Fall Flight Research Articles

Volatiles from nutritional fungal symbiont influence the attraction of Anisandrus maiche (Coleoptera: Curculionidae) to ethanol-baited traps.

Anisandrus maiche Stark (Coleoptera: Curculionidae: Scolytinae) is a non-native ambrosia beetle from central Asia that has been spreading throughout the eastern United States since 2005. Preferred hosts of A. maiche are not well characterized within its currently invaded range, but it is established in managed and natural forests throughout Indiana. Current monitoring and detection efforts for this beetle rely on ethanol-baited traps, but fungal volatiles may alter the attraction of A. maiche to ethanol. In this study, we conducted trapping experiments in Indiana to determine the extent to which a suite of common fungal alcohols influences the response of A. maiche to ethanol-baited traps. We then evaluated isoamyl and isobutyl alcohol as potential attractants for A. maiche and their ability to enhance attraction to ethanol. Lastly, we used SPME-GC-MS to identify volatiles from Ambrosiella cleistominuta (Mayers & Harr.), the fungal symbiont of A. maiche, grown for 7 and 14 days on malt extract agar. Benzyl alcohol, isobutyl alcohol, hexanol, methyl phenylacetate, phenethyl alcohol, and piperitone reduced the attraction of A. maiche to ethanol-baited traps in the field. Moreover, adding methyl benzoate and isoamyl alcohol individually to ethanol-baited traps did not further increase A. maiche capture. When paired with ethanol, isoamyl alcohol repelled beetles in the early flight period but did not significantly increase trap capture during the fall flight. These results represent a first step in understanding the role of fungal volatiles in the colonization behavior of A. maiche and may ultimately inform management strategies for this species.

Influence of local weather on collision risk for nocturnal migrants near an electric power transmission line crossing Kittatinny Ridge, New Jersey

Collisions with tall anthropogenic structures (power lines, wind turbines, communication towers, and buildings) are a regular cause of mortality for nocturnal avian migrants. To better understand relationships between weather and migrant collision risk, we compared nocturnal hourly mean barometric pressure, temperature, relative humidity, wind direction, and wind speed to avian passage rates (targets/km/h) and flight heights during 1 year of spring and fall migrations near a recently reconstructed transmission line crossing Kittatinny Ridge, New Jersey, using 2 marine radars. We found lower spring flight heights associated with decreasing barometric pressures, temperatures, and relative humidity across all wind directions. Spring flight heights showed the strongest decreases with increasing wind speeds for headwinds and crosswinds while flight heights slightly increased with stronger tailwinds. Spring passage rates increased with lower relative humidity and higher temperatures. With increasing wind speeds, spring passage rates declined faster with headwinds and crosswinds, and only slightly with tailwinds. We found lower fall flight heights with decreasing temperatures and relative humidity, but the relationships varied by wind direction. The lowest flight heights occurred under tailwind and crosswind conditions. Increasing fall passage rates were associated with increasing barometric pressures and when wind speeds were lowest. Fall passages rates declined with higher wind speeds but were more gradual under tailwinds and crosswinds when compared to headwinds. Overall, 2–4% of birds migrated under conditions that would have placed them at risk of collision with the transmission lines. Similar studies conducted along migratory pathways could be used to predict nights where birds exhibit low flight heights around other obstacles along their migration path. These predictions could improve detection rates for carcass searches documenting relatively rare collision events. For sites with topographic features likely to concentrate nocturnal migrants, radar studies could be conducted before siting towers so that impacts to migratory birds could be avoided at these sites.

Climate effects on late-season flight times of Massachusetts butterflies.

Although the responses of living organisms to climate change are being widely investigated, little attention has been given to such effects late in the growing season. We studied the late-season flight times of 20 species of butterflies in a geographically limited region, the state of Massachusetts in the USA, by examining change in dates of flight over a 22-year period and in response to average monthly temperature and precipitation. By analyzing the last 10% of each year's observations reported by observers of the Massachusetts Butterfly Club, we found that seven species remain in flight significantly later into the fall than they did two decades earlier, while two species show reduced late-season flight. Life history characteristics of the species, particularly voltinism and average fall flight dates, influenced whether warmer fall months led to increases or decreases in fall flight. Warmer Novembers often led to later fall flight, and wetter Augusts usually extended fall flight. These results document the effects of climate on late-season flight times of butterflies, add to an understanding of how warmer autumn conditions alter the phenology of different butterfly species, and show the usefulness of citizen science data.

