Lacewing Larvae Research Articles

Relative consumption of three aphid species by the lacewing, Chrysoperla rufilabris, and effects on its development and survival

Relative consumption of three aphid species, Aphis gossypii Glover, Myzus persicae (Sulzer) and Lipaphis erysimi (Kaltenbach) (Homoptera: Aphididae), by larvae of the lacewing, Chrysoperla rufilabris (Burmeister) (Neuroptera: Chrysopidae), was determined in the laboratory, together with effects on lacewing development and survival. Percentages of survival of C. rufilabris from first instar to adult eclosion were significantly different among lacewing larvae fed different aphid species. When larvae were fed A. gossypii and M. persicae, all larvae developed to adulthood. All larvae died prematurely when they were fed L. erysimi. Developmental duration of C. rufilabris larvae was significantly shorter when larvae were fed A. gossypii (18.0 d) than when larvae were fed M. persicae (19.2 d). The number of fourth instar aphids consumed during development by C. rufilabris larvae differed significantly among individuals fed different aphid species. Chrysoperla rufilabris consumed an average of 168 M. persicae, followed by 141.6 A. gossypii, and only 26.6 L. erysimi. The percentage of these total number of aphids consumed by each larval stadium of C. rufilabris varied significantly among aphid species. The percentage of A. gossypii consumed by each larval stadium was similar to that for M. persicae, 12.1 and 11.4% by the first instar, 15.7 and 13.1% by the second instar, and 72.2 and 75.5% by the third instar, respectively; whereas in the case of L. erysimi, 23.3% of the total number of aphids were consumed by the first instar, 30.1% by the second instar, and 46.6% by the third instar.

Evaluation of Green Lacewings for Suppressing Azalea Lace Bug Populations in Nurseries

Abstract Greenhouse and nursery studies were conducted to determine an optimal release rate and efficacy of green lacewing (glw) larvae, Chrysoperla carnea (Stephens), for suppression of azalea lace bug (alb), Stephanitis pyrioides (Scott). In a greenhouse study, different densities of lace bugs (40 or 80 per plant) did not influence the percent mortality caused by green lacewings. However, greater numbers of green lacewing larvae released resulted in higher lace bug mortality (5 and 20 glw per plant resulted in an average lace bug mortality of 79% and 97%, respectively). Lacewing larvae released in a production nursery, at rates of 5/plant and 10/plant, and acephate (Orthene) significantly reduced lace bug populations, with green lacewings at 10/plant and acephate reducing lace bug densities more than green lacewings at 5/plant. In a second nursery trial, lacewing larvae released into production blocks of azaleas resulted in a 97% reduction in lace bugs. These studies suggest that augmentative release of green lacewing larvae may provide an alternative control tactic that can be integrated into lace bug pest management programs.

Selection of Molting and Pupation Sites byColeomegilla maculata(Coleoptera: Coccinellidae): Avoidance of Intraguild Predation

Molting