Head capsule width as an instar indicator for larvae of the cranberry fruitworm (Lepidoptera: Pyralidae) in southeastern New Brunswick

The objective of this study was to determine the number of instars of the cranberry fruitworm Acrobasis vaccinii Riley in southeastern New Brunswick based on the distribution of head capsule widths from field and laboratory observations. In 2000, head capsules from field samples were measured across their widest point, and the results were plotted against observed frequencies. The data from field samples suggested that A. vaccinii exhibited five instars in 2000. In 2001, larvae were reared in the laboratory until the final molt, and head capsules were counted and measured. The results were also plotted against observed frequencies. None of the laboratory specimens exhibited more than five instars, supporting the results of the previous year. Various factors are invoked to explain the difference between these results and those of a previous study conducted 50 yr earlier and 200 km away, in which six instars and larger head capsules were reported.     

Susceptibility of Oriental fruit moth (Lepidoptera: Tortricidae) larvae to selected reduced-risk insecticides

To determine their baseline susceptibility to chlorantraniliprole, spinetoram, spinosad, and acetamiprid, oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), neonates were placed on diet cubes containing a range of concentrations of each insecticide. Mortality was assessed after 96 h. Two populations-a long-term laboratory colony from Rutgers University and a colony established in 2007 from a southwestern Illinois (Calhoun County) field population-were tested. We used probit and logit analyses to compare the responses of Calhoun colony neonates from parents reared on 'Gala' apples (Malus spp.) with those of Calhoun colony neonates from parents reared on lima bean, Phaseolus lunatus L., diet. We also compared the responses of Calhoun colony neonates with those of Rutgers colony neonates (all from parents reared on apples). LC50s (ppm in diet) for Calhoun colony progeny of adults reared on apples were 0.08, 0.06, 0.41, and 0.30, respectively, for chlorantraniliprole, spinetoram, acetamiprid, and spinosad. Parental food source (apples versus lima bean diet) did not consistently influence the concentration-mortality relationships for neonates. Based on LC50s and toxicity ratio tests, Calhoun colony neonates were slightly but significantly less susceptible to spinetoram and acetamiprid than were Rutgers colony neonates. Similarly, LC90s and toxicity ratio tests indicated that Calhoun colony neonates were slightly but significantly less susceptible to chlorantraniliprole as well. However, toxicity ratios (Calhoun/Rutgers) were low in all instances, and the highest ratio was 1.73 at LC90 for chlorantraniliprole. Overall, the two colonies responded similarly to these insecticides. Results reported here provide baseline data for future monitoring of resistance development.     

Activity of Plodia interpunctella (Lepidoptera: Pyralidae) in and around flour mills

Studies were conducted at two flour mills where male Indian meal moths, Plodia interpunctella (Hübner), were captured using pheromone-baited traps. Objectives were to determine the distribution of male P. interpunctella at different locations in and around the mills throughout the season, and to monitor moth activity before and after one of the mills was fumigated with methyl bromide to assess efficacy of treatment. Commercially available sticky traps baited with the P. interpunctella sex pheromone were placed at various locations outside and within the larger of the two mills (mill 1). Moths were captured inside mill 1 after methyl bromide fumigations. The highest numbers of P. interpunctella were caught outside the facility and at ground floor locations near outside openings. Additional traps placed in the rooms above the concrete stored-wheat silos at mill 1 during the second year captured more moths than did traps within the mill's production and warehouse areas. In another study, moths were trapped at various distances from a smaller flour mill (mill 2) to determine the distribution of moths outdoors relative to the mill. There was a negative correlation between moth capture and distance from the facility, which suggested that moth activity was concentrated at or near the flour mill. The effectiveness of the methyl bromide fumigations in suppressing moth populations could not be assessed with certainty because moths captured after fumigation may have immigrated from outside through opened loading bay warehouse doors. This study documents high levels of P. interpunctella outdoors relative to those recorded inside a food processing facility. Potential for immigration of P. interpunctella into flour mills and other stored product facilities from other sources may be greater than previously recognized. Moth entry into a food processing facility after fumigation is a problem that should be addressed by pest managers.     