IMAGING ANALYSIS OF THE HARD X-RAY TELESCOPE ProtoEXIST2 AND NEW TECHNIQUES FOR HIGH-RESOLUTION CODED-APERTURE TELESCOPES

ABSTRACT Wide-field (≳100 deg ) hard X-ray coded-aperture telescopes with high angular resolution (≲2′) will enable a wide range of time domain astrophysics. For instance, transient sources such as gamma-ray bursts can be precisely localized without the assistance of secondary focusing X-ray telescopes to enable rapid followup studies. On the other hand, high angular resolution in coded-aperture imaging introduces a new challenge in handling the systematic uncertainty: the average photon count per pixel is often too small to establish a proper background pattern or model the systematic uncertainty in a timescale where the model remains invariant. We introduce two new techniques to improve detection sensitivity, which are designed for, but not limited to, a high-resolution coded-aperture system: a self-background modeling scheme which utilizes continuous scan or dithering operations, and a Poisson-statistics based probabilistic approach to evaluate the significance of source detection without subtraction in handling the background. We illustrate these new imaging analysis techniques in high resolution coded-aperture telescope using the data acquired by the wide-field hard X-ray telescope ProtoEXIST2 during a high-altitude balloon flight in fall 2012. We review the imaging sensitivity of ProtoEXIST2 during the flight, and demonstrate the performance of the new techniques using our balloon flight data in comparison with a simulated ideal Poisson background.

Attraction of Lovebugs (Diptera: Bibionidae) to Visual and Olfactory Stimuli

Abstract We evaluated volatile organic compounds and colors for attractancy to adult lovebugs, Plecia nearctica Hardy, under field conditions in central and southern Florida. In olfactory tests, sticky traps placed at 10 m intervals (1 m height) and baited with the floral compound phenylacetaldehyde (PAA), essential oil anethole and anisaldehyde were highly attractive to both sexes of lovebugs during spring and fall flights. However, PAA was superior, capturing at least 3 times as many lovebugs in direct comparisons. Methyl salicylate, eugenol and benzaldehyde were weak attractants, whereas geraniol and citrus oil were not attractive. Heptaldehyde, 1-phenylethanol and acetophenone also were not attractive in tests that included PAA. In visual studies with unbaited sticky traps, lovebugs were most attracted to different hues of yellow and white at both high population densities (spring flight) and low population densities (fall flight). There was little statistical difference among the remaining colors (gr...

Flight Phenology of MaleCactoblastis cactorum(Lepidoptera: Pyralidae) at Different Latitudes in the Southeastern United States

ABSTRACT Long term trapping studies of the invasive moth Cactoblastis cactorum (Berg) were conducted at various latitudes from Puerto Rico to South Carolina. Three flight periods per year were identified at the 5 temperate sites studied, which covered the majority of the infested range on mainland United States. In general, the 3 flight periods across a latitudinal gradient from south Florida to central, coastal South Carolina were a spring flight during Feb–-May, a summer flight during Jun–Aug, and a fall flight during Sep–Nov. At any 1 site, each flight period lasted about 2 months. In the tropical areas of the Florida Keys and a Caribbean Island, the insect exhibited overlapping generations. Previous studies of this insect (as a biological control agent) report 2 flight periods per year in its native range of Argentina and its introduced range of Australia and South Africa. A synthetic pheromone-baited trap was a good indicator of generational time, and we suggest that trapping assays in these areas wi...

