Contributions of climatic and crop varietal changes to crop production in the North China Plain,since 1980s

The North China Plain (NCP) is the most important agricultural production area in China. Crop production in the NCP is sensitive to changes in both climate and management practices. While previous studies showed a negative impact of climatic change on crop yield since 1980s, the confounding effects of climatic and agronomic factors have not been separately investigated. This paper used 25 years of crop data from three locations (Nanyang, Zhengzhou and Luancheng) across the NCP, together with daily weather data and crop modeling, to analyse the contribution of changes in climatic and agronomic factors to changes in grain yields of wheat and maize. The results showed that the changes in climate were not uniform across the NCP and during different crop growth stages. Warming mainly occurred during the vegetative (preflowering) growth stage of wheat and maize, while there was a cooling trend or no significant change in temperatures during the postflowering stage of wheat (spring) or maize (autumn). If varietal effects were excluded, warming during vegetative stages would lead to a reduction in the length of the growing period for both crops, generally leading to a negative impact on crop production. However, autonomous adoption of new crop varieties in the NCP was able to compensate the negative impact of climatic change. For both wheat and maize, the varietal changes helped stabilize the length of preflowering period against the shortening effect of warming and, together with the slightly reduced temperature in the postflowering period, extend the length of the grain‐filling period. The combined effect led to increased wheat yield at Zhengzhou and Luancheng; increased maize yield at Nanyang and Luancheng; stabilized wheat yield at Nanyang, and a slight reduction in maize yield at Zhengzhou, compared with the yield change caused entirely by climatic change.     

Influence of soil temperature, rainfall, and planting and harvest dates on Chaetocnema confinis (Coleoptera: Chrysomelidae) damage to sweetpotato roots

A study was carried out in 10 counties of North Carolina from 2004 to 2006 to determine the effect of planting and harvest times on flea beetle, Chaetocnema confinis Crotch (Coleoptera: Chrysomelidae), damage to sweetpotato, Ipomoea batatas (L.), storage roots. Planting and harvesting of sweetpotatoes later in the season resulted in less damage than early planting and harvesting. Regression analysis was done to study the relationship of weather parameters with the flea beetle damage. Weather parameters included air temperature (Celsius), soil temperature at 5- and 10-cm depth (Celsius), rainfall (millimeters), and soil moisture (volume:volume) at 0-10-, 10-40-, and 40-100-cm depth. The best regression model included mean soil temperature at 10-cm depth, total rainfall, and number of adults caught on yellow sticky traps as independent variables (all between 1 August and harvest date of each field). Soil temperature and adult catches on yellow sticky traps of C. confinis were positively related to damage, whereas rainfall was negatively correlated. The model explained 45% of the total variation in the flea beetle damage. Soil temperature alone accounted for 32% of the total variation in flea beetle damage followed by rainfall (9%) and adult catches (4%). When the time interval was limited to 30 d before harvest, soil temperature was still the best explanatory variable accounting for 23% of the total variation in flea beetle damage followed by rainfall (7%) and adult catches (4%). Understanding the effects of planting/harvesting and weather factors on flea beetle damage will be useful in predicting the time when the sweetpotato crop is at greater risk from high levels of damage by C. confinis.     

Drench treatments for management of larval Japanese beetle (Coleoptera: Scarabaeidae) in field-grown balled and burlapped nursery plants

Insecticide drenches were applied to postharvest field-grown nursery plants harvested as 60-cm-diameter balled and burlapped (B&B) root balls for controlling third instars of Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae). Bifenthrin, chlorpyrifos, lambda-cyhalothrin, and thiamethoxam were drench-applied in fall and spring tests at volumes of runoff (1X; approximately equal 2.57 liters per drench per root ball) or twice runoff (2X). Tests also examined consecutive drenches (two, four, or six) and B&B rotation between drenches. Fall-applied drenches did not meet the Domestic Japanese Beetle Harmonization Plan (DJHP) standards of < or =1 grub and ranged from 0 to 90% control. However, most fall-applied drenches significantly reduced grub numbers relative to the untreated root balls. Spring-applied drenches were more effective than fall drenches: chlorpyrifos treatments gave 94-100% control, whereas other spring-applied treatments were less consistent, including thiamethoxam (83-100% control) and bifenthrin (61-100% control). Lambda-cyhalothrin was not effective. A higher drench volume (2X) did not significantly improve treatment efficacy; however, grub numbers decreased as the number of drenches increased for fall-applied chlorpyrifos and thiamethoxam and spring-applied bifenthrin. Rotation of root balls significantly reduced grub numbers compared with nonrotated treatments for fall-applied chlorpyrifos (six drenches) and bifenthrin (two or six drenches), but these treatments did not meet DJHP standards. The study indicates chlorpyrifos, bifenthrin, and thiamethoxam drenches can control Japanese beetle in the spring and may provide a new postharvest option to certify B&B plants for Japanese beetle.     

