Chrysoperla Sinica Research Articles

Cycloxaprid: A novel cis-nitromethylene neonicotinoid insecticide to control imidacloprid-resistant cotton aphid (Aphis gossypii)

Imidacloprid is a nicotinic acetylcholine receptor (nAChR) agonist with potent insecticidal activity. However, resistance to imidacloprid is a significant threat and has been identified in several pest species. Cycloxaprid with cis-configuration is a novel neonicotinoid insecticide, which shows high activity against imidacloprid-resistant pests. The LC50 of imidacloprid against the resistant Aphis gossypii was 14.33mgL−1 while it was only 0.70mgL−1 for the susceptible population, giving a resistance ratio of 20.47. In this imidacloprid-resistant population, a point mutation (R81T) located in the loop D region of the nAChR β1 subunit was found out. But this point mutation did not decrease the activity of cycloxaprid against A. gossypii. The LC50 of cycloxaprid was 1.05 and 1.36mgL−1 for the imidacloprid-susceptible and imidacloprid-resistant populations, respectively. In addition, cycloxaprid provided better efficacies against resistant A. gossypii than imidacloprid in the fields. Although cycloxaprid was highly toxic to A. gossypii, it showed high selective activity between A. gossypii and its predominant natural enemies, Harmonia axyridis and Chrysoperla sinica. These results demonstrate that cycloxaprid is a promising insecticide against imidacloprid-resistant A. gossypii and suitable for the integrated pest management.

Development and Reproduction ofMallada basalis(Neuroptera: Chrysopidae) on Artificial Diets

Abstract The green lacewing, Mallada basalis (Walker) (Neuroptera: Chrysopidae), has a broad prey range and effective searching abilities. Because rearing procedures based on natural or factitious foods for the larvae of this economically important predator are often time consuming and/or expensive, the main objective of our study was to develop an artificial diet suitable for mass rearing. We analyzed the development, survival, longevity, and reproduction of M. basalis (F1 generation) fed 3 artificial diets. These diets were formulated based on those of Chrysoperla sinica Tjeder and Chrysopa pallens (Rambur) (Neuroptera: Chrysopidae). All 3 of the diets contained chicken egg, beer yeast powder, sucrose, trehalose, vitamin C, and potassium sorbate. The first artificial diet (AD1) also contained honey and distilled water. AD2 also included pupal hemolymph of the Chinese oak silk moth (Antheraea pernyi Guerin-Meneville; Lepidoptera: Saturniidae), and AD3 also included whole A. pernyi pupae, which had been b...

Identification and expression pattern of candidate olfactory genes in Chrysoperla sinica by antennal transcriptome analysis

Chrysoperla sinica is one of the most prominent natural enemies of many agricultural pests. Host seeking in insects is strongly mediated by olfaction. Understanding the sophisticated olfactory system of insect antennae is crucial for studying the physiological bases of olfaction and could also help enhance the effectiveness of C. sinica in biological control. Obtaining olfactory genes is a research priority for investigating the olfactory system in this species. However, no olfaction sequence information is available for C. sinica. Consequently, we sequenced female- and male-antennae transcriptome of C. sinica. Many candidate chemosensory genes were identified, including 12 odorant-binding proteins (OBPs), 19 chemosensory proteins (CSPs), 37 odorant receptors (ORs), and 64 ionotropic receptors from C. sinica. The expression patterns of 12 OBPs, 19 CSPs and 37 ORs were determined by RT-PCR, and demonstrated antennae-dominantly expression of most OBP and OR genes. Our finding provided large scale genes for further investigation on the olfactory system of C. sinica at the molecular level.

The complete mitochondrial genome of the Chrysoperla sinica (Tjeder)

The complete mitochondrial genome of the Chrysoperla sinica was sequenced in this study. It is 16,057 bp in length, and contains 22 transfer RNA genes, 13 protein-coding genes (PCGs), 2 rRNA genes and 1 non-coding AT-rich region. But, C. sinica lack long tandem repeats. The Chrysoperla sinica mitogenome displays a very high level of similarity (99.27%) with Chrysoperla nipponensis. The genome base composition is 39.24% A, 39.70% T, 11.98% C, and 9.08% G. Similar to other insects, all PCGs are initiated by a typical ATN codon, except COX1, which starts with TCG. Nine PCGs have the standard, complete stop codon (TAA or TAG), and the other four PCGs end with the incomplete stop codon (TA or T).

