Showing papers on "Lepidoptera genitalia published in 2005"

Egg maturation strategy and its associated trade-offs: a synthesis focusing on Lepidoptera

Abstract: 1. Insects vary considerably between and within orders, and even within the same genus, in the degree to which the female's lifetime potential egg complement is mature when she emerges as an adult. 2. The 'ovigeny index' (OI) - the number of eggs females have ready to lay divided by the lifetime potential fecundity - quantifies variation in the degree of early life concentration of egg production, and also variation in initial reproductive effort. 3. Here, an integrated set of hypotheses is presented, based on a conceptual model of resource allocation and acquisition, concerning trade-offs at the interspecific level between initial investment in egg production (as measured by OI) and other life-history traits in holometabolous insects. 4. The evidence supporting each of these hypotheses is reviewed, and particular attention is paid to the Lepidoptera, as relevant life-history data are rapidly accumulating for this ecologically and economically important group. 5. There is evidence at the interspecific level supporting: (i) a link between OI and a trade-off between soma and non-soma in Trichoptera and Hymenoptera (the proportionate allocation to soma decreases with increasing OI); (ii) a negative correlation between OI and dependency on external nutrient inputs (via adult feeding) in Hymenoptera and in Lepidoptera; (iii) a negative correlation between OI and the degree of polyandry (and nuptial gift, i.e. spermatophore, use) in Lepidoptera; (iv) negative correlations between OI and resource re-allocation capabilities (egg and thoracic musculature resorption) in Hymenoptera and in Lepidoptera; (v) a negative correlation between lifespan and OI in Trichoptera, Hymenoptera, and Lepidoptera, indicating a cost of reproduction; (vi) a link between winglessness and an OI of one in Lepidoptera; (vii) a negative correlation between OI and the degree of female mobility in winged Lepidoptera; and (viii) a negative correlation between OI and larval diet breadth (as mediated by oviposition strategy) in Lepidoptera.

Development of genetic sexing strains in Lepidoptera: from traditional to transgenic approaches.

Abstract: The sterile insect technique (SIT) is currently being used for the control of many agricultural pests, including some lepidopteran species. The SIT relies on the rearing and release of large numbers of genetically sterile insects into a wild population. The holokinetic chromosomes of Lepidoptera respond differently to radiation than do species where there is a localized centromere. This difference has enabled a variation of the SIT to be developed for Lepidoptera where a substerilizing dose of radiation is given to the insects before their release with the result that a certain level of sterility is inherited by the F1 offspring. The development of genetic sexing strains for fruit flies, enabling the release of males only, has resulted in enormous economic benefits in the mass rearing and has increased the efficiency of the field operations severalfold. This article outlines Mendelian approaches that are currently available to separate large numbers of males and females efficiently for different lepidopteran species and describes their difficulties and constraints. Successful transgenesis in several lepidopteran species opens up new possibilities to develop genetic sexing strains. The proposal to develop genetic sexing strains described in this article takes advantage of the fact that in Lepidoptera, the female is the heterogametic sex, with most species having a WZ sex chromosome pair, whereas the males are ZZ. This means that if a conditional lethal gene can be inserted into the W chromosome, then all females should die after the application of the restrictive condition. The assumptions made to accommodate this model are discussed, and the advantages to be gained for control programs are elucidated.

Spatio‐temporal variation in Lepidopteran larval assemblages associated with oak, Quercus crispula: the importance of leaf quality

Abstract: . 1. Lepidoptera larval abundance and diversity in the canopies of oak (Quercus crispula) trees and saplings were surveyed in a cool-temperate, deciduous broadleaf forest in northern Japan. 2. In general, newly developed leaves were soft, rich in water and nitrogen, and low in tannin, whereas they became tough, poor in water and nitrogen, and high in tannin as the season proceeded. Leaf quality also varied among forest strata, such variations resulting in seasonal and among-strata differences in the structure of the Lepidoptera larval assemblage. 3. The greater Lepidoptera larval abundance and species richness may related to the higher leaf quality on spring foliage compared with summer foliage. On the other hand, diversity (Shannon's H′) and evenness (Pielou's J′) were greater on summer foliage than on spring foliage. Strengthened defences of the host plants against herbivory may cause these differences by filtering the larvae of Lepidoptera species and by constraining the super-dominance of a few species on summer foliage. 4. Canonical Correspondence Analysis (CCA) ordination also revealed a stratified structure of the Lepidoptera larval assemblage in the forest. In both spring and summer, the assemblage composition was more similar between sunlit and shaded canopies than between canopies and saplings. Such assemblage stratification was highly correlated with toughness and tannin content (in spring and summer) or water content (in summer). 5. This study emphasised the importance of spatio-temporal variations in leaf quality, even within the same host plant species, for promoting herbivore diversity in forests.

