Fluorescent dust marking and sentinel pupal bags were used in 1998 and 1999 to examine dispersal, spatial distribution, and duration of activity of mass-released Spalangia cameroni Perkins in a swine facility. In 1998, four releases were conducted in the period May–November and in 1999 a final release was completed in August. Males were observed in large numbers on window sites shortly after releases, whereas females seemed to remain in the environment. However, in one trial, and probably due to high air temperatures in the facility, a similar flight propensity toward the window sites was noted for the females. The distribution of parasitoids was clearly aggregated within a perimeter of 3 m from the release point. The duration of activity of marked S. cameroni, measured as the number of attacked sentinel pupal bags and parasitism, declined to a low level within 2 wk from the time of release. The results are discussed in relation to release strategies of S. cameroni in control of nuisance flies.

The effect of temperature on development, survival, and adult longevity of Lydella jalisco Woodley (Diptera: Tachinidae), a parasitoid of the Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Pyralidae), was studied under laboratory conditions. Development times of L. jalisco larvae and pupae decreased with temperatures in the range 15–35°C. However, survival was greater at cooler temperatures similar to those encountered in the parasitoid’s native habitat; percentage of adult emergence was 62.5% at 20°C compared with 9.5% at 35°C. The lower temperature threshold for development of larvae was 14.5°C, whereas for pupae it was 13.8°C. Adult lifespan was also affected by high temperatures. Adult parasitoids lived 20 to 25 d at temperatures in the range 15–25°C, whereas they lived 4 to 6 d at 35–40°C. For <10 consecutive hours, temperatures exceeding 30°C prevail in the Lower Rio Grande Valley of Texas during the months of May through September when populations of E. loftini reach an economic threshold. Therefore, the potential efficacy of L. jalisco as a biological control agent of E. loftini in south Texas should be examined closely because mated females of L. jalisco require 7–14 d for maximum egg fertilization and embryonic development.

Cost-effective and ecologically sensitive monitoring techniques are required to assess effects of anthropogenic disturbances on biodiversity. Pitfall trapping is widely used in biodiversity monitoring programs to measure the diversity of organisms active within leaf-litter. We compared catch rates and species richness of ground beetles (Coleoptera: Carabidae), rove beetles (Coleoptera: Staphylinidae), and spiders (Araneae) across five different diameters of pitfall traps (4.5, 6.5, 11, 15, and 20 cm) and three sizes of rain covers (64, 79.2, and 225 cm²) to determine optimal trap size for studying litter-dwelling arthropod biodiversity. In general, larger pitfall traps collected more individuals, and more species, of all three taxa. Further tests on data standardized to trap circumference showed that catch rates are not directly proportional to trap size, and even the smallest traps collected a disproportionately high number of certain taxa. When catch rate data were standardized by trap circumference smaller traps collected more small-bodied carabid and staphylinid species and large traps collected more wolf spiders (Lycosidae) than smaller traps. Roof size had no effect on species richness or catch rate of beetles or spiders. For the purposes of ecological monitoring, using more small pitfall traps would be the most efficient sampling technique to characterize the dominant epigaeic arthropod fauna; small traps collect few nontarget vertebrates, and sorting the samples involves generally less processing time. From a conservation perspective, however, including several large pitfall traps in the sampling regime would help detect rare species.

The degree of abundance and diversity of springtails (order Collembola) often indicates the extent of disturbance by various agricultural practices. We examined how transgenic herbicide-tolerant soybean varieties and their associated weed management systems affect the abundance of 21 surface-active springtail species during three successive soybean growing seasons. With six soybean varieties (three transgenic, three nontransgenic), we tested three weed management systems: (1) targeted application of specific herbicides to the corresponding tolerant transgenic varieties; (2) conventional pre- and postemergence herbicide applications; and (3) mechanical cultivation. Each method posed its own potential costs and benefits to springtails. In targeted plots, springtail numbers were similar to or higher than those in conventional plots, suggesting that the later and repeated targeted applications to transgenic soybeans do not adversely affect springtail numbers in the short term. We attributed the observed treatment effect differences on springtail numbers to resultant differences in weed cover and degree of soil disturbance (indirect effects), rather than to any direct toxic effects of the herbicides. The treatments affected some species but not others; most of the affected species responded similarly to differences in weed treatment. Our results overall suggested no deleterious short-term effects of transgenic soybean targeted weed-management systems on abundance of the springtail species examined.