Bt rice producing Cry1C protein does not have direct detrimental effects on the green lacewing Chrysoperla sinica (Tjeder)

The effects of insect-resistant genetically engineered rice producing Cry1C protein derived from Bacillus thuringiensis (Bt) on Chrysoperla sinica (Tjeder) (Neuroptera: Chrysopidae) were assessed in laboratory bioassays. Survival and development of C. sinica larvae were not adversely affected when the larvae were fed a diet containing purified Cry1C protein at 200 µg/g fresh weight, representing a worst-case exposure scenario; in contrast, C. sinica larvae were adversely affected when the diet contained avidin or potassium arsenate. Life table parameters of C. sinica adults did not differ when the adults were fed with Bt or non-Bt rice pollen together with a 2-M sucrose solution. Life table parameters of C. sinica adults also did not differ when the adults were fed an artificial diet with or without purified Cry1C protein at a nominal concentration that was approximately 20 times higher than that in rice pollen; in contrast, C. sinica adults were adversely affected when the diet contained potassium arsenate. In all bioassays with lacewings, the bioactivity and stability of the Cry1C protein in the diet and Cry1C protein uptake by the lacewings were confirmed by enzyme-linked immunosorbent assay (ELISA) and by bioassays with a Cry1C-sensitive lepidopteran. These results demonstrate that neither larvae nor adults of C. sinica are sensitive to Cry1C protein at concentrations higher than those encountered in the field, demonstrating that the growing of Bt rice producing Cry1C protein is unlikely to pose a risk to C. sinica.

Trade-off between flight activity and life-history components in Chrysoperla sinica

We studied the effects of flight duration on two important life-history traits, i.e., longevity and life-time egg production, of Chrysoperla sinica females, through an experimental flight manipulation bioassay, using a flight mill apparatus. In addition, we assessed the potential transgenerational effects of maternal flight durations on survival and on the development of the progeny. We found experimental evidence of a negative link between flight activity (1, 2 and 3 h) and longevity and reproductive activity in C. sinica females. Although, the development of the progeny 1st instars was significantly longer for females that flew longer, all other recorded life history traits of the progeny, including juvenile survival and overall development time and size of the pupae, were not affected. Hence, these findings suggest that the growth of new populations originated by females that flew long distances maybe be slower only for the first generation.

Use of an artificial diet system to study the toxicity of gut-active insecticidal compounds on larvae of the green lacewing Chrysoperla sinica

A semi-liquid artificial diet was established and found to be a suitable food source for Chrysoperla sinica larvae, comparable to aphid prey. Using the artificial diet, we established and validated a dietary exposure assay by using the insecticidal potassium arsenate (PA) as positive control. Dose-dependent responses were documented for all observed life-table parameters of C. sinica larvae such as survival rate, pupation rate, larval weight, and larval development time. Thus, the dietary assay can detect the effects of insecticidal compounds on the survival and development of C. sinica larvae. Using the established dietary assay, we subsequently tested the toxicity of Cry1Ab, Cry1Ac, and Cry2Aa proteins (which are produced by transgenic maize, cotton or rice plants) to C. sinica larvae. Artificial diets containing Galanthus nivalis agglutinin (GNA) or PA were included as positive controls. Survival and development of C. sinica larvae were not affected when the artificial diet contained purified Cry1Ab, Cry1Ac, or Cry2Aa at 200μg/g diet. In contrast, C. sinica larvae were adversely affected when the diet contained PA and GNA. The stability and bioactivity of the Cry proteins in the diet and Cry protein uptake by the lacewing larvae were confirmed by bioassay with a Cry-sensitive insect species and by ELISA. The current study describes a suitable experimental system for assessing the potential effects of gut-active insecticidal compounds on green lacewing larvae. The experiments with the Cry proteins demonstrate that C. sinica larvae are not sensitive to Cry1Ab, Cry1Ac, and Cry2Aa.

Bt rice expressing Cry2Aa does not cause direct detrimental effects on larvae of Chrysoperla sinica

To assess the potential effects of Cry2Aa-expressing insect-resistant Bt rice on Chrysoperla sinica larvae, we conducted two tritrophic bioassays using a non-target (Laodelphax striatellus) and a target herbivore (Chilo suppressalis) as prey. None of the tested life-table parameters of C. sinica did differ when fed with L. striatellus nymphs reared on either Bt or control rice plants. Similarly, C. sinica larval survival and development were not affected when fed C. suppressalis larvae that were reared on Cry2Aa-contained artificial diet compared to those fed control diet. However, the 7-day larval weight was significantly decreased in the Bt treatment and none of the C. sinica larvae developed to the adult stage. To clarify whether the observed effects were due to the direct toxicity of Cry2Aa or prey-quality mediated, we conducted a dietary exposure assay in which the toxicity of Cry2Aa to C. sinica larvae was tested. Potassium arsenate (PA) was included as a positive control. None of the tested life-table parameters of C. sinica was adversely affected when fed Cry2Aa at 500μg/ml sucrose solution. In contrast, C. sinica larvae were adversely affected by feeding on sucrose solution containing PA. In the feeding assays, exposure of C. sinica larvae to Cry2Aa was confirmed by ELISA. Our results demonstrate that C. sinica larvae are not sensitive to Cry2Aa at concentrations exceeding the levels that the larvae may encounter in Bt rice fields. Consequently the detrimental effects observed in the tritrophic studies using Bt rice-fed C. suppressalis as prey can be attributed to the decreased prey quality due to the sensitivity of C. suppressalis larvae to Cry2Aa.

