This chapter reviews the statistical methods used in commodity treatment bioassays that are done in the laboratory and that serve as the basis for confirmatory tests. It describes experimental and statistical procedures used to determine a treatment level for use in quarantine treatments and to estimate the efficacy of a given treatment by a confirmatory test. In quarantine entomology, statistical analyses are used to estimate the probability that a commodity treatment will succeed. Three interrelated assumptions are inherent in the probit 9 requirement. First, 99.9968% effectiveness is assumed to be the minimum level necessary for commodity protection. Second, the requirement implies that the probit model is always suitable for the analyses of data from commodity treatment bioassays. Finally, the probit 9 requirement assumes that no criterion other than death is relevant to the future establishment of the pest species in a new environment.

To assess the toxicity of bifenthrin and four mixtures of insecticides to tarnished plant bug, we used an insecticide dip method of green bean to treat adults of a laboratory colony; mortality was assessed after 48 h. LC(50)s for imidacloprid, bifenthrin, acephate, thiamethoxam, and dicrotophos were 0.12, 0.39, 0.62, 0.67, and 3.96 ppm, respectively. LC(75)s for imidacloprid, bifenthrin, acephate, thiamethoxam, and dicrotophos were 0.61, 4.22, 5.10, 2.65, and 7.86 ppm, respectively. Based on the LC(50)s and LC(75)s, dicrotophos was much less toxic than the other chemicals tested. PoloMix software was used to determine syngerism, antagonism, or addition effects of the mixtures. Three out of four analyses of the joint action of bifenthrin plus imidacloprid or acephate or dicrotophos showed that toxicity was not independent and not correlated. For bifenthrin plus dicrotophos, observed mortality was greater than expected mortality at most concentrations suggesting synergism. Mixtures of bifenthrin plus imidacloprid and bifenthrin plus acephate showed observed mortality significantly less than expected, suggesting antagonism. LC(50)s for bifenthrin plus dicrotophos, acephate, imidacloprid, and thiamethoxam were 0.38, 1.06, 0.17, and 0.26 ppm, respectively. LC(75)s for bifenthrin plus dicrotophos, acephate, imidacloprid, and thiamethoxam were 13.61, 13.18, 0.67, and 0.80 ppm, respectively. Based on the LC(50)s and LC(75)s, bifenthrin plus acephate was 3- to 10-fold less toxic than the other chemicals tested. Bifenthrin plus acephate is frequently used in tank mixes to control tarnished plant bug and other cotton pests, and the effectiveness of each individual chemical appears to be reduced in one to one ratio mixtures.

The Asian citrus psyllid (ACP), Diaphorina cirri Kuwayama (Hemiptera: Psyllidae), vectors a pathogen that causes huanglongbing (HLB) in Florida citrus. The need to suppress ACP populations has resulted in greatly increased insecticide use in Florida. Horticultural mineral oils (HMOs), typically applied as 1-2% v/v aqueous emulsions at 937 L water ha(-1), are also used for insect pest management for citrus in Florida. Low-volume applications of other insect control products can reduce costs and application time and are effective for ACP control. The efficacy of low-volume applications of HMOs for ACP has not been tested. We initiated a three-year trial in February 2011 in a commercial Valencia orange grove in Lee County, Florida to compare low-volume (18.7 L ha(-1)) sprays of HMO applied every two weeks to a grower standard (GS) (mixes of insecticide and HMO) and an untreated control. HMO and GS treatments significantly reduced ACP adult and nymph populations. Yields were greater for HMO-treated than untreated trees in the final study year. GS and HMO treatments reduced fruit drop in 2013. Fruit quality was generally unaffected by treatments. ACP suppression, higher yields and eventual production gains indicated that frequent, low-volume application of HMO may be a viable alternative for suppressing ACP populations. (C) 2015 Elsevier Ltd. All rights reserved.