Temporal variation in allozyme frequencies at 10 allozyme loci was assessed by sampling six local populations of the cotton bollworm, Helicoverpa zea (Boddie), near cotton fields over 3 yr (1995–1997) in Leflore County, MS. Population structure over local and regional areas and changes in population structure over generations were analyzed using F-statistic estimators. There was low population differentiation at both local and regional scales, suggesting that extensive gene flow occurred within the spatial scale under investigation. Allele frequencies, heterozygosity, and the mean number of alleles per locus were stable over time and space. Measurements of population differentiation, F_ST, ranged from 0.0002 to 0.0072 over generations. However, there was no significant population subdivision when evaluated by bootstrapping over loci. Moreover, population differentiation as a whole and differentiation between regions was also very low, indicating that extensive gene flow occurs at both local and regional scales. Egg populations were more differentiated relative to the corresponding male moth populations, suggesting that population differentiation is greatest at egg/larval stages decreasing in adult populations due to movement. Almost all observed genetic variance was accounted for among traps within generations. Little variance was observed among generations or among years. These results further indicate that allele frequencies were stable over the duration of this study.

We investigated the seasonal population dynamics of the bruchid beetle, Bruchidius dorsalis Fahraeus, in relation to the phenology of its host plant Gleditsia japonica Miq. (Fabaceae: Caesalpinoidea) in two geographically distinct areas of Japan. We compared life cycles to clarify influences of seasonal variation in temperature and host plant availability on insect life cycles. Results from a 4-yr study indicated that in Sagamihara (warmer climate): (1) B. dorsalis has a trivoltine life cycle, (2) it cannot reproduce during a period of more than 1 mo until new seeds become available in early or mid-August, and (3) it overwinters in several different developmental stages (young and old instars, and adults). However, studies over 3 yr in Tatsuno (cooler climate) indicated the following: (1) B. dorsalis has a bivoltine life cycle, (2) G. japonica phenology lags several weeks behind that in Sagamihara, and (3) B. dorsalis overwinters as diapausing larvae (late fourth instar) or as adults. Thus, the life cycles of B. dorsalis are more constrained in cooler areas, not only because of the direct effects of lower temperature on insect development, but also because of the phenological delay in host plant development.

The damage caused by two species of introduced mole cricket pests (Scapteriscus vicinus Scudder and Scapteriscus borellii Giglio-Tos) was studied during 1995, 1996, and 1997 in Brunswick County, NC. Surface tunneling activity in bermudagrass was quantified weekly starting in late July or early August using a modification of the damage grid evaluation method of Cobb and Mack (1989). Soil moisture was monitored in three depth ranges (0–10.2, 10.2–20.3, and 20.3–30.5 cm) and percentage soil moisture based on dry soil weight was determined gravimetrically. Most sites had a higher percentage of S. borellii than S. vicinus, with the percentage of S. borellii ranging from 42–95%. The percentage soil moisture ranged from 1.2–24.9, 1.3–19.3, and 1.3–20.4% at 0–10.2, 10.2–20.3, and 20.3–30.5-cm, respectively. Moisture percentages in the 10.2–20.3- and 20.3–30.5-cm ranges were not significantly different. Mean percentage soil moisture in the 0–10.2 cm range was significantly greater than for the 10.2–20.3 and 20.3–30.5-cm ranges combined. Average damage ratings (0–9) increased linearly with Julian date, but due to differences in damage levels among the years, three separate linear equations were used to describe the relationship. Mean damage ratings increased by one rating point (11%) every 2–3 wk. A significant nonlinear relationship was found between percentage soil moisture and mean damage ratings. Management implications of the findings are discussed.

Life table studies of European corn borer, Ostrinia nubilalis (Hübner), populations with and without inoculative releases of Trichogramma ostriniae (Peng & Chen) were conducted in sweet corn and field corn. Inoculative releases of T. ostriniae (at 72,000 females per hectare) provided relatively high parasitism of European corn borer eggs (≈37%) throughout the season. The increase in egg parasitism was not offset by compensatory changes in other mortality rates such as egg predation, eggs not hatching, and death of early instars after egg hatch. Early instar disappearance was a key mortality factor accounting for >70% of total mortality from egg deposition to established larvae. Egg parasitism by T. ostriniae was also a key mortality factor. Releases of T. ostriniae increased total egg and larval mortality of O. nubilalis from 61 to 92% in sweet corn and from 80 to 93% in field corn.

