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.     

Functional response of Chrysoperla carnea (Neuroptera: Chrysopidae) to Helicoverpa armigera (Lepidoptera: Noctuidae): Effect of prey and predator stages

Abstract Understanding predator–prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea (Stephens), preying upon eggs and first instar larvae of the cotton bollworm, Helicoverpa armigera Hübner. The first and second instar larvae of C. carnea exhibited type II functional responses against both prey stages. However, the third instar larvae of C. carnea showed a type II functional response to the first instar larvae of H. armigera, but a type III functional response to the eggs. For the first instar larvae of C. carnea, the attack rate on H. armigera eggs was significantly higher than that on the larvae, whereas the attack rate of the second instar C. carnea on H. armigera larvae was significantly higher than that on the eggs. For the third instar larvae of C. carnea, the attack rate on the larvae was 1.015 ± 0.278/h, and the attack coefficient on the eggs was 0.036 ± 0.005. The handling times of the third instar larvae on larvae and eggs were 0.087 ± 0.009 and 0.071 ± 0.001 h, respectively. The highest predation rate was found for the third instar larvae of C. carnea on H. armigera eggs. Results of this study revealed that the larvae of C. carnea, especially the third instar, had a good predation potential in controlling H. armigera eggs and larvae. However, for a comprehensive estimation of the bio‐control abilities of C. carnea toward H. armigera, further field‐based studies are needed.     

Obligatory ontogenetic colour change correlated with sexual maturity in adult Chrysoperla congrua (Walker) (Neuroptera: Chrysopidae)

Soon after pupal eclosion, adult Chrysoperla congrua undergo obligatory ontogenetic colour change. This phenomenon, unique among lacewings to C. congrua , is investigated further and its functional significance is discussed. Four to 5 days after eclosion, adult C. congrua undergo obligatory ontogenetic colour change from yellow-brown to green, which corresponds with maturation of gonads in both sexes. Courtship displays by both sexes involving abdominal tremulation (calling) always occurred soon after colour change. I propose that colour change in adult C. congrua serves not only as camouflage in a dynamic habitat, as suggested by previous authors, but may also serve as a visual cue to conspecifics of sexual maturity and receptiveness to a potential mate.     

A comparative analysis of Chrysoperla carnea catches in light- and suction-traps

ABSTRACT.

• 1 The lacewing C.carnea was caught weekly at Rothamsted in six traps, in 1973 and between 1975 and 1980. The traps were in three pairs: two light-traps in woodland, two light-traps in open fields, and two suction-traps, sampling at 12 m and 1.2 m above the ground.
• 2 Standardized trap phenologies were compared seasonally, for each year, using multivariate methods. Trap environments caused the greatest phenological difference, which was between the woodland and the other traps. The suctiontraps and the light-traps in open fields also differed. The greatest similarity was between the woodland light-traps, the next between the suction-traps, but the two light-traps in open fields were relatively dissimilar.
• 3 These results were supported by analysis of the sex-ratio of catches in each trap. We suggest an overall phenology in which the wood is important as an overwintering site for adults in autumn and as a source in spring.
• 4 Assessment of consistency over years showed no year was typical, but 1979 was markedly dissimilar from other years; 1976 was particularly similar to 1975.
• 5 The use of generalized Procrustes analysis (Gower, 1975) is recommended for similar sets of ecological data.

     

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.     

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.     

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.     

Influence of spinosad on immature and adult stages of <Emphasis Type="Italic">Chrysoperla carnea</Emphasis> (Stephens) (Neuroptera: Chrysopidae)

