Adult Emergence Period Research Articles

Cold Storage of the Predatory Midge Aphidoletes aphidimyza (Diptera: Cecidomyiidae)

Long-term cold storage of a commercial biological control agent for aphids, the predatory midge Aphidoletes aphidimyza (Rondani), was investigated as a way to reduce rearing costs and to preserve genetically important lines. Prolonged cold storage of last instars in cocoons at temperatures of 1-11 degree C in total darkness was sufficient as an environmental cue to induce diapause, even though larvae had been reared under conditions that would not induce diapause. Mortality and emergence patterns of midges diapausing in response to cold storage did not differ from those of larvae reared under diapause-inducing conditions (8-h day at 21 degree C, 16-h night at 15 or 18 degree C) before cold storage. For commercial application, cold storage regimes with lowest mortality (< 10%) and highest percentage of emergence in the first 4 d of the adult emergence period were: 2 wk at 10-11 degree C, up to 4 wk at 5 degree C, and up to 2 mo at 1 degree C after acclimation for 10 d at 5 degree C. Larvae stored at 5 degree C survived 8 mo with <9%, mortality, and fecundity of females was not significantly different than in unstored controls. These effects are useful for preserving A. aphidimyza lines for future research. However, the adult emergence period was too protracted for commercial application. Methods for synchronizing emergence (including cold chill at 1 degree C and 2-4-d heat shock at 33 degree C) were tested, but only desiccation for a week, followed by remoistening, gave promising results.

Change in Activity of Adult Monochamus alternatus HOPE (Coleoptera : Cerambycidae) in Relation to Age

Age-related changes in the mobility of adult Monochamus alternatus was analysed by repeated weekly marking and recapture in a stand of Pinus thunbergii. During periods of adult emergence in 1980-1983, 1-5 day old adults, which had emerged in field cages, were released. The proportion of beetles recaptured a week after release decreased with ages up to 17 days after emergence. After the age of 17 or 24 days they were caught at an almost constant rate. Wild beetles were also caught, marked individually, and released in the same stand. The proportion of wild beetles recaptured a weel after release was about 10% in June and July, and about 20% in August and September. These results suggest that the beetles' mobility rose from the time of emergence to the time of reproductive maturation, at which point it dropped.

Control of grass grub (Costelytra zealandica) adults with soil insecticides

Abstract Four soil insecticides (lindane, isazophos, fensulfothion, and carbofuran) were tested primarily for use against grass grub adults and compared with foliar applications of a synthetic pyrethroid (cypermethrin). Separate treatments of the four soil chemicals were applied at 2 times just before the adult emergence and mating period, again just after this period, and in the autumn when mature larvae were present. Lindane was also applied 2 and 4 months before adult emergence. The progress of all soil treatments was monitored by larval and adult bioassays and chemical residue analysis on soil collected from the treated field plots. The lindane treatments were shown to be ineffective against mature larvae, but all treatments applied before adult emergence gave a significant reduction (85–95%) in the subsequent generation. Isazophos and fensulfothion were not sufficiently active against adults to be of practical use, but they affected both immature and mature larvae. Carbofuran was not active. The cype...

有効積算温度にもとづくエビガラスズメ成虫の発生時期の予測

有効積算温度にもとづくエビガラスズメ成虫の発生時期の予測

Studies on Varietal Resistance of Cowpeas to the Cowpea Weevil, Callosobruchus rhodesianus (Pic)

Eighteen cowpea varieties were evaluated for their resistance to cowpea weevil, Callosobruchus rhodesianus (Pic) infestation. The experiments were conducted at 27°C and 65–70% r.h. The varieties showed a differential response to infestation by C. rhodesianus with respect to oviposition, egg hatch, adult emergence, adult survival and development period. The intrinsic rates of increase and the indices of susceptibility of the varieties were estimated. The varieties were categorized into three groups of susceptibility (low, medium and high) to C. rhodesianus infestation based on the adult survival data. IT 82D-1064 and IT 81D-1032 were the least susceptible varieties.