Reproductive traits and longevity of Anoplophora glabripennis (Motschulsky) from the Ravenswood, Chicago, IL, and Bayside, Queens, NY, populations were compared for first-generation adults that emerged from cut infested wood and for second-generation adults that were reared on artificial diet. Illinois females were significantly more fecund than those from New York when they emerged from infested wood and tended to be more fecund when reared on artificial diet. Weights of adult females that emerged from infested wood varied with the hosts they emerged from; but when reared on artificial diet, Illinois females were significantly heavier than New York females. There were no significant differences between the two populations in egg viability or adult longevity. In general, females laid more eggs and survived longer in the laboratory on sugar maple, Acer saccharum Marshall, than has generally been reported for this tree species. Larval food source and quality had significant effects on female fecundity and longevity. The above differences between the two populations and the effects of host quality and host species should be taken into account when management decisions are made in the current eradication program for A. glabripennis in the United States.

This 10-yr field study examined prolonged dormancy (dormancy of more than 1 yr) in Colorado potato beetles, Leptinotarsa decemlineata (Say), from Upstate New York. The research focused on whether the life cycle of the Colorado potato beetle could reduce the effectiveness of crop rotation as a pest management tactic. One set of experiments quantified variation in the occurrence and duration of prolonged dormancy in a natural population. A second set of experiments tested the effect of artificial selection for increased incidence of prolonged dormancy. Of the ≈12,600 unselected beetles in the field cages overall survival (= % emergence) averaged 56.5 ± 18.4% (mean ± SD, range = 23.5–84.3%, n = 19 cages). Most (97.7%) of the emerging beetles surfaced after one winter; the remainder (2.3%) emerged after more than one winter in dormancy. The range of variation in the incidence of prolonged dormancy among the experimental cages during the 10-yr period was 0–7.2%. The incidence of emergence from prolonged dormancy was higher among beetles from the first summer-generation [mean ± SD = 3.0 ± 2.0% (10 cages)] than from the second [1.0 ± 1.5 (7 cages)], and significantly more females than males emerged from prolonged dormancy (female:male = 97:64). Most (≈70%) of the beetles that underwent prolonged dormancy emerged after two winters in diapause; the majority of the remainder (≈29%) emerged after 3–7 yr in diapause; and, one beetle (≈1%) emerged after 9 yr. Artificial selection for prolonged dormancy over three generations did not result in a significant increase in the incidence of delayed emergence, nor did it result in incidences of prolonged dormancy greater than those in the controls (unselected field-reared beetles and lines selected for 1-yr dormancy). From our results, we conclude that the Colorado potato beetle has considerable variation in both the incidence and duration of prolonged dormancy, and that this variation has strong environmental and genetic determinants. Viewed in the context of the beetle’s life history, these findings lead us to suggest that the evolution of resistance to crop rotation would require strong and sustained selection over large areas.

In rearing parasitoids for biological control releases and in natural populations, female parasitoids may encounter variable distributions of host quality. Here I examine how the proportion of hosts that are small versus large or old versus young affects sex ratio and offspring production of the parasitoid wasp Spalangia cameroni Perkins parasitizing Musca domestica L. pupae. With increasing proportion of small hosts or old hosts, overall number of offspring did not significantly decrease and the overall proportion that were male (i.e., from small and large hosts combined) did not significantly increase. A greater proportion of sons from small versus large and from old versus young hosts was not restricted to the case of equal numbers of different host types. The proportion of sons produced from small hosts as well as the proportion of sons from large hosts decreased as the proportion of small hosts increased, and the proportion of sons produced from young hosts decreased as the proportion of old hosts increased. These results are relevant to recommendations for rearing S. cameroni for biological control releases and to testing evolutionary sex ratio theory, specifically a combined host-quality and local mate competition model.

