Electroantennogram responses of Chrysoperla carnea (Stephens) to volatiles

Electrophysiological responses of adult males and females of C. carnea to commonly occurring plant volatiles were recorded using the electroantennogram technique. Responses to 28 volatiles evaluated indicate that both depolarization and recovery to the baseline were rapid in females compared to males. Normalized EAG responses relative to the standard, trans-caryophyllene reveal significant differences between the chemicals as also between the sexes. The response of males to several of the compounds, particularly the terpenoids was higher than females. The pooled averages to the different classes of chemical compounds reveal greater response for fatty acid derivatives and terpenoids, particularly the oxygenated monoterpenes and the sesquiterpenes. These findings are discussed in relation to volatiles released in the cotton ecosystem.     

Post-exposure temperature influence on the toxicity of conventional and new chemistry insecticides to green lacewing Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae)

Chrysoperla carnea (Stephens) is an important biological control agent currently being used in many integrated pest management (IPM) programs to control insect pests. The effect of post-treatment temperature on insecticide toxicity of a spinosyn (spinosad), pyrethroid (lambda cyhalothrin), organophosphate (chlorpyrifos) and new chemistry (acetamiprid) to C. carnea larvae was investigated under laboratory conditions. Temperature coefficients of each insecticide tested were evaluated. From 20 to 40 °C, toxicity of lambda cyhalothrin and spinosad decreased by 2.15- and 1.87-fold while toxicity of acetamiprid and chlorpyrifos increased by 2.00 and 1.79-fold, respectively. The study demonstrates that pesticide effectiveness may vary according to environmental conditions. In cropping systems where multiple insecticide products are used, attention should be given to temperature variation as a key factor in making pest management strategies safer for biological control agents. Insecticides with a negative temperature coefficient may play a constructive role to conserve C. carnea populations.     

Suppression of aphids on strawberry by augmentative releases of larvae of the lacewing Chrysoperla carnea (Stephens)

In laboratory feeding experiments, larvae of Chrysoperla carnea consumed up to 790 Chaetosiphon fragaefolii during their development. In gauzehouse experiments, releases of C. carnea larvae significantly reduced numbers of C. fragaefolii on potted strawberry plants. In open field experiments numbers of C. fragaefolii were significantly reduced at release rates of eight chrysopid larvae per plant, but a release experiment on larger strawberry plants grown under protection did not give a significant reduction in aphid numbers, even at a release rate of 25 larvae per plant.     

Small-scale production of the common green lacewing Chrysoperla carnea (Stephens) (Neuropt., Chrysopidae): minimizing costs and maximizing output

This paper outlines a system for the production of common green lacewings in the laboratory, using easily available and inexpensive equipment and producing a healthy surplus of insects for experimental purposes. An economic breakdown of costs is given.     

Functional Response of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) to Sugarcane Whitefly Aleurolobus barodensis (Maskell) in Laboratory Conditions

A functional response study of Chrysoperla carnea (Stephens) larvae to different densities of sugar cane whitefly Aleurolobus barodensis (Maskell) was conducted in test tubes at 26?±?2 °C, 65?±?5 % RH. Chrysoperla carnea showed two different types of functional response in larval instars. First instar exhibits type II. However, second and third larval instars revealed type III functional response. Based on modified Holling’s disk equation, the highest searching rates (a) of 0.82?±?0.0247 h^?1 was found for first instar larva. For second and third larval instars, the attack coefficient (b) were 0.002?±?0.030 and 0.0025?±?0.0424 respectively. The shortest handling time (T_h) per prey was observed at third instar stage (1.574?±?0.0568 h) followed by second and first instar with 1.72?±?0.0411 h and 1.919?±?0.0568 h respectively.     