Influence of host plant stages on carob moth (Lepidoptera: Pyralidae) development and fitness

Different generations of the carob moth, Ectomyelois ceratoniae (Zeller), use different date, Phoenix dactylifera L., fruit stages as they become available during the summer months in southern California. These are the kimri, khalal, and tamar fruit stages. This study was conducted to determine whether carob moth development and fitness were affected by these different fruit stages. Developmental time from neonate larvae to adult, when reared at 31.9 degrees C and 82.1% RH, ranged from 30.5 to 32.3 d for females and 27.1 to 29.5 d for males on the different field-collected fruit stages. Males and females had the highest emergent weight when reared as larvae on kimri fruit and the lowest on tamar fruit. Females laid the most eggs when reared on kimri fruit and the least when reared on tamar fruit. Estimates of population doubling times ranged from 5.4 d on artificial diet (included as a control) to 7.5 d on tamar fruit. This short doubling time shows the ability of carob moth to develop rapidly under optimal conditions. Degree-day (DD) estimates for carob moth development ranged from 636 DD on kimri fruit to 658 DD on tamar fruit, which translate to 32-50 d under field temperatures in the area where dates are grown. Potential implications for field management of E. ceratoniae include improved timing of insecticide treatments to limit population growth early in the season rather than the conventional late season approach.     

空心莲子草野螟各虫态的形态学观察

采用室内观察的方法,使用万能视频成像装置( LY-WN-HP SUPERCCD),对空心莲草野螟Herpetogramma fuscescens（Warren,1892）各虫态的形态学特征进行了系统观察.结果发现:成虫体小型,灰褐色.卵椭圆形,初产时乳白色,块状,外被腊质层.孵化前,部分卵壳分离为白色蜡质外层和棕黄色内...     

Prediction of survival ratios of Cadra cautella (Lepidoptera: Pyralidae) different life stages after treated with ultraviolet radiation in dates

Date palm, is a tree of economic importance which is grown around the world, including Saudi Arabia. Its fruit is nutritious and possesses medicinal benefits. Almond moth, is a serious date fruits pest in the field as well as in the storage and causes severe economic losses. In the given research, ultraviolet radiation type B (UV-B, 315 nm) harmful effects were evaluated against all developmental stages of C. cautella. One and 3-d-old eggs, 12 and 18-d-old larvae, 1-d and 6-d-old pupae, and 1-d-old adults, were exposed to UV-B for different intervals. Eggs were exposed for 0–30 min and 0% hatchability was achieved both for 1-d and 3-d-old eggs after 30 min. The larvae were exposed for 6–24 h, and after 24 h, mortality was 100 and 97% for 12 and 18-d-old larvae, respectively. Similarly, the pupae were exposed for 0–30 h, and 100% mortality was achieved after 30 h for 1-d-old pupae. Furthermore, none of the 6-d-old pupae emerged as an adult after 12 h of exposure. When adults were exposed for 1–4 d, no mortality was observed; however, UV-B reduced fecundity and hatchability in the treated adults. The susceptibility order was as follows: eggs > larvae > pupae > adults. Several uncharacteristic behaviors of C. cautella were noted, such as females depositing eggs openly on food items and containers, mature larvae exiting from food, larvae starting to wander for pupation, and pupation occurring typically outside the food. The application of UV-B could be an effective management strategy because all developmental stages of C. cautella were susceptible to UV-B that might be helpful to protect the dates from C. cautella infestation.     

Effects of snowdrop lectin on Mexican rice borer (Lepidoptera: Pyralidae) life history parameters

The effects of the snowdrop lectin, Galanthus nivalis agglutinin (GNA), delivered through an artificial diet, on growth, development, and life history parameters of the Mexican rice borer, Eoreuma loftini (Dyar), were evaluated in the laboratory. Incorporation of GNA at three treatment levels, 0.5, 1.0, and 2.0% of total dietary protein, in the larval diet significantly decreased larval survivorship and percentage of adults emerging relative to a control diet lacking GNA, whereas differences were not observed among the three treatment levels. Both larvae and pupae in the control were 8-25% larger than those in the GNA treatments, but differences were not observed between larvae in the GNA treatments. Furthermore, presence of GNA did not affect larval and pupal developmental periods, longevities, and fecundities compared with the control. Mexican rice borer life history parameters, such as net reproductive rate and intrinsic rate of increase, were substantially reduced by the presence of GNA in the diet, but differences were not evident among the three GNA treatment levels.     