"Endomicrobia" and other bacteria associated with the hindgut of Dermolepida albohirtum larvae

Symbiotic bacteria residing in the hindgut chambers of scarab beetle larvae may be useful in paratransgenic approaches to reduce larval root-feeding activities on agricultural crops. We compared the bacterial community profiles associated with the hindgut walls of individual Dermolepida albohirtum third-instar larvae over 2 years and those associated with their plant root food source among different geographic regions. Denaturing gradient gel electrophoresis analysis was used with universal and Actinobacteria-specific 16S rRNA primers to reveal a number of taxa that were found consistently in all D. albohirtum larvae but not in samples from their food source, sugarcane roots. These taxa included representatives from the "Endomicrobia," Firmicutes, Proteobacteria, and Actinobacteria and were related to previously described bacteria from the intestines of other scarab larvae and termites. These universally distributed taxa have the potential to form vertically transmitted symbiotic associations with these insects.     

Spatial ecology of the Japanese beetle, Popillia japonica

A cornerstone of spatial ecology is the quantification of the patchy nature of animal and plant populations in space. By using spatial covariance, total covariance, and quantile variance, we found that patchiness of Japanese beetle grub populations varied more between years than between fairways at a central New York golf course. We also observed that populations tended to shrink and swell around patches with perennially low density, that locations with perennially low grub density were associated with high soil organic matter content, and that locations with frequently high grub density were associated with intense adult beetle activity in the vicinity.     

Why the larch bud-moth cycle collapsed in the subalpine larch-cembran pine forests in the year 1990 for the first time since 1850

The larch bud-moth cycle has been observed in the sub-alpine larch-cembran pine forests 16 times since 1850. Infestation is easily recognized by the characteristic red-brown discoloration of the larch crowns due to the wasteful feeding of the bud moth larvae. The heaviest defoliation recurs at intervals of 8.47±0.27 (SE) years, and the larval density per kilogram of larch branches varies more than 10000-fold over four or five generations. The basic regulatory mechanism for this cycle is the induced change in food quality for the two or more subsequent larval generations. Defoliation functions as a negative feedback mechanism acting on larval density. In 1989 local discoloration in the Upper Engadine valley was observed in the usual first focus. In 1990 and 1991, however, instead of the expected widespread defoliation damage, larval densities decreased drastically. Based on extensive field data collected from 1961 to 1991 on the development and the survival of the bud moth (Zeiraphera diniana Gn.) and the phenology of the host, Larix decidua L., this paper shows the effect of weather on survival in the egg stage and on the coincidence of larval hatching with the sprouting of the larch. It is shown that the winter and spring weather conditions in 1989–1991 were conducive to unusually high egg mortality. Since these conditions occurred in three successive generations, population growth was effectively reduced and the cycle collapsed prematurely. Thus the rather persistent cyclicity of the larch-larch bud-moth system was disturbed by weather conditions with a very low probability of occurrence, but due to the inherent high resilience of the system, the next population peak with visible defoliation is expected to occur 1996/1997, provided that the weather conditions return to the climatic standard.     

Impact of four insecticides on Japanese beetle (Coleoptera: Scarabaeidae) egg predators and white grubs in turfgrass

Field experiments were conducted to measure the effects of four commonly used turfgrass insecticides (isofenphos, diazinon, imidacloprid, halofenozide) on white grubs (Coleoptera: Scarabaeidae) and ant predators of white grub eggs. Ant populations were measured over time with canned tuna, whereas predation by the ants was measured with artificially placed Japanese beetle, Popillia japonica Newman, eggs. The effectiveness of each insecticide at controlling Japanese beetle grubs, when applied at different times during the growing season, also was measured. Isofenphos and diazinon significantly reduced both ant numbers and white grub egg predation, whereas imidacloprid and one halofenozide treatment did not significantly impact either measurement. A second halofenozide treatment significantly reduced white grub egg predation. Isofenphos and diazinon were ineffective at controlling Japanese beetle grubs when applied in June but were highly efficacious when applied in August. Evidence of enhanced biodegradation was found in plots that received both June and August applications of diazinon. Both June and August applications of imidacloprid and halofenozide provided good control of white grubs.     

