Increasing vineyard floral resources may not enhance localised biological control of the leafroller Epiphyas postvittana (Lepidoptera: Tortricidae) by Dolichogenidea spp. (Hymenoptera: Braconidae) parasitoids

In agroecosystems, the efficacy of biological control exerted by many parasitoids is predicted to be enhanced where the availability of floral resources is increased. Such resources may attract parasitoids and enhance their longevity and fecundity. In Hawke's Bay, New Zealand, this prediction was tested by adding varying quantities of potted flowering alyssum (Lobularia maritima) (Brassicaceae) to plots containing apple plants (Malus domestica) inoculated with larvae of the leafroller, Epiphyas postvittana (Lepidoptera: Tortricidae). In two replicated trials, over 90% of the parasitoids from recovered larvae were Dolichogenidea spp. (Hymenoptera: Braconidae). In both trials increasing the percentage of alyssum did not result in a corresponding increase in the leafroller parasitism rate. Instead, the primary influence on parasitism rates was due to Dolichogenidea spp. dispersing from a nearby orchard. A significant negative correlation was observed in leafroller parasitism as a function of distance from this orchard. A vineyard to the north of the study site also influenced parasitism rates. Our results suggest the orchard was a regional source population for this parasitoid, and the abundance of local resources such as alyssum did not influence parasitoid foraging. At the level of our entire study block, our effective area of resource provision was 0.1%. A level of resource provision higher than that used in this study may be necessary to test for a positive influence on local parasitism rates. From our results, it appears that for parasitoids with relatively high dispersal rates, the availability of local resources may not be as important as a regional source population.     

Effects of buckwheat flowers on leafroller (Lepidoptera: Tortricidae) parasitoids in a New Zealand vineyard

Abstract 1 The provision of floral resources in agricultural ecosystems can potentially enhance biological control of pests by providing nutrients to parasitoids. To test this, the effect of buckwheat Fagopyrum esculentum Moench flowers on leafroller parasitoids was investigated in a New Zealand vineyard. 2 Relative abundance of parasitoids was assessed with yellow sticky traps in buckwheat and control plots. Male Dolichogenidea tasmanica (Cameron) (Hymenoptera: Braconidae) were significantly more abundant in the presence of buckwheat. No significant result was found for female D. tasmanica or either sex of Glyptapanteles demeter (Wilkinson) (Hymenoptera: Braconidae), the other leafroller parasitoid caught. 3 The relative parasitism rate of leafrollers by D. tasmanica was assessed with a leafroller release and recover technique. No difference in parasitism was found between buckwheat and control plots. 4 The sex ratio (% males) of D. tasmanica emerging from recovered leafroller larvae was significantly lower in the presence of buckwheat than in control plots on one of the two release dates. Possible reasons for this increase in female production are discussed.     

Use of day-degree estimates for rearing management of Ctenopseustis obliquana (Lepidoptera: Tortricidae) in the laboratory

Abstract

The brownheaded leafroller (BHLR), Ctenopseustis obliquana (Walker) (Lepidoptera: Tortricidae) was reared on an artificial diet at seven constant temperatures. The mean life cycle at optimum rearing temperature of 20 ± 1°C was: egg development 8.7 days; larval period, M 37.4, F 41.2 days; pupal period, M 14.9, F 13.3 days; pupal weights, M 50.5, F 68.2 mg; and a fecundity of 670 eggs per female. Estimated lower threshold temperatures and mean cumulative number of day- degrees for various stages of development were 7.8°C and 105D° for eggs, 5.2°C and 538D° for larvae, and 7.2°C and 186D° for pupa. Total mean day-degree accumulation from egg to adult was 829D°.

These data were used to develop an efficient rearing management system embracing colony maintenance, storage, manipulation, production, and quality assessment procedures.     

Reduction in leafroller (Lepidoptera: Tortricidae) abundance in orchards and vineyards 1976–2016, in Hawke's Bay,New Zealand

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A biological assessment of Glypta variegata (Hymenoptera: Ichneumonidae) as a parasitoid of Choristoneura rosaceana (Lepidoptera: Tortricidae)

In laboratory trials, Glypta variegata, a common endoparasitoid of leafrollers in North America, successfully parasitized first through third instar Choristoneura rosaceana and first to fourth instar Pandemis limitata. Significantly more second instar C. rosaceana were parasitized when temperatures fluctuated between 30.3 and 12.0°C (16 L:8 D) than when temperatures fluctuated between 17.5 and 4.0°C (12 L:12 D), similar to fall conditions in southern British Columbia, Canada. Under the warmer simulated summer conditions, an average female wasp began to parasitize C. rosaceana 8 days post-emergence (range: 4-16 days), lived 31 days (range: 24-37 days) and successfully parasitized 28 larvae (range: 1-89). When parasitized, C. rosaceana larvae consumed less food in their last two instars than did unparasitized female larvae.     