Evaluation of lectin-expressing transgenic sugarcane against stalkborers (Lepidoptera: Pyralidae): effects on life history parameters

The impact of snowdrop lectin (Galanthus nivalis agglutinin, GNA) expressed in transgenic sugarcane on life history parameters of Mexican rice borer [Eoreuma loftini (Dyar)] and sugarcane borer [Diatraea saccharalis (F.)] (both Lepidoptera: Pyralidae) was evaluated. In the laboratory, lyophilized sugarcane leaf sheath tissue was incorporated in a meridic diet resulting in a GNA concentration of 0.47% of total protein, and used for insect bioassays over two successive generations. Deleterious effects of GNA were not observed on survival, weight, and developmental periods of larvae and pupae, nor on adult fecundity and egg viability of D. saccharalis. Moreover, in the first generation, addition of transgenic sugarcane tissue to the diet enhanced larval growth in D. saccharalis resulting in higher larval and pupal weight compared with diet with nontransgenic sugarcane, but this effect was not observed in the second generation. In contrast, larval survival, percent adult emergence, and female fecundity of E. loftini were significantly reduced when fed transgenic sugarcane diet compared with nontransgenic sugarcane diet. In addition, a substantial reduction of female pupal weight of E. loftini was observed in the second generation. For both species, the only consistent effect of GNA in both generations was a reduction in adult female longevity. Life table parameters showed that GNA at the level found in the transgenic diet negatively affected development and reproduction of E. loftini, whereas it had a nil to positive effect on development and reproduction of D. saccharalis.     

Techniques for monitoring cranberry tipworm (Diptera: Cecidomyiidae) in rabbiteye and southern highbush blueberries

Several monitoring techniques were evaluated for their effectiveness, based on the highest mean captures of cranberry tipworm, Dasineura oxycoccana (Johnson), in detecting D. oxycoccana in rabbiteye, Vaccinium ashei Reade, and southern highbush, V. corymbosum L. x V. darrowi Camp, blueberry plantings. There were no significant differences in captures of D. oxycoccana adults on unbaited sticky board traps, regardless of color (yellow, white, green, or blue). In a separate experiment, three monitoring techniques, yellow unbaited sticky boards, larval/adult emergence from infested buds, and bud dissection, were evaluated for detecting D. oxycoccana, eggs, larvae, and adults. In total, four bud types were examined, including rabbiteye floral, rabbiteye leaf, southern highbush floral, and southern highbush leaf. The emergence monitoring technique detected significantly more D. oxycoccana adults than the other techniques evaluated. Emergence and dissection techniques performed equally well for detecting D. oxycoccana larvae. Dissection was the only technique capable of detecting D. oxycoccana eggs. Overall, the highest numbers of D. oxycoccana eggs were detected in southern highbush leaf buds. However, larval infestation was lower for southern highbush leaf buds compared with other bud types sampled. Hypotheses to explain this phenomenon are discussed. The fewest number of eggs was recorded for southern highbush flower buds, potentially because these buds develop before peak emergence of D. oxycoccana. Managing D. oxycoccana in infested plantings can be improved by incorporating monitoring techniques, specifically bud dissection to search for eggs, that will aid growers in making timely insecticide applications.     