The effect of temperature and soldier proportion on worker survival, soldier production, and wood consumption of the Formosan subterranean termite, Coptotermes formosanus Shiraki, was evaluated in the laboratory with termites from a single colony. Soldier production was influenced by temperature and the initial proportion of soldiers. On average, termites had a significantly higher survival rate when the initial soldier proportion was <20%. Soldier caste development was at its highest at 30°C, and when treatment started with no soldiers in the colony. Termite survival was significantly higher at 30°C than at 25 and 33°C after 12 d of testing. There was a significant interaction of temperature and soldier proportion on termite survival after 36 d. C. formosanus could support higher proportions of soldiers with an increase in temperature. There was no significant decrease in survival rates with increasing numbers of soldiers at 25 and 33°C. At 60 d, survival at 20 and 25°C declined significantly when soldier proportions exceeded 20%. At 30 and 33°C, termite survival did not decline significantly when soldier proportions increased from 20 to 30% (30°C) or 40% (33°C). Consumption rates increased significantly with rising temperature up to 30°C. Consumption rates tended to increase as soldier proportion increased. There was no significant interaction between temperature and soldier proportion on wood consumption rate.

Idiarthron subquadratum (Orthoptera: Tettigoniidae) is a sporadic pest of coffee in parts of Mesoamerica. Mark-recapture techniques were employed to determine the adult population size in coffee plantations in the municipality of Siltepec, Chiapas, Mexico, where the insect has caused crop losses of around 50% over the past decade. Eight experimental blocks 50 by 50 m were defined in an area of 2,500 m². A trap was designed consisting of a bamboo tube 30 cm in length and closed at one end. Trials indicated that insect trapping efficiency was not improved by the presence of baits. Traps placed above the ground in coffee bushes or as banana leaves placed on the side of an experimental gauze cage captured significantly more I. subquadratum individuals than traps placed on the ground. Tests with different types of paint combinations for marking insects revealed that nitrocellulose paint was durable, water-resistant and nontoxic to I. subquadratum. Mark-recapture experiments were performed at 48-h intervals over a 1-mo period. Concurrently, direct nocturnal observations of I. subquadratum individuals feeding on coffee leaves and berries were made on four occasions during the study period. The prevalence of I. subquadratum feeding damage was also quantified at three sample dates during the study. Jackson’s negative and positive index, Fisher-Ford model, Lincoln-Petersen index, and Jolly-Seber’s stochastic model gave statistically similar mean population estimates. All of these mark-recapture models were also statistically similar to estimates generated by direct nocturnal counts of insects observed feeding on coffee bushes. In contrast, Bailey’s triple capture model gave a population estimate significantly lower than the other models. I. subquadratum feeding damage to coffee berries was significantly greater in blocks interplanted with banana. We conclude that mark-recapture methods combined with analysis using the Lincoln-Petersen model are simpler and less time consuming than direct nocturnal observations and give quantitatively similar population estimates.

RESUMEN Idiarthron subquadratum (Orthoptera: Tettigoniidae) es una plaga esporádica del café en algunas partes de Mesoamérica. Técnicas de marca-recaptura se usaron para determinar el tamaño de población del adulto en cafetales del municipio de Siltepec, Chiapas, México donde el insecto ha causado pérdidas al cultivo de alrededor de 50% durante la década pasada. Ocho parcelas experimentales de 50 por 50 m fueron definidos en un área de 2,500 m². Se diseñó una trampa consistente en un canuto de bambú de 30 cm de longitud y cerrado por uno de sus extremos. Pruebas indicaron que la eficiencia del trampeo del insecto no fue mejorada por la presencia de cebos. Las trampas puestas sobre plantas de café u hojas de plátano puestas sobre un lado de una caja experimental de tela fina capturaron significativamente más individuos de I. subquadratum que trampas puestas sobre el suelo. Pruebas con diferentes tipos de combinación de pinturas para marcar insectos revelaron que la pintura de nitrocelulosa fue más durable, resistente al agua y no tóxica a I. subquadratum. Los experimentos de marca-recaptura se realizaron a intervalos de 48-h durante un mes. Al mismo tiempo, se hicieron observaciones en la noche cuando los individuos de I. subquadratum se alimentaban de hojas y frutos del café en cuatro ocasiones durante el periodo de estudio. La prevalencia del daño de la alimentación de I. subquadratum también fue cuantificada en tres fechas de muestreo durante el estudio. Los índices positivo y negativo de Jackson, el modelo de Fisher-Ford, el índice de Lincoln-Petersen, y el modelo estocástico de Jolly-Seber dieron estimaciones de las medias de la población estadísticamente similares. Todos estos modelos de marca-recaptura fueron también es

Thrips are important pests of dendrobium orchid flowers in Hawaii primarily because of the risk that exported flowers found to be infested will be rejected by quarantine inspectors. Using nondestructive sampling, the population dynamics of thrips infesting dendrobium orchids was monitored at two farms on the Island of Hawaii over a period of 1 yr. Average thrips populations varied between 0 and 1.0 thrips per spray (flower spike). At both sites, adult thrips almost always outnumbered nymphs. The western flower thrips, Frankliniella occidentalis (Pergande), was the predominant species found. Using randomization tests, adult thrips were found to be randomly distributed on orchid sprays. The binomial probability distribution was used to graphically describe the accuracy of scouting results as a function of sample size and the proportion of thrips-infested flowers. Efficient methods for counting adult thrips included nondestructive field counts (direct observation), flower shakes, and extractions via Berlese funnels.