Singing from the Grave: DNA from a 180 Year Old Type Specimen Confirms the Identity of Chrysoperla carnea (Stephens)

Historically serving as repositories for morphologically-based taxonomic research, natural history collections are now increasingly being targeted in studies utilizing DNA data. The development of advanced molecular techniques has facilitated extraction of useable DNA from old specimens, including type material. Sequencing diagnostic molecular markers from type material enables accurate species designation, especially where modern taxonomic hypotheses confirm morphologically cryptic species complexes. One such example is Chrysoperla carnea (Stephens), which belongs to a complex of about 20 cryptic species, most of which can only be reliably distinguished by their pre-mating courtship songs or by DNA analysis. The subtle morphological variation in the group has led to disagreement over the previous designation of the lectotype for C. carnea, an issue that has been further compounded because Chrysoperla carnea is a highly valued biological control agent in arable crops. Archival DNA extraction and sequencing from the 180 year old lectotype specimen, combined with Bayesian and Likelihood based phylogenetic analyses of modern specimens from the entire complex, were used to establish unambiguously the true identity of Chrysoperla carnea.     

Interpopulation variation in Chrysoperla carnea reproduction: implications for mass-rearing and storage

To determine whether diverse populations and biotypes of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) can be mass-produced and stored under uniform conditions, we assessed reproduction in five North American populations, four from the carnea biotype and one from the mohave biotype. Non-diapause adults from the carnea biotype varied significantly in only one aspect of reproduction, viz., the preoviposition period, whereas the duration and rate of oviposition, as well as fecundity, did not vary significantly. Relative to the carnea populations, the mohave population typically had delayed oviposition and a lower rate of oviposition; however, its oviposition period was long, and thus its fecundity differed only from that of the most productive carnea populations.The shelf-life (= survival during storage, and subsequent survival and reproduction after storage) was evaluated for four populations of the carnea biotype. Survival of diapausing adults during the first 18 weeks of storage was high among all four populations; adults from three populations also showed high survival after 35 weeks of storage. A high incidence of females from all four populations laid some fertile eggs after being stored for up to 31 weeks or longer. After six or more weeks of storage, average fecundity was high and ranged from 400–900 eggs/female. Duration of storage (up to 39 weeks) was a significant determinant of fecundity in two of the four populations.In practice, diverse populations of C. carnea can be efficiently mass-produced (with or without storage) under uniform conditions in the insectary. Thus, the choice of which populations to mass-produce and use in augmentation can be based primarily on the characteristics (e.g., climate, habitat, crop) of the intended area of release, rather than on considerations concerning mass-rearing.     

Compatibility of Spinosad, Tebufenozide and Azadirachtin with Eggs and Pupae of the Predator Chrysoperla carnea (Stephens) Under Laboratory Conditions

Under laboratory conditions, the toxicity of three novel insecticides, spinosad (Tracer ® ), tebufenozide (Mimic ® ) and azadirachtin (Align ® ), was tested against eggs and pupae of the predator Chrysoperla carnea (Stephens). In a first series of assays, eggs were dipped in an aqueous concentration and no ovicidal activity was scored for the three insecticides. In the second, when females were ovipositing on treated substrate for 24 h, fecundity and hatching percentages were similar as compared to controls and the offspring developed normally until the adult stage. However, spinosad, at the highest concentrations tested, caused a slight, significant reduction in the adult life span and fecundity. In a third series of experiments, pupae developed into normal adults after topical treatment for the three insecticides. Herewith, a pharmacokinetic study indicated low accumulation in the body after pupal cuticle penetration when administrating 14 C-labelled insecticide. Fourthly, pupation of last-instar larvae in treated substrate was normal for spinosad and tebufenozide. Only azadirachtin caused a slight reduction in the number of pupae and adults; however, fecundity and fertility of surviving adults was normal. In conclusion, the current results indicate that the three insecticides are not toxic to eggs and pupae of C. carnea .     

Resistance,its stability and reversion rate of resistance to imidacloprid,indoxacarb and chlorfenapyr in a field population of green lacewing Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae)

Abstract

Green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) is a valuable bio-control agent that predates over various insect pests with high efficacy. It has developed considerable resistance to different classes of insecticides. This study was planned to investigate resistance level, stability and reversion rate against some new chemical insecticides using a field collected population of C. carnea. Field collected strain of C. carnea showed 313.44-fold, 216.50-fold and 276.83-fold resistance to imidacloprid, indoxacarb and chlorfenapyr compared to susceptible population, respectively. Baseline susceptibility values of C. carnea to imidacloprid, indoxacarb and chlorfenapyr were 2627.31, 502.10 and 581.89?ppm, while the insecticide resistance decrease rate was ?0.039, ?0.048 and ?0.040, respectively. Rotation of these insecticides requires quality measures maintaining survival of C. carnea in an intense environment where repeated applications are required to avoid economic damage by pests.     

