes is related to landscape features of the suburban residential environment.     

Ionoregulatory and toxicological responses of stonefly nymphs (Plecoptera) to acidic and alkaline pH

The acute toxicities of acidic and alkaline pH to nymphs of the stonefliesPteronarcys dorsata, P. proteus, andTallaperla maria were determined in 96-hr static bioassays. The acidic and alkaline 96-hr LC₅₀ values were 2.8 to 3.3 and 12.1 to 10.3, respectively. Exposure to pH 3.0 for 72 hr or longer caused a significant loss of sodium from nymphs ofP. proteus. Morphological changes, including distension of cuticular disk and increased number of vesicles, were observed in gill tissue from nymphs ofP. dorsata exposed to pH 2.5 for 9 hr while minor changes were observed in nymphs exposed to pH 4.0 for 96 hr. Changes in gill tissue ultrastructure included an increase in number of vesicles and a decrease in number and size of mitochondria in nymphs exposed to alkaline pH of 11.75.     

Low risk of Lyme borreliosis in a protected area on the Tyrrhenian coast, in central Italy

A comprehensive Lyme borreliosis risk assessment process was applied in S. Rossore Estate, on the Tyrrhenian coast, near Pisa, Italy. Host-seeking Ixodes ricinus nymphs peaked in May in oak-dominated deciduous wood (median, Q1–Q3, number of nymphs/50 m dragging = 4.5, 2.5–8), whereas host-seeking larvae peaked in August in the same habitat type (6.0, 4–17/50 m dragging). Prevalence of I. ricinus infestation was 88.9% in wild rodents (n = 11), 64.3% in fallow deer (n = 28) and 0.0% in wild boars (n = 5). Borrelia burgdorferi sensu lato was not isolated from rodents' organs, and from 80 I. ricinus nymphs and 50 adults. Moreover, PCR for B. burgdorferi sl carried out on 110 nymphs and 12 adult ticks also gave negative results. Forest workers were at higher risk of tick bite than other Estate employees (relative risk (RR): 1.7, p = 0.02). In spite of high levels of tick exposure, B. burgdorferi sl specific antibodies were not detected in sera from Estate personnel (n = 30) and sentinel animals (dogs, n = 23, fallow deer, n = 61).     

Evaluation of new insect growth regulators against mosquitoes with notes on nontarget organisms

Three new insect growth regulators (IGRs) were tested against Culex, Aedes and Psorophora mosquitoes. In the laboratory the 3 IGRs were active in the range of 0.3 to 1.5 ppb against Cx. quinquefasciatus. In field tests, the IGRs fenoxycarb and S-31183 formulations yielded complete control of floodwater mosquitoes at the rates of 0.005 to 0.01 lb AI/acre. In field tests against Cx. tarsalis, S-31183 formulations produced complete inhibition of emergence at the rates of 0.005 to 0.025 lb AI/acre. Fenoxycarb formulation produced similar results at the rate of 0.1 lb AI/acre. It is possible that initial and residual field activity of both IGRs can be increased by employing suitable formulations.