Chrysoperla Lucasina Research Articles

Safety of the Entomopathogenic Fungus Beauveria bassiana for Wild and Laboratory-Reared Chrysoperla lucasina Strains.

The need to reduce the impact of plant protection products on agroecosystems fosters the use of augmentative biological control involving the release of beneficial species into the field, the employment of entomopathogenic microbials, and the protection of naturally occurring biocontrol agents. This study aimed to investigate the compatibility of the entomopathogenic fungus Beauveria bassiana with the generalist insect predator Chrysoperla lucasina, in comparative experiments involving a laboratory-reared and a wild chrysopid strain. The larvae of the predators were exposed to different concentrations of fungal conidia up to a concentration of 107 conidia/mL by contact and ingestion. The treated insects showed only slight differences in terms of survival and immature development time compared to the untreated control insects. A significant decrease in the proportion of the male adults of C. lucasina that emerged from the laboratory-reared larvae that were exposed to higher concentrations of the fungus suggested a potentially different susceptibility between the sexes. A slightly lower adult emergence rate was observed in the wild strain, while no significant differences were recorded in the adult reproductive performance. These findings indicate that the B. bassiana strain ATCC 74040, at concentrations commonly used in the field, did not pose a significant risk to C. lucasina and can be safely used in combination with this predator for sustainable pest management.

First attempt to develop a rearing method for the native green lacewing Chrysoperla lucasina in Tunisia

Green lacewing (Chrysoperla lucasina) is well known for its polyphagous predator larvae which are commonly used in pest’s biological control worldwide. In Tunisia, this auxiliary occurs in the nature in association with several pests but it has never been mass reared and released in biological control programs. Hence, the chrysopid species C. lucasina was chosen for an attempt of rearing in order to strengthen its natural populations. The study was carried out in the insectarium of the company ControlMed specialized in Trichogramma parasitoid production. All equipment used for green lacewing larvae and adult rearing was newly designed for this study. Two diets were given to larvae and adults to assess their biological performances. The first diet was based on pollen for adults and eggs of Ephestia kuehniella for larvae. The second diet consisting of a pasty mixture of honey, yeast and eggs of E. kuehniella, was supplied to adults and larvae. The laboratory rearing conditions were kept constant with 26 ± 2°C, 65 ± 5% RH and a photoperiod of 16L: 8D. The diets based on pollen and E. kuehniella eggs gave the best biological parameters for both adults and larvae. This study which allowed to design a simple technique to rear green lacewing based on affordable material, is a first step for developing a mass rearing of chrysopids in Tunisia. However, further improvements are required for adult and larvae diets to increase reproductive and developmental performance, as well as an economic feasibility study.

Identification of different Chrysoperla (Neuroptera: Chrysopidae) species collected from Ardabil province (Iran) by using claw shape

The family Chrysopidae has several genera of which the genus Chrysoperla is more important of them. These lacewings are beneficial insects when they have high potential for predation on harmful aphids which can be used in their biological control programs. Due to high importance of these lacewings in Ardabil province in northwest zone of Iran, identification of their species was done. By examining the collected specimens with morphological features, wing venation, male reproductive organ, and claws shape (as the best way to identify the species) fi nally 4 species were identified including Chrysoperla carnea (Stephens), Chrysoperla kolthoffi Navas, Chrysoperla lucasina Lacroix, and Chrysoperla sillemi Esben-Petresen.

The suitability of native flowers as pollen sources for Chrysoperla lucasina (Neuroptera: Chrysopidae).

Green lacewings (Neuroptera: Chrysopidae) are key biological control agents found in a broad range of crops. Given the importance of enhancing their presence and conservation, in this study, we aim to identify and to determine the relative importance of the pollen consumed by Chrysoperla lucasina (Lacroix, 1936) from 29 pollen types offered by 51 native plant species sown in an experimental farm in Villarrubia in the south of Spain. For the purposes of this study, C. lucasina specimens were captured in the late spring of 2016 and 2017. The pollen types and other components in the alimentary canal of C. lucasina were microscopically identified using the transparency method, which is a novel technique applied to green lacewings captured in the field. The results show that (i) C. lucasina feeds on over half of the pollen types offered by the sown plant species, with no differences in behaviour by sex or year; (ii) Capsella bursa-pastoris was the most frequently identified pollen type in the alimentary canal; (iii) the majority of pollen types identified correspond to sown native plant species and not to surrounding plant species; and that (iv) most of the adults studied also consumed honeydew. Our feeding study has important implications for the selection of plant mixtures for ground cover restoration and flower vegetation strips in Mediterranean agroecosystems, which complements our previous findings on how C. lucasina use native plant species as host and reproduction sites. The plant species Capsella bursa-pastoris and Biscutella auriculata, which are best suited to provide pollen, host and reproduction sites for C. lucasina in late spring, should consequently be included in the proposed plant mixtures for Mediterranean agroecosystems.