Infection of Harmonia axyridis (Coleoptera: Coccinellidae) by Hesperomyces virescens (Ascomycetes: Laboulbeniales): Role of mating status and aggregation behavior

The ectoparasitic fungus Hesperomyces virescens was studied on Harmonia axyridis in North Carolina, in the southeastern United States. A primary goal was to investigate transmission of the disease by examining the correlation between the pattern of fungal infection and seasonal change in host behavior. Beetles were collected as they arrived at their winter quarters at two sites; in one site they were also subsampled at mid- and late winter. Insects were sexed and weighed, fungal thalli were counted, and their location on the host body mapped; spermathecae of females were examined for sperm. Infection levels varied between sites, differed significantly between the sexes in one site but not the other, and increased by ∼40% during winter. The distribution of thalli on the body changed seasonally, in concert with behavioral changes in the host. At fall flight, thalli were found most often on the posterior elytra of mated females, virgin females, and males. This is suggestive that the disease had been spread among both sexes via successful and failed copulation attempts; however, the relatively low incidence of infection on the male venter does not fit the sexual transmission scenario. During winter, thallus location shifts in concert with beetle aggregation behavior, with infections more often located on the head and legs. Fresh weight of beetles decreased by approx. 20% during winter, but was not affected by disease status. Prior to spring flight, uninfected females were preferred as mating partners, but the probable relationship between female age and infection status complicates interpretation of the data.

Seasonal Migration and Overwintering Habitats of Chinch Bug (Hemiptera: Lygaeidae) in Northeastern Mississippi

The chinch bug, Blissns leucopterus leuco-pterus (Say), has become an important early-season pest of corn, Zea mays L., in the southeastern United States. Information on overwintering of chinch bugs is available but it is primarily from studies conducted in the central and midwestern states. Studies were conducted to describe chinch bug overwintering sites, changes in population densities in bromesedge, Andropogon virginicus L., and the timing of spring and fall flights from and to overwintering sites in a northeastern Mississippi environment during a three year period. Adults were found to over winter in many sites on the study area. High numbers of chinch bugs were found to congregate in bromesedge plants along roadsides or within cut-over woodland. Adults began to move into bromesedge for overwintering in September, but the largest increase occurred in October. Winter mortality from December to the end of February was slight probably because of mild winters during the three year study. Adult numbers in bromesedge began to decline in March as insects began to leave the overwintering site, and the rate of evacuation increased rapidly as temperatures warmed in April. Significant negative correlations were found to exist between the decline in numbers of chinch bugs in bromesedge and spring daily average and maximum temperatures. Fall and spring flight to and from overwintering sites based on captures of adults on aerial traps were found to be in general agreement with the timing of adult increase and decline on bromesedge.

Butterfly Migrations in Florida: Seasonal Patterns and Long-Term Changes

Flight traps at Gainesville, in north-central Florida, operating from 1984 to spring 2000, separated butterflies migrating into the Florida peninsula (SSE ± 90°) from those migrating out of the Florida peninsula (NNW ± 90°). Five species flew southward in the fall and northward in the spring: Phoebis sennae (L.), Agraulis vanillae (L.), Junonia coenia (Hübner), Urbanus proteus (L.), and Eurema lisa (Boisduval & LeConte). Five species had significant northward flights in spring but no significant migration in fall: Pieris rapae (L.), Vanessa virginiensis (Drury), Vanessa atalanta (L.), Eurytides marcellus (Cramer), and Libytheana bachmanii (Kirtland). Danaus plexippus (L.) had a southward flight in fall but no significant migration in spring. Eurema daira (Godart) switched from a net movement northward in early fall to a net movement southward in late fall, whereas Eurema nicippe (Cramer) maintained a net movement northward throughout the fall. The major migrants differed significantly in the seasonal timing and duration of peak migration. When the numbers trapped were greatest, the proportion of those flying in the migratory direction was greatest. The numbers of spring migrants of A. vanillae increased during the course of the study, whereas both the spring and fall migrations of J. coenia declined. The fall migrations of P. sennae and U. proteus declined sharply. In 1990–1999, the fall migrations of P. sennae and U. proteus averaged only 37 and 15% of what they had averaged in 1984–1989. Reduced planting of soybeans in source areas for migrants probably contributed to these steep declines.