Bacillus thuringiensis toxin (Cry1Ab) has no direct effect on larvae of the green lacewing Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae)

Earlier studies have shown that larvae of the green lacewing predator Chrysoperla carnea are negatively affected when preying on lepidopteran larvae that had been fed with transgenic maize expressing the cry1Ab gene from Bacillus thuringiensis. To test whether the observed effects were directly caused by the Cry1Ab toxin, we have developed a bioassay which allows us to feed high concentrations of the toxin directly to the predator. The results of these feeding studies show no direct toxic effect of Cry1Ab on C. carnea larvae. The amount of toxin ingested by first instar C. carnea in the present study was found to be a factor 10,000 higher than the concentration ingested when feeding on Bt-reared lepidopteran larvae, a treatment that was previously shown to have a negative impact on the predator. In addition, feeding first instar C. carnea with the Cry1Ab toxin did not affect the utilisation of subsequently provided prey. Furthermore, the quality of the prey provided to first instars did not affect the sensitivity of second and third instar C. carnea to the Bt-toxin. The presented results strongly suggest that C. carnea larvae are not sensitive to Cry1Ab and that earlier reported negative effects of Bt-maize were prey-quality mediated rather than direct toxic effects. These results, together with the fact that lepidopteran larvae are not regarded as an important prey for C. carnea in the field, led us to conclude that transgenic maize expressing Cry1Ab poses a negligible risk for this predator.     

Effects of three modern insecticides, pyriproxyfen, spinosad and tebufenozide, on survival and reproduction of Chrysoperla carnea adults

Three novel insecticides, pyriproxyfen, spinosad and tebufenozide, were evaluated for their effect on survival and reproduction of Chrysoperla carnea adults using two methods of exposure: direct contact and ingestion. Pyriproxyfen and tebufenozide proved to be harmless to adult survival, whereas spinosad 72 h after treatment reduced the number of adults by 39.8% and 87.2% in topical and ingestion treatment at the maximum concentration recommended (800 mg a.i. litre^?1). Fecundity was not affected irrespective of the insecticide or time of application (before or after the onset of oviposition). Concerning fertility, only pyriproxyfen exerted a negative effect on hatching when the eggs were deposited by females treated by ingestion in the post‐oviposition period at the highest concentration tested (150 mg a.i. litre^?1).     

普通草蛉幼虫对麦二叉蚜和麦长管蚜的捕食功能反应与搜寻效应

[目的]为评价普通草蛉Chrysoperla carnea幼虫对麦二叉蚜Schizaphis graminum和麦长管蚜Sitobion avenae的捕食反应和选择偏好,以明确普通草蛉幼虫对这2种蚜虫的控害能力.[方法]室内设置不同密度的麦二叉蚜和麦长管蚜,统计普通草蛉2龄和3龄幼虫对2种猎物的捕食量,研究普通草蛉幼虫对麦二叉蚜和麦长管蚜的捕食功能反应和搜寻效应.[结果]相同猎物密度下,普通草蛉2龄、3龄幼虫对麦二叉蚜的捕食量均低于麦长管蚜且存在显著性差异,对2种小麦蚜虫的捕食功能反应均拟合Holling Ⅱ功能反应模型和Holling Ⅲ功能反应新模型.3龄幼虫对麦二叉蚜和麦长管蚜的瞬时攻击率分别为1.089和1.106,大于2龄幼虫对猎物的瞬时攻击率,同一龄期草蛉幼虫对麦长管蚜的瞬时攻击率及日最大捕食量大于麦二叉蚜,2龄和3龄幼虫对麦长管蚜的处理时间为0.005 d和0.004 d,均小于对麦二叉蚜的处理时间.普通草蛉幼虫对麦长管蚜的最佳寻找密度高于麦二叉蚜,其中2龄普通草蛉幼虫捕食麦长管蚜的最佳寻找密度最高,为39.200.普通草蛉幼虫对小麦蚜虫的搜寻效应随猎物密度增加而降低,对麦长管蚜的搜寻效应高于麦二叉蚜,麦长管蚜搜寻效应的下降趋势大于麦二叉蚜.[结论]普通草蛉幼虫对麦二叉蚜和麦长管蚜有较大的控害潜能,对于麦长管蚜的取食及控制能力高于麦二叉蚜.     