Further additions to the Lepidoptera of Algarve,Portugal. II(Insecta: Lepidoptera)

Abstract: Resumen en: 99 species of Lepidoptera are added to the total of 1270 recorded for Algarve given in CORLEY et. al., (2000). 53 of these are additions to the Portugue...

Sequence similarity-based proteomics in insects: characterization of the larvae venom of the Brazilian moth Cerodirphia speciosa.

Abstract: Using a combination of tandem mass spectrometric sequencing and sequence similarity searches, we characterized the larvae venom of the moth Cerodirphia speciosa, which belongs to the Saturniidae family of the Lepidoptera order. Despite the paucity of available database sequence resources, the approach enabled us to identify 48 out of 58 attempted spots on its two-dimensional gel electrophoresis map, which represented 37 unique proteins, whereas it was only possible to identify 13 proteins by conventional non-error tolerant database searching methods. The majority of cross-species hits were made to proteins from the phylogenetically related Lepidoptera organism, the silk worm Bombyx mori. The protein composition of the venom suggested that envenoming by C. speciosa toxins might proceed through the contact with its hemolymph, similarly to another toxic Lepidoptera organism, Lonomia obliqua.

Are bark beetle outbreaks less synchronous than forest Lepidoptera outbreaks

Abstract: Comparisons of intraspecific spatial synchrony across multiple epidemic insect species can be useful for generating hypotheses about major determinants of population patterns at larger scales. The present study compares patterns of spatial synchrony in outbreaks of six epidemic bark beetle species in North America and Europe. Spatial synchrony among populations of the Eurasian spruce bark beetle Ips typographus was significantly higher than for the other bark beetle species. The spatial synchrony observed in epidemic bark beetles was also compared with previously published patterns of synchrony in outbreaks of defoliating forest Lepidoptera, revealing a marked difference between these two major insect groups. The bark beetles exhibited a generally lower degree of spatial synchrony than the Lepidoptera, possibly because bark beetles are synchronized by different weather variables that are acting on a smaller scale than those affecting the Lepidoptera, or because inherent differences in their dynamics leads to more cyclic oscillations and more synchronous spatial dynamics in the Lepidoptera.

A long-term survey of parasitoid species composition and parasitism of Trichoplusia ni (Lepidoptera: Noctuidae), Plutella xylostella (Lepidoptera: Plutellidae), and Pieris rapae (Lepidoptera: Pieridae) in Minnesota cabbage.

Abstract: Field studies were conducted near Rosemount, MN, during the years 1991–1994, 1996–1997, and 1999–2003, to assess the diversity of and parasitism by larval and pupal parasitoids of cabbage looper, T...

Extrinsic effects on fecundity-maternal weight relations in capital-breeding Lepidoptera

