Adaptation of Habrobracon hebetor (Hymenoptera: Braconidae) to Rearing on Ephestia kuehniella (Lepidoptera: Pyralidae) and Helicoverpa armigera (Lepidoptera: Noctuidae)

Food characteristics strongly regulate digestive enzymatic activity of insects through direct influences on their midgut mechanisms. Insect performance is better on diets that contain nutrients in proportions that fit its digestive enzymes. Little is known about the influences of rearing history on parasitism success of Habrobracon hebetor Say. This research focused on the effect of nutrient regulation on survival, development, and parasitism of H. hebetor. Life history and digestive enzyme activity of fourth-stage larvae of H. hebetor were studied when reared on Ephestia kuehniella Zeller. This parasitoid was then introduced to Helicoverpa armigera (Hübner), and above-mentioned parameters were also studied in the first and fourth generations after transfer. In term of parasitism success, H. hebetor preferred E. kuehniella over He. armigera. When the first and fourth generations of He. armigera-reared H. hebetor were compared, the rearing history affected the life history and enzymatic activity of the parasitoid. A better performance of H. hebetor was achieved after it was reared on He. armigera for the four generations. Because, digestive α-amylase and general protease of the parasitoid were matched with the new host, it used reserve energy for a better performance. Thus, a better performance of H. hebetor could be obtained when the parasitoid was reared on its original host for at least four generations.     

Host suitability of three avocado cultivars (Persea americana Miller: Lauraceae) to oriental fruit fly (Bactrocera (invadens) dorsalis (Hendel) (Diptera: Tephritidae))

The oriental (invasive) fruit fly Bactrocera (invadens) dorsalis (Hendel) (Diptera: Tephritidae) has invaded Africa and is currently established in over 30 countries and has caused in massive fruit losses. Avocado (Persea americana Miller) is among the fruit with which the pest is associated. The aim of the study was to determine the host status of a ‘black-skinned’ cultivar “Hass” and two ‘green-skinned’ cultivars “Pinkerton” and “Fuerte” to B. (invadens) dorsalis. In the laboratory study conducted in Kenya in 2012 and 2013, punctured and unpunctured recently-harvested fruit were exposed to sexually-mature fruit fly in ‘no-choice’ experiments. B. (invadens) dorsalis readily developed in the punctured fruit but not in the uncompromised fruit (fruit not damaged by insects or handling). This result was confirmed in Tanzania in 2013 where flies were introduced to unpunctured fruit. In the field studies the fruit of each cultivar were caged in situ with flies for 72 h. On dissection only fruit damaged by false codling moth (Thaumatotibia leucotreta (Meyrick)) were found to harbor B. (invadens) dorsalis. In the light of these results the risk imposed for “Hass”, “Pinkerton” and “Fuerte” by B. (invadens) dorsalis is negligible under standard export conditions. The findings of this study and the implications to regional and international trade are discussed.     

桔狭胸天牛幼虫记录（鞘翅目：瘦天牛科）

本文记述桔狭胸天牛Philus antennatus(Gyllenhal)幼虫形态特征及发生、为害情况。     

木槿曼粉蚧生物学特征的初步研究

木槿曼粉蚧是我国南方大豆上的一种新害虫。为了明确其各个虫态识别特征及其在大豆上的生活史及主要生物学特征,在室内恒温条件下[温度(25±1)℃,相对湿度70%±5%,光周期为L∶D=12∶12],观察描述了雌雄不同虫态的形态特征及其个体生活史、各虫态主要习性和危害特征等。结果表明:木槿曼粉蚧具有典型的性二型现象。雌虫包括卵、1龄若虫、2龄若虫、3龄若虫和雌成虫。雄虫包括卵、1龄若虫、2龄若虫、预蛹、蛹和雄成虫。若虫期各龄期体长、体宽、触角节数等形态结构具有明显差异,可作为区分龄期的依据。在25℃条件下,以大豆为寄主的雌性个体若虫期为33.34 d,成虫期19.03 d,平均产卵269.6粒;雄性个体若虫期24.60 d,预蛹期2.27 d、蛹期3.33 d,成虫寿命仅3.83 d。     