Life histories of some Benthic invetebrates form streams of the Northern Jarrah Forest, Western Australia

Life history patterns of thirteen species of invertebrates from streams of the northern jarrah forest were examined over a 1-year period. Five species had univoltine cycles with a single cohort and demonstrated a high degree of synchrony of larval development and a restricted period of adult emergence. Two species of Leptophlebiidae also had univoltine cycles but showed the more typical pattern of Australian mayflies, with extended recruitment, multiple overlapping cohorts and a long period of adult emergence. Uroctena sp., a small gammarid, had a generation time of 1 year but showed considerable spatial variation in the degree of synchrony of development. This appeared to be a result of differences in the constancy of stream discharge and was not attributable to differences in the temperature regime of the streams. At least three species demonstrated cohort splitting which resulted in an apparently bivoltine cycle. A life-history pattern of alternating long and short development times is described which, on average, would produce two generations every 3 years. This is considered to be a highly adaptive strategy for Australian stream insects with slow life cycles and can explain the extended periods of recruitment and adult emergence so often observed. Streams of the northern jarrah forest are depauperate compared with other Australian streams, despite predictable temperature and discharge regimes. The insular nature of the south-west Bassian region and its long period of isolation may be the principle cause of this reduced diversity. The invertebrate community of these streams is simple in structure and has a high degree of seasonality that is atypical of the temperate streams of Australia and New Zealand.

OBSERVATIONS ON THE DISTRIBUTION, EMERGENCE AND BEHAVIOUR OF CENTRAL AFRICAN CHAOBORIDAE

SUMMARY The distribution of four species of Chaoboras over selected parts of Zimbabwe is given. The effect of temperature on the duration of the larval life cycle is discussed in relation to the generation time and the lunar periodicity of the adult emergence period. There were apparently two generations of larvae present in the habitat at any one time, although these generations were not distinct due to the variations in the time taken by the larvae to complete development at any temperature. The emergence was synchronized to the lunar cycle, but the actual moon phase at which emergence occurred was variable, as the two populations under observation both changed from new moon emergences to full moon emergences during the study. Some observations on the behaviour of adult Chaoboras edulis are given.

Role of carbohydrates in insect resistance in Phaseolus vulgaris

The bruchid beetles Acanthoscelides obtectus (Say) and Zabrotes subfasciatus Boheman, are major storage pests of the economically important legume Phaseolus vulgaris (haricot bean). In the present study, resistance of a wild line of P. vulgaris G12953, towards these two insects is confirmed. Mature seeds from both resistant and susceptible lines were fractionated and tested in feeding trials in an attempt to elucidate the basis of resistance. The heteropolysaccharide fraction isolated from the resistant line and a susceptible line were each incorporated into artificial beans over a concentration range up to 10% dry wt. At a concentration of 4%, the approximate physiological concentration within the seed, the heteropolysaccharide fraction from the resistant line was very toxic resulting in 80–85% larval mortality of A. obtectus with an LC 50 of 2.5%. Furthermore, surviving larvae showed a marked increase in their development period. The corresponding fraction from a susceptible line, on the other hand, even at twice the physiological concentration, had a negligible effect upon larval development both in terms of adult emergence and development period. The effects of albumin proteins and globulin proteins on larval development of A. obtectus were also tested by incorporation into artificial beans at a range of concentrations up to 10%. Whilst those from the susceptible line had little effect upon development both the albumins and globulins from the resistant line were found to cause a slight decrease in adult emergence and a small increase in the median development period. These effects, however, are not sufficient to account for the observed seed resistance of G12953. Mature seeds from the resistant line and nine susceptible lines were also screened for the following secondary plant compounds: proteinase inhibitors, α-amylase inhibitors, lectins (phytohaemagglutinins), saponins, tannins and alkaloids. Although some of these antimetabolites were found to be present none, except for α-amylase inhibitors, were thought to play any significant role in conferring seed resistance. It is concluded that this example of insect resistance in seeds of P. vulgaris, line G12953, is due, at least in part, to the presence of a heteropolysaccharide which has an unusually high arabinose and fucose content. In the absence of other antimetabolic compounds the levels of this heteropolysaccharide present in G12953 are sufficiently high to account for the observed resistance. However, it is possible regarding seed resistance towards Z. subfasciatus, that α-amylase inhibitors may be having a synergistic effect.

Apple, Evaluation of Dimilin for Spotted Tentiform Leafminer Control, 1986

Abstract The trial was conducted in a 1.2 acre block of mixed varieties. The block was split into 2 equal sections. Two trees at the corner of one section were left untreated and served as controls. Six trees were chosen in each section for monitoring STLM. Treatments were applied using the alternate-row middle technique with a Bean airblast sprayer calibrated to deliver 50 GPA at 2 mph. Spray dates were timed to coincide with adult emergence and oviposition period for both first (14 and 24 Apr) and second (10 and 18 Jun) broods. A routine fungicide (Dithane M45) and insecticide (Lorsban, Guthion, and Penncap M) schedule was maintained during the course of the experiment. The effect of Dimilin on STLM was evaluated by counting mines observed during a 5-min. examination per tree.