This is the most informative compilation I have ever read. The original workshop took place in 2006, and all information was updated to produce the book. Worldwide outbreaks of Bemisia in the past 25 yr have been economically devastating. In the future, we can expect this trend to continue, especially with the spread of insecticide-resistant biotype Q. I read about whiteflies in the context of pesticide resistance and tolerance but had no idea how quickly an insect species can evolve. (When you do …

I began reading this volume thinking that my review might be biased. I had selected a systematics text from the stack: I do not like systematics texts, which seem so dry and boring. What a welcome surprise. In my opinion, “The Owlets of Eastern North America” is the most beautifully conceived and well-organized book about the Lepidopteran Family Noctuidae imaginable! Principal funding came from awards from the U.S. Department of Agriculture, Forest Service, Forest Health Technology Enterprise Team; The University of Connecticut; and The Nature Conservancy. The USFS Forest Initiative funding was discontinued early into the work, and its completion was facilitated by grants from The Nature Conservancy. The Forest Service should have given the authors sufÞcient funds to Þnish such a monumental work, but as usual, longterm projects are not their forte. The introductory sections are extremely informative. I have seen Noctuids as an entomologist in western forests and never realized their importance in the ecology of forests, grasslands, and terrestrial ecosystems. Owlets are both tasty morsels and crucial sources of food for bats, grizzly bears, and forest omnivores. They are important pollinators because of their key relationship with birds (especially songbird nestlings). They are indicators of climate change. However, two dozen Eastern species are pests. These include cutworms, the corn earworm (Helicoverpa zea Boddie) and tobacco budworm (Heliothis virescens F.). Regardless of the crop pest species, no native eastern noctuid species is a forest insect pest and rarely does any species cause defoliation in an Eastern forest ecosystem. A section on morphology and chaetotaxy are extremely clear. I now understand how owlets are classiÞed, and that their setae are keys to the process. The owlets can be collected and reared, if necessary, if the investigator is patient. In addition, of course many are attacked by parasites and parasitoids. Diversity is a hallmark of the owlets. Wait until you as a reader get to the 550 pictures and the species illustrations. Wow! I have never seen anything like Wagner et al. do with each species. A picture of the larvae is matched with photos of a live adult and museum (pinned) specimen. One thing that struck me immediately, and then began to amuse me mightily, was the names of the owlets. Have you ever met a Four-lined Chocolate or the Scaled Zale? As I read one page, I found that I could not wait to read the next. This is one of just a few entomological page-turners I have ever read. I recommend this text for graduate and undergraduate courses on entomology or forest entomology or forest ecology. Would I buy The Owlets? Yes. Now I love and appreciate them! I cannot wait until the authors complete a companion volume on Western species.

The topical toxicities of five commercial grade pesticides commonly sprayed in apple orchards were estimated on adult worker honey bees, Apis mellifera (L.) (Hymenoptera: Apidae) and Japanese orchard bees, Osmia cornifrons (Radoszkowski) (Hymenoptera: Megachilidae). The pesticides were acetamiprid (Assail 30SG), λ-cyhalothrin (Warrior II), dimethoate (Dimethoate 4EC), phosmet (Imidan 70W), and imidacloprid (Provado 1.6F). At least 5 doses of each chemical, diluted in distilled water, were applied to freshly-eclosed adult bees. Mortality was assessed after 48 hr. Dose-mortality regressions were analyzed by probit analysis to test the hypotheses of parallelism and equality by likelihood ratio tests. For A. mellifera, the decreasing order of toxicity at LD₅₀ was imidacloprid, λ-cyhalothrin, dimethoate, phosmet, and acetamiprid. For O. cornifrons, the decreasing order of toxicity at LD₅₀ was dimethoate, λ-cyhalothrin, imidacloprid, acetamiprid, and phosmet. Interaction of imidacloprid or acetamiprid with the fungicide fenbuconazole (Indar 2F) was also tested in a 1∶1 proportion for each species. Estimates of response parameters for each mixture component applied to each species were compared with dose-response data for each mixture in statistical tests of the hypothesis of independent joint action. For each mixture, the interaction of fenbuconazole (a material non-toxic to both species) was significant and positive along the entire line for the pesticide. Our results clearly show that responses of A. mellifera cannot be extrapolated to responses of O.cornifrons, and that synergism of neonicotinoid insecticides and fungicides occurs using formulated product in mixtures as they are commonly applied in apple orchards.