Relative Abundance of Carsonella ruddii (Gamma Proteobacterium) in Females and Males of Cacopsylla pyricola (Hemiptera: Psyllidae) and Bactericera cockerelli (Hemiptera: Triozidae)

Carsonella ruddii (Gamma Proteobacterium) is an obligate bacterial endosymbiont of psyllids that produces essential amino acids that are lacking in the insect’s diet. Accurate estimations of Carsonella populations are important to studies of Carsonella-psyllid interactions and to developing ways to target Carsonella for control of psyllid pests including pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae) and potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae). We used two methods, namely fluorescence in situ hybridization and quantitative polymerase chain reaction (qPCR), to estimate relative abundance of Carsonella in bacteriocytes and whole bodies of psyllids, respectively. Using these two methods, we compared Carsonella populations between female and male insects. Estimations using fluorescence in situ hybridization indicated that Carsonella was more abundant in bacteriocytes of female C. pyricola than in those of males, but Carsonella abundance in bacteriocytes did not differ between sexes of B. cockerelli. Analyses by qPCR using whole-body specimens indicated Carsonella was more abundant in females than in males of both psyllids. Neither fluorescence in situ hybridization nor qPCR indicated that Carsonella populations differed in abundance among adults of different ages (0–3 wk after adult eclosion). Using fluorescence in situ hybridization, Carsonella was observed in ovarioles of newly emerged females and formed an aggregation in the posterior end of mature oocytes. Results of our study indicate that female psyllids harbor greater populations of Carsonella than do males and that sex should be controlled for in studies which require estimations of Carsonella populations.     

Helicoverpa zea (Lepidoptera: Noctuidae) and Spodoptera frugiperda (Lepidoptera: Noctuidae) Responses to Sorghum bicolor (Poales: Poaceae) Tissues From Lowered Lignin Lines

The presence of lignin within biomass impedes the production of liquid fuels. Plants with altered lignin content and composition are more amenable to lignocellulosic conversion to ethanol and other biofuels but may be more susceptible to insect damage where lignin is an important resistance factor. However, reduced lignin lines of switchgrasses still retained insect resistance in prior studies. Therefore, we hypothesized that sorghum lines with lowered lignin content will also retain insect resistance. Sorghum excised leaves and stalk pith Sorghum bicolor (L.) Moench (Poales: Poaceae) from near isogenic brown midrib (bmr) 6 and 12 mutants lines, which have lowered lignin content and increased lignocellulosic ethanol conversion efficiency, were examined for insect resistance relative to wild-type (normal BTx623). Greenhouse and growth chamber grown plant tissues were fed to first-instar larvae of corn earworms, Helicoverpa zea (Boddie) and fall armyworms Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), two sorghum major pests. Younger bmr leaves had significantly greater feeding damage in some assays than wild-type leaves, but older bmr6 leaves generally had significantly less damage than wild-type leaves. Caterpillars feeding on the bmr6 leaves often weighed significantly less than those feeding on wild-type leaves, especially in the S. frugiperda assays. Larvae fed the pith from bmr stalks had significantly higher mortality compared with those larvae fed on wild-type pith, which suggested that bmr pith was more toxic. Thus, reducing lignin content or changing subunit composition of bioenergy grasses does not necessarily increase their susceptibility to insects and may result in increased resistance, which would contribute to sustainable production.     