Abstract: Capital-breeding Lepidoptera depend for reproduction on metabolic resources assembled either entirely or primarily by their larvae, the former termed 'perfect' the latter 'imperfect'. Empirical evidence suggests that maternal size determines capital-breeder fecundity. The fecundity-maternal size relation is usually formulated as F = bW + a, where F is fecundity, W is final maternal size in units such as weight of newly transformed pupae, b is the slope, and a the intercept. Exhaustive search yielded 71 fecundity-maternal pupal weight relations for 41 capital breeders in 15 families, 58 of which, including 2 previously unpublished, were based on individual specimens, and 13 on grouped specimens. In 22 individual-specimen relations, cohorts divided into 2 or more subgroups were reared simultaneously at different temperatures, on different diets, or exposed to other extrinsic factors. These 22 'multiform' relations were compared with 36 'uniform' relations, and where possible cohort subgroups were compared. Pupal weights of cohort subgroups were affected much oftener than underlying slopes and intercepts. Individual-specimen slopes based on transformed data ranged 0.52-2.09 with a mean and standard error of 1.13±0.04, and slopes did not differ significantly among perfect, imperfect, multiform, and uniform categories. Despite the evident similarity, one relation does not apply to all capital breeders. Tradeoffs sometimes occur between fecundity, F, and mean egg weight, E. Reaction norms of fecundity and pupal weight across extrinsic-factor ranges were overwhelmingly congruent, which supports axiomatic status for the dependence of fecundity on capitalbreeder maternal size. Cooler rearing temperatures usually produced heavier female pupae and greater fecundities, a phenomenon of population dynamics interest. The two sides of practically all fecundity-maternal weight regressions are not statistically independent, in effect stating F = b(W + [F × E]) + a, which artificially inflates test statistics. Where desirable, the fully independent relation R = b(W [F × E]) + a can be used, where R is reproductive bulk, the mathematical product of F × E. Additional key words: temperature, diet quality, population dynamics 'Capital-breeding' describes Lepidoptera that depend for reproduction entirely or primarily on metabolic resources assembled by their larvae, in contrast to 'income-breeding', which describes those that depend for reproduction primarily or entirely on resources assembled by their adults (Boggs 1992, Miller 1996, Tammaru and Haukioja 1996). The gypsy moth, Lymantria dispar (L.) (Lymantriidae), is a capital breeder; the monarch butterfly, Danaus plexippus (L.) (Nymphalidae), an income breeder. In four butterfly income breeders in two families, income contributed ≥ 80% to fecundity, and capital ≤ 20% (Boggs 1997, Fischer and Fiedler 2001a). Based on sizes of superfamilies (Kristensen and Skalski 1999) and the extent to which income breeding is phylogenetically limited, probably ≈90% of extant Lepidoptera are capital breeders. Most outbreak Lepidoptera also are capital breeders (Miller 1996, Tammaru and Haukioja 1996). Capital breeders have an ovigeny index, OI, of 1 or >> 0, referring to the proportion of lifetime potential fecundity that consists of mature eggs at eclosion, whereas income breeders have an OI of 0 or <<1 (Jervis and Ferns 2004). Capital breeders with nonfeeding adults and OIs of 1 are here termed 'perfect', whereas those with OIs of >>0 whose adults may feed, but do so less than income breeders, are termed 'imperfect'. Maternal size is widely believed to determine fecundity in capital breeders (Leather 1988, Honek 1993). This belief derives not from experimentation but from long empirical observation. Direct fecundity-size relations occur in the lepidopteran phylogenetic sequence at least as early as Tineidae, the basal-most lineage of Ditrysia (Titschack 1922, Kristensen and Skalski 1999) and are probably part of the ground plan of Ditrysia, if not all Lepidoptera. This dependence implies that whatever influences maternal size may influence fecundity and its associated quality attributes, and thus population fluctuations. Fecundity can be a proxy for net reproductive rate (Carey 1993, Huey and Berrigan 2001) and has been implicated in capitalbreeder population fluctuations, as in Bupalus piniaria L. (Geometridae) (Klomp 1966), Bucculatrix pyrivorella Kuroko (Bucculatricidae) (Fujiie 1980), Leucoptera spartifoliella (Hübner) (Lyonetiidae) (Agwu 1974), and in capital-breeding Noctuidae (Spitzer et al. 1984). Traditionally, the relation between fecundity, F, and maternal weight, W, usually has been defined by linear regression as F = bW + a, where W refers to newly transformed pupae or newly eclosed adults, b is the slope, and a is the intercept or scaling parameter. Honek (1993) devised a fecundity-maternal weight relation for insects generally, as well as one for Lepidoptera, but he did not segregate capital breeders for special study nor exhaustively seek examples. Honek noted that weight appears on both sides of fecundity-maternal weight regressions, but that statistically independent measures of fecundity and maternal weight are practically 144144 JOURNAL OF THE LEPIDOPTERISTS’ SOCIETY nonexistent. In effect, such relations state that F = b(W + [F × E]) + a, where E is mean egg weight. The resulting nonindependence inflates test statistics and minimizes variation between response and explanatory variables. The practical usefulness of the traditional regressions is not necessarily impaired, but their statistics should not be used where strict independence between the variables is assumed. As discussed further on, a fully independent alternative relation emerged from this study. In any capital-breeder reared under homogeneous conditions, intrinsic effects alone will produce a direct relation between fecundity and maternal size. If a cohort of eggs or hatchlings is divided into subgroups, and each subgroup reared at a different level of an extrinsic factor, such as a different temperature, or on a different diet, then extrinsic effects are likely to be added to the intrinsic ones. Here I examine extrinsic effects on fecundity-maternal pupal weight relations during rearing of capital breeders. I focus on effects produced by different temperatures—as might occur during anomalous weather, or between microhabitats, or between generations or seasons—and by differing diet quality—as might occur on variably stressed or different kinds of foodplants, or on different kinds or amounts of adult nourishment. MATERIALS AND METHODS I assembled as many statistical fecundity-maternal weight relations as possible from a personal reference collection, electronic databases including Biosis, Biological Abstracts, and the Zoological Record, and from citations in references. Most relations were based on observations of specimens individually, a few on means of grouped specimens. Individual-specimen relations were admitted if based on samples numbering ≥ 20, grouped-specimen relations if based on groups numbering ≥ 5. No relations were excluded because of non-English text. In the 58 assembled individual-specimen relations, weights and fecundities were available in numerical form for three published and two unpublished ones (Table 1); weights and fecundities for the remainder were transcribed from enlarged photocopies of published scatterplots. Because transcription creates error—when one point covers another, for instance—I tested slopes of transcribed relations against corresponding slopes given in sources. A few departures were statistically significant, but most were not (F-tests, P = 0.99–0.009; median P = 0.76; n = 35). If P was < 0.25, I retranscribed, but in no case did retranscription change the outcome appreciably. I accepted scatterplots at face value despite minor inconsistencies, except that for Philosamia ricini Hutt. (Singh and Prasad 1987), which seemed too anomalous. In the 13 groupedspecimen relations, most weights and fecundities were available in numerical form (Table 2). Study relations consisted of perfect and imperfect groups and uniform and multiform subsets. 'Uniform' denotes homogeneous conditions of development expected to produce only intrinsic effects, and 'multiform' denotes heterogeneous conditions expected to produce extrinsic as well as intrinsic effects. I examined relations for extrinsic effects first by metaanalysis (Gates 2002) and second by comparing cohort subgroup relations provided in sources or obtained by deconstruction. A standardized maternal weight was desirable, and I chose fresh pupal weight. By the pupal stage metabolic resources for ovigenesis are in place. Moreover, pupal weight has been most often used in describing fecundity-size relations (42 of 58 relations in Table 1, 12 of 13 in Table 2), and explanatory variables based on weight outnumber those based on lineal dimensions such as forewing length and pupal diameter. I maximized the number of relations for study by converting female adult fresh weight, Wa, to fresh pupal weight, Wp, where Wp = Wa × 1.85, a factor based on four observations: (1) first-day female pupae of Malacosoma disstria (Hbn.) (Lasiocampidae) in a previously unpublished study averaged 1.98 times heavier than first-day adults (n = 30 weighings, paired); (2) a corresponding value of 1.81 for Epiphyas postvittana (Walker) (Tortricidae) (n >130 weighings, unpaired) (Danthanarayana 1975); (3) a corresponding value of 1.74 for Streblote panda (Hbn.) (Calvo and Molina 2005); and (4) a corresponding value of 1.67 for Cnephasia jactatana (Walker) (Tortricidae) (Ochieng'Odero 1990). Fecundity had been estimated in sources by various methods, all internally consistent and all accepted here. Methods included counting unlaid eggs in dissections of newly eclosed females, counting only eggs actually laid, and combining eggs laid with residual eggs in ovaries af