The suggestion in the literature that dispersal of the Colorado potato beetle, Leptinotarsa decemlineata (Say), by flight is stimulated by crowding was tested in three flight chamber experiments. In the first experiment the rate of take-off in flight chambers averaged 35.0% (SE ± 5.64) over a 3-h period. The rate of flight take-off was independent of insect density (2–128 beetles per release) or age (7–18 after emergence). For the second experiment the cumulative incidence of flight take-off rates during a 3-h period was similar for all insect densities. The mean percentage of beetles that flew was greatest in the first 30 min, was low during the following 30 min and minimal thereafter. At the highest density tested, i.e., 128 beetles per release, the take-off rate was initially lower; however, it resulted in the same 3-h cumulative rate as for other densities. The data show that interactions between crowded individual adult potato beetles do not promote flight take-off and might occasionally lower it. The third experiment included a 1-h acclimatization to the experimental setup but had no effect on the mean rate of flight take-off or its pattern over the subsequent 3-h period. These results provide evidence that the massive dispersal of adult beetles occasionally observed in potato fields is not the result of crowding as suggested by some, but is probably caused by the poor quality or near absence of the host plants (food source) in the fields with abundant beetles.

A behavioral ethogram for feeding and nonfeeding behaviors of Lygus hesperus Knight, the western tarnished plant bug, was developed using third instars on host and nonhost plants, as well as an artificial diet. Individual insects were simultaneously recorded with an AC electronic monitoring system and a time-lapse video cassette recorder. The electronic monitor provided information on the various stylet penetration behaviors exhibited, whereas the video was used in evaluating nonfeeding and surface exploration behaviors on plants and stylet activities in the diet. From these recordings, seven distinct feeding waveforms and over 20 nonfeeding behaviors were described. Artificial diet correlations were performed to verify ingestion and possible salivation activities during other waveforms. Some behaviors were found only to occur on particular substrates. These included the release of a salivary bubble following a period of feeding on the artificial diet and a continual labial dabbing behavior on mature cotton plants. An association was observed between ingestion and specific positions of the labium and antennae during the construction of an ethogram. A subsequent experiment was conducted that confirmed this relationship on mature and immature cotton.

In West Africa Callosobruchus maculatus F. causes major losses during storage of cowpea (Vigna unguiculata Walper). The larvae of C. maculatus are parasitized inside the seeds by Dinarmus basalis (Rondani). African farmers introduce aromatic plants into storage systems at the beginning of the storage period that release toxic volatile compounds into the headspace of the stores. The susceptibility of C. maculatus and D. basalis to two plant sulphur-containing compounds, methylisothiocyanate (MITC) and dimethyl disulfide (DMDS), was analyzed under laboratory conditions. The adults of C. maculatus and D. basalis had the same susceptibility to MITC but the parasitoid was more susceptible to DMDS than its host. The larvae were less affected by the treatments than the adults; the seed coat acts as a barrier for volatile penetration. Susceptibility to DMDS was high when the C. maculatus larvae were extracted from the seeds. DMDS was more toxic than MITC and differences in penetration inside the seeds could explain these results. The higher susceptibility of D. basalis to the treatments could have consequences on biological control in storage systems. The presence or absence of leaves of the shrub Boscia senegalensis Lamarck (Capparaceae), which release MITC into the jar atmosphere could have an impact on numbers of C. maculatus and D. basalis. When D. basalis adults were put into the storage systems in the absence of B. senegalensis leaves, successive generations of the parasitoids maintained the C. maculatus population at a low density. In the presence of B. senegalensis leaves, the D. basalis population was more affected by the treatment than its host C. maculatus and was incapable of preventing the increase in bruchid population. This traditional method appears to increase seed weight losses by limiting the efficiency of the biological control.

