Winter Moth Research Articles

Decline in Winter Moth Populations in North America: Direct Versus Indirect Effect of Introduced Parasites

Decline in Winter Moth Populations in North America: Direct Versus Indirect Effect of Introduced Parasites

IMPROVED PHEROMONE TRAP EXCLUSION OF THE BRUCE SPANWORM OPEROPHTERA BRUCEATA (HULST) (LEPIDOPTERA: GEOMETRIDAE) WHEN MONITORING WINTER MOTH OPEROPHTERA BRUMATA (L.) POPULATIONS

Abstract(Z,Z,Z)-1,3,6,9-Nonadecatetraene is a sex pheromone that attracts males of both the winter moth Operophtera brumata (L.) and the Bruce spanworm O. bruceata (Hulst). Tests were run to maximize the specificity of a pheromone trap for the winter moth by the addition of a previously discovered Bruce spanworm male inhibitor (BSMI), (E,Z,Z)-1,3,6,9-nonadecatetraene. Trap capture inhibition of O. bruceata would facilitate monitoring of winter moth as males of the two species are difficult to distinguish without dissection. Wind tunnel tests with O. bruceata males responding to the pheromone indicated that BSMI has a more potent inhibitory effect if males physically contact the compound. Field tests in an area where only O. bruceata was found demonstrated that pheromone-baited traps caught fewer O. bruceata with BSMI placed on the outside of the entrance holes than when it was placed on the inside of the trap, catching respectively 97 and 82% fewer males than traps baited with the pheromone alone. In an area where O. brumata predominated, BSMI, whether inside or outside the trap, did not affect O. brumata captures. However, O. brumata trap captures were reduced when BSMI was placed on rubber rings glued to the outside of the entrance holes to the traps even though control rings did not affect O. brumata captures. Evidence is presented indicating that hybridization is taking place between these two species where O. brumata has recently been introduced and that the response of the hybrids to the BSMI is intermediate between the two species.

The Effects of Temperature on Flight Muscle Potentials in Honeybees and Cuculiinid Winter Moths

ABSTRACT Amplitudes of extracellular action potentials in indirect flight muscles of honey-bees and cuculiinid winter moths decline with decreasing muscle temperatures and fall suddenly to zero. Action potential durations increase with amplitude decline. Amplitudes at 11 °C are only 20% of values near 30°C in workers of Apis mellifera mellifera. They fall to zero at approx. 10°C. In the cuculiinid winter moth Eupsilia devia, amplitudes at 1°C are approx. 12% of values at 27°C. They fall to zero between 0 and 1°C. The duration of action potentials in bees and cuculiinid winter moths is about 7 ms at 27 °C and increases to 52 ms at 11 °C in bees and to 66 ms at 1°C in moths. The ratios of action potential rise time to fall time are about 1 at 27°C for bees and moths. They decrease to 0·45 at 11 °C in bees and to 0·56 at 1°C in moths. Results suggest that bees can heat flight muscles only if muscle temperatures are above 10°C, whereas cuculiinid winter moths can shiver with muscle temperatures near 0°C.

Density dependence and the stabilization of animal numbers : 3. The winter moth reconsidered.

Latto and Hassell (1987) disagree with the conclusion of Den Boer (1986), that the winter moth population at Wytham Wood, studied by Varley and Gradwell, was not regulated. They attempt to demonstrate regulation by means of a simulation model. In the present paper the validity of this model is tested step by step. The fixing of the initial and final densities, as practised by Den Boer and rejected by Latto and Hassell, did not prevent population explosions and extinctions, as was assumed by Latto and Hassell. It is shown that the deterministic formulation of the density dependence of pupal predation, as used by Latto and Hassell, deviates systematically from the field data. Replacing the values of the key-factor (k1) by random values drawn from a normal distribution (Latto and Hassell) affects the dynamics such that the ability of pupal predation to govern density is improved in the model. Changing mortalities other than the key-factor does not significantly influence the pattern of fluctuations nor the limits of density. Models should leave intact the essentials of the reality under study, while removing distracting elements (Levins 1968). As both the timing of the key-factor, and its correlation with pupal predation are essential features of the winter moth population at Wytham Wood between 1950 and 1968, the model of Latto and Hassell does not apply to this population. By simply changing log10 (eggs/female) it is shown that the power of the density dependence of pupal predation to govern possible trends in density of the winter moth population at Wytham Wood is weak. On the other hand, the model of Latto and Hassell gives insight into the conditions that might favour regulation of numbers. Although the model of Poethke and Kirchberg (1987) preserves more features of the pertinent winter moth population than that of Latto and Hassell (1987) it still deviates in one essential aspect: the succession in time of both the (coupled) mortalities and the deviations from the deterministic density dependence are taken at random. Therefore, also this model is still too far from the field population to be a sound base for the statistical speculation proposed by Poethke and Kirchberg.