Effects of temperature and photoperiod on the development and reproduction of Adoxophyes honmai (Lepidoptera: Tortricidae)

Abstract: The effects of constant temperature and photoperiod on the development and reproduction of Adoxophyes honmai Yasuda (Lepidoptera: Tortricidae) were investigated. The durations of the larval and pupal stages decreased in the range from 15 to 28°C, but the developmental periods were longer at 30°C than at 28°C. The developmental zero and the thermal constants were calculated to be 9.8°C and 104.1 degree-days for eggs, 9.3°C and 232.6 degree-days for larvae, 11.5°C and 76.3 degree-days for pupae, and 10.3°C and 417.0 degree-days from egg to adult emergence. The temperature significantly affected the number of eggs deposited by a single female, the proportion of eggs hatched, and the longevity of adult females. At both 15 and 20°C, larval and pupal developmental periods were significantly shorter for the long-day length of 16L:8D than for the short-day length of 10L:14D.

Geometric morphometric analysis of wings variation between two populations of the Scythris obscurella species-group: geographic or interspecific differences? (Lepidoptera: Scythrididae)

Abstract: The wings of scythridids of two population from Valle d’Aosta and Maritime Alps were examined through geometric morphometrics analysis. All the specimens belong to the the“Scythris obscurella group”. Currently, 10 species are assigned to the group, and the uncertain identification of many specimens is due mainly to their marked similarity in external features. Aim of the work is to evaluate the overall shape variation, and thence to test if the specimens could be divided at population level, or at specific level employing both the pairs of wings. Size and shape variation of each wing were examined separately through GPA. The left-right asymmetry of scythridids wings was examined by t-test, and the shape variation of forewings was compared to the one of hindwings. For each wing, shape variation was correlated to size variation.