Life cycle changes during 12 successive generations of laboratory colonisation of the leafroller Cnephasia jactatana (Walker) (Lepidoptera: Tortricidae) on artificial diet

Abstract

Close monitoring of the lepidopteran leafroller Cnephasia jactatana under laboratory colonisation revealed few distinct effects of successive rearing on artificial diet on the life cycle. The second laboratory generation had a prolonged development time and altered sex synchronism in pupation and eclosion patterns. Some deleterious changes were observed in later generations, including decreases in fertility, egg hatch and sperm motility, failure of mating adults to separate, and pupal and adult malformations. These changes were not adaptive, but were due to incompatibility with the general purpose diet (GPD) used; they were absent under sub-colonisation on a sheepnut-bean based diet (SBD). Success in the laboratory colonisation of C. jactatana is attributed to a random mating protocol, choice of environmental conditions representing the wild habitat, and a rapid rate of population growth.     

Screening of cry gene contents of Bacillus thuringiensis strains isolated from avocado orchards in Mexico, and their insecticidal activity towards Argyrotaenia sp. (Lepidoptera: Tortricidae) larvae

Aims:  To screen for Bacillus thuringiensis strains from avocado orchards in two Mexican states with lepidopteran-specific cry gene content and evaluate their insecticidal activity against Argyrotaenia sp., an undescribed species present in avocado orchards.
Methods and Results:  Lepidopteran-active cry 1, cry 2 and cry 9 genes were detected by PCR analysis in 37 isolates. cry 1 genes were more frequent in Michoacán, but were undetected in Nayarit isolates. cry 9 and cry 2 genes were detected in isolates from both states, although cry 2 genes were less frequent. A variety of crystal shapes were observed among the isolates. According to gene profile, eight isolates were selected and tested against 2-day old Argyrotaenia sp. larvae. Standard strain HD-125 caused the highest mortality followed by strain MR-26 from Michoacán at a concentration of 500 μg ml⁻¹, respectively.
Conclusions:  Bacillus thuringiensis strains isolated from avocado orchards exhibit a low toxic activity towards Argyrotaenia sp. larvae, in spite of their specific cry gene content.
Significance and Impact of the Study:  Toxic activity of B. thuringiensis is not necessarily related to insect pest habitat and neither to specific cry gene content associated to other lepidopterans.     

Biology and performance of two indigenous larval parasitoids on Tuta absoluta (Lepidoptera: Gelechiidae) in Sudan

Tuta absoluta is an alien invasive pest in Sudan. Since it was detected in the country, the pest continues to cause major tomato losses. Alarmed by its devastating nature and the speed of spread, tomato growers resorted to the indiscriminate use of broad-spectrum insecticides. Promising indigenous parasitoid(s) may contribute to suppression of this pest. The biology and performance of the native parasitoids, Bracon nigricans Szépligeti (Braconidae) and Dolichogenidea appellator (Telenga) (Braconidae), was therefore evaluated against different immature stages of T. absoluta under laboratory conditions. A significantly higher number of fourth instar larvae was accepted for oviposition by B. nigricans. Similarly, fourth instar larvae yielded a considerably higher number of parasitoid offspring compared to third instar larvae. The male ratio of B. nigricans offspring which emerged from both larval instars was high, 0.96 and 0.66 for third and fourth instar larvae of T. absoluta, respectively. There was, however, no significant difference in the number of males and females that emerged from fourth instar larvae. Conversely, the number of hosts killed by stinging behaviour or host feeding was significantly higher on third instar larvae. B. nigricans potential fecundity varied with the age of the wasp with the lowest fecundity on the day of eclosion. The performance of D. appellator in terms of the total number of offspring produced and female progeny was similar for second and third instar larvae of T. absoluta. The preimaginal developmental time for both parasitoid species did not vary with either host stage or sex of the parasitoid. B. nigricans adult longevity was similar for both sexes, while that of D. appellator significantly varied with females living longer than males. Prospects for conservative biological control of T. absoluta are discussed in the light of the results of this study.     