NOTE ON THE LIFE CYCLES OF INUROIS KYUSHUENSIS AND ARICHANNA MELANARIA (LEPIDOPTERA, GEOMETRIDAE), PESTS OF RHODODENDRON KIUSIANUM IN THE KUZYU MOUNTAINS

Life cycles of the winter moth, Inurois kyushuensis and the Butler moth, Atichunna melanaria fraterna are briefly described. Both species are serious pests of Rhododendron kiusianum, one of Japan’s natural monuments which grows in the Kuzyu Mountains.

POPULATION STUDIES ON THE WINTER MOTH OPEROPHTERA BRUMATA (L.) (LEPIDOPTERA: GEOMETRIDAE) IN APPLE ORCHARDS IN NOVA SCOTIA

AbstractThe winter moth Operophtera brumata (L.) is a serious introduced pest of apple trees in Nova Scotia. It spread westward through orchards of the Annapolis Valley in the 1950’s and to other deciduous trees throughout Nova Scotia later. The parasites Cyzenis albicans (Fall.) and Agrypon flaveolatum (Grav.) were liberated during 1961 in Nova Scotia and gradually spread throughout the winter moth population. Population dynamics studies were conducted in insecticide-free orchards and corroborated with observations in neglected unsprayed apple trees over a wide area. The winter moth population reached a balanced level in unsprayed orchards at varying densities below the limits of its food supply, but well above an acceptable level for commercial apple production. In young orchards, where trees cover a small percentage of the ground, natural dispersal of larvae appeared to be a suppressing factor. In mature orchards mortality was density dependent during the prepupal to adult stage; mortality was partly due to parasitism and predation but also to other factors.

Agrotis segetum . [Distribution map

Abstract A new distribution map is provided for Agrotis segetum (Denis & Schiffermueller) [Lepidoptera: Noctuidae] Turnip moth, black/common cutworm, winter moth. Attacks beet, cotton, cucurbits, maize, turnip, sunflower, tomato, lucerne, leeks. Information is given on the geographical distribution in EUROPE, Austria, Azores, Belgium, Bulgaria, Cyprus, Czechoslovakia, Denmark, Finland, France, Germany, East Germany, West Greece, Hungary, Ireland, Italy, Majorca, Malta, Netherlands, Norway, Poland, Portugal, Romania, Sardinia, Sicily, Spain, Sweden, Switzerland, Turkey, United Kingdom, Yugoslavia, USSR, Azerbaijan, Byelorussia, Estonia, Kazakhstan, Kirghizia, Latvia, Lithuania, Moldavia, Russian, SFSR, Tadzhikistan, Turkmenistan, Ukraine, Uzbekistan, AFRICA, Algeria, Angola, Ascension Island, Benin, Botswana, Canary Islands, Cape Verde Islands, Egypt, Ethiopia, Ivory Coast, Kenya, Libya, Madeira, Malawi, Mali, Morocco, Mozambique, Namibia, Senegal, South Africa, St. Helena, Sudan, Tanzania, Togo, Tunisia, Uganda, Zaire, Zambia, Zimbabwe, ASIA, Afghanistan, Bangladesh, Bhutan, Burma, China, Hongkong, India, Assam, Haryana, Himachal Pradesh, Karnataka, Kerala, Punjab, Rajasthan, Tamil Nadu, Uttar Pradesh, West Bengal, Indonesia, Java, Iran, Iraq, Israel, Jammu & Kashmir, Japan, Jordan, Korea, Lebanon, Malaysia, Nepal, Pakistan, Philippines, Sakhalin Island, Saudi Arabia, Sikkim, South Yemen, Sri Lanka, Syria, Taiwan, Yemen.

On the stabilizing effect of density-dependent mortality factors.

For nearly twenty years den Boer (1968, 1971, 1973, 1982, 1985 and 1986 a) has been trying to stimulate ecologists to investigate the possibilities of "spreading of risk". He has shown that spatial heterogeneity has a stabilizing effect on animal populations (den Boer 1982). Together with density-dependent processes spatial heterogeneity is thus responsible for the persistence of populations. The relative importance of each of these two stabilizing influences may differ between populations, but so far population ecologists have focused their interest on density-dependent processes. It was thus of particular interest when den Boer (1986b) showed that density-dependent mortality does not necessarily have any stabilizing effect at all. Comparing the original data (Varley and Grad well 1968) with some null model simulations he showed that density-dependent pupal pr?dation in the winter moth did not regulate density. More generally he concluded that "the range of variation of any supposed regulating factor should be as great, or at least nearly as great, as the range of variation of all other factors together influencing density, i.e. it should be the key factor".