Influence of food on the fecundity ofChrysopa carnea Stephens [Neuroptera,Chrysopidae]

Zusammenfassung Für die Eiproduktion ben?tigtChrysopa carnea Nahrung im ausgewachsenen Stadium. In der vorliegenden Arbeit wurden verschiedene Nahrungssubstanzen ausprobiert (Tab. 1). Die Resultase zeigen eine ziemlich unterschiedliche Wirkung. Die Eiproduktion gint zurück, wenn nur eine künstliche Nahrung (Tab. 2) geboten wurde, w?hrend Blütennahrung die Eizahl stark erh?hte. Die st?rkste Eiproduktion wurde mit künstlicher Nahrung und Blüten erzielt. Für verschiedenen Pollen konnte jedoch eine verschiedene Wirkung nachgewiesten werden.      

Toxicity of Fipronil to the Predatory Lacewing Chrysoperla carnea (Neuroptera: Chrysopidae)

All the developmental stages of Chrysoperla carnea (Stephens) were treated with fipronil using different modes of exposure under laboratory conditions. Eggs were dipped in an aqueous range of concentrations and no effects were recorded, except at the highest concentration. Pupae treated topically on the silk cocoon moulted to healthy adults, without any deleterious effects on their reproduction. In contrast, larvae and adults were killed by the compound, irrespective of the mode of treatment, even at rates below the maximum field recommended rate in Spain (30 g c.p./ha). Sublethal concentrations of fipronil did not affect the fecundity or fertility of survivors. We conclude that fipronil is very toxic under laboratory conditions to this predatory lacewing.     

Molecular systematics of the Chrysoperla carnea group (Neuroptera: Chrysopidae) in Europe

The green lacewing Chrysoperla carnea is a complex of cryptic species whose differentiation has been so far based upon morphology, ecophysiology, behaviour and preliminary mitochondrial DNA data using cytochrome oxidase subunit II (COII) and NADH dehydrogenase subunit II. In this work we extended the DNA data by screening nucleotide sequences of COII, cytochrome oxidase I, cytochrome b and the large ribosomal subunit of the mtDNA. These new data suggest that C. carnea s.s. is a well-supported, separate taxon, but that other taxa of the complex are not consistently differentiated by the current DNA data.     

Femoral chordotonal organ in the legs of an insect,Chrysoperla carnea(Neuroptera)

The femoral chordotonal organ (FCO) inChrysoperla carneais situated in the distal part of the femur and consists of two scoloparia, which are fused at their distal end. The distal scoloparium contains 17-20 scolopidia, and the proximal one six scolopidia. Each scolopidium consists of two sensory cells and three types of enveloping cells (glial, scolopale and attachment cell). The sensory cells of different scolopidia do not lie at the same level in the FCO. Therefore the attachment cells of different scolopidia have different lengths. In the FCO, three types of ciliary roots are found in different sensory cells. The dendrite of the sensory cell terminates in a distal process, which has the structure of a modified cilium (9x2+0). The very distal part of the cilium is surrounded by an extracellular electron dense material, the cap, and ends in a terminal dilation. The scolopale cell contains the electron dense scolopale rods, consisting of plentiful microtubules. In their middle third the scolopale rods are fused and form the scolopale. In the FCO septate junctions, desmosomes and hemidesmosomes are found.     

Impact of azadirachtin on vine weevil (Coleoptera: Curculionidae) reproduction

Abstract 1 The dose–response of azadirachtin on vine weevil, Otiorhynchus sulcatus (Fabricius), reproduction is investigated by confining adults to feed on treated Taxus × media leaves, and by counting and evaluating development in the resulting eggs. 2 A dosage‐dependent reduction in oviposition is discovered for foliar surface residues of azadirachtin, with an EC₅₀ of 25–50 parts per million (p.p.m) and 99.2% inhibition of viable egg production with 100 p.p.m. 3 Switching weevils from treated to untreated foliage allows reproductive capability to be restored for weevils that cease egg laying after azadirachtin exposure of 50 p.p.m. Weevils that had already started laying eggs in untreated groups soon cease oviposition once switched to azadirachtin‐treated foliage. 4 A transovarial effect results in a decrease in the percentage of viable eggs as the azadirachtin concentration increases. 5 The amount of feeding on foliage does not appreciably decrease at these hormonally effective concentrations, and adult weevil mortality is only slightly greater in the azadirachtin‐treated groups. Therefore, the overall effect of azadirachtin on weevil populations in the field is difficult to assess, except by collecting weevils to determine whether they are able to lay viable eggs.     