Life history of Closterotomus (Calocoris) trivialis (Costa) (Heteroptera: Miridae) in olive and citrus orchards in Crete

The population density of Closterotomus trivialis (Costa) and its damage potential were studied in citrus and olive orchards of Crete. C. trivialis was found to be most abundant in wild radish Raphanus raphanistrum L., annual mercury Mercurialis annua L., Urtica sp. and upright pellitory Parietaria officinalis L. compared to mallow Malva sylvestris L., prickly goldenfleece Uropermum picroides (L.), sowthistle Sonchus oleraceus L., citrus or olive trees. Its damage potential on the setting of olive fruit was investigated at the early inflorescence stage. When 1, 5 or 10 adults of C. trivialis were enclosed with stems at the 55th and 57th phenological growth stages, the number of fruits was significantly reduced compared to controls.The developmental biology of individuals of C. trivialis was studied on R. raphanistrum at seven constant temperatures 15, 20, 25, 30, 32.5, 35 and 37 °C, under laboratory conditions. No nymphs survived above 35 °C. The highest nymph to adult survival (89.6%) was found at 20 °C and the lowest (40.6%) at 32.5 °C. Mean developmental time as well as adult longevity decreased with increasing temperature. The developmental time from 1st nymphal instar to adult ranged from at least 9.0 at 32.5 °C to 27.8 days at 15 °C. The adults lived from 2.9 days at 32.5 °C to 45.3 days at 15 °C. It required 212.7 degree-days to complete development above a minimum threshold of 7.72 °C as estimated by linear regression and 8 °C as estimated by nonlinear model. The importance of these findings in the management of this species through the prediction of its seasonal appearance is discussed.     

Efficacy of entomopathogenic nematodes (Nemata: Rhabditida) to control Brazilian apple leafroller Bonagota salubricola (Meyrick, 1937) (Lepidoptera: Tortricidae)

The Brazilian apple leafroller, Bonagota salubricola (Meyrick, 1937) (Bonagota cranaodes) (Lepidoptera: Tortricidae), is one of the main pest problems in apple orchards is Brazil. The purpose of this work was to evaluate B. salubricola larval and pupal susceptibility to different species of entomopathogenic nematodes, isolated in Rio Grande do Sul state in Brazil, under laboratory and field (apple orchard) conditions. Bioassays for isolates selection and determination of lethal concentration were performed in tubes of 1.5 ml (eppendorf), each containing one B. salubricola third instar larvae and filter paper. Field experiments were performed in commercial orchard, with application of 100 infecting juveniles (IJs)/cm² for each apple plant previously infected with five B. salubricola larvae covered with plastic trays containing thin cloth. Nematodes H. bacteriophora RS107 and H. bacteriophora RS57 had LC₅₀ of 13 and 4.5 IJs/larvae (4.3 and 1.5 IJs/cm²), respectively. In the field, H. bacteriophora RS107 and H. bacteriophora RS57, applied with sorbitol as an adjuvant, reached 70.2 and 61.1% larval mortality, respectively. The results showed that both isolates had biological activity against B. salubricola under laboratory and field conditions.     

Influence of Different Types of Phyllostachys pubescens (Poales: Poaceae) Leaves on Population Parameters of Pantana phyllostachysae (Lepidoptera: Lymantriidae) and Parasitic Effects of Beauveria bassiana (Moniliales: Moniliaceae)

We found that Pantana phyllostachysae, a dangerous pest of moso bamboo (Phyllostachys pubescens), showed differences in growth and development after feeding on diverse types of moso bamboo leaves. The mortality rate of Pa. phyllostachysae due to Beauveria bassiana, an entomopathogenic fungus, was also affected by the varied larval diet. Larval and pupal developmental duration of Pa. phyllostachysae was longer when feeding on “off-year” bamboo leaves. Pupal weight and adult fertility were higher when feeding on “on-year” bamboo leaves. Mortality due to B. bassiana was significantly lower in larvae fed on on-year bamboo leaves than in larvae fed on off-year bamboo leaves. Larvae fed on new bamboo leaves had a shorter development period and higher survival rate than those fed on off-year bamboo leaves. However, mixed feed (mixture of new, on-year, and off-year bamboo leaves) decreased the egg production of Pa. phyllostachysae. After infection by the second generation of B. bassiana, the survival time of Pa. phyllostachysae fed on mixed feed increased significantly compared with the first generation. We also fed Pa. phyllostachysae different proportion of new bamboo leaves in mixed feed to simulate natural conditions. We found that increasing the proportion of new bamboo leaves in the food promoted pupal development and increased egg production; it also increased the resistance of larvae to the first generation of B. bassiana. The pathogenicity of the second generation of B. bassiana declined in all mixed feed treatments.     