New source of genetic polymorphisms in Lepidoptera

Abstract: The variability level of the ISSR (inter-simple sequences repeat) primer (GACA) 4 was examined in the three Lepidoptera families Pyralidae, Sphingidae and Pieridae. Our study shows that the tetra-repeat (GACA) n is evidently present in sufficient numbers in these butterflies to provide informative DNA fingerprints. The variability is mostly rather high, but within a comparable range to other ISSR studies. Although less polymorphisms may be encountered in some butterfly families, this study indicates that high variability of this marker may be a common characteristic of Lepidoptera genomes. An appeal for a minimal level of standardization of ISSR-PCR data analysis is formulated to enable an exact comparison between the groups of organisms studied with this fingerprint technique.

Suppression of codling moth Cydia pomonella L. (Lepidoptera: Tortricidae) population in South African apple and pear orchards using Sterile Insect Release

Abstract: Codling moth, Cydia pomonella L. (Lepidoptera: Tortricidea), is the key pest of apples and pears in South Africa. To date the control of codling moth in apple and pear orchards has depended on the application of insecticides and in some cases pheromone mediated mating disruption. Due to the development of resistance to insecticides and restrictions placed on the use of certain insecticides, control of codling moth has become problematic. Sterile insect release (SIR) of codling moth has been investigated as a potential addition to the current control strategy. The cost-benefit of codling moth SIR under local conditions, mass culture methods and initial field trials have been completed. It is envisioned that codling moth SIR will be used in conjunction with insecticide sprays and/or pheromone disruption. A largescale pilot project is planned for the South Western Cape. INTRODUCTION Apple and pear production forms a significant part of the South African deciduous fruit industry, and consists of 22 901 ha of apples and 13 495 of pears. Codling moth, Cydia pomonella L. (Lepidoptera: Tortricidea) is a widely distributed primary pest of apples and pears in South Africa. The fruit production areas in the South Western Cape are confined to valleys isolated from each other by mountains. The geographic structure of the South Western Cape combined with the relatively low mobility of codling moth, would allow for the control of codling moth on an area-by-area basis. Currently the control of codling moth in apple and pear orchards depends on the application of insecticides and in some cases pheromone disruption. Despite wellmanaged and costly control programs, codling moth remains a significant economic pest. Insecticide resistance, the restrictions placed on the use of insecticides and favourable weather conditions have resulted in increased levels of codling moth induced fruit damage. The direct cost of codling moth control (insecticides and pheromone disruption) is significant. Despite the relatively high cost of control, codling moth damage is a significant loss and populations remain high enough in orchards to cause extensive damage if control measures are not applied or applied incorrectly. In addition, the current control methods employed are limited and highly selective. If true integration of codling moth control is to be achieved, additional non-chemical control methods will have to be developed and applied. STERILE INSECT RELEASE (SIR) Sterile insect release (SIR) has been used in an attempt to eradicate codling moth in areas of western Canada (Bloem et al., 2000) and the United States (Calkins et al., 2000). The method involves the release of large numbers of sterilized codling moths into orchards over a wide area. Released sterile moths mate with fertile wild moths resulting in sterile progeny, thus controlling the population. A method of treating moths with a relatively low radiation dose, which results in full sterility of female moths and partial sterility of male moths, has also been used (Bloem et al., 1999). The partially sterile male mate with fertile wild moths and the progeny are sterile. The lower radiation dose results in more competitive and effective moths released into the field. The costs associated with SIR are relatively high when compared to conventional chemical control, and the method requires intensive management. The Canadian SIR program involved the release of sterile codling moths for twenty weeks at a rate of 900 moths per acre per week. In 1997 the release rate was increased to 1500 moths per acre per week. Results of surveys carried out in 1997 showed that codling moth damage was absent from 91% of treated orchards and insecticide applications to control codling moth were reduced to an average of one per annum (Bloem et al., 2000). Calkins et al. (2000) released sterile codling moths in 180 hectares of pheromone treated orchards in Washington State. The initial phases of the program sterile moths were released during the second half of the season. In 1997 sterile moths were released at a rate of 1120 per hectare for the duration of the season. Moths were released from specially adapted vehicles at 30 intervals in the treated orchards. Results indicate that codling moth populations were effectively suppressed in the treated orchards, fruit damage was significantly reduced as were the number of insecticide applications. PROPOSED SIR PILOT PROJECT Based on the above results, a local