Impact of the Conservation Reserve Program on Duck Recruitment in the U.S. Prairie Pothole Region

The U.S. Department of Agriculture (USDA)'s Conservation Reserve Program (CRP) resulted in the conversion of about 1.9 million ha of cropland to perennial grass cover in the Prairie Pothole Region of North Dakota, South Dakota, and northeastern Montana by 1992. Many wildlife managers believed this cover would provide benefits to wildlife, including upland nesting ducks. During 1992-1995, we evaluated success of 5 duck species nesting in CRP fields and nearby Waterfowl Production Areas (WPA) throughout the region. We examined relationships between daily survival rates (DSR) of duck nests in CRP cover and landscape-level habitat and population parameters. We computed DSR of duck nests in other major cover types in our study area from data collected during 1980-1984 (pre-CRP) and 1990-1994 (CRP) periods. We then applied recruitment models to estimate duck production in our study area during peak CRP years (1992-1997) and compared these results with those that simulated the scenario in which cropland was in place of CRP cover (i.e., the CRP had not occurred). DSR were higher in all habitats combined during the CRP period compared to the pre-CRP period. Regressions of DSR in CRP cover on the percent of each study plot in perennial cover and geographic location were significant (P < 0.01) for 4 of 5 duck (Anas spp.) species. Estimated nest success and recruitment rates for the 5 species combined during 1992-1997 were 46% and 30% higher, respectively, with CRP cover on the landscape compared to a scenario where we simulated cropland in place of CRP. Our model estimated an additional 12.4 million recruits from our study area to the fall flight as a consequence of the CRP during 1992-1997. Our results document benefits to 5 duck species in the northern plains associated with a farm program that provided financial incentives to landowners for planting undisturbed grass cover as an alternative to annual crops.

A comparison of Antarctic stratospheric radiative heating rates calculated from high‐resolution interferometer sounder and U.K. Meteorological Office data

Radiative heating rates have been calculated in the region of the Antarctic polar vortex during 1994 using the National Center for Atmospheric Research Community Climate Model (CCM2) radiative transfer model. Temperature and tropospheric water vapor retrievals were used from the high‐resolution interferometer sounder (HIS) on board the ER‐2 in 1994 to compute clear sky heating rates in April, August, and October. The lower stratospheric heating rate is shown to be sensitive to the skin temperature due to the exchange of radiation within the ozone 9.6 μm band. This implies a coupling between the surface and the lower stratosphere, with the formation of sea ice decreasing the skin temperature and increasing lower stratospheric cooling rates. Computations show weak heating (strong cooling) rates for the fall flight, of the order of −0.7 K/day (potential temperature), with progressively greater heating (smaller cooling) rates associated with the late winter and spring flights and large variations in latitude. HIS temperatures are independent of numerical weather prediction analyses and so provide a useful comparison. Vertical mean (350–420 K) temperature differences between HIS retrievals and collocated U.K. Meteorological Office (UKMO) assimilations are generally within 3 K; HIS temperatures are greater for most flights around and poleward of the vortex edge. Calculated heating rates result in weaker HIS heating (stronger HIS cooling) for most flights resulting from the greater HIS temperatures. Heating rate differences are generally within 0.2 K/day for the 350–420 K vertical mean. The calculations show evidence of a minimum in the cooling rate in the region of the vortex edge for the August and October flights, also seen in the collocated UKMO results as well as in hemispheric calculations.

Role of Green Peach Aphid Flights in the Epidemiology of Potato Leaf Roll Disease in the Columbia Basin.

Three distinct and highly predictable green peach aphid (GPA) (Myzus persicae) flights that occur seasonally in the spring, summer, and fall were detected at a southern, central, and northern location in the Columbia Basin of the Northwestern United States. Intensity and timing of the flights was approximately the same at the three locations. Timing and number of alatae captured in the spring and summer flights was associated with heat unit accumulation. The spring flight, which originates on the overwintering peach tree host, colonized but did not introduce potato leafroll virus (PLRV) into virus-free potato plots. The summer flight, which originates from volunteer potatoes and spring herbs originally colonized by the spring flight, did introduce PLRV into virus-free potatoes. The fall flight was too late to affect potato production. When plots contained a point source of PLRV, the virus spread rapidly in a plant-to-plant mode to all plants in plots after aphids arrived in the spring. Rate of spread from point sources of infection was not affected by timing or intensity of the spring flight, but timing of virus spread in the plots depended on time of arrival of the aphids. Once PLRV was introduced to virus-free plots by the summer flight, virus spread to other plants within the plots. GPA overwintered on peach trees. Although GPA apterae and alatae were present on winter annual weed and crop hosts in the fall, none survived winters on these species. In addition to the GPA, one other vector of PLRV, Macrosiphum euphorbiae, was rarely collected in aphid traps. These results suggest that chemical control of aphids could be delayed until mid-July if PLRV-free potato seed were available.