Characterization of a nucleopolyhedrovirus of Epinotia granitalis (Lepidoptera: Tortricidae)

A nucleopolyhedrovirus (NPV) from the cypress bark moth Epinotia granitalis Butler was partially characterized. Electron microscopy indicated that E. granitalis NPV (EpgrNPV) is a singly embedded nucleocapsid NPV with a relatively small polyhedron, ranging from 480 to 1100nm in diameter. Phylogenetic analysis revealed that EpgrNPV is a Group II NPV that is related to but distinct from Adoxophyes honmai NPV. The LC(50) against third instar E. granitalis larvae was 10(5.5) polyhedral occlusion bodies per gram (OBs/g diet), and the average time to death was 14 days. E. granitalis was the only EpgrNPV-susceptible species in a series of infection tests using insect species belonging to the family Tortricidae. Other test species, including Eucoenogenes ancyrota, A. honmai, Adoxophyes dubia, Pandemis heparana, Homona magnanima, and Archips insulanus, were not susceptible to the infection.     

梨小食心虫蛹重对成虫繁殖力和寿命及下一代幼虫发育的影响

【目的】本文旨在明确营养状况不同造成的梨小食心虫Grapholitha molesta(Busck)雌、雄蛹重量差异对其羽化的成虫产卵量、产卵期、寿命及下一代(F1)幼虫发育的影响。【方法】室内条件下,通过不同的饲养方法,获得个体重量不同的梨小食心虫雌、雄蛹,待其羽化交配后,记录其产卵量、产卵时间和成虫寿命;卵孵化前后,分别测量卵和初孵幼虫大小,计算卵孵化率,统计幼虫发育历期。【结果】雌蛹重量对梨小食心虫的成虫产卵量影响显著,其重量与产卵量呈正相关(y=15.505x-59.292);同一条件下,雌蛹与雄蛹重量也呈正相关(y=0.823x-0.538)。同时,雌蛹重量对成虫产卵期影响也较大,蛹重大的个体羽化的雌虫比蛹重小的个体羽化的雌虫产卵高峰期提前1 d;较重、中等和较轻蛹羽化出的雌虫个体每天产卵量高于10粒/雌的时间分别为9~10,7和5~6 d;产卵量高于5粒/雌的时间分别为12~13,9和6~7 d。而雄蛹重量对产卵量、雄成虫寿命影响没有明显影响。较轻的蛹羽化的雌成虫寿命比较重蛹羽化的雌成虫短2~3 d;而雄蛹重量对其羽化的雄成虫寿命影响没有明显规律。雌、雄蛹重量对其羽化成虫的卵孵化率、卵和初孵幼虫的大小影响均不显著,对F_1幼虫发育历期影响也不显著。【结论】梨小食心虫雌蛹重对羽化成虫的产卵量和产卵期等影响显著,田间防治时应注意在不同条件下完成发育的个体,尤其是雌虫,由于营养差异引起的个体大小对随后种群增长的影响。     

Diapause induction in the oblique-banded leafroller Choristoneura rosaceana (Lepidoptera: Tortricidae): Role of photoperiod and temperature

Induction of diapause in the larval stage of the oblique-banded leafroller, Choristoneura rosaceana (Harris), was found to be dependent on both photoperiod and temperature. At constant temperatures of 24, 20 and 16°C, short photoperiods induced diapause. The critical photoperiod was between 14–15 h of light per day at 20 and 16°C. At 14 h light: 10 h dark, all larvae expressed diapause. Temperature had a modifying effect, and slightly shifted the larval response to diapause-inducing photoperiods. High constant temperatures of 28°C and above induced diapause in some individuals (< 20%), while fluctuating temperatures of 32 and 16°C in a 12-h cycle resulted in 67% diapause induction, suggesting that diapause could also be induced by fluctuating temperatures, particularly if the higher temperature exceeds 25°C.The first- and the second-instar larvae were the only two stages sensitive to diapause induction. Exposure of adult, egg and third, fourth, and fifth-larval instars to diapause-inducing conditions did not produce diapause. Although diapause was induced in the first or the second instars, it was always expressed in the third or fourth instar.     

Complete mitochondrial genome of the hemp borer,Grapholita delineana (Lepidoptera: Tortricidae): Gene variability and phylogeny among Grapholita

The mitochondrial genome (mitogenome) has been extensively used in phylogenetics and species-level evolutionary investigations. The lepidopteran family Tortricidae (leaf-roller moths), including the genus Grapholita, contains numerous species of economic importance, but for the majority of Grapholita species, their mitogenomes remain poorly studied. Here, we sequence and annotate the full mitogenome of Grapholita delineana, an important pest of hemp worldwide and compare it with the mitogenomes of two congeneric species available from GenBank. The G. delineana mitogenome is 15,599 bp long, including 37 typical mitochondrial genes and an A + T-rich region. Gene content, order and orientation are identical to other reported tortricid mitogenomes. Analyses of nucleotide diversity, Ka/Ks, genetic distance and number of variable sites together suggest that nad6 is the fastest-evolving gene among the mitochondrial PCGs of Grapholita. Our analyses indicate that Grapholita, as presently defined, is not monophyletic, confirming previous morphological and multiple-gene studies, using mitogenomic evidence. Our study provides information on comparative mitogenomics of Tortricidae especially Grapholita.     