Phylogeography of Eldana saccharina Walker (Lepidoptera: Pyralidae)

The pyralid moth Eldana saccharina Walker is an indigenous insect widely distributed throughout sub-Saharan Africa. Studies have shown that populations from West Africa have distinct behavioural differences compared to populations from East and southern Africa. In addition, the parasitoid guilds attacking populations in these different regions are markedly different. This marked geographical variation evoked a hypothesis of genetic differentiation. To evaluate this hypothesis a molecular analysis was conducted on populations of E. saccharina from throughout much of the species’ range, using the cytochrome c oxidase subunit I (COI) region of the mitochondrial genome. A minimum spanning network and a maximum parsimony tree separated the 21 specimens into three distinct groups. Results revealed the presence of substantial genetic differentiation that is related to geographic variation.     

Phenology and infestation patterns of plum curculio (Coleoptera: Curculionidae) on four highbush blueberry cultivars

The plum curculio, Conotrachelus nenuphar (Herbst), is a well known pest in apple and peach orchards, but it also is capable of having an economic impact in highbush blueberries. Host phenology and plum curculio oviposition patterns were determined on four highbush blueberry cultivars differing in fruit maturation period. Numbers of oviposition scars were higher on early- ('Weymouth') and mid-season ('Duke' and 'Bluecrop') blueberries than on late-season 'Elliott' in 2001, 2002, and 2003. In 2002, eggs were first present on the three earliest cultivars 21 d before those on 'Elliott', whereas eggs were found on 'Elliott' >40 d after the last sample with eggs for the other three cultivars. The pattern of host phenology and infestation levels suggested that plum curculio oviposition synchronizes well with the availability of suitable fruit for oviposition on early and mid-season cultivars compared with a late-season cultivar of highbush blueberries. The implications of a transition to use of reduced-risk insecticides are discussed in relation to plum curculio management.     

Activity of conventional and reduced-risk insecticides for protection of grapevines against the rose chafer, Macrodactylus subspinosus (Coleoptera: Scarabaeidae)

Abstract:  Bioassays were conducted to compare the residual toxicity and leaf protection activity of conventional broad-spectrum and reduced-risk insecticides against the rose chafer, Macrodactylus subspinosus . Insecticides were applied to a Vitis labrusca (F.) vineyard and residues were aged for 1, 3 or 7 days before leaves were collected and exposed to beetles in no-choice tests. Azinphosmethyl caused rapid knockdown and mortality for up to 1 week after application, with 1-day-old residues providing 95.6% protection against feeding, dropping to 51.6% when residues were a week old. Fenpropathrin caused mortality and knockdown after beetles had been exposed to fresh residues for 72 h. Although these effects diminished as residues aged, this compound provided the best protection of leaves against beetle feeding, with 77.9% reduction in feeding compared with the control after 7 days of aging in the vineyard. Of the reduced-risk insecticides, imidacloprid caused the greatest initial mortality and knockdown of beetles, providing protection against feeding that was equivalent to azinphosmethyl. Exposure to azadirachtin caused a low level of knockdown and mortality when residues were 1- and 3-days old. Protection against feeding was also low, lasting for only 3 days. Beetles were minimally affected by capsaicin and kaolin, with mortality and knockdown seen only when beetles were exposed to 1-day-old residues for 72 h. Foliage protection from these compounds was minimal, with between 10 and 15% reduction in feeding injury. Results are discussed in relation to development of semi-field bioassay methods for evaluating reduced-risk insecticides, and the management of M. subspinosus within grape pest management programs.     

Stage-specific control of grape berry moth, Endopiza viteana (Clemens) (Lepidoptera: Tortricidae), by selective and broad-spectrum insecticides