Population Dynamics of White-Winged Scoters

A significant (P < 0.01) decline between 1961 and 1993 in ratio of harvested young per adult in the Atlantic Flyway (age ratio) of white-winged scoters (Melanitta fusca) led us to examine annual survival rates and harvest of this species. Compared to waterfowl with similar life histories, black scoters (M. nigra) and surf scoters (M. perspicillata), the decline in age ratios of white-winged scoter age ratios was not significantly different (P = 0.11). Adult females banded at Redberry Lake, Saskatchewan that winter along both coasts, had high annual survival rates (0.773 ? 0.0176 [SE]). High harvest in the Atlantic Flyway was not followed by an increase in production (age ratios) the following year or 2, i.e., there was no short-term rebound in recruitment by the population. Harvest of white-winged scoters in the Atlantic Flyway was explained by the age ratio in the fall flight and by hunter effort. J. WILDL. MANAGE. 61(1):222-227

Response of staging brant to disturbance at the Izembek Lagoon, Alaska : D. H. Ward, R. A. Stehn & D. V. Derksen, Wildlife Society Bulletin, 22(2), 1994, pp 220–228

Human disturbance of migrating waterfowl concerns managers of wildlife populations and refuges. Human disturbance may reduce food intake through interruption of foraging bouts or by displacement from feeding areas (Madsen 1985, Belanger and Bedard 1989), and it may increase energy expenditure from additional time in flight (Korschgen et al. 1985). Reduced food intake and increased energy expenditure can affect the ability of waterfowl to acquire nutrient reserves for successful migration (Fredrickson and Drobney 1979, Davis and Wiseley 1974, Belanger and Bedard 1990). Furthermore, nutrient reserves acquired during fall migration may influence overwinter survival (Haramis et al. 1986). Over 90% of the Pacific Flyway population of brant (Branta bernicla nigricans) annually migrates to the Izembek Lagoon, Alaska and adjacent areas in fall (Bellrose 1976, Reed et al. 1989). During the 4to 10-week staging period, brant feed predominantly on energyrich common eelgrass (Zostera marina) prior to a transoceanic flight to coastal wintering areas in Washington, Oregon, California, and Mexico (Hansen and Nelson 1957, Morehouse 1974, Bellrose 1976). The Izembek Lagoon, a wetland of international importance (Smart 1987), also is a major staging area for Canada geese (Branta canadensis taverneri), emperor geese (Chen canagica), and other waterbirds (Ward and Stehn 1989). Brant are disturbed by aircraft and other human activities. Jones and Jones (1966) noted that aircraft caused brant to take flight in fall at the Izembek Lagoon. Aircraft influence movements of molting brant and evoke escape responses (Derksen et al. 1979, Jensen 1990). Aircraft, boats, and hunters affect distribution of wintering brant and cause premature departures from feeding areas (Owens 1977, Kramer et al. 1979, Henry 1980). However, few data have been published concerning the extent to which disturbance affects behavior of fall-staging brant. Our objective was to measure current disturbance levels and to determine the extent to which disturbance affects the behavior of brant at the Izembek Lagoon during fall. This baseline information is needed to monitor any future changes in these levels and to provide guidelines for alleviating conflicts where increased human activities cause excessive disturbance.