内蒙古牧草上一新害虫--沙打旺小食心虫(鳞翅目: 卷蛾科: 小卷蛾亚科)

记述内蒙古牧草沙打旺上的 1种新害虫——沙打旺小食心虫 Grapholitashadawana,sp.nov.,模式标本保存在中国科学院动物研究所标本馆。     

Remating Behavior of Cnephasia jactatana Walker Females (Lepidoptera: Tortricidae)

Cnephasia jactatana Walker is an important pest of kiwifruit in New Zealand. We investigated, under laboratory conditions, the effects of multiple mating on the reproductive performance of C. jactatana females and how such effects varied with male virginity and larval nutrition. We found that in permanent pairs, remating increased female fecundity and fertility but suboptimally fed females benefited more from remating. Regardless of this benefit, mass-reared pairs had a lower remating frequency. Females remating with a virgin male or a male that had delivered a spermatophore presented similar fecundity and fertility; however, females receiving a second ejaculate from a virgin male had increased daily fecundity. Female weight clearly affected remating behavior since those that received a second ejaculate were significantly heavier. Neither mating length nor size of the first spermatophore influenced female remating. Further, mass-reared and individually reared males produced spermatophores of similar size.     

中国新记录属——带小卷蛾属分类研究（鳞翅目：卷蛾科）

本研究首次发现带小卷蛾属Metacosma在我国分布,记述了采自安徽、湖南和贵州的2新种：三角带小卷蛾Metacosma triangulata,sp．nov．和梯形带小卷蛾Metacosma trapezia,sp．nov．。文中给出了新种的成虫及雄性外生殖器照片,编制了本属分种检索表。研究标本保存在南歼大学生命科学学院昆虫标本室。 1．三角带小卷蛾Metacosma triangulata,新种（图1,3） 翅展10．0mm。 正模：♂,安徽岳两（30．52&#176;N,116．22&#176;E）温泉,1995-Ⅷ-05,胡祥富采,玻片号ZAH04002。 本种与M.impolitana Kuznetsov相似,区别是：本种雄性外生殖器爪形突大,三角形,抱器端对称;而Mimpolitana Kuznetsov爪形突小,乳突状,抱器端不对称（左侧具5根粗刺,右侧6根）。 2．梯形带小卷蛾Metacosma trapezia,新种（图2,4） 翅展11．0mm。 正模：♂,湖南石门（27．34&#176;N,110．01&#176;E）壶瓶山南坪,504m,2002-Ⅴ-04,于海丽采,玻片号YHL0246。副模：1♂,贵州省道真县仙女洞,600m,2004-Ⅷ-17,肖云丽采;1♂,贵州江口黑湾,600m,2001-Ⅶ-27,李后魂,王新谱采。 本种与Mimpolitana Kuznetsov相似,区别是：本种爪形突梯形,抱器端对称;而坛impolitana Kuznetsov爪形突小,乳突状,抱器端不对称（左侧具5根粗刺,右侧6根）。本种与三角带小卷蛾Metacosma triangulata,sp．nov．的区别主要在爪形突形状上,本种爪形突为梯形,后者为三角形。     

Effects of kaolin on the composition of generalist predator assemblages and parasitism of Choristoneura rosaceana (Lep., Tortricidae) in apple orchards