Improved insect performance from host‐plant defoliation: winter moth on oak and apple

ABSTRACT. 1. We test the hypothesis that defoliation has short‐term and long‐term negative effects on performance of winter moth Operophtera brumata L. on two species of food plants: Garry oak (Quercus garryana Dougl.) and apple (Malus domesticus L.).2. Pupal weight (and hence potential fecundity of females) decreased with increased defoliation in the current year on both tree species.3. Pupal weight increased, however, with increased level of defoliation in the previous year.4. Increased weight of pupae from larvae which had fed on previously defoliated trees may buffer population decline by increasing fecundity of moths in the next generation.

Do pupal predators regulate the winter moth?

Do pupal predators regulate the winter moth?

Pesticide Use and Levels of Insect and Scab Injury on Fruit in Nova Scotia Apple Orchards

A commercial pest management company recorded pesticide use and levels of insect and scab injury to apples from 1980 to 1983. Mean numbers of insecticide and miticide applications were 2.5 and 0.5 per year, respectively. Mean costs of insecticides and miticides (material only) were $44.44 and $23.50/ha. These totals varied little from year to year despite large variations in costs of controlling individual pests. Scouting costs rose from $25.00/ha in 1980 to $37.50/ha in 1983. Targets of most insecticide applications were winter moth, Operophtera brumata (L.); codling moth, Cydia pomonella (L.); and apple maggot, Rhagoletis pomonella (Walsh). European red mite, Panonychus ulmi (Koch), was the target of most miticide applications. Despite low frequencies and low total costs of insecticide applications, total insect injury averaged only 2.3% of the fruit, declining from 3.8% in 1980 to 2.0% in 1983. Scab injury averaged 1.9%, varying from 0.9% in 1981 to 3.7% in 1983. Success of the integrated pest management (IPM) program is attributed to pest monitoring and use of economic thresholds as well as to a range of tactics designed to minimize impact of pesticides on natural enemies and to delay onset of resistance among the pests.

Supervised control of apple pests in southern England

Supervised control involving use of insecticides and acaricides only when assessments showed that these were necessary, was compared with normal spray programmes applied to apple tree plots of at least 0·4 ha on 23 sites for 1–5 years at each site, giving a total of 57 trials. Pest assessments and spray thresholds were adapted from those in use in the Netherlands in 1974. The growers' usual insecticides and acaricides were used in the supervised programmes when necessary and their normal fungicidal programmes were used. Pests reaching the spray threshold included aphids (rosy apple, apple-grass, green apple, rosy leaf-curling, and woolly), apple sucker, common green capsid, winter moth, apple sawfly, tortricids (fruitlet mining, fruit tree, and summer fruit), codling moth and fruit tree red spider mite. Minor pests included common earwig, apple leaf midge and green and brown leaf weevils. An average of 3·2 insecticides and acaricides was applied per annum to the supervised plots compared with 5·0 in the growers' programmes. The greatest savings were pre-blossom and at petal fall. Little pest damage to foliage was recorded with either programme. Approximately 4·1 % of fruit on the supervised plots showed pest damage (on a severe assessment) compared with 2·9% with the growers' programmes. Supervised control saved 10·78% of growers' normal pesticide costs; it can prevent serious pest damage while utilizing smaller amounts of insecticides and acaricides.

Development of a pheromone monitoring system for the winter moth, Operophtera brumata (L.), in apples and in sitka spruce

Winter moth ( Operophtera brumata) can be an important pest both in top fruit orchards and in Sitka spruce plantations. Monitoring systems are required in both these crops to identify areas at risk and so to optimize the use of insecticide treatments. This paper is a report of work carried out to determine some of the requiments for a working monitoring system baed on the recently identified pheromone (3 Z,6 Z,9 Z)-1,3,6,9-nonadecatetraene. Experiments were carried out to discover the best trap design, pheromone dose level, lure change interval and trap height. Recommendations for the systems are made.