To assess the toxicity ofthiamethoxam and three mixtures of insecticides to oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), we added the insecticides to diet and fed it to neonates of two laboratory colonies; mortality was assessed after 96 h. Thiamethoxam was much less toxic than insecticides previously tested. Five of six analyses of the joint action of chlorantraniliprole plus acetamiprid, esfenvalerate, or thiamethoxam indicated that toxicity was not independent and not correlated. For chlorantraniliprole plus acetamiprid, mortality was slightly lower than expected at low concentrations and greater than expected at high concentrations. For chlorantraniliprole plus esfenvalerate, mortality was less than expected at nearly all concentrations, suggesting antagonism despite the two compounds' different modes of action. For chlorantraniliprole plus thiamethoxam, observed mortality exceeded expected mortality at low concentrations, but this trend did not continue at higher concentrations. Although the null hypothesis of independent and uncorrelated toxicity was rejected for chlorantraniliprole plus acetamiprid and chlorantraniliprole plus thiamethoxam in three of four analyses, differences between observed and expected mortality were minor and inconsistent over the range of concentrations tested. We do not expect these mixtures to exhibit significant synergism or antagonism in the field. Apparent antagonism between chlorantraniliprole and esfenvalerate is particularly relevant because these insecticides (or chlorantraniliprole plus a different pyrethroid) may be used together in apples or peaches for control of oriental fruit moth and hemipteran pests. The effectiveness of each insecticide against oriental fruit moth might be reduced in such applications.

Laboratory colonies of oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), were reared on 'Gala' apples (Malus pumila Mill.) and lima bean (Phaseolus lunatus L.) diet. Neonates were placed on wheat germ diet containing a range of concentrations of esfenvalerate or lambda-cyhalothrin; mortality was assessed after 96 h. For a long-term laboratory colony, LC50 values of esfenvalerate and lambda-cyhalothrin were 0.35 and 0.12 ppm, respectively, for progeny of insects reared on apples. For a colony established from Calhoun Co., IL, in 2007, LC50 values of esfenvalerate and lambda-cyhalothrin were 0.37 and 0.10 ppm, respectively, for progeny of insects reared on apples. LC50 values of these insecticides did not differ significantly for either colony when progeny of insects reared on lima bean diet were tested. We observed no consistent evidence of pyrethroid resistance in the Calhoun colony after laboratory culture for 21-23 generations. We described the dose-response relationship for esfenvalerate applied topically in 1 microl of acetone to male moths from the long-term laboratory colony and estimated the LD99 to be 0.022 microg per moth. Application of 0.022 microg of esfenvalerate per moth to approximately 600 male moths from two putatively susceptible populations resulted in mean survivorship approximately equal to the expected level of 1.0%. Application of the same dose to 374 field-captured moths from two Calhoun Co. orchards with histories of pyrethroid use resulted in mean survivorship of 9.4 and 82%. We propose that 0.022 microg of esfenvalerate in 1 microl of acetone can be used as a diagnostic dose for monitoring pyrethroid resistance in oriental ruit moth in the field.