Life History of Potamanthus myops (Walsh) (Ephemeroptera: Potamanthidae) in a Central Michigan Stream

The life history of Potamanthus myops (Potamanthidae) was investigated for 1 year in a 4th-order central Michigan stream. Potamanthus myops has a univoltine life cycle with emergence occurring from June until mid-August. Adults averaged 16 mm in length. Fecundity was high, averaging 4559 eggs per female (range 32976498), with females ovipositing over riffle sections from late afternoon until after dark. Eggs hatched in approximately 2 weeks with limited nymphal growth occurring through the summer and autumn. There was no significant growth during the winter months (October to March), with nymphs undergoing accelerated growth (0.99 to 4.7%o dry wt/day) from April to June. A total of 3939 degree-days (base T = 0 C) were required for P myops to develop from the egg stage until emergence 1 year later. INTRODUCTION Potamanthidae is a relatively uncommon mayfly family with most known species occurring in Asia (Edmunds et al., 1976). The genus Potamanthus Pictet has a Holarctic distribution (Edmunds et al., 1976), with eight species recognized in eastern North America (McCafferty, 1975). Potamanthidae are placed within the superfamily Ephemeroidea, known typically as the burrowing mayflies. Although members of most families within this superfamily burrow, Potamanthidae are considered clingers and sprawlers (Edmunds, 1984) on rock substrate in streams. Members of this family are in the collector-gatherer functional group (Merritt and Cummins, 1984), feeding on epilithic material. Earlier studies on Potamanthus myops (Walsh) were taxonomic, yielding little life history information (Ide, 1935; McCafferty, 1975). More recently, studies by Lord (1975) and Meier and Bartholomae (1980) have dealt with the life history and ecology of E myops. Munn (1982) found densities of P myops nymphs to range from 4.6/M2 during July to 68.0/M2 by late August. Population biomass was highest in late June just prior to peak adult emergence with a mean of 67.6 mg/M2, decreasing rapidly to 13.4 mg/M2 by the end of July. This paper presents the life history of Potamanthus myops in a central Michigan fourth-order stream (Strahler, 1957). Life history parameters investigated include emergence period of adults, fecundity and oviposition behavior of females, along with size distribution and growth rates of nymphs for 1 year. DESCRIPTION OF STUDY AREA The Chippewa River is a fourth-order hardwater stream located in Midland Co., Michigan. The area consists of mixed farmland and hardwood forest. The riparian zone consists of dense forest along the river's southern bank and low shrub vegetation on its northern bank. At this site the stream averaged 60 m in width during base flow and was shallow most of the year, with discharge rates varying from 5 m3/sec in August to 18 m3/sec in March. Water temperatures ranged from 1 C during winter when the river was ice-covered, to 31 C during midsummer. Dissolved oxygen during the day varied from 64% saturation (9.1 mg/liter) in mid-winter to 120% saturation (11.2 mg/ 1Present address: Illinois Natural History Survey, Aquatic Biology Section, 607 E. Peabody, Champaign, IL 61820.

Egg development and life cycle of Chaetopteryx villosa (Trichoptera)

Combined field and laboratory investigations showed that C. villosa was univoltine in the Breitenbach, Germany. Speed and duration of embryogenesis were determined by temperature. Lowest values of accumulated temperature occurred at 6 and 8°C, when the duration of embryogenesis was shortest, and egg mortality was low. Egg masses exposed at upstream field sites needed similar time and accumulated temperatures for embryogenesis to those expected from laboratory experiments. At a downstream site embryogenesis was accelerated, possibly depending on increased daily temperature fluctuations in spring. At all field sites the emergence period of adults lasted from September until December. Size and weight of both sexes were significantly lower at the upstream site, not necessarily as a result of temperature, but possibly caused by differences in nutrition.