Attraction of green lacewings (Neuroptera: Chrysopidae) to native plants used as ground cover in woody Mediterranean agroecosystems

Using native seeds to establish semi-natural habitats is a novel strategy to restore biodiversity and ecosystem services such as biological control. As green lacewings (Neuroptera: Chrysopidae) are regarded as major biological control agents in different crops, the objective of this study was to test the attractiveness of selected native plant species to lacewings. During a two-year (2016–2017) field experiment near Villarrubia (Andalusia, Spain), 42 native plant species belonging to 13 families were planted. Plant development was monitored, and arthropods were vacuumed from each plot twice during the peak May flowering period. Green lacewings were observed to use 28 of the 36 well developed species to reproduce, feed and/or rest. Chrysoperla lucasina was the predominant species among the captured adults. No clear pattern of attraction common to all species was observed during the two-year sampling period. In 2017, eight plant species showed above-average chrysopid abundance. In addition, Acari abundance correlated positively with chrysopid abundance. Given the attraction of chrysopids, the effect of pests and disease on olive orchards and satisfactory plant development, we consider Biscutella auriculata, Borago officinalis, Silene colorata, Crepis capillaris, Nigella damascena and Papaver rhoeas to be the native plant species best suited to host chrysopids and to restore ground cover in perennial Mediterranean crops.

Abundance and Population Decline Factors of Chrysopid Juveniles in Olive Groves and Adjacent Trees.

Numerous species of the family Chrysopidae, commonly found in agroecosystems, whose larvae predate on several pests of economic importance, are regarded as biological control agents. Their abundance and diversity are influenced by vegetation cover, although little is known about the effects of semi-natural habitats on their populations. The objective of this study is to gain a better understanding of the relationship between the trees in semi-natural habitats adjacent to olive groves, juvenile stages of the family Chrysopidae and factors influencing their population decline, which is crucial for an effective habitat management program aimed at conserving these important predators. Using cardboard band traps (eight per tree), the juvenile stages were collected from 25 almond, oak, olive and pine trees over a one-year sampling period. The population decline was caused by parasitoids (26.5%), predators (5.1%) and unknown factors (13.2%). In addition, chrysopids established in olive trees showed the lowest rate of parasitism. We identified ten chrysopid species that emerged from the juveniles collected from almond, oak, olive and pine trees, with a predominance of Pseudomallada prasinus. The chrysopid–parasitoid complex was composed of five species; Baryscapus impeditus (Eulophidae), which was the most abundant, was preferentially associated with Chrysopa pallens, Chrysoperla lucasina and Chrysoperla mediterranea.

Late Summer Oviposition of Green Lacewings (Neuroptera: Chrysopidae) on Olive Groves and Adjacent Trees.

In this study, we assess how chrysopids (generalist predators widely used as biological control agents) use olive, almond, oak, and pine trees for oviposition. We sampled clutches of chrysopids from tree canopies in August 2016 and 2017. Additionally, we checked the stage (alive, predated, emerged, or parasitized) and the site (upper side, edge, or underside of leaves) and mode (single and cluster clutches) for oviposition in every clutch. The clutches collected alive in August 2016 were raised in the laboratory and identified to species level. No differences in clutch abundance were observed amongst tree species, years and locations, suggesting that chrysopids are geographically well spread and that all of the tree species are equally suitable to support clutches of active chrysopids in this period. Additionally, chrysopids preferred to lay their clutches on the edge and upper side of the leaves and the single clutches were the most frequent. We collected clutches of 9 chrysopid species (Neuroptera: Chrysopidae) belonging to four genera, from which Pseudomallada prasinus (Burmeister, 1839), Cunctochrysa baetica (Hölzel, 1972), and Chrysoperla mutata (McLachlan, 1898) were the most abundant. The almond trees shelter the highest chrysopid species richness. We found C. mutata as the only Chrysoperla Steinmann, 1964 species laying on the olive trees and Chrysoperla lucasina (Lacroix, 1912) and Chrysoperla pallida Henry et al., 2002 on the almond trees. Although every tree species is able to shelter a similar abundance of eggs of chrysopids, conserving different trees ensures the existence of a diverse assemblage of chrysopids that might respond to periodical perturbations and moves to olive groves in the case of a pest outbreak.