Orientation of Fall‐migrating Butterflies in North Peninsular Florida and Source Areas

AbstractPhoebis sennae (Pieridae), Agraulis vanillae (Heliconidae) and Urbanus proteus (Hesperiidae) migrate into peninsular Florida each fall from summer breeding areas throughout the south‐eastern United States. Fall flight directions of the three species were studied at 78 sites for clues to their means of orientation and migratory routes. Mean flight directions for a visit to a site were calculated using conventional circular statistics. The distribution of flight directions permitted using linear procedures to combine visit means. The overall mean direction (OMD) of a species at a site was defined as the mean of visit means, weighted by frequency/angular variance, with a lower limit of 0.2 imposed on angular variance. In intensive studies at two sites at Gainesville, Florida, mean flight directions during fall migration were largely independent of time of day and crosswinds. The OMDs of the three species at the two Gainesville sites were similar (142 to 156°) and not significantly different among species at a site or, for the same group of dates, between sites for a species. However, day‐to‐day variation among species and between sites was not concordant. Visits to 65 sites on a grid throughout the southeastern United States and to 11 sites along transects inland from the Gulf and Atlantic coasts yielded 10 cases of a P. sennae OMD at a grid or transect site differing significantly from its OMD at the main Gainesville site. In each of these, the OMD was more easterly at sites inland from the Gulf coast or more southerly or south‐westerly at sites inland from the Atlantic coast. By unknown means and with large, unexplained day‐to‐day variations in directions, P. sennae converge on peninsular Florida from widespread summer breeding grounds. They do this without closely following the Atlantic or Gulf coasts.

Development of the wave-shifter fiber readout for SIGHT

The Scintillation Imaging Gas-filled Hard X-ray Telescope (SIGHT) is a balloon-borne telescope with a planned first flight in fall 1993; the telescope will image X-rays in the 35-300 keV range. The heart of the telescope is a high-pressure xenon gas scintillation drift chamber (GSDC) which combines gas scintillation with the time projection concept. The wave-shifter fiber readout for the GSDC is described. The authors present results of light attenuation studies and technical details of handling the fibers in a high-pressure environment. Techniques for coupling optical fibers to photomultiplier tubes in a manner that increases both the phototube quantum efficiency and the response uniformity are detailed. >

Age related changes in the calling behaviour and the attractiveness of obliquebanded leafroller virgin females, Choristoneura rosaceana, under different constant and fluctuating temperature conditions

AbstractC. rosaceana (Lepidoptera: Tortricidae) virgin females initiated calling in the first scotophase following emergence at both 15° and 20 °C constant temperature under a 16L:8D photoperiod. As females aged, the onset of calling occurred much earlier, and the time spent calling increased significantly at both temperature conditions. For a given age, the onset of calling occurred significantly earlier at 15 °C than at 20 °C, but the duration of calling did not vary with temperature. Similar results were obtained under warm and cold thermocycles that simulated natural conditions prevailing during the summer and fall flight periods. A comparison of the degree of attractancy of different‐aged females (0, 3, and 5 days old) in the field showed that the attractiveness of 0‐day‐old females relative to that of 3‐day old females did not vary between flights. However, compared to day‐5 females, the relative attractiveness of 0‐ and 3‐day‐old females was greater in the summer than in the fall flights. The potential adaptative value of these changes for seasonal mating success are discussed.

Sinistrality in the Southern and Tawny Mole Crickets (Gryllotalpidae: Scapteriscus)