Comparison of scarab grub populations and associated pathogens and parasitoids in warm- or cool-season grasses used on transitional zone golf courses

Seven different turfgrass species or mixes used on golf courses in the United States' transitional climatic zone were maintained as randomized and replicated plots in separate stands mowed at fairway (1.6 cm) or rough (6.4 cm) cutting heights and sampled in autumn to assess the density and species composition of scarab grubs; incidence of disease and parasitism thereof; and extent of turf damage from foraging insectivorous skunks, Mephitis mephitis. Influence of grass species on parasitism by spring or autumn-active tiphiid wasps was further assessed on implanted grubs in open enclosures. Masked chafers (Cyclocephala spp.) were three-fold more abundant than Japanese beetle, Popillia japonica Newman, grubs in plots of Zoysia and Cynodon sp. mowed at fairway height, and P. japonica were five-fold more abundant than masked chafer grubs in cool-season turf plots mowed at rough height. Phyllophaga spp. accounted for <1% of grubs in the samples. Milky disease bacteria (Paenibacillus sp.) were the predominant pathogens of Cyclocephala spp., followed by Serratia sp. bacteria and gregarines (Stictospora cf. villani). Cyclocephala grub densities, milky disease incidence (25%), and parasitism by the native tiphiid Tiphia pygidialis Alien (10-12%) were especially high in zoysiagrass. Japanese beetle grubs were infected by Paenibacillus, Serratia, Stictospora, and microsporidia (Ovavesicula sp.), but incidence of individual pathogens was relatively low (<6%) and similar among grasses within each stand. Few nematode-infected grubs were found. Skunk damage was mainly in the cool-season fairway-height grasses, probably reflecting difficulty in foraging in the much tougher stolons and rhizomes of the warm season turfgrasses. The degree of natural suppression of scarab grubs provided by endemic pathogens or parasitoids is unlikely to be compromised by the grass species used on a particular site.     

Space-for-time substitution reveals a hump-shaped distribution of dung beetles

Unraveling how climate change impacts the diversity and distribution patterns of organisms is a major concern in ecology, especially with climate-sensitive species, such as dung beetles. Often found in warmer weather conditions, beetles are used as bio-indicators of environmental conditions. By using an altitudinal gradient as a proxy for climate change (i.e., space-for-time substitution), we assessed how changes in climatic variables, such as temperature and precipitation, impact patterns of dung beetle diversity and distribution in the Peruvian Andes. We recorded dung beetle diversity using three different types of baits, feces, carrion, and fruits, distributed in 18 pitfall traps in five different altitudinal sites (from 900 to 2500 m, 400 m apart from each other) in the rainy and dry season. We found that (i) dung beetle richness and abundance were influenced by the climate gradient, (ii) seasonality influenced beetle richness, which was high in the wet season, but did not influence abundance, (iii) dung beetle richness and abundance fit to a hump-shaped distribution pattern along the altitudinal gradient, and (iv) species richness is the beta-diversity component that best describes the composition of dung beetle species along the altitudinal gradient. Our data show that the distribution and diversity of dung beetles are different at larger scales, with different patterns resulting from the response of species to both abiotic and biotic factors.     

Linking weather conditions and winter tick abundance in moose

Climate change may modify species distribution to higher latitudes, resulting in potential changes of parasite diversity and transmission dynamics in areas where animals might not be locally adapted to these new parasite species. In addition, climate change may increase the frequency and severity of infestations of parasites that are already present in a region, by promoting the development and survival of infectious stages. Over the last decades, the number of moose (Alces americanus) infested by winter ticks (Dermacentor albipictus) has increased in eastern Canada, possibly because milder climatic conditions are increasing winter tick survival. Our main objective was to determine which meteorological variables are more likely to influence winter tick load on moose. We compiled several weather variables that may limit winter tick survival and explored which weather variables, or their interactions, influenced the winter tick load of 4,100 hunted moose from 2013 to 2019 in Québec, Canada along a latitudinal gradient. Winter tick load in fall decreased with the maximum number of consecutive days in spring with average daily temperatures below −15°C and with the number of consecutive days in summer with a relative humidity <80% when snowmelt in spring was earlier. These results suggest that cold temperatures and prolonged periods of low humidity, amplified by early snowmelt, limit the survival of adult female ticks and eggs, thus limiting their subsequent load on moose during the following fall. With climate change, precipitation increases and warm temperatures occur earlier in spring and are more frequent in summer. Our results suggest that climate change may have a positive long-term influence on winter tick abundance in the environment and thereby increase winter tick load on moose, which could lead to a significant decrease in moose body condition and survival.     