Biological control of mealybugs with lacewing larvae is affected by the presence and type of supplemental prey

The diversity of prey and food sources in crops has a major effect on biological pest control by generalist predators. In this study, we tested if and how supplemental prey or food affects the control of the citrus mealybug Planococcus citri (Risso) by larvae of the green lacewing Chrysoperla lucasina (Lacroix). The larvae of this predator are the only stage that feed on prey, thus ideally the supplemental food should result in high larval survival but a low developmental rate. Juvenile survival and developmental time of lacewing larvae were measured on various food items, either alone or mixed with mealybugs. Mealybugs were a suboptimal prey: up to 50 % of the lacewing larvae died before they reached the pupal stage and the developmental time was relatively long when feeding exclusively on mealybugs. Mixing mealybugs with supplemental prey increased larval survival, but also reduced larval developmental time and thereby the period in which the larvae could prey on mealybugs. Moreover, adding eggs of Ephestia kuehniella Zeller, which appeared to be of high quality for lacewings, reduced the consumption of mealybugs by lacewing larvae in the laboratory. The addition of the prey mite Acarus siro (L.) also reduced larval mortality, but did not reduce mealybug predation rates by lacewing larvae. Greenhouse trials showed better mealybug control by lacewing larvae with supplemental prey of low quality (prey mites) rather than alternative prey of high quality (Ephestia eggs). In conclusion, biological control of mealybugs by lacewing larvae was strongly affected by the nutritional quality of the supplemental food source.

PROGRAM PETAAL: A BIOCONTROL STRATEGY OF THE SYCAMORE LACE BUG CORYTHUCHA CILIATE (SAY) (HEMIPTERA: TINGIDAE) IN URBAN AREAS

The aim of the study was to propose a biocontrol strategy of the sycamore lace bug Corythucha ciliate (Say) combining four successive treatments of entomopathogenic nematodes (EPN) (Steinernema spp.) and the predatory insect Chrysoperla lucasina. Based on the results of former trials realized as part of the project, this strategy has been implemented in situ in six cities of different climatic regions of France. The 1st treatment with EPN on trunk, targeting overwintering adults of C. ciliate, showed a significant reduction of 60% of pest populations. The 2nd treatment with EPN enabled to reduce populations on foliage of about 50%, three weeks after application whereas the 3rd treatment, an eggs’ release of C. lucasina targeting first larval population of C. ciliate, did not show any efficacy on the whole, except on one site. Finally, the curative effect of the 4th treatment with EPN, applied at the time of the summer populations’ peak of the sycamore lace bug, could not be evaluated given that C. ciliate populations dropped drastically at this period.

Within-Species Mate Preferences Do Not Contribute to the Maintenance of Sexually Monomorphic Mating Signals in Green Lacewings

We know much less about the evolutionary forces and constraints that maintain similar mating displays in females and males than we do about sexually dimorphic mating displays. Both female and male green lacewings have sexually monomorphic vibrational mating signals and are equally choosy against heterospecific mating signals. This similarity in between-species sex roles may explain a large part of the presence of species-specific female signals in these species, but does not necessarily predict why female and male signals are similar. We tested for within-species sex-specific similarities in mate preferences in Chrysoperla lucasina that may contribute to the maintenance of sexually monomorphic mating signals in this species. We found weak preferences and low levels of discrimination for signals with varying fine-scale temporal features (volley duration, period, and volley-duty cycle). The longer signals that both sexes produced in response to playback were sexually monomorphic, but some females and most males also produced shorter signals with significantly reduced volley durations and periods. Notably, all of these signals had indistinguishable volley-duty cycles, the ratio of volley duration to volley period. We propose that mating signals in C. lucasina are maintained in both sexes because of similar between-species mate preferences, but the sexually monomorphic mating signals cannot be attributed to significant within-species mate preferences. What differences are present in within-species sex roles may be resolved by a male-biased signal polymorphism, in long and short signals that are hypothesized to have distinct functions during mate calling and courtship.