Wing folding in the Insecta evolved early in the history of the group and often the wings are folded one on top of the other over the abdomen. Whether or not the right wing is folded over the left or vice versa is of little importance except when the two wings have evolved different tasks. Such is the case in a number of families of Orthoptera: Gryllidae, Gryllotalpidae, Haglidae, and Tettigoniidae. In these families the forewings of the males are specialized for sound production. The plectrum, or scraper, of one wing is drawn across the pars stridens, or file, on the underside of the other wing. This action causes certain membranes of the wing to vibrate and produce sound. Usually the right wing rests over the left in crickets and the left rests over the right in katydids. Interestingly, the females, whose wings are not usually adapted to produce sound, follow the same rules (Masaki et al. 1987). In many species, because of the specialization of the two wings, they differ considerably with respect to pigmentation, reduction in the number of teeth on the file, and in retrogression of the file (Masaki et al. 1987). In the haglids the males may sing using the left over the right or the right over the left (Morris & Gwynne 1978) and apparently can switch while singing (Spooner 1973). I have examined the wingedness of both sexes in two species of mole cricket, Scapteriscus acletus and S. vicinus, to determine how they relate to the other three groups. Individuals were collected as part of another study (Forrest 1986 ) from the routine sound-trapping station on the Agronomy Farm of the University of Florida (Walker et al. 1983). Quarter-monthly samples of up to 50 individuals were collected during the crickets' spring and fall flights of 1981 and 1982. A total of 1431 S. acletus females, 1222 S. acletus males, 714 S. vicinus females, and 284 S. vicinus males were captured and classified as to wing overlap. These are the largest samples of singing Orthoptera where the wingedness of individuals has been studied. In neither sex of either species did rightand left-wingedness differ from 50:50. Female acletus were 51% right-winged (734:697), males were 49% right-winged (602:620). For vicinus, females were 51% right-winged (367:347) and males were 48% right-winged (135:149). I also examined 19 (2 males and 17 females) Neocurtilla hexadactyla, the northern mole cricket, from the Florida State Collection of Arthropods. Both males had right wings over left but only 5 of the 17 females were this way. Checking two other species of mole cricket, Scapteriscus abbreviatus [n= 13; males (4:4), females (1:4)] and Gryllotalpa africana (n=4), revealed at least some specimens with each configuration. Masaki et al. (1987) found equal numbers of left-winged and right-winged males of a scaly cricket, Ornebius kanetataki. I examined 30 male Cycloptilum antillarTium, another mogoplistine, from the collection and found 16 (53%) with their right wing over their left. It is interesting that the mole crickets and scaly crickets would differ so greatly from the other gryllids and tettigoniids with respect to the constancy of wing overlap. One possible reason for the differences might be because of the ancestry of the group. Evidence from the fossil record leaves no doubt that mole crickets developed from

東京都心におけるケブカクロバエの周年経過

The breeding and emerging periods of Aldrichina grahami (Aldrich) were studied along with the fluctuation of adults for tracing its life cycle by using both baited and emergence traps in the backyard of the National Institute of Health, Tokyo, from December 1981 to March 1983. Seasonal activity of the adult in each year was similar, which confirmed the previous works reported from the same locality. A number of both sexes were trapped from March to July, and a large amount of females were caught in September to December. The first flight in early fall represents only aged females attracted. The breeding stage first appeared in the beginning of September and ended in the middle of coming May. Early fall generation derived from eggs deposited in September quickly grew up and emerged as adults in late fall (October to November). Prepupae or pupae of late fall generation derived from eggs in November to December became dormant during winter. After the dormancy, most adults emerged in March, though a few appeared in the end of January and the beginning of February. Spring generation from eggs in February to May normally developed within relatively short periods (0.5-1.5 months). No developing stages were observed from late May to early September, although male and female adults were trapped until the end of July. From the above, it is concluded that this blow fly can develop in the Tokyo area during 8.5 months from September to the middle of May excepting the coldest season in which dormant prepupae and pupae are dominant. The first appearance of aged females in September may suggest the adult aestivation in Aldrichina grahami.

Geographical Variation in Flights of the Mole Cricket, Scapteriscus spp. (Orthoptera: Gryllotalpidae)1

Scapteriscus acletus Rehn and Hebard and S. vicinus Scudder were accidentally introduced to the United States from South America, and between 1920 and 1960 they spread from northernmost to southernmost mainland Florida, a north-south distance of 600 km (= 5.7° lat.). Latitudinal variation in the life cycles of these recently established populations was studied by monitoring seasonality of flight for 1 to 3 + years at nine stations in peninsular Florida. Flights of both species generally showed a large spring peak and a small fall peak annually, with the fall peak of one year and the spring peak of the next attributable to a single generation of adults. Geographical variations in S. vicinus flights were minor, with the median cricket of both spring and fall flights captured at stations in north Florida several weeks later than in south Florida. Flights of S. acletus were likewise similar along the latitudinal gradient, except that at three stations in south Florida a summer peak of flight occurred that rivaled or exceeded the spring and fall peaks. This suggests that S. acletus has, in less than 40 years, made the transition from one to two generations per year, a latitudinal change that is rare in native eastern North American crickets.