Effect of different prey species on the life history parameters of Chrysoperla sinica (Neuroptera: Chrysopidae)

Results of studies on prey suitability for generalist predators are important for efficient mass rearing and implementing Integrated Pest Management Programmes (IPM). The green lacewing, Chrysoperla sinica (Tjeder), is a polyphagous natural enemy attacking several pests on various crops in China. We investigated the effect of feeding it different species of prey on its pre-imaginal development, survival, adult longevity and fecundity under laboratory conditions. The prey species tested were nymphs of Aphis glycines Matsumura, cotton aphid Aphis gossypii Glover, peach aphid Myzus persicae Sulzer, corn aphid Rhopalosiphum maidis Fitch and cowpea aphid Aphis craccivora Koch, and eggs of the rice grain moth, Corcyra cephalonica Stainin. None of these species of prey affected the pre-imaginal survival or percentage survival of the eggs of the predator. However, eggs of C. cephalonica and nymphs of M. persicae and A. glycines were the best of the prey species tested, in that when fed on these species the pre-imaginal developmental period of C. sinica was shorter and its adult longevity, fecundity and percentage survival greater than when fed the other species of prey. In contrast, when fed nymphs of A. craccivora the pre-imaginal development period was longer, adult longevity shorter and fecundity lower. These findings could be helpful in defining more optimum conditions for the mass rearing of C. sinica for use in integrated pest management (IPM) programmes for various crops.

Consumption of Bt rice pollen expressing Cry2Aa does not cause adverse effects on adult Chrysoperla sinica Tjeder (Neuroptera: Chrysopidae)

Adults of Chrysoperla sinica Tjeder are prevalent pollen feeders in rice fields in China. They are therefore exposed to insecticidal proteins when foraging insect-resistant genetically engineered rice pollen containing Bacillus thuringiensis (Bt) proteins. Laboratory bioassays were conducted to evaluate the potential impacts of Cry2Aa-expressing transgenic rice (T2A-1) pollen on fitness of adult C. sinica. Survival, pre-oviposition period, fecundity and adult dry weight did not differ between lacewings that had consumed Bt or non-Bt rice pollen. To ensure lacewing adults were not sensitive to Cry2Aa protein independent from the plant background and to add certainty to the toxicity assessment, C. sinica adults were fed with an artificial diet containing Cry2Aa protein at an approximately 10 times higher concentration than in rice pollen. Artificial diet containing potassium arsenate (PA) was included as a positive control. No difference was detected for any of the life-table parameters tested between Cry2Aa-containing and pure diet. In contrast, the pre-oviposition, fecundity and dry weight of C. sinica were significantly adversely affected by feeding on PA-containing diet. In both bioassays, the uptake of Cry protein by adult C. sinica and the bioactivity of Cry protein in the food sources were confirmed by ELISA measurements and sensitive insect bioassays, respectively. These results indicate that adults of C. sinica are not affected by Cry2Aa-expressing rice pollen and are not sensitive to Cry2Aa protein at concentrations exceeding the levels in pollen, thus demonstrating that growing Bt rice expressing Cry2Aa protein will pose a negligible risk to adult C. sinica.

Effects of Organic Management on Predator Densities of Myzus persicae (Sulzer) During Transition to Organic Agriculture in Peach Fields in China

We studied the effects of organic management (OM) on densities of six predator species of green peach aphid (GPA), three coccinellid predators (Propylea japonica, Harmonia axyridis, Coccinella septempunctata), and three non-coccinellid predators (Chrysoperla sinica, Epistrophc baltcata, and Misumenops tricuspidatus) in five OM peach fields, compared and paired with five conventional management (CM) fields from the first year of OM in 2004–2009. Coccinellid and non-coccinellid predator densities were significantly higher on several sampling dates in OM fields than in CM fields. Coccinellid predator density was significantly lower in the first two years of OM than in the last three years in the OM fields. The density of non-coccinellid predators in the fourth year of OM was much greater than during the first year of OM, and there was a significant increase by the sixth year of OM compared to the first two years of OM. The leaf density index of GPA was significantly lower in the fifth and sixth year of OM than the first three years of OM in the OM peach fields. Our study suggests organic management can resume and increase predator densities of green peach aphid during transition to organic agriculture in peach fields.