To determine their baseline susceptibility to chlorantraniliprole, spinetoram, spinosad, and acetamiprid, oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), neonates were placed on diet cubes containing a range of concentrations of each insecticide. Mortality was assessed after 96 h. Two populations-a long-term laboratory colony from Rutgers University and a colony established in 2007 from a southwestern Illinois (Calhoun County) field population-were tested. We used probit and logit analyses to compare the responses of Calhoun colony neonates from parents reared on 'Gala' apples (Malus spp.) with those of Calhoun colony neonates from parents reared on lima bean, Phaseolus lunatus L., diet. We also compared the responses of Calhoun colony neonates with those of Rutgers colony neonates (all from parents reared on apples). LC50s (ppm in diet) for Calhoun colony progeny of adults reared on apples were 0.08, 0.06, 0.41, and 0.30, respectively, for chlorantraniliprole, spinetoram, acetamiprid, and spinosad. Parental food source (apples versus lima bean diet) did not consistently influence the concentration-mortality relationships for neonates. Based on LC50s and toxicity ratio tests, Calhoun colony neonates were slightly but significantly less susceptible to spinetoram and acetamiprid than were Rutgers colony neonates. Similarly, LC90s and toxicity ratio tests indicated that Calhoun colony neonates were slightly but significantly less susceptible to chlorantraniliprole as well. However, toxicity ratios (Calhoun/Rutgers) were low in all instances, and the highest ratio was 1.73 at LC90 for chlorantraniliprole. Overall, the two colonies responded similarly to these insecticides. Results reported here provide baseline data for future monitoring of resistance development.

Even as an insect pathologist, the prospect of reading an entire book on the proper performance and data analysis of arthropod bioassays was not a task I envisionedmyself absolutely enjoying. Although the topic is one that I amverymuch interested in, at least forme, it was not the type of book that I expected to have trouble putting down. Much to my surprise, I found Bioassays with Arthropods, 2nd Edition to be not only tremendously informative but also a pleasure to read. In the preface, Jacqueline L. Robertson outlines the authorsO desire towrite a textbook that enhances readability and keeps readers interested in the subject matter. Mission accomplished! Each chapter of the text begins with the main character, Dr. Paula Maven, in a somewhat eccentric situation. Dr. Maven is a factious character with no previous experience in pest management, but she has accepted a research appointment to establish an integrated pest management program for tomatoes. Our introduction to Dr. Maven begins in chapter 1 where she is interested inperformingherÞrst bioassay toÞnd a dose of insect growth regulator to control populationsofAscalaphagiganticus; a factious insect resulting frombioterrorism that is wreaking havoc on tomatoes. This undertaking sounds deceivingly simple enough. However, Paula quickly encounters the most basic of problemswhenperforming a laboratorybioassay, how to keep the insects alive in the laboratory and how to collect or rear them in sufÞcient numbers to perform meaningful bioassays. PaulaOs Þrst bioassay is a complete failure in terms of establishing a doseÐresponse relationship, but it is successful in helping her identify her deÞciencies. Help is available in the form of Dr. Garland Tarleton. Paula attends Dr. TarletonOs 1-d workshop where the lesson is on quantal response bioassays. From this workshop, Paula gains an appreciation for the basics of performing a bioassay, including experimental design, experimental units, randomization, treatments, controls, replication, order of treatments within a replication and the use of computer programs to lighten the burden of data analysis. From the basic knowledge and experience gained from Dr. TarletonOs course, Paula and her assistant begin down the road of gathering bioassay data useful in the development of a control program for A. giganticus. At Þrst, the questions can be addressed with simple binary quantal response bioassays with one explanatory variable. As the infestation worsens and A. giganticus becomes an ever-increasing problem for tomato growers, Dr. Maven is forced to answer additional questions, including natural variation in response, quarantine statistics, pesticide resistance, chemical mixtures, speed of kill, binary quantal response with multiple explanatory variables, effect of erroneous assumptions about body weight, and Þnally multinomial quantal response. Throughout the process Dr. MavenOs knowledge builds on her previous set of experiments, just as it does for all of us genuine scientists performing bioassays. As Paula leads us through each type of assay, the reader is provided not only with the correct design but also statistical equations with clear explanations of their meaning. The authors also provide guidance on the use of LeOra Software, including PoloPlus, PoloMix, PoloDose, and PoloEncore, for straightforward, user-friendly statistical analysis. It is this step by step process throughout the book that is so helpful in tying all of these complex topics together into a story that is fun to read. I found myself anxious to see how Paula would avert the next obstacle thatA. giganticus put in her way. Robertson, Russell, Preisler, and Saven have put together a wonderful reference text for both beginning and experienced researchers. As they state in chapter 1, “Mindless experimental design that results in data subjected to equally mindless analyses is a waste of time and resources.” This text is a good reminder for all of us performing bioassays that assumptionsmade in the pastmay ormay not be true, and not all data sets can be subjected to the same analyses that were used previously simply becausewe knowhow to perform them.