Efficacy of Plectranthus glandulosus (Lamiaceae) and Callistemon rigidus (Myrtaceae) Leaf Extract Fractions to Callosobruchus maculatus (Coleoptera: Bruchidae)

As part of on-going efforts to use eco-friendly alternatives to chemical pesticides, methanol crude extracts of Plectranthus glandulosus and Callistemon rigidus leaves were sequentially fractionated in hexane, chloroform, ethyl acetate, and methanol to establish the most active fraction(s) against Callosobruchus maculatus in cowpea. Cowpea seeds (25 g) were treated with 0.5, 1, 2, and 4 g/kg of extract to evaluate the contact toxicity and F₁ progeny production of the beetles in the laboratory. Mortality was recorded 1, 3, and 7 d postexposure. P. glandulosus hexane fraction was more toxic than the other fractions recording 100% mortality at 4 g/kg, within 7 d with LC₅₀ of 0.39 g/kg. Hexane fraction of C. rigidus showed superior toxicity, causing 100% mortality at 4 g/kg within only 1 d of exposure with LC₅₀ of 1.02 g/kg. All the fractions greatly reduced progeny emergence, with C. rigidus hexane fraction being the best progeny inhibitor. Fractions of P. glandulosus and C. rigidus leaves had sufficient efficacy to be a component of storage pest management package for C. maculatus.     

黄蝉花素抑制斜纹夜蛾生长发育作用

室内测定了黄蝉花素对斜纹夜蛾幼虫的抑制生长发育活性。结果表明,黄蝉花素对斜纹夜蛾幼虫的抑制生长发育活性与其处理浓度具有一定的相关性。与对照相比,处理组食物消耗量减少,幼虫生长发育被抑制,发育历期延长。处理组幼虫在蛹期不能正常化蛹而形成畸形蛹,羽化后的成虫表现为形态畸形。在预蛹期和蛹期由于不能正常蜕皮导致死亡率较高。研究显示黄蝉花素作为一类新型的昆虫生长发育控制剂或害虫田间种群管理的先导化合物值得进一步研究。     

Compatibility of entomopathogenic nematodes (Nematoda: Rhabditida) with registered insecticides for Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) under laboratory conditions

The fall armyworm, Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) is considered the main key pest of corn crops in Brazil. Entomopathogenic nematodes (EPNs) may be used to control this pest, applied together with other different entomopathogen agents or phytosanity products in the spraying mixture. Thus, the objective of work was to evaluate the compatibility of EPNs with different insecticides used of S. frugiperda control in laboratory conditions. Three species of EPNs (Heterorhabditis indica, Steinernema carpocapsae and Steinernema glaseri) and 18 insecticides registered to control of S. frugiperda in corn crops were tested. Compatibility of the insecticides with EPNs was evaluated by observing mortality and infectivity of infecting juveniles (IJs) 48 h after immersion in solution of the insecticide formulations. Among all insecticides tested, Lorsban™ (chlorpyrifos), Decis™ (deltamethrin), Match™ (lufenuron), Deltaphos™ (deltramethrin + triazophos), Dimilin™ (diflubenzuron), Stallion™ (gamacyhalothrin), Karate Zeon™ (lambdacyhalothrin) Tracer™ (spinosad), Vexter™ (chlorpyrifos), Galgotrin™ (cypermethrin), Certero™ (triflumuron), and Talcord™ (permethrin) were compatible (class 1) with the three nematode species tested under laboratory conditions.     