Chrysoperla carnea (Neuroptera: Chrysopidae) controls Myzus persicae (Homoptera: Aphididae) despite behavioural differences between aphid clones that are associated with MACE-based insecticide resistance

The predator Chrysoperla carnea (Stephens) was equally effective against two clones of the aphid Myzus persicae (Sulzer) (Homoptera: Aphididae) that differed in their insecticide resistance profile. This differs from results of similar experiments with Aphidius colemani (Viereck) (Hymenoptera: Braconidae) on the same clones of M. persicae.     

Evidence of field-evolved resistance to organophosphates and pyrethroids in Chrysoperla carnea (Neuroptera: Chrysopidae)

The toxicity of some of the most commonly used insecticides in the organophosphate and pyrethroid classes were investigated against different Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) populations collected over three consecutive years (2005-2007). The populations were tested using leaf dip bioassays for residual effects and topical applications to measure the response of larvae that would come into direct contact with field application of insecticides. In leaf dip assays, the LC50 (micrograms per milliliter; 120 h) values for chlorpyrifos and profenofos were in the range of 59.3-1,023 and 180.02-1,118 respectively. The LC50 values for lambda-cyhalthrin, alphamethrin, and deltamethrin were 359.08-2,677, 112.9-923.5, and 47.81-407.03, respectively. The toxicity for the above insecticides in topical application was similar to toxicity in leaf dip assays. The susceptibility of a laboratory population, which was locally developed and designated as (Lab-PK), to deltamethrin was comparable with another susceptible laboratory population. Resistance ratios for five field populations were generally low to medium for deltamethrin, but high to very high for chlorpyrifos, profenofos, lambda-cyhalthrin and alphamethrin compared with the Lab-PK population. Our data also suggested that the five field populations had multiple resistance to two classes of insecticides. The populations showed resistance to two organophosphates tested and to lambda-cyhalthrin and alphamethrin; however, resistance to deltamethrin was only found at two locations. This pattern indicates occurrence of two divergent patterns of resistance within pyrethroids. The resistance to the insecticides was stable across 3 yr, suggesting field selection for general fitness had also taken place in various populations of C. carnea. The broad spectrum of resistance and stability of resistance to insecticides in C. carnea in the current study suggested that it could be a prime candidate for mass releases and compatible with most spray programs.     

Ingestion of spinosad bait GF-120 and resulting impact on adult Chrysoperla carnea (Neuroptera: Chrysopidae)

The spinosad bait spray GF-120 Naturalyte F® (Dow AgroSciences LLC, Indianapolis, IN, USA) is widely used in commercial olives in California. Because of concern about its non-target effects on beneficial insects, we studied its impact on feeding behavior, mortality, and reproductive parameters of adult green lacewings, Chrysoperla carnea (Stephens), under laboratory conditions. Male and female feeding rate and quantity, and subsequent mortality, were compared over a 5-day period following a 24-h exposure to honey, GF-120, or the bait component (without spinosad) in two-choice and no-choice assays. All treatments were ingested equally when offered alone. Spinosad did not impart repellency or preference to GF-120 relative to the bait. Honey was preferred in choice tests with GF-120 or bait. Significant mortality occurred when GF-120 was offered alone, but was not significant when it was offered in choice with honey or bait. In a separate assay of female longevity and reproduction, mortality rate as a function of time was similar in all treatments, except for some significantly earlier mortality due to GF-120 compared with honey. GF-120 ingestion significantly reduced fecundity compared with bait during the first week after treatment. Egg hatch was not significantly affected. The preference of adult C. carnea for food should ameliorate the potential negative effect of GF-120 on adult C. carnea mortality in the field. The laboratory study finds that GF-120 is a potentially safer choice for C. carnea than an aqueous suspension of spinosad, and provides no new evidence for definitive risk to field populations.