pilot codling moth SIR program was proposed in 2002. The purpose of the pilot program is to demonstrate the method and to establish the economic feasibility of the method in commercial apple and pear orchards in South Africa. Due to financial constraints, the initial pilot will be limited to a total area of 500 ha. The selected orchards are planted in close proximity to each other and the area is semi-isolated from other orchards. No alternate host trees occur outside of the orchards. The orchards have been under integrated pest management of a number of years. Codling moth populations in the selected orchards are currently controlled with the use of pheromone disruption and the application of insecticides. The orchards are situated on two separate farms, and both farms have extensive pest and disease monitoring programs, thus historic data is available for all orchards. It is proposed that the selected orchards will be treated with 2000 sterile moths per hectare per week from September to March (26 weeks) during the first year of the program. The laboratory reared moths will be marked with dye which is incorporated into the larval diet, thus allowing to easy identification in the field. All moths will be treated at 150 Gy of gamma radiation from a cobalt 60 source at the rate of 5 Gy per minute. Moths will be released from modified vehicles twice weekly at 30 meter transects. All orchards will be treated with pheromone disruption at full rate and would receive three applications of an insect growth regulator (flufenoxuron) during the first moth flight (October to November). Orchards will be monitored at weekly intervals using pheromone baited (10 mg) adhesive traps (1 trap per 2 hectares). Regular fruit damage assessment will be carried to determine the degree of control in orchards and to ensure that if supplementary insecticide treatments are applied correctly. COST BENEFIT ANALYSIS The development of insecticide resistance in codling moth populations has resulted in an increasing number of insecticide applications being applied. Pheromone disruption has been widely adopted to supplement insecticide applications. Current codling moth control programs consist of pheromone disruption combined with intensive insecticide applications. For example, the two farms involved in the current SIR program have applied pheromone disruption to all orchards, a total of 650 hectares. In addition, insect growth regulator insecticides have been applied followed by multiple organophosphate sprays. During the 2002/03 season, fruit damage, as determined by systematic fruit damage assessments was on average less that 0.5%. The costs associated with the production of large numbers of insects for use in SIR are relatively high. In addition, the method requires intensive management and maintenance of sophisticated infrastructure. This cumulative cost has to be justified in terms of benefits accrued by the use of the method. Initial estimates of production costs indicate that the treatment of an orchard for 26 weeks with 2000 moths per hectare per week are comparable to the costs of codling moth pheromone disruption. Thus the use of SIR in the initial season, that is in combination with pheromone disruption, will be relatively high. However, if successful, there will be a net saving in following years as codling moth populations are suppressed and the number of pesticide applications are reduced. RESEARCH AND DEVELOPMENT Current research and development needs include the development of suitable culture methods and the assessment of the overall fitness of laboratory cultured moths in the field. A locally adapted maize meal based diet has been developed and tested. A laboratory colony of codling moth imported from Canada and a colony of locally collected codling moths have been established. Radiated and non-irradiated have been assessed under field condition using mark and recapture methods (Bloem et al. 1998). The distribution of laboratory reared moths, in conventional and pheromone treated orchards has been assessed. Results indicate that locally produced moths are competitive and within the parameters set by the Canadian SIR program CONCLUSIONS The suppression of codling moth populations in South African apple and pear orchards using sterile insect release appears to be economically feasible under current conditions. The proposed pilot program in 500 hectares of commercial orchards will allow for a more comprehensive assessment of the method. ACKNOWLEDGEMENTS My thanks to the Deciduous Fruit Producers Trust (DFPT) and the South African Apple and Pear Producers Association (SAAPPA), and D Henrico for their support. Literature Cited Bloem, K.A. and Bloem, S. 2000. Sterile insect technique for codling moth eradication in British Columbia. Pp 207-214. In: Ken-Hong Tan (ed.), Area-Wide Control of Fruit Flies and Other Insect Pests. Proc. FAO/IAEA Symp. Penang, Malaysia, 1998. Penerbit University Sains Malaysia, Pulau Pinang. Bloem, S.K., Bloem, A. and Knight A.L. 1998. Assessing the quality of mass-reared codling moths (Lepidoptera: Tortricidae) by using field release-recapture tests. Journal of Economic Entomology. 91: 1122-1130. Bloem, S.K., Bloem, A., Carpenter, J.E. and Calkins, C.O. 1999. Inherited sterility in codling moth (Lepidoptera: Tortricidae): effects of substerilizing doses of radiation on insect fecundity, fertility and control. Ann. Entomol. Soc. Am. 92: 1-8. Calkins, C.O., Knight, A.L., Richardson, G. and Bloem K.A. 2