The relationship between the emergence period of adults in the first generation of the rice water weevil and their ovarian development

The relationship between the emergence period of adults in the first generation of the rice water weevil and their ovarian development

Life histories of some Australian Siphlonurid and Oligoneuriid mayflies (Insecta : Ephemeroptera)

The life histories of nine populations of mayflies were investigated through monthly field collections over a 3-year period. Seven species were studied, one each from the genera Tasmanophlebia, Ameletoides and Mirawara (Siphlonuridae) and four from Coloburiscoides (Oligoneuriidae). Nymphs were sorted and measured and life histories inferred from size frequency diagrams, and cohorts were separated using a technique for distinguishing multiple overlapping normal distributions. The life histories were all relatively poorly synchronized with adult emergence extended over 5 months or more in every case. A wide size range of nymphs was present in most populations for most of the year and these often formed multiple overlapping cohorts. The time required for development by different cohorts of a single population was quite varied. Marked differences in the length and timing of the adult emergence period, and of the importance of particular cohorts, were apparent in different years. It was concluded that more than a single year's data from one site was necessary to interpret the life histories of Australian mayflies adequately. The four Coloburiscoides species investigated displayed a wide range of development times and patterns, the shortest being displayed by C. haleuticus. This species had some cohorts that seemed to complete their development in about 6 months, whereas C. giganteus had some cohorts that required up to 3 years and also appeared to have a nymphal or early-instar diapause of between 9 and 11 months. The life-history patterns found in this study did not readily fit into the classification schemes proposed by Northern Hemisphere workers. The general asynchrony found in this and previous Australian studies makes it doubtful that a useful classificatory system for Australian mayfly life histories can be developed.

Comparative Fitness of Temephos-resistant, -susceptible, and Hybrid Phenotypes of the Southern House Mosquito (Diptera: Culicidae)

Laboratory and field populations of the southern house mosquito, Culex quinquefasciatus Say, that were either homozygous resistant, or susceptible to temephos and their F1 hybrids, were crossed in several directions and examined for various biotic characters in the first gonotrophic cycle. Egg production, fertility, and the acquisition of blood meals were adversely affected by inbreeding, but could be improved by hybridization. Egg hatchability appeared to be associated with resistance to temephos and to be influenced by maternal factors. Larval rate of development and survival were significantly lower in the homozygous-resistant strain and appeared to be influenced by the genotype of the male. Pupation and adult emergence periods were longer in strains selected for temephos-resistance.

Maintenance of the phenology of the winter moth (Lepidoptera: Geometridae)

Adult winter moths (Operophtera brumata (L.)) are active in late autumn or early winter. The eggs overwinter in the canopy of trees and hatch simultaneously with the bursting of host tree buds. Many young larvae disperse on the wind on silk strands. Larvae are polyphagus and feed until late spring when they pupate in soil or leaf litter. The duration of the egg and pupal stages is genetically determined and varies with latitude. The egg stage is long in the north and short in the south, while the pupal stage is short in the north and long in the south. The literature on the ecology and physiology of winter moth is reviewed. The factors maintaining the unusual phenology are discussed. It is concluded that the larval stage is early because mature leaves of many host trees are unsuitable as food, because parasitism against later larvae is more intense, and because summer temperatures may be injurious to larvae. The adult period is late in the year so that the final stages of pupal development occur in cool conditions and so that adults emerge after most insect predators have ceased activity. Throughout most of the range retarding the adult emergence period would cause activity to be impeded by severe winter weather; in the south this is not so and it is suggested that eggs must be on the trees for a minimum period to ensure synchronization of egg hatch with bud burst. The protracted adult emergence period may be an adaptation reducing predation by birds.

Toxicity of α-Tomatine to Larvae of the Mediterranean Fruit Fly (Diptera: Tephritidae)1

α-tomatine, a glycoalkaloid present in solanaceous plants, exerts an antibiotic effect on Ceratitis capitata (Wiedemann) larvae. Increased concentrations of α-tomatine (25–200 ppm) resulted in decreased larval survival, lower pupal weights, an extended pupation period, and a prolonged period of adult emergence. The LC50, for α-tomatine fed to C. capitata larvae was estimated to be 52.7 ppm.

Growth and development of Australian soldier fly,Inopus rubriceps(Diptera: Stratiomyidae), in New Zealand

Abstract Larvae of Inopus rubriceps (Macquart) were reared from eggs originating from spring and autumn adult emergence periods (1975–78), under both insectary and field conditions. Rate of development appeared to depend largely on temperature. Autumn-hatched larvae showed little growth for the initial 6 months, but then grew rapidly until the end of summer. Spring-hatched larvae also grew rapidly over summer, but their development slowed over winter. Year-to-year differences were found in larval survival, weight gain, and rate of development, and in subsequent adult emergence. Pest status appeared to be related to the cumulative yearly heat budget. Overall, larval survival was higher and growth and development were more rapid in the insectary than under field conditions. A male-dominant sex ratio was demonstrated.