Frankliniella fusca (Hinds) is a species of thrips that is a pest of peanuts and an important vector of tomato spotted wilt virus. In previous research, populations of thrips declined in peanut during midseason for unexplained reasons. Nematodes in the genus Thripinema are parasites of thrips that render infected females sterile. A new species, T. fuscum Tipping & Nguyen, was recently described as a parasite of F. fusca in peanut. In 1997 and 1998, the temporal changes in percent parasitism of F. fusca in plots of peanuts were determined. Parasitism of adult female thrips increased from an estimated 1% on seedling peanut each year to a maximum of 68% later in the 1997 growing season and 38% in the 1998 growing season. Treatments of several insecticides for control of thrips reduced percent parasitism of the females on most sample dates in 1997, but parasitism was not significantly affected in 1998. Estimates of the numbers of F. fusca in the flowers and terminal buds of peanuts declined each year as parasitism increased. The very high levels of parasitism in 1997 were associated with near extinction of larval populations of thrips during midseason. As a result, the spread of tomato spotted wilt virus by this vector species was reduced. Thus, T. fuscum may be an important natural enemy of F. fusca responsible for suppression of populations of thrips in peanut.

Conservation and augmentation of indigenous natural enemies are promising strategies for biologically based pest management in outdoor urban environments. This research sought to determine whether the addition of wildflower plantings would enhance the occurrence, abundance and impact of beneficial arthropods in the landscape, and to determine the potential compatibility of pest-resistant turfgrass and natural control of Japanese beetle, Popillia japonica Newman, and fall armyworm, Spodoptera frugiperda (J.E. Smith). A bermudagrass cultivar (susceptible to fall armyworm), a zoysiagrass cultivar (resistant to fall armyworm), and two different commercially available wildflower mixes all harbored a diverse array of beneficial arthropods in both large and small plot evaluations. A wildflower mix containing 15 species of flowers provided significant, season-long increases in foliar-dwelling spiders and bigeyed bugs during 1-yr of a 2-yr study in large (1,512 m²) plots. Ground-dwelling spiders were more abundant in bermudagrass turfgrass than in wildflowers both years, whereas ants were not significantly affected by cover type. Each wildflower mix evaluated in a separate 2-yr small plot study increased the abundance of some, but not all beneficial arthropod taxa sampled. This increased abundance was only occasionally also observed in adjacent turfgrass areas. However, fall armyworm eggs and larvae, and Japanese beetle eggs were consistently and heavily preyed upon in small plots regardless of turfgrass species in the plot or surrounding border of flowers or mulch. Most beneficial taxa, even Geocoris uliginosus, which was more common in turfgrass, were represented in flowers, suggesting that these floral plantings may be useful in providing refugia for beneficials when insecticide applications are required to suppress turfgrass pests.

The density of Japanese beetle (Popillia japonica Newman) and the prevalence of its natural enemies were evaluated in southern Michigan. Third instars were collected in spring and fall and adults during the summer of 1999 and 2000 at 11 golf courses. Larvae were also collected once in fall of 2000 from 24 additional sites including golf courses (n = 8), blueberry farms (n = 7) and low-maintenance turf (n = 9). Larval density in the irrigated rough at the 11 primary golf course sites averaged 9.5/0.1 m² (range, 3.7–21.0). At the 24 additional sites, where habitat was more diverse, Japanese beetle larval density averaged 2.9/0.1 m² (range, 0.60–14.4). The larval parasitoid Tiphia vernalis Rohwer and the adult parasitoid Istocheta aldrichi (Mesnil) were absent from all sites in this study. Cephaline gregarines (Stictospora sp.) were the most common parasites, infecting 36.1% of all larvae in fall of 2000. The microsporidean Ovavesicula popilliae Andreadis was absent at all but two locations near Kalamazoo, MI. The bacterial pathogen Paenibacillus popilliae (Dutky) and entomopathogenic nematodes were uncommon, infecting <1% of larvae. Overall, two parasites (T. vernalis and I. aldrichi) and two pathogen (O. popilliae), reported to be widespread and epizootic in some eastern states, were absent or nearly so (O. popilliae was found at two of 35 locations) in Michigan. Stictospora sp. was found at most locations in Michigan (25/36) where Japanese beetle infestations have been active for more than 20 yr, but was scarce or absent from areas where Japanese beetle has become established in the last 10 yr.