Toxicity of spinosad to immature stages of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) and its effect on the reproduction and survival of adult stages after direct spray and ingestion treatments were evaluated. Spinosad was harmless to C. carnea eggs and pupae irrespective of concentrations or method of treatments. Direct spray of spinosad to first instar caused significant reduction in rate of pupation and L1-adult survival, but did not affect the rate of adult emergence. Third-instar bioassay revealed significant difference in L3-adult survival. When C. carnea first instars were fed upon spinosad-treated-Brevicoryne brassicae (L.), significant differences in investigated parameters were not observed among different treatments. The weight of third instar and pupae were comparable regardless of tested spinosad concentrations. Also, feeding on spinosad treated-B. brassicae had no negative impact on fecundity and fertility. Furthermore, ingestion of spinosad contaminated-B. brassicae significantly prolonged larval and larval + pupal periods. The larval feeding capacity of C. carnea did not differ significantly between larvae fed on spinosad-treated and untreated aphids with the exception of first instar. When C. carnea adults were allowed to oviposit on spinosad treated-substrate, total number of eggs laid, percent of eggs laid on the treated substrate and egg hatching did not differ from those of control. However, when adults were fed on spinosad-treated artificial diet, negative effects on adult survival and fecundity were observed.

一种半固体人工饲料连代饲养日本通草蛉幼虫

以棉蚜和his gossypii Glover饲养日本通草蛉Chrysoperla nipt）oensis（Okamoto）作为对照,用一种半固体人工饲料连续饲养10代日本通草蛉,对日本通草蛉各生长阶段的生长和发育指标进行观测。结果显示,用人工饲料饲养的日本通草蛉的幼虫历期为13～15d,蛹期为8d,较对照组的7d和6d分别延长6～8d和2d;用棉蚜饲养的对照组日本通草蛉幼虫累计存活率为94％,成虫获得率为87％,而人工饲料饲养连续10代的幼虫累计存活率为81％～89％,成虫获得率69％～79％。取食人工饲料的日本通草蛉成虫,在产卵前期、产卵量、产卵期及寿命方面与对照组存在显著的差异,人工饲料组草蛉的产卵前期为5．07—5．22d,而对照组草蛉的产卵前期为4．12d,人工饲料组草蛉的产卵量为190～390粒,对照组的单雌产卵量为667．2粒,人工饲料组草蛉的寿命为36—38d,对照组成虫寿命52d。以上结果表明,这种半固体人工饲料可以满足日本通草蛉幼虫生长发育基本需要,可用于日本通草蛉的室内继代饲养,但需要进一步优化配方。     

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.     

Acoustic recognition of sibling species within the holarctic lacewing Chrysoperla carnea (Neuroptera: Chrysopidae)

Abstract. Individuals of Chrysoperla curnea (Stephens) from central Europe exhibit courtship songs that are radically different from those of nearctic members of the same species. Additionally, the two geographically distinct populations will not hybridize under laboratory conditions. It is likely, therefore, that the two song morphs are distinct, sibling species; consequently Chrysoperla plorabunda (Fitch) is raised from synonymy, to include New World specimens formerly placed in C.camea. Within the nearctic region, other plorabunda -like individuals have been found to possess uniquely different calls, suggesting that the carnea-plorabunda complex may in fact consist of numerous morphologically indistinguishable species.     

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.     

Interspecific hybridization between introduced and indigenous green lacewings (Neurop., Chrysopidae: Chrysoperla) at different adult densities

Abstract  We investigated laboratory hybridization in different-capacity cages between the indigenous Chrysoperla nipponensis and its close relative, Chrysoperla carnea , which has been recently introduced from Germany to Japan. Fertility varied depending on the combination of cross and cage capacity, and was decreased by reduced adult density in all crosses. Conspecific crosses showed significantly higher fertility than interspecific crosses. Interspecific crosses, especially C. nipponensis females ×  C. carnea males, showed low fertility at all adult densities. There will be few losses of identity of the indigenous C. nipponensis via interspecific hybridization with the introduced C. carnea , even if C. carnea were to become established in the wild.     