Oviposition Preference and Offspring Performance of Mechoris ursulus (Coleoptera: Attelabidae) in Cyclobalanopsis glaucoides (Fagales: Fagaceae) and Quercus franchetii (Fagales: Fagaceae) in Central Yunnan,China

Mechoris ursulus (Roelofs) (Coleoptera: Attelabidae) is a pest weevil of Fagaceae oak trees in eastern Asia. The female has a distinct branch-cutting behavior in conjunction with oviposition in the acorns of its host plant. This study analyzed the factors influencing oviposition preference by carrying out continuous field surveys over the course of 2009–2010 and through laboratory rearing. The field survey showed that for both of the hosts, Cyclobalanopsis glaucoides Schottky (Fagales: Fagaceae) and Quercus franchetii Skan, M. ursulus preferred branches with fewer acorns and larger acorns on the same branch for oviposition. Laboratory rearing experiments showed offspring performance (i.e., survival rate and fresh weight of larvae) was significantly and positively correlated with acorn size. Preference for larger acorns could maximize the fitness of offspring by providing sufficient food source and space.     

Fractionated Extracts From Gnidia kraussiana (Malvales: Thymeleaceae) as Bioactive Phytochemicals for Effective Management of Callosobruchus maculatus (Coleoptera: Chrysomelidae) in Stored Vigna unguiculata (Fabales: Fabaceae) Seeds

One of the most important global problems is protecting food from insect pests. The negative effects of synthetic insecticides on human health led to a resurgence of interest in botanical insecticides due to their minimal ecological side effects. Therefore, the insecticidal potential of hexane, acetone, and methanol extracts of Gnidia kraussiana Meisn roots at 1 and 5g/kg, and neem seed oil (NSO), used as standard insecticide, were evaluated. Ovicidal and larvicidal toxicity was tested by treating freshly laid eggs and larvae at different immature stages of Callosobruchus maculatus (F.). Cowpea (Vigna unguiculata) (L.) Walp seed damage and weight loss were assessed after a storage period of 4 mo. Repellency effects were detected in choice test using a linear olfactometer. All the fractions were toxic to C. maculatus; however, their bioactivities were inversely correlated with products polarity. Extracts proved to be more toxic than the commercial NSO. The acetone extract was more effective against immature stages of C. maculatus than the methanol extract; eggs, first-, and second-instar larvae being the more susceptible. No cowpea seed damage and weight loss were recorded from the seeds treated with hexane and acetone extracts at the dosage of 5 g/kg, after 4 mo of storage. Extracts evoked stronger repellency effects compared with the tested standard insecticide. According to the above, hexane and acetone extracts are good candidates for incorporation in integrated pest management programs for the control of C. maculatus in stored cowpea seeds.     

Mechanically-applied wax matrix (SPLAT-GBM) for mating disruption of grape berry moth (Lepidoptera: Tortricidae)

An ATV-mounted mechanical applicator was designed to treat vineyards with SPLAT-GBM™ for mating disruption of grape berry moth, Paralobesia viteana (Lepidoptera: Tortricidae). SPLAT-GBM was applied to vineyards in 0.8 g drops at a density of 1544 or 3089 drops per hectare for a total of 1.3 or 2.5 kg per hectare. Trials were conducted in 2008 and 2009 in vineyards receiving grower-standard insecticide sprays for control of grape berry moth and other insect pests. In the first trial, SPLAT-GBM applied twice at 1.3 or 2.5 kg/ha caused a significant reduction in grape berry moth infestation at harvest on clusters at the border of the vineyards where infestation is highest, compared with the no-pheromone control, but three applications at 2.5 kg/ha did not result in lower infestation compared with both the control and other treatments. In the second trial, application of SPLAT-GBM 2.5 kg/ha in mid-June and late-July caused a significant reduction in grape berry moth infestation at harvest on clusters at the border of the vineyards. Application in early-May and late-June resulted in infestation that was similar to the other program, but not statistically different from the control. In both trials, there were no significant differences between any of the treatments of SPLAT-GBM and the control inside the vineyards where infestation is low. Among treatments of SPLAT-GBM, infestation was similar regardless of number, rate, or timing of the applications. This study shows that mechanical application of wax matrix drops to release pheromone is an effective method for control of grape berry moth using mating disruption.     