The insect growth regulators (IGRs) tebufenozide and methoxyfenozide and the broad-spectrum insecticides azinphosmethyl, carbaryl, and fenpropathrin were compared for their activity against adult, egg, and larval stages of the grape berry moth, Endopiza viteana (Clemens) (Lepidoptera: Tortricidae), under laboratory and vineyard conditions. Adult mortality was not affected by exposure to field-equivalent rates of tebufenozide or methoxyfenozide on grape clusters, whereas all the broad-spectrum compounds significantly reduced adult survival, compared with the untreated controls. Surviving adult moths laid significantly more eggs on berries treated with the IGRs than on berries treated with any of the broad-spectrum insecticides. Survival of these eggs through to late larval and pupal stages was significantly lower on methoxyfenozide-treated grapes than on untreated grapes, and no pupae were found when grapes were treated with azinphosmethyl or fenpropathrin. Neither of the growth regulator insecticides limited egg eclosion or larval development by E. viteana when insecticides were applied before egg laying, whereas broad-spectrum insecticides were effective against both eggs and neonates at this timing. When applied after egg eclosion, all insecticide treatments significantly reduced survival of grape berry moth larvae. Under vineyard conditions, berries with 1-d-old residues of tebufenozide or methoxyfenozide received more E. viteana eggs than berries treated with broad-spectrum compounds. After aging for 7 or 14 d, no significant effects on E. viteana survival were detected among treatments. Whereas broad-spectrum insecticides provide control of multiple life stages of E. viteana, integration of tebufenozide or methoxyfenozide into vineyard management programs for control of this pest will be most successful if applications are timed for egg hatch.     

Insecticide susceptibility of Cnaphalocrocis medinalis (Lepidoptera: Pyralidae) in China

Insecticide control is the major measure for suppression of Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae) damage, and a few insecticides used for long time have proved to fail to control this pest in China. Several new chemicals have been introduced for control of C. medinalis. However, there was no baseline susceptibility data of C. medinalis to insecticides used or will be in use. In this study, a seedling dipping method was developed for bioassay of insecticide susceptibility of C. medinalis. Dose responses of C. medinalis to 11 insecticides were tested. Interpopulation sensitivity to insecticides was compared. Based on LC50 values, C. medinalis was most susceptible to antibiotic insecticides (abamectin, emamectin benzoate, and spinosad) and least sensitive to monosultap and a Bacillus thuringiensis (Bt) product. Chlorantraniliprole and insect growth regulator (IGR) insecticides (tebufenozide and hexaflumuron) exhibited great efficacy against C. medinalis. No susceptibility difference was observed for antibiotic insecticide and IGR insecticides among three populations. Narrow variation in tolerant level was detected for organophosphates insecticides, chlorantraniliprole, monosultap, and Bt. The results in this study provided baseline susceptibility data of C. medinalis to 11 insecticides and also offered useful information for choice of alternative insecticide and for integrated resistance management of C. medinalis.     

Biology and demography of Glyphodes pyloalis Walker (Lepidoptera: Pyralidae) on mulberry

Lesser mulberry pyralid, Glyphodes pyloalis Walker, is a monophagous pest of mulberry and has recently been reported in northern Iran. The biology and life table of this pest were studied in controlled conditions (24 ± 1 °C, 75 ± 5% RH and 16:8 LD). Mortality rate, metamorphosis, appearance of adult insects and adult sex ratio were recorded daily. Data were analyzed based on an age-stage, two-sex life table. Developmental rate among individuals and between sexes were also considered. The developmental periods for the egg, first through fifth instar larvae, prepupae and pupae were 4.06 ± 0.03, 2.93 ± 0.03, 2.03 ± 0.02, 2.01 ± 0.01, 2.10 ± 0.03, 4.09 ± 0.03, 2.04 ± 0.02 and 9.7 ± 0.09 days, respectively. The mean total developmental period from egg to adult was 35.40 ± 0.37 days. The maximum adult longevity was 7 and 11 days for males and females, respectively. The pre-oviposition period lasted 2.14 ± 0.04 days. Laboratory observation showed that adults are nocturnal and female lay eggs at night. The intrinsic rate of increase (r_m) and the finite rate of increase (λ) were 0.14 ± 0.005 d^? 1 and 1.15 ± 0.01 d^? 1. The net reproductive rate (R₀), gross reproductive rate (GRR) and mean generation time (T) were 134.67 ± 20.6 female offspring, 294.71 ± 4.07 eggs/female and 34.44 ± 0.2 days, respectively. Life expectancy of freshly laid egg was 32.15 days.     