Arable weed vegetation of the northeastern part of the Czech Republic: effects of environmental factors on species composition

Factors determining changes in species composition of arable field weed vegetation in the northeastern part of the Czech Republic were studied. Gradsect sampling, i.e. a priori stratified selection of sampling sites, was used for the field research. Using this method, a data set of 174 vegetation plots, covering a whole range of basic environmental characteristics in the study area, was compiled in 2001–2003. A set of environmental variables (altitude, annual precipitation, mean annual temperature, soil type, soil pH and crop type) together with date of sampling was obtained for each plot. Ordination methods were used to determine the effects of variables on arable weed composition. For each variable, the gross and net effect on weed species composition were calculated. All variables considered in this study had a significant effect on weed species composition and explained 7.25% of the total variation in species data. Major changes in weed species composition in the study area were associated with different crop types. The second most important gradient in the variability of weed vegetation in the study area was associated with altitudinal and climatic changes followed by seasonal changes and different soil types and pH. Our results show that on a regional scale, the relative importance of different crop types and their associated management on changes in arable weed species composition is higher than the relative importance of climatic variables. The relative importance of climatic variables decreases with their decreasing length of gradient.     

Investigating the relationships between the distribution of British ground beetle species (Coleoptera, Carabidae) and temperature, precipitation and altitude

Aims We examine the relationships between the distribution of British ground beetle species and climatic and altitude variables with a view to developing models for evaluating the impact of climate change. Location Data from 1684 10‐km squares in Britain were used to model species–climate/altitude relationships. A validation data set was composed of data from 326 British 10‐km squares not used in the model data set. Methods The relationships between incidence and climate and altitude variables for 137 ground beetle species were investigated using logistic regression. The models produced were subjected to a validation exercise using the Kappa statistic with a second data set of 30 species. Distribution patterns for four species were predicted for Britain using the regression equations generated. Results As many as 136 ground beetle species showed significant relationships with one or more of the altitude and climatic variables but the amount of variation explained by the models was generally poor. Models explaining 20% or more of the variation in species incidence were generated for only 10 species. Mean summer temperature and mean annual temperature were the best predictors for eight and six of these 10 species respectively. Few models based on altitude, annual precipitation and mean winter temperature were good predictors of ground beetle species distribution. The results of the validation exercise were mixed, with models for four species showing good or moderate fits whilst the remainder were poor. Main conclusions Whilst there were many significant relationships between British ground beetle species distributions and altitude and climatic variables, these variables did not appear to be good predictors of ground beetle species distribution. The poor model performance appears to be related to the coarse nature of the response and predictor data sets and the absence of key predictors from the models.     

Factors influencing the geographical distribution of Dendroctonus rhizophagus (Coleoptera: Curculionidae: Scolytinae) in the Sierra Madre Occidental, México

The bark beetle, Dendroctonus rhizophagus Thomas & Bright, is endemic to the Sierra Madre Occidental (SMOC) in México. This bark beetle is a major pest of the seedlings and young saplings of several pine species that are of prime importance to the nation's forest industry. Despite the significance of this bark beetle as a pest, its biology, ecology, and distribution are poorly known. Three predictive modeling approaches were used as a first approximation to identify bioclimatic variables related to the presence of D. rhizophagus in the SMOC and to obtain maps of its potential distribution within the SMOC, which is a morphotectonic province. Our results suggest that the bark beetle could have an almost continuous distribution throughout the major mountain ranges of the SMOC. This beetle has a relatively narrow ecological niche with respect to some temperature and precipitation variables and inhabits areas with climatic conditions that are unique from those usually prevalent in the SMOC. However, the bark beetle has a broad ecological niche with respect to the number of hosts that it attacks. At the macro-scale level, the D. rhizophagus distribution occurs within the wider distribution of its main hosts. The limit of the geographical distribution of this bark beetle coincides with the maximum temperature isotherms. Our results imply a preference for temperate habitats, which leads to the hypothesis that even minor changes in climate may have significant effects on its distribution and abundance.     