Mating Communication Systems of Four Plusiinae Species Distributed in Japan: Identification of the Sex Pheromones and Field Evaluation

Abstract: The sex pheromones of four Plusiinae species in the family Noctuidae, Ctenoplusia albostriata (CA), Macdunnoughia purissima (MP), Syngrapha ain (SA), and Diachrysia stenochrysis (DS) were identified by GC-EAD and GC-MS analyses. These were subsequently evaluated by a series of field trials in different ecological habitats. CA females produced (Z)-5-decenyl acetate (I), (Z)-7-dodecenyl acetate (II), and (Z)-7-dodecen-1-ol (III) in a ratio of 2:100:13. While the antennae of CA males responded to all three components, neither I nor III was essential to capture males. The MP females produced II, III, and (Z)-5-dodecenyl acetate (IV) in a ratio of 100:80:20, and this blend captured the most MP males. Compounds II and III were also identified from SA females, and mixtures ranging from 4:1 to 2:3 were equally attractive to males. DS females only produced one active compound, (Z)-7-decenyl acetate (V), and DS is the first Plusiinae species identified as using only the ω3-compound and none of ω5-compounds, such as II and III, which are common components of Plusiinae pheromones. Using previously published chemical and biosynthetic data, together with the finding from this study, we propose a classification of the Plusiinae sex pheromones.

Biology of some phytoseiid predators (Acari: Phytoseiidae) on eggs of Phthorimaea operculella and Spodoptera littoralis (Lepidoptera: Gelechiidae and Noctuidae)

Abstract: Cinq especes de phytoseiides sont testees pour evaluer leur potentiel de predation sur les oeufs de Phthorimea operculella et de Spodoptera littoralis comme source alternative de nourriture au laboratoire. Pour Typhlodromus swirskii, le temps de developpement observe est plus court et la reproduction meilleure sur les oeufs de P. operculla, alors que le developpement est ralenti et la reproduction est deprimee pour N. californicus sur les deux types d'oeufs. La femelle de T. swirskii consomme un plus grand nombre d'oeufs de P. operculla et S. littoralis que N. californicus. Le nombre d'oeufs produit par jour est plus eleve (2,1 et 1,3) pour T. swirskii que pour N. californicus (1,1 et 0,9) respectivement pour les deux proies. La survie des immatures est moins bonne pour Typhlodromus balanites, Paraseiulus talbii et Typhlodromus transvaalensi sur les oeufs de ces deux especes.

The genus Bryotropha Heinemann in the western Palaearctic (Lepidoptera: Gelechiidae)

Abstract: tributed throughout the Holartic region. Although Bryotropha specimens can be readily recognized as members of this genus, the individual species are often difficult to separate as they usually have neutral colours and lack striking wing markings. Many species are also very similar in genital characters. Since the old descriptions are often not very precise, misidentifications and introduction of synonyms are commonplace within this genus. The present paper is

Biology and Life History of Ascia monuste monuste (Lepidoptera: Pieridae), a Potential Pest of Cruciferous Vegetables

Abstract: Ascia monuste (L.) (Lepidoptera: Pieridae) is a subtropical and tropical species with several subspecies and forms. In recent years, it has become a sporadic insect pest of crucifer vegetables in southern Texas. In some isolated fields, the gregarious larvae have completely consumed all aboveground parts of large cabbage or collard plants (leaves, petioles, and stems). To understand more about this subspecies, I studied its biology on cabbage, including the development of immature stages, the longevity of adults, and other parameters in the laboratory and the greenhouses. At 25 ± 2°C, developmental time averaged 4.7, 2.8, 2.3, 3.1, 3.2, 6.0, and 9.d d for eggs, first, second, third, fourth, fifth instars and pupae, respectively, yielding an average of 17.4 d for all larval stages and an average generation time of 31.7 d for both sexes. Adult longevity averaged 19.8 d for females and 16.3 d for males under greenhouse conditions. The sex ratio was 1:0.76 (females:males) or 56.8% females. Each egg c...