Foraging Behavior of Lacewing Larvae (Neuroptera: Chrysopidae) on Plants with Divergent Architectures

We investigated the effects of plant architecture on predator–prey interactions by quantifying the behavior of green lacewing larvae on perennial grasses with divergent leaf architectures. Crested wheatgrass produces flat, broad leaves similar to those of wheat, whereas Indian ricegrass bears linear leaves that are tightly rolled inward. In the absence of prey, lacewing time budgets and residence times were similar on the two grasses, although predators tended to search longer on crested wheatgrass. On plants infested with the Russian wheat aphid, lacewing larvae dislodged, contacted, and captured significantly more aphids on Indian ricegrass than on crested wheatgrass. Comparisons between aphid-free and aphid-infested plants suggest that differences in plant architecture modified prey accessibility rather than predator movement. Aphids on seedlings and mature plants of crested wheatgrass frequently occurred in concealed locations, such as in the rolls of immature leaves or in the blade–sheath junctions of mature leaves; aphids on Indian ricegrass were more likely to feed in exposed locations. Our focal-animal observations were consistent with results from population-level experiments and suggest that short-term, behavioral studies may help predict the effectiveness of predators at larger spatial and temporal scales.     

Nontarget impact of spinosad GF-120 bait sprays for control of the Mexican fruit fly (Diptera: Tephritidae) in Texas citrus

Bait sprays containing the toxicant spinosad (GF-120) were applied to citrus groves in the Rio Grande Valley of Texas where Mexican fruit flies were detected in surveillance traps. The sprays were applied as a supplement to a continuous sterile insect release program. Sterile fly captures were 47-63% lower in the treated groves compared with control groves. Eight of 10 secondary pest populations declined in the test groves subsequent to spray applications, but they also declined in the control groves, suggesting that the decline was a seasonal phenomenon rather than a result of the bait sprays. Citrus whitefly, Dialeurodes citri (Ashmead), populations increased modestly and citrus blackfly, Aleurocanthus woglumi (Ashby), populations remained unchanged compared with pretreatment levels. Thus, no outbreaks of secondary pests occurred as a result of the spinosad bait sprays in this instance, as has been reported for malathion bait sprays in citrus. The bait sprays had no detectable effect on populations of specific indicator species of parasitoids (including Aphytis spp. and Comperiella bifasciata Howard), or on numbers of beneficial insects in general, in the treated groves.     

Non-target effects of kaolin and coppers applied on olive trees for the predatory lacewing Chrysoperla carnea

Kaolin clays and copper salts might be considered as alternative chemical control products for controlling olive pests in the contexts of both organic farming and integrated pest management programmes. Chrysoperla carnea (Stephens) (Neur. Chrysopidae) represents one of the most significant generalist predators of olive grove pests. In this study, we evaluated the side effects of these compounds on the predatory lacewing. First, kaolin and two copper salts (copper oxychloride and Bordeaux mixture) were tested on C. carnea eggs to determine their effects on egg viability and larval hatching suppression by topical application. Second, L₃ larvae were exposed to the pesticide residues on treated olive tree leaves. Third, a series of three residual tests in adults were sequentially performed as follows: residues on glass surfaces, on olive tree leaves and on small olive trees. Finally, kaolin- and water-treated eggs of Ephestia kuehniella Zeller (Lep. Pyralidae) were offered to L₃ larvae in both dual- and no-choice tests. C. carnea egg hatching was reduced by the kaolin treatment compared to the control treatment. Residual treatments were harmless to larvae and adults, without any deleterious effects on reproduction. L₃ larvae consistently preferred to feed on water-treated E. kuehniella eggs compared to kaolin-treated eggs. The larvae from the no-choice test that had fed ad libitum until pupation on kaolin-treated E. kuehniella eggs, pupated and emerged as healthy adults in reduced proportions compared with those that fed on water-treated eggs. In conclusion, our data suggest that both kaolin and copper products appeared to be largely harmless or only slightly harmful to the predator.     

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.     

光周期和温度对中华通草蛉成虫生殖的影响

研究表明,在25℃和长光周期（L：D＝15：9）条件下饲养至产卵高峰的中华通草蛉成虫,经短光周期（L：D＝9：15）处理后,与长光周期相比,虽然产卵速度有所下降,但产卵期延长,产卵量明显提高;在15℃和短光周期条件下处理后,成虫的生殖受到强烈抑制,产卵速度显下降,部分个体逐渐停止产卵,并进入滞育状态。