Abstract:  In three apple orchards, we tested how the hydrophilic kaolin clay particle film Surround WP affected the diversity of generalist arthropod predator assemblages in orchard foliage and the parasitism of the pest species Choristoneura rosaceana (Harris) (obliquebanded leafroller) (Lep., Tortricidae). In two orchards, kaolin was applied to orchard foliage once a week for 4 weeks, between mid-June and mid-July in 2004 and 2005. In the third orchard kaolin was applied to foliage twice over 2 weeks in June 2004. We quantified the proportion of larvae C. rosaceana parasitized, larval populations, and the relative abundance and assemblage composition of generalist predators (spiders and insects) in the orchards. Kaolin altered the species composition of the generalist predator assemblages and reduced the relative abundances of certain generalist predators, most notably jumping and crab spiders (Salticidae and Philodromidae), assassin bugs (Reduviidae), ants (Formicidae) and coccinellids (Coccinellidae). In contrast, the relative abundances of web-spinning spiders (Araneidae, Dictynidae, Theridiidae) were not affected. Kaolin did not affect the proportion of parasitized C. rosaceana larvae, which ranged from 24% to 47% in control and kaolin treatments, or the relative proportions of parasitoid taxa. The kaolin formulation did not affect the abundance of C. rosaceana larvae, but in one orchard, kaolin did reduce the abundance of the combined numbers of C. rosaceana and another tortricid pest, Argyrotaenia velutiana . Although kaolin does not affect parasitism of C. rosaceana , it significantly changes the composition of generalist predator assemblages in orchard foliage.     

中国绿小卷蛾属Eucoenogenes分类研究(鳞翅目:卷蛾科:新小卷蛾亚科)

本文报道了中国绿小卷蛾属6种,包括2新种和1新记录种：长绿小卷蛾Eucoenogenes elongata,sp．nov．,武夷绿小卷蛾Eucoenogenes wuyiensis,sp．nov．和叉绿小卷蛾Eucoenogenes cyanopsis(Meyrick)。文中给出中国已知6个种的检索表。模式标本保存在南开大学生物系。1．长绿小卷蛾Eucoenogenes elongata,新种(图1～2)翅展13．5mm。正模：♂,云南巍山县巍宝山,海拔2200m,2001-Ⅶ-20,李后魂,玻片号ZAH03725。本种与同属其它种的区别在于：雄性爪形突下垂,抱器瓣狭长,左侧颈部具5根粗刺,右侧具四根。2．武夷绿小卷蛾Eucoenogenes wuyiensis,新种(图3～4)翅展13．0mm。正模：♂,福建武夷山仙峰岭,海拔1000m,2004-Ⅴ-26,于海丽采,玻片号ZAH04215副模：1♂,同正模。本种与其余种明显不同,区别在于：雄性爪形突细长,尾突侧生,三角形,抱器瓣颈部具一根粗刺。     

DNA barcoding confirms polyphagy in a generalist moth,Homona mermerodes (Lepidoptera: Tortricidae)

Recent DNA barcoding of generalist insect herbivores has revealed complexes of cryptic species within named species. We evaluated the species concept for a common generalist moth occurring in New Guinea and Australia, Homona mermerodes, in light of host plant records and mitochondrial cytochrome c oxidase I haplotype diversity. Genetic divergence among H. mermerodes moths feeding on different host tree species was much lower than among several Homona species. Genetic divergence between haplotypes from New Guinea and Australia was also less than interspecific divergence. Whereas molecular species identification methods may reveal cryptic species in some generalist herbivores, these same methods may confirm polyphagy when identical haplotypes are reared from multiple host plant families. A lectotype for the species is designated, and a summarized bibliography and illustrations including male genitalia are provided for the first time.     

褐小卷蛾属分类研究及一新种记述(鳞翅目:卷蛾科:新小卷蛾亚科)

This paper deals with two species of the genus Antichlidas Meyrick. Antichlidas trigonia sp. nov. is described as new to science. The adult photograph and the genital structures of the new species are provided. A key to the described species is given.     

短期高温对梨小食心虫成虫存活率和适应性的影响（英文）

【目的】梨小食心虫Grapholita molesta （Busck）（鳞翅目：卷蛾科）是一种世界性的害虫,能使蔷薇科的果树严重减产。本研究旨在评估此害虫的耐热性及适应性。【方法】将梨小食心虫成虫暴露在不同温度（36, 38, 40, 42, 44 和46℃）和不同暴露时间（0.5, 1, 2, 4和8 h）下,测定其存活率以及短期高温（38或40℃热驯化1 h）对其热耐受力、寿命、生殖力及卵孵化率的影响。【结果】随着高温暴露时间的延长,梨小食心虫成虫存活率下降。在38或40℃热驯化1 h后,能显著提高梨小食心虫成虫在42℃下2 h的存活率（P<0.05）。在41℃处理1 h,梨小食心虫出现热休克现象,其寿命显著延长,但产卵量显著下降。进一步的试验证明雄虫受高温影响较大,导致与其配对后的雌虫产卵量降低。然而,不论亲代受到怎样的热刺激,其后代的孵化率均不受影响。【结论】结果说明,超过41℃,1 h的高温能对梨小食心虫带来负面影响,但梨小食心虫成虫有适应高温的潜力。