区域种植业气候适宜度及其对种植活动的响应——以四川省盐亭县为例

在分析盐亭县近63年来(1950—2012)种植业生产发展的基础上,选取该县农村社会经济条件相对稳定的近32年(1981—2012)为研究时段。运用农业生态气候适宜度方法,依据水稻、红薯、玉米、小麦和油菜等5种主要作物生育期的光、热、水等气候条件,分别估算各种作物的资源适宜指数、效能适宜指数和利用指数,构建小尺度区域种植业气候适宜度模型和种植活动对区域种植业气候适宜度的影响度模型,进行小尺度区域种植业气候适宜度以及种植活动对种植业气候适宜度的影响度估算,并对种植业生产对气候变化的适应进行探讨。研究结果表明,(1)近32年来盐亭县大春作物的平均资源适宜指数、效能适宜指数和利用指数(分别为0.578、0.281和48.37%)均大于小春作物(分别为0.304、0.128和42.24%),大春作物的气候适宜度高于小春作物,且作物间的气候适宜度差异较大。(2)受季风气候波动的影响,该县作物气候适宜度有明显的年际波动;该县近32年来气候变化对大春作物气候适宜度有轻微不利影响,而对小春作物气候适宜度趋于有利。(3)盐亭县近32年来种植业平均的资源适宜指数为0.466、效能适宜指数为0.212、利用指数为45.49%;受5种作物资源适宜指数、效能适宜指数,以及作物播种面积与产量年际波动的综合影响,该县种植业气候适宜度亦有明显的年际波动;气候变化对该县种植业气候适宜度总体上有不利影响。(4)近32年来该县种植活动对种植业气候适宜度的影响度平均值为0.00092,其年际波动较大。通过作物种植组合结构的调整,在20世纪90年代中期前对种植业气候适宜度的提高有微弱的正向影响,对气候变化有一定程度的适应;而后期则有负向作用。     

Colonization of potato fields in eastern North Carolina by Colorado potato beetle

Rotated and non-rotated commercial potato fields were sampled intensively to follow Colorado potato beetle,Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), colonization and subsequent oviposition patterns in the spring of 1990 and 1991. Maximum densities of colonizing adults ranged from 0 to 14,891/ha and maximum egg mass densities ranged from 0 to 48,451/ha. Crop rotation generally resulted in lower potato beetle populations. Regardless of crop rotation management practices, colonization of fields planted in potatoes began at field edges and progressed inward in all fields for both years. Management of potato beetles is discussed in light of these findings.     

Climate impact on suicide rates in Finland from 1971 to 2003

Seasonal patterns of death from suicide are well-documented and have been attributed to climatic factors such as solar radiation and ambient temperature. However, studies on the impact of weather and climate on suicide are not consistent, and conflicting data have been reported. In this study, we performed a correlation analysis between nationwide suicide rates and weather variables in Finland during the period 1971–2003. The weather parameters studied were global solar radiation, temperature and precipitation, and a range of time spans from 1 month to 1 year were used in order to elucidate the dose-response relationship, if any, between weather variables and suicide. Single and multiple linear regression models show weak associations using 1-month and 3-month time spans, but robust associations using a 12-month time span. Cumulative global solar radiation had the best explanatory power, while average temperature and cumulative precipitation had only a minor impact on suicide rates. Our results demonstrate that winters with low global radiation may increase the risk of suicide. The best correlation found was for the 5-month period from November to March; the inter-annual variability in the cumulative global radiation for that period explained 40 % of the variation in the male suicide rate and 14 % of the variation in the female suicide rate, both at a statistically significant level. Long-term variations in global radiation may also explain, in part, the observed increasing trend in the suicide rate until 1990 and the decreasing trend since then in Finland.     

Alternative management tactics for control of Phyllotreta cruciferae and Phyllotreta striolata (Coleoptera: Chrysomelidae) on Brassica rapa in Massachusetts

The flea beetles Phyllotreta cruciferae (Goeze) and Phyllotreta striolata (F.) (Coleoptera: Chrysomelidae: Alticinae) are significant pests of crops in the Brassicaceae family. From 2001 to 2003, the efficacy of both new and commonly used treatments for the control of flea beetles in brassicas, Brassica rapa L., were evaluated in three small plot, randomized complete block design trials. Row cover and carbaryl (applied as a weekly foliar spray) were found to be the most consistent at reducing damage in comparison with untreated controls in all trials. Two new products that may provide adequate flea beetle control are spinosad (in either conventional or organic formulations) and thiamethoxam. The plant-derived compounds azidiractin and pyrethrin did not protect treated plants from flea beetle feeding. Treatment of plants with kaolin, or removal of the beetles with a vacuum, also did not reduce the level of crop damage. The level of damage at harvest was found to be correlated with population size of flea beetles in each plot, as measured by captures on yellow sticky traps and direct visual counts. Removal of the outer two leaves of individual B. rapa plants reduced the total number of holes per plant by 40%, while only removing 15% of the leaf area.     