POPULATION SYNCHRONY IN MAYFLIES: A PREDATOR SATIATION HYPOTHESIS.

The larvae of mayflies (Order: Ephemeroptera) inhabit most permanent freshwater environments (rivers, lakes, ponds). The duration of the mayfly life cycle varies from a few weeks to several years depending on the response of each species to regional climate and nutrition (Needham et al., 1935). Most of the mayfly life cycle is spent in either the egg or larval stage because almost none of the adults feed and, depending on the species, live only about 10 min to 48 h before reproduction and death. Adults of many species appear in flight in large numbers during a brief period each year and form vast mating swarms over the water surface. Both the size and periodicity of mayfly swarms have been conspicuous enough to stimulate detailed descriptions by early naturalists (see Needham et al., 1935 for review) as well as more recent speculation concerning the ecological and evolutionary significance of swarm periodicity (Corbet, 1964; Edmunds and Edmunds, 1980). Population synchronization in aquatic insects, especially mayflies, refers to a tendency for the adult reproductive stage of individuals in a given population to be active in the environment during a short, well defined period of the year (i.e., seasonal synchronization within a time frame >24 h but usually less than 2-4 wk) and/or the day (i.e., time frame <24 h and usually about 1-2 h in duration). For our purpose here, each 24-h period represents a unit of observation and the sum of such units describes the emergence period for each species under consideration. It has been suggested that the adaptive value of adult synchronization for an insect species resides largely with increasing the probability of finding a mate (Corbet, 1964). If so, synchronization should be developed best in species having short-lived adults that are spatially dispersed. This hypothesis is difficult to test because spatial dispersion cannot be adequately determined. In addition, no one has demonstrated for any aquatic species that individuals emerging very early or late in the emergence period fail to mate successfully. Here we argue that mating success is unlikely to have been the only factor selecting for adult synchronization in mayflies. We hypothesize that predator provides a better conceptual framework for assessing adult emergence patterns in mayflies and perhaps other aquatic insects. satiation was used initially to describe the interaction between periodical cicadas (Insecta: Homoptera) and their predators (see Lloyd and Dybas, 1966 for review). Predator occurs when the quantity of a particular prey item (e.g., cicada) at a given point in time far exceeds the potential number that can be taken by a fixed density of local predators (e.g., birds). The predators are satiated and the remaining prey survive to reproduce providing prey densities remain above the level necessary for satiation. Thus, a predator hypothesis for any predator-prey system predicts an inverse relationship between prey mortality due to predation and prey availability above the level needed to satiate predators as long as the number of predators remains more or less fixed for a given time interval. In this paper we present quantitative data on adult mortality during each day of the adult emergence period for the mayfly Dolania americana Edmunds and Traver to demonstrate how emergence

Morphological and Phenological delimitation ofChironomus prior sp.n. andc. tardussp. n. (Diptera: Chironomidae), sibling species from arctic Alaska

Abstract Two discrete periods of adult emergence indicated that an unknown Chironomus population consisted of a pair of sibling species. Morphometric analysis of all life history stages confirmed this hypothesis. The new species Chironomus prior and C. tardus can be distinguished as larvae, pupae, and male and female adults, although many traditional taxonomic characters are of little use. Populations of both species in several ponds emerged with high intraspecific synchrony and consistent seasonal phenology over four summers, and protandrous emergence was often detected. Sexual dimorphism in weight is of the same magnitude as the size difference between these species, and life cycles of sympatric populations appear to differ primarily in the timing of prepupal development and emergence.

Japanese beetle (Coleoptera: Scarabaeidae)

A combination of the synthetic sex attractant (R,Z)-5-(1-decenyl) dihydro-2(3H)-furanone with a 3∶7 mixture of phenethyl propionate (PEP) and eugenol (4-allyl-2-methoxphenol) caught significantly morePopillia japonica Newman than either the sex attractant or the mixture did alone. Also, the synthetic sex attractant captured significantly more males than the PEP-eugenol did during the period of heavy adult emergence of the beetles. The two lures were not significantly different in their attractancy to males about a week later and thereafter. A combination of PEP-eugenol and virgin females in the same trap late in the season also significantly increased beetle captures.