Parasitoid assemblages reared from geometrid defoliators (lepidoptera: geometridae) of larch and fir in the alps

Abstract: 1 Geometrid larvae were collected from larch and fir in the Swiss Alps in 1991–94. Eight geometrid species were found in sufficient numbers to rear out parasitoids: Agriopis aurantiaria, Bupalus piniarius, Epirrita autumnata, Eupithecia lariciata, Odontopera bidentata, Lycia isabellae and Semiothisa liturata were collected from larch, and Puengeleria capreolaria was obtained from fir. 2 Parasitoid species belonging to five different guilds and four families were obtained; however, the taxonomic status of some of these is not completely resolved. 3 The parasitoid complex of the larch-feeding species was totally different from that of Tortricidae and Tenthredinidae, which feed on the same host tree. In general, there was little overlap in the parasitoid complexes of the larch geometrids, with the most dominant parasitoid of each species reared from only one host. By contrast, many parasitoid species found during our study are also known to attack the same hosts or closely related hosts on different host tree species in different environments, suggesting that host specificity in geometrid parasitoids is more related to host taxonomy than to host plant or habitat.

New records of Cryptinae (Hymenoptera: Ichneumonidae) from Turkey with some hosts.

Abstract: Summary Seven species of Cryptinae (Hymenoptera: Ichneumonidae) are recorded for the first time to the Turkish fauna. Of these, Gambrus opacus Szepligeti was reared from the pupa of Malacosoma neustria (L.) (Lepidoptera: Lasiocampidae), that of Meringopus cyanator (Gravenhorst) from the pupae of both M. neustria (L.) and Lymantria dispar L. (Lepidoptera: Lymantriidae).

Comparación de dos técnicas de medición de cápsulas cefálicas para separar estadios larvales de copitarsia incommoda (walker) (lepidoptera: noctuidae)

Abstract: The objective of the present work is to compare two measurement techniques: the distance between genae, used in the method of Dyar (1890) and the distance between frontal setae, used by Podoler (1978). The first one is commonly used to determine the larval instar in Lepidoptera. We measured cephalic capsules and the distance between frontal setae of Copitarsia incommoda. Based on our results, we concluded that Podoler’s technique is more precise than that of Dyar.

Spatial and temporal dynamics of potato tuberworm (Lepidoptera: Gelechiidae) infestation in field-stored potatoes

Abstract: The potato tuberworm, Phthorimaea operculella (Zeller), is a major pest of potatoes in fields and traditional storage. A common method of nonrefrigerated storage is to pile potatoes in straw-covered heaps in the field. Tubers may be stored up to 3-4 mo in this manner, until the next harvest. We studied the dynamics of potato tuber moth infestation associated with such field storage in a 12-wk experiment in Israel. We set up six potato heaps, and sampled them for potato tuber moth at different locations at weekly intervals. Potato tuber moth infestation was significantly higher at the perimeter of the heaps than at their center, but it did not differ between bottom, mid-height, and top of the heaps. The proportion of potato tuber moth-infested potato tubers increased from 10 to 65% over the course of the experiment, and the mean number of potato tuber moth larvae per tuber increased from 0.25 to 2.50. Potato tuberworm populations increased sharply after 3, 6, and 9 wk of study, possibly corresponding to successive generations that developed within the heaps. This interpretation is supported by calculations of potato tuberworm generation length based on temperature data. Catches in pheromone traps that were placed near the heaps were not correlated (spatially and temporally) with potato tuberworm densities within heaps, hinting that migration among heaps did not considerably affect within-heap population dynamics. Potato tuberworm levels were not correlated with ambient temperatures, perhaps because of the warm, humid, and constant microclimate within the heaps. We discuss the significance of our findings for control efforts of the potato tuberworm.

Susceptibility of Eldana saccharina (Lepidoptera: Pyralidae), Busseola fusca and Sesamia calamistis (Lepidoptera: Noctuidae) to Bacillus thuringiensis Cry toxins and potential side effects on the larval parasitoid Cotesia sesamiae (Hymenoptera: Braconidae)

Abstract: Laboratory trials were conducted to determine the efficacy of four Bacillus thuringiensis (Bt) Cry toxins at five different concentrations (0.016, 0.08, 0.4, 2, 10 μg/mL) for controlling three lepidopteran stem-borer species (i.e., the pyralid Eldana saccharina and the noctuids Busseola fusca and Sesamia calamistis) as well as to evaluate their indirect effect on the braconid larval parasitoid Cotesia sesamiae. In addition, larvae from the treatments above, after having been parasitized, were either fed a contaminated (group 1) or a toxin-free (group 2) diet and compared with a control (i.e., parasitized larvae which have never fed on Bt-toxin). All Bt Cry toxins induced larval feeding inhibition. Compared with the control, significant mortality resulted at all concentrations and for all species of Lepidoptera. Cry1Ab was the most toxic with 10 days post treatment mortalities ranging from 81% in B. fusca and S. calamistis to 100% in E. saccharina. In contrast, Cry1Ac had comparatively low toxicity particu...