Temporal dynamics of the arthropod community in pear orchards intercropped with aromatic plants

Increasing attention has been paid to enhancing biological control through habitat management in agricultural systems for enhanced pest management. Pest management benefits can be realised by intercropping, which can increase natural enemy abundance and, in turn, reduce pest abundance. In this study, the composition and temporal dynamics of arthropod communities in pear orchards when intercropped with aromatic plants were investigated, and the effectiveness and applicability of aromatic plants as intercrops for enhancing insect control were assessed. When compared with natural grasses or clean tillage, intercropping significantly reduced pest abundance and increased the ratio of natural enemies to pests. Intercropping also shortened the occurrence duration and depressed the incidence peak in annual dynamics curves of the pest subcommunity and the arthropod community, mainly because of the repellent effects of aromatic plants. Equally important, intercropping significantly reduced the numbers of major pests, such as Psylla chinensis, Aphis citricola and Pseudococcus comstocki, while their incidence period was delayed to varying degrees, and the numbers of their dominant natural enemies (Coccinella septempunctata, Phytoseiulus persimilis and Chrysoperla sinica) increased. Intercropping with aromatic plants led to a considerable improvement in arthropod pest management by enhancing the activity of the beneficial arthropod community within the pear orchard ecosystem.

Migratory Adaptations in <I>Chrysoperla sinica</I> (Neuroptera: Chrysopidae)

The green lacewing Chrysoperla sinica (Tjeder) (Neuroptera: Chrysopidae) is a common natural enemy of various insect pests in China and is frequently employed for augmentation biological control. Adults of this species perform migration flights after emergence, the nature of which affects its value for biological control program. In this manuscript, we report characteristics of C. sinica migratory populations captured during 2008-2009 using a light trap at Beihuang Island (Bohai Gulf), 40-60 km from mainland China, and their relationships with flight performance. In total, 1,452 migratory C. sinica adults were caught for these 2 yr. Throughout the sampling period, migratory populations consisted of >50% female individuals, most of which were in preoviposition period and had low degrees of ovarian development. During autumn, most migratory females were unmated. C. sinica females began oviposition since 7 d after emergence. Flight mill tests showed that 5-d-old females in preoviposition period flew over the longest distance (i.e., 4.50 ± 1.31 km) over 8 h and mating status did not affect flight performance. For 3-d-old individuals, males flew over larger distances than females, and unmated individuals exhibited stronger flight capability than mated ones. Hence, gender, mating status, and age all determine C. sinica flight performance. Based upon those findings, we can indicate that C. sinica migratory populations appear adapted to long-distance flights. This research should help understand C. sinica population dynamics and aid its incorporation within integrated pest management (IPM) packages for several crops.

Flight Mill Performance of the Lacewing Chrysoperla sinica (Neuroptera: Chrysopidae) as a Function of Age, Temperature, and Relative Humidity

The lacewing Chrysoperla sinica (Tjeder) (Neuroptera: Chrysopidae) is an important predator of several insect pests in China and has considerable potential as a biological control agent. An inoculative approach would be the releasing adults early in the season to ensure that populations are present before pest densities increase. However, an understanding of adult flight activity under different conditions is necessary to develop appropriate release strategies. Therefore, we used a 32-channel, computer-monitored flight mill system to determine the effect of age on the flight activity of unmated female and male adults. Both sexes had high total flight activity levels as well as the longest individual flight bouts 2 and 3 d after emergence. The effects of temperature (between 13 and 33 degrees C at 75% RH) and relative humidity (between 30 and 90% RH at 23 degrees C) on the flight activity of 3-d-old unmated adults also were determined. Flight activity declined at the lowest (13 degrees C) and highest (33 degrees C) temperatures tested, as well as at the lowest relative humidity (30% RH). These findings are discussed within the context of selecting the appropriate environmental conditions for releasing C. sinica.

PHOTOPERIODIC CONTROL OF ADULT DIAPAUSE IN CHRYSOPERLA SINICA (TJEDER) (NEUROPTERA: CHRYSOPIDAE— I. CRITICAL PHOTOPERIOD AND SENSITIVE STAGES OF ADULT DIAPAUSE INDUCTION

Abstract Photoperiodic sensitivity for diapause induction of the green lacewing, Chrysoperla sinica (Tjeder) was examined at 22°C. The adult diapause of C. sinica was induced by short‐day photoperiods, and the critical photoperiod for its induction was between 12.5L‐11.5D and 13L‐11D.Adults developed without diapause under long‐day conditions, and entered diapause under short‐day conditions. The adult stage was the uppermost sensitive stage for adult diapause induction, adults could go into diapause only when the emerging adults were under diapause‐inducing short‐day photoperiods. The short‐day photoperiodic experience by transferring between 15L: 9D and 9L: 15D at preimaginal stages did not result in adult diapause under 15L: 9D photo regime, although some treatments extended the pre‐oviposition period in adult stage. The results showed that the 3rd instar larvae and pre‐pupae were more sensitive to the photoperiodic change from 15L: 9D to 9L: 15D photo regime than the other preimaginal stages.