Use of a sex attractant and an inhibitor for monitoring winter moth and bruce spanworm populations

A single sex pherormone component was isolated from abdominal tip extracts of female Bruce spanworm.Operophtera bruceata (Hulst). This was identified as (Z,Z,Z)-1,3,6,9-nonadecatetraene by capillary gas chromatography (GC), electroantennography, and mass spectrometry. In addition, hexane extracts of female abdominal tips from Bruce spanworm and the winter moth.O. brumata L., were analyzed by GC coupled to an electroantennographic detector (GC-EAD). The extracts ofO. bruceata andO. brumata females elicited only a single response, at the same retention time, from antennae of their conspecific and reciprocal males. In field tests conducted in Saskatchewan, traps baited with the synthetic tetraene captured Bruce spanworm males. In tests carried out on Vancouver Island, British Columbia, where the two species coexist, both Bruce spanworm and winter moth males were captured. The attractancy of lures containing the synthetic pheromone alone and in combination with several structurally related analogs was field tested at both locations. One of these, an isomer of the natural pheromone, (E,Z,Z)-1,3,6,9-nonadecatetraene, inhibited the capture of Bruce spanworm males but had no effect upon the number of winter moth males which were taken. Thus, populations of these two very similar species can be distinguished by employing traps baited with pheromone ± the inhibitor. Coneorifice Hara traps were found useful for field trapping males of both species.

Thermoregulation in Winter Moths

Thermoregulation in Winter Moths

Screening and Use of Sex Attractants in Monitoring of Geometrid Moths in Bulgaria

Abstract Four candidate sex attractants for geometrid moths have been screened individually and in mixtures. As a result, in addition to the confirmation of the known sex attractants of Operophtera brumata L. and Alsophila aceraria Denis & Schiff (= A. quadripunctata Esper), possible sex attractants for five other geometrid species have also been established. For O. brumata and A. aceraria an inhibitor has been found. For the same species the possibility for seasonal monitoring by means of sex pheromone traps was demonstrated.

Boll Weevil Mortality Factors Within Flower Buds of Cotton

Accurate Asessment of insect mortality factors can be a valuable tool in the development of life tables. Life tables present summaries of population changes within a generation (Varley et al. 1973) and have predictive value in population dynamics. Life-table studies of insects often have a large proportion of mortality attributed to unknown or indiscriminate causes. For example, in the elegant studies of Varley et al. (1973), the key mortality factor of the winter moth was “winter mortality,” which resulted from several factors. Though some of the factors were identified, their individual impacts were not evaluated. Life-history studies can be more informative and their analysis simplified when the insects leave a durable record of their presence, development, and death, as do bark beetles, leaf miners, and gall insects (Varley et al. 1973). The boll weevil, Anthonomus grandis grandis Boheman (Fig. 1), a key pest of cotton (Adkisson 1973), also leaves a record that contains evidence of the cause of mortality and the developmental stage at which mortality occurred (Sterling 1978, Jones & Sterling 1979, Fillman & Sterling 1983).

Short synthesis of 1,3Z,6Z,9Z-tetraene hydrocarbons. Lepidopteran sex attractants

A short, convergent synthesis of 1,3Z,6Z,9Z-tetraene hydrocarbons was developed. A key step was the regioselective alkylation of 1,5-dibromo-2-pentyne. The method was used to synthesize tetraenes of chain lengths C18–C20, to be used in field trials as sex attractants and (or) inhibitors of the winter moth, Operophterabrumata L., and the Bruce span worm O. bruceata H. (Lepidoptera: Geometridae).

Distribution and Parasitism of Winter Moth, Operophtera brumata (Lepidoptera: Geometridae), in Western Oregon

In Oregon, winter moth, Operophtera brumata (L.), is distributed throughout the northern region of the Willamette Valley, where it is commonly found on commercial hazelnut, Corylus avellana L.; crabapple, Malus silvestris Mill.; and flowering plum, Prunus cerasifera J. F. Ehrh. Adults emerge in early November through December, eggs overwinter, larvae eclose in mid-March and develop through five instars, and pupae occur in the soil from May to November. Six species of native parasitoids were reared from field-collected larvae, but parasitism averaged only 4.5 and 12.2% in 1980 and 1981, respectively. The exotic parasitoids Cyzenis albicans (Fallen) (Tachinidae) and Agrypon flaveolatum (Gravenhorst) (Ichneumonidae) were released for biological control of winter moth in 1981 and 1982. C. albicans was recovered from four of seven release sites. No A. flaveolatum have been recovered

Density dependence and the stabilization of animal numbers : 1. The winter moth.

The claim of Varley and Gradwell that the highly density-dependent pupal predation (k 5) in the population of the winter moth in Wytham Wood, England would keep density within limits (regulate) is compared in this paper with the density limits in the null model: pupal predation causes the same mean generation mortality (35%) as in the field, but is not density-dependent, i.e. either constant or randomly fluctuating between years according to the actual frequency distribution, ceteris paribus. According to this null model the winter moth would have fluctuated between narrower limits than in the field; the claim of Varley & Gradwell must thus be rejected. It is more generally concluded that a regulating factor should be the key factor, but this is not a sufficient condition. It should also prevent in some way the low throughs in the time series that usually accompany the operation of a dominating density-dependent mortality factor.