Intra- and interspecific density dependence mediates weather effects on the population dynamics of a plant–insect herbivore system

Temperature and precipitation are two major factors determining arthropod population densities, but the effects from these climate variables are seldom evaluated in the same study system and in combination with inter- and intraspecific density dependence. In this study, I used a 19 year time series on plant variables (shoot height and flowering incidence) and insect density in order to understand direct and indirect effects of climatic fluctuations on insect population densities. The study system includes two closely related leaf beetle species (Galerucella spp.) and a flower feeding weevil Nanophyes marmoratus attacking the plant purple loosestrife Lythrum salicaria. Results suggest that both intraspecific density dependence and weather variables affected Galerucella population densities, with interactive effects of rain and temperature on insect densities that depended on the timing relative to insect life cycles. In spring, high temperatures increased Galerucella densities only when combined with high rain, as low rain implies a high drought risk. Low temperatures are only beneficial if combined with little rain, as high rain cause chilly and wet conditions that are bad for insects. In summer, interactive effects of rain and temperature are different because high temperatures and little rain cause drought that induce wilting in plants, thus reducing food availability for the leaf feeding larvae. In contrast, the density of the flower feeding weevil was less affected by temperature and precipitation directly, and more indirectly interspecific density dependent effects through reduced resource availability caused by previous Galerucella damage.     

Unraveling the drivers of intensifying forest disturbance regimes in Europe

Natural disturbances like wildfire, windthrow and insect outbreaks are critical drivers of composition, structure and functioning of forest ecosystems. They are strongly climate‐sensitive, and are thus likely to be distinctly affected by climatic changes. Observations across Europe show that in recent decades, forest disturbance regimes have intensified markedly, resulting in a strong increase in damage from wind, bark beetles and wildfires. Climate change is frequently hypothesized as the main driving force behind this intensification, but changes in forest structure and composition associated with management activities such as promoting conifers and increasing standing timber volume (i.e. ‘forest change’) also strongly influence susceptibility to disturbances. Here, we show that from 1958 to 2001, forest change contributed in the same order of magnitude as climate change to the increase in disturbance damage in Europe's forests. Climate change was the main driver of the increase in area burnt, while changes in forest extent, structure and composition particularly affected the variation in wind and bark beetle damage. For all three disturbance agents, damage was most severe when conducive weather conditions and increased forest susceptibility coincided. We conclude that a continuing trend towards more disturbance‐prone conditions is likely for large parts of Europe's forests, and can have strong detrimental effects on forest carbon storage and other ecosystem services. Understanding the interacting drivers of natural disturbance regimes is thus a prerequisite for climate change mitigation and adaptation in forest ecosystem management.     

Does host range influence susceptibility of herbivorous insects to non-host plant proteinase inhibitors?

We examined the influence of proteinase inhibitors on digestive enzymes and development of oriental beetle,Exomala orientalis Waterhouse, European chafer,Rhizotrogus majalis (Razoumowsky),Phyllophaga white grub,Phyllophaga anxia (LeConte), cranberry root grub,Lichnanthe vulpina (Hentz), Japanese beetle,Popillia japonica Newman, Asiatic garden beetle, Maladera castanea (Arrow) (Coleoptera: Scarabaeidae), and the black cutworm,Agrotis ipsilon (Rottemburg) (Lepidoptera: Noctuidae). We demonstrated that all species within our test group had alkaline midguts that contained proteinase activity that could be inhibited,in vitro with serine proteinase inhibitors. Our data suggests that host range may influence the susceptibility to non-host inhibitors. Chronic ingestion of the serine proteinase inhibitor, Kunitz-soybean trypsin inhibitor (STI), significantly reduced proteolytic activityin vivo in those species with relatively specialized feeding habits (i.e., cranberry root grub, Japanese beetle, Asiatic garden beetle, and black cutworm). Chronic ingestion of STI also resulted in reduced larval growth and delayed pupation for black cutworm, and elevated larval mortality for Japanese beetle. However, chronic ingestion of STI did not influence larval survival for those species with relatively generalized feeding habits (i.e., oriental beetle, European chafer). Based on these results, we propose mechanistically-based criteria for selecting proteinase inhibitors for phytochemical defense against herbivorous insects.