豆大蓟马的生物学特性研究

豆大蓟马[Megalurothrips usitatus(Bagnall)]是海南豇豆的重要害虫,是影响豇豆质量安全的主要因素。通过室内试验,对豆大蓟马的发育速率、有效积温、产卵量和成虫寿命等生物学特性进行研究。结果表明:在15~35℃温度范围内,豆大蓟马的世代发育历期为10.57~46.29 d,其中卵期为2.72~8.71 d,若虫期为3.54~16.24 d,预蛹期为0.76~3.62 d,蛹期为2.02~8.74 d,产卵前期为1.00~9.16 d;各虫态发育速率与温度呈二次回归关系,且呈显著相关;卵、若虫、预蛹及蛹期的发育起点温度分别为6.18、9.80、9.37、8.83℃,有效积温依次为76.55、76.77、17.06、46.73日·度,完成世代发育起点温度和有效积温分别为9.35℃和238.87日·度;温度对豆大蓟马的存活率影响显著;成虫寿命随着温度的升高而缩短,15℃下平均寿命为63.24 d,35℃下平均寿命为11.20 d;30℃时产卵量最高,平均产卵232.78粒/雌,分别是15℃和35℃下的3.84倍和8.87倍。本研究结果为进一步开展豆大蓟马的科学防控提供了基础资料。     

Efficacy of entomopathogenic nematodes (Nematoda: Rhabditida) and insecticide mixtures to control Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) in corn crops

The main insect pest in Brazilian corn is fall armyworm, Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae). Entomopathogenic nematodes (EPNs) can be used to control this pest, and can be applied together with various insecticides. Thus, the objective of this work was to evaluate the efficacy of mixtures of EPNs and insecticides to control S. frugiperda in corn crops. In laboratory bioassays three species of EPNs were tested (Heterorhabditis indica, Steinernema carpocapsae and Steinernema glaseri) together with 18 registered insecticides to control S. frugiperda in corn. Efficacy of association between insecticides and EPNs on S. frugiperda larvae was evaluated against the insect's third instar, 2 and 4 days after applications in laboratory. Experiments in the field were performed in two consecutive years, with located application of H. indica and S. carpocapsae (250 IJs/cm²) mixed with chlorpyrifos (0.3 L/ha) and lufenuron (0.15 L/ha) on the corn husk. In laboratory, after two days exposure the interaction between chlorpyrifos and H. indica was synergistic, while interaction with cypermethrin, spinosad, methoxyfenozide and deltamethrin + triazofos was additive, as was interaction between lufenuron, chlorpyrifos and cypermethrin with S. carpocapsae. In contrast, the interaction between chlorpyrifos (Vexter™ and Lorsban™) and lufenuron with S. glaseri was synergistic. In the field, the best treatment was the mixture of H. indica with lufenuron (0.15 L/ha), with 62.5% and 57.5% larval mortality in the two evaluation years in the field, respectively.     

Development,Survival, and Reproduction of Orius insidiosus (Hemiptera: Anthocoridae) Reared on Frankliniella invasor (Thysanoptera: Thripidae)

The minute pirate bug Orius insidiosus (Say) is an important predator in mango agroecosystems. It attacks several species of thrips, particularly Frankliniella invasor Sakimura, which is considered a species of economic importance in mango. We investigated the effect of six diets on the development, survival, and reproduction of O. insidiosus: 1) first instars of F. invasor, 2) second instars, 3) adults, 4) pollen, 5) pollen plus thrips larvae, and 6) water. Individuals fed on thrips larvae, with or without pollen, completed their immature development significantly faster. Nymphs of O. insidiosus were able to complete their development feeding on pollen only, while individuals that received water as a diet were unable to reach the adult stage. The highest intrinsic growth rate was obtained when O. insidiosus were fed on pollen plus thrips larvae, and the lowest when individuals were fed on thrips adults. Our studies show that a diet of pollen plus F. invasor larvae is optimal for O. insidiosus development and population growth.