Life table studies of Elasmopalpus lignosellus (Lepidoptera: Pyralidae) on sugarcane

The lesser cornstalk borer, Elasmopalpus lignosellus (Zeller) (Lepidoptera: Pyralidae) is an important pest of sugarcane (a complex hybrid of Saccharum spp.) in southern Florida. Reproductive and life table parameters for E. lignosellus were examined at nine constant temperatures from 13 to 36 °C with sugarcane as the larval food source. The pre- and postoviposition periods decreased with increasing temperatures and reached their minimums at 33 and 36 °C, respectively. The oviposition period was longest at 27 °C. The mean fecundity, stage-specific survival, stage-specific fecundity, intrinsic rate of increase, and finite rate of increase were greatest at 30 °C and decreased with increasing or decreasing temperature. The net reproductive rate was greatest at 27 °C. The Logan-6 model best described the relationship between temperature and intrinsic rate of increase. The generation and population doubling times were longest at 13 and shortest at 33 and 30 °C, respectively. The most favorable temperatures for E. lignosellus population growth were between 27 and 33°C. Life table parameters for E. lignosellus reared on sugarcane were greater than for the Mexican rice borer [Eoreuma loftini (Dyar) (Lepidoptera: Crambidae)] reared on an artificial diet at 30 °C. The intrinsic rates of increase for the sugarcane borer [Diatraea saccharalis (F.) (Lepidoptera: Crambidae)] reared on sugarcane or corn were the same as for E. lignosellus reared on sugarcane at 27 °C, but the net reproductive rate was four times higher for the former than the latter borer species.     

Effects of Elasmopalpus lignosellus (Lepidoptera: Pyralidae) damage on sugarcane yield

Feeding by lesser cornstalk borer, Elasmopalpus lignosellus (Zeller) (Lepidoptera: Pyralidae), larvae on sugarcane (a complex hybrid of Saccharum spp.) causes leaf damage, dead hearts, and dead plants that can result in stand and yield loss. A 2-yr greenhouse experiment was conducted to examine sugarcane variety and plant age-specific feeding responses to E. lignosellus. Plants growing from single-eye setts of three varieties were exposed to a single generation of E. lignosellus larvae beginning at the three-, five-, and seven-leaf stages. Results indicated that the physical damage and resulting yield loss of plants attacked by E. lignosellus larvae were dependent on the variety and leaf stage at which they were infested. Significantly more plant damage was observed in all three varieties when infested at the three- than at the seven-leaf stage. Larvae caused significantly more plant damage and reduced yield in CP 89-2143 than in CP 78-1628. Tiller production increased in CP78-1628 and CP 88-1762 when infested at the three-leaf stage, whereas tiller production, biomass and sugar yield decreased in CP 89-2143 when infested at all leaf stages, compared with the untreated control. There was no reduction in yield when CP 78-1628 was infested at the three- or five-leaf stages. Biomass was reduced in CP 88-1762 when plants were infested at any of the leaf stages, but sugar yield was reduced only when infested at the seven-leaf stage. These results indicate that compensation in response to E. lignosellus damage was variety dependent and declined with the delay in infestation time.     

Susceptibility of Plodia interpunctella (Lepidoptera: Pyralidae) developmental stages to high temperatures used during structural heat treatments

Heating the ambient air of a whole, or a portion of a food-processing facility to 50 to 60 degrees C and maintaining these elevated temperatures for 24 to 36 h, is an old technology, referred to as heat treatment. There is renewed interest in adopting heat treatments around the world as a viable insect control alternative to fumigation with methyl bromide. There is limited published information on responses of the Indian meal moth, Plodia interpunctella (Hübner), exposed to elevated temperatures typically used during heat treatments. Time-mortality relationships were determined for eggs, fifth-instars (wandering-phase larvae), pupae, and adults of P. interpunctella exposed to five constant temperatures between 44 and 52 degrees C. Mortality of each stage increased with increasing temperature and exposure time. In general, fifth-instars were the most heat-tolerant stage at all temperatures tested. Exposure for a minimum of 34 min at 50 degrees C was required to kill 99% of the fifth-instars. It is proposed that heat treatments aimed at controlling fifth-instars should be able to control all other stages of P. interpunctella.