Predators of Marchalina hellenica (Hemiptera: Marchalinidae) on pine forests in Turkey

The honeydew of Marchalina hellenica is collected by honeybees for pine honey production, which is of great economic importance in Turkey. During 2009–2011 we investigated the predators of M. hellenica, which is distributed mainly in the areas with a Mediterranean climate – in the Aegean, Marmara and Mediterranean regions of Turkey. The findings showed that M. hellenica has many predators in the studied areas and that these play an important role in the forest ecosystem. These predators are: Anystis baccarum (L.) (Acarina: Anystidae); Allothrombium triticium Zhang and Allothrombium pulvinum Ewing (Acarina: Trombidiidae); Neoleucopis kartliana (Tanasijtshuk) (Diptera: Chamaemyiidae); Myrrha octodecimguttata (L.), Rodolia cardinalis Mulstant, Scymnus subvillosus (Goeze) (Coleoptera: Coccinellidae), Dichochrysa genei (Rambur), Dichochrysa prasina (Burmeister) and Chrysoperla lucasina (Lacroix) (Neuroptera: Chrysopidae); Wesmaelius subnebulosus (Stephens) (Neuroptera: Hemerobiidae), Cardiastethus nazarenus Reuter and Elatophilus pachycnemis Horvath (Hemiptera: Anthocoridae). The most efficient and common predator was N. kartliana, here recorded for the first time from Turkey.

Identification of Semiochemicals Released by Cotton, Gossypium hirsutum, Upon Infestation by the Cotton Aphid, Aphis gossypii

The cotton aphid, Aphis gossypii (Homoptera: Aphididae), is increasing in importance as a pest worldwide since the introduction of Bt-cotton, which controls lepidopteran but not homopteran pests. The chemical ecology of interactions between cotton, Gossypium hirsutum (Malvaceae), A. gossypii, and the predatory lacewing Chrysoperla lucasina (Neuroptera: Chrysopidae), was investigated with a view to providing new pest management strategies. Behavioral tests using a four-arm (Pettersson) olfactometer showed that alate A. gossypii spent significantly more time in the presence of odor from uninfested cotton seedlings compared to clean air, but significantly less time in the presence of odor from A. gossypii infested plants. A. gossypii also spent significantly more time in the presence of headspace samples of volatile organic compounds (VOCs) obtained from uninfested cotton seedlings, but significantly less time with those from A. gossypii infested plants. VOCs from uninfested and A. gossypii infested cotton seedlings were analyzed by gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS), leading to the identification of (Z)-3-hexenyl acetate, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT), which were produced in larger amounts from A. gossypii infested plants compared to uninfested plants. In behavioral tests, A. gossypii spent significantly more time in the control (solvent) arms when presented with a synthetic blend of these four compounds, with and without the presence of VOCs from uninfested cotton. Coupled GC-electroantennogram (EAG) recordings with the lacewing C. lucasina showed significant antennal responses to VOCs from A. gossypii infested cotton, suggesting they have a role in indirect defense and indicating a likely behavioral role for these compounds for the predator as well as the aphid.

Seasonal occurrence and biological parameters of the common green lacewing predators of the common pistachio psylla, Agonoscena pistaciae (Hemiptera: Psylloidea)

Species in the carnea complex of the common green lacewing are predators of the common pistachio psylla, Agonoscena pistaciae in both cultivated pistachio plantations and on wild pistachio plants in Iran. The seasonal occurrence of common green lacewings was monitored in pistachio orchards from 2007 to 2008. In addition, the effect of different temperature regimes on prei- maginal development, survival and prey consumption of the predatory lacewing Chrysoperla lucasina fed on A. pistaciae nymphs were studied under controlled conditions. The adults of common green lacewings first appeared on pistachio trees in mid April and were most abundant in early July, decreased in abundance in summer and increased again in October. The relative density of common green lacewings was higher in pistachio orchards where the ground was covered with herbaceous weeds than in those without weeds. In the laboratory females of C. lucasina laid an average of 1085 eggs over 60 days at 22.5°C. The maximum prey consumption occurred at 35°C when the larvae consumed 1812 fourth instar psyllid nymphs during their larval period. The intrinsic rate of natural increase (rm) was 0.11. The total development (egg-adult) required 385 degree-days above the theoretical lower devel- opmental threshold of 9.6°C.