To estimate the toxicity of novaluron to eggs from two populations of Oriental fruit moth, Grapholita molesta (Busck), we dipped eggs on waxed paper into a range of concentrations. Treated eggs were held on wheat germ diet, and mortality was assessed after 10 days. We compared the concentration-mortality relationships for eggs from parents reared on 'Gala' apples with those of eggs from parents reared on lima bean diet. We also compared the responses of a long-term laboratory colony of G. molesta from Rutgers University and a colony established from Calhoun County in southwestern Illinois. LC50's of novaluron ranged from 0.10 to 0.83 ppm and did not differ significantly based on parental diet. LC50's differed significantly between colonies; LC50's for the Calhoun colony were approximately 2.5 and 8 times greater than those for the Rutgers colony in bioassays that used eggs from parents reared on diet and apples, respectively. LC90's ranged from approximately 38 to 1000 ppm. For the Calhoun colony, the LC90 for novaluron applied to eggs from parents reared on apples was approximately 10 times greater than the LC90 for novaluron applied to eggs from parents reared on lima bean diet. For eggs from parents reared on apples, the LC90 for the Calhoun colony was approximately 9 times greater than the LC90 for the Rutgers colony. Differences in the colonies' responses may represent natural variation among populations or may be the result of selection by novaluron or other insecticides used in Calhoun County orchards before we collected larvae for our colony.

A common measure of the relative toxicity is the ratio of median lethal doses for responses estimated in two bioassays. Robertson and Preisler previously proposed a method for constructing a confidence interval for the ratio. The applicability of this technique in common experimental situations, especially those involving small samples, may be questionable because the sampling distribution of this ratio estimator may be highly skewed. To examine this possibility, we did a computer simulation experiment to evaluate the coverage properties of the Robertson and Preisler method. The simulation showed that the method provided confidence intervals that performed at the nominal confidence level for the range of responses often observed in pesticide bioassays. Results of this study provide empirical support for the continued use this technique.

Providing clear examples of the use of state-of-the-art computer programs for analyses of bioassay data, Bioassays with Arthropods, Second Edition explains the statistical basis and analysis for each kind of quantal response bioassay. The first edition was a must-have reference for designing, conducting, and interpreting bioassays: this comp

Similar adult immersion tests (AITs) for acaricide susceptibility of Boophilus microplus were done in Texas, USA (Muñoz strain) and in Queensland, Australia (N-strain and Ultimo isolates). Engorged adult female ticks were immersed in one of a series of dilutions of commercial acaricide in water and then incubated at room temperature for 7 days. Data on oviposition were collected 7 days after exposure to acaricide and subjected to probit analysis. For most data, we observed poor fit to the probit model. Substantial differences in both LC50 and LC99 for the susceptible strains occurred between the respective laboratories and confidence intervals for all acaricides and all strains were unacceptably wide. For amitraz, the discriminating concentration (double the LC99.9 or LC99) recommended by FAO was 0.25%, but our estimates ranged from 0.46% to 9000%. For cypermethrin, the recommended DD was 0.0050%, with our estimates ranging from 0.00022% to 0.74%. For coumaphos the recommended DD was 0.50% but our estimates ranged from 0.66% to 130%. Finally, for moxidectin, the recommended DD was 0.10%, while our estimates ranged from <0.0001% to 5.9%. The method does not provide a means to discriminate between amitraz-susceptible and -resistant, nor between cypermethrin-susceptible and -resistant B. microplus.

Confirmatory tests were performed on a two-component quarantine treatment against the codling moth ( Cydia pomonella L.) (Lepidoptera: Tortricidae) for seven apple [ Malus sylvestris (L.) var. domestica (Borkh.) Mansf.] cultivars ('Delicious,' `Golden Delicious,' `Braeburn,' `Fuji,' `Gala,' `Jonagold,' and `Granny Smith') intended for export to Japan and Korea. Treatment consists of a 55-day cold storage at 40 °F (2.2 °C) or below, followed by a 2-hour methyl bromide fumigation (0.056 oz/ft 3 or 56 g·m -3 ) at 50 °F (10 °C). No eggs or larvae survived this treatment. Comparison tests were conducted on all cultivars to demonstrate no difference in insect responses between a previously accepted cultivar and proposed cultivars. Concentration-mortality responses were determined for each of the components and no statistical differences were found in the regression slopes of pest mortality with controlling variable (either cold exposure or fumigation) among all cultivars. Descriptive mathematical models, developed for the effects of cold storage on egg mortality and for methyl bromide fumigation on larvae mortality, were sigmoid curve equations.

Analysis of bioassays data from experiments with mixtures require use of special statistical techniques, especially when responses are recorded over time. Often, response curves from bioassays with mixtures do not fit a probit or legit curve. In addition, observations recorded over time are not independent. As a result, standard statistical packages for probit or legit analysis are not applicable. In these bioassays, the shape of the response curve depends on the type of interactions between mixture components. Here we present models that describe response (e.g., mortality) curves over time when mixtures are applied to insects. The shapes of the response curves depend on the modes of both action and interaction between the mixture compounds. We describe a procedure to assess whether the assumed modes of interaction (e.g., independent action or similar action additive models) are appropriate. We demonstrate use of the statistical methods with data obtained when a baculovirus and a synthetic organic insecticide were mixed.

A citrus leaf disk bioassay was developed to monitor the susceptibility of citrus rust mite, Phyllocoptruta oleivora (Ashmead), populations to abamectin. Disks from leaves of several citrus cultivars were equally suitable bioassay substrates, and there was no difference in mortality when mites were sprayed directly or exposed to dry abamectin residue. The concentration-response relationship was determined at intervals over 2 yr for a reference population of citrus rust mites that had been maintained in culture and never exposed to acaricides. Three diagnostic concentrations of abamectin were selected based on the response of the reference population and were used to test the susceptibility of 15 populations of mites from commercial citrus groves. Comparisons with the reference population showed reduced levels of susceptibility in some populations. Populations of citrus rust mites from 6 commercial groves were sprayed twice in 1997 with combinations of acaricides designed to exert different intensities of selection pressure from abamectin. None of these populations showed a change in their response to abamectin in pre- and postspray bioassays, although their susceptibility was usually less than that of mites from the susceptible reference population. Biweekly counts of rust mites on fruit in these 6 groves suggested that, relative to groves which received no abamectin or 1 abamectin spray, mite control was not adversely affected in the groves sprayed twice with abamectin. The bioassay method is discussed in relation to factors that affect the interpretation of results from its use, and factors that may affect the development of resistance to abamectin in citrus rust mite populations are presented. This study has provided baseline data with which the results of ongoing tests of the response of citrus rust mite populations to abamectin can be compared.

Our investigation estimates time-temperature relationships and demonstrates the effect of rapid heating on mortality of Caribbean fruit fly, Anastrepha suspensa (Loew). Mature larvae (third instars) in water were exposed to each of seven temperatures (44, 45, 46, 47, 48, 49, and 50 degrees C) and each of five power levels (11, 27.5, 55, 88, and 122 W) in a research-quality microwave oven. Controls were immersed in water for 30 min and not exposed to microwave energy. Data were analyzed by a probit model with three explanatory variables. The variables were time to reach target temperature, power, and final temperature. Temperature needed to control the larvae increased as power increased. Of the power-temperature levels, the only combinations that resulted in >99% mortality were the lowest power (16 W) at 49 or 50 degrees C and 30 W at 50 degrees C. Time required for >99% mortality decreased with increased power. Thus, as power delivered to larvae increased and time needed to reach exposure temperature deceased, percent mortality decreased. We conclude that rapid heating imposes serious constraints on the use of heat-induced mortality; this result raises important questions that must be addressed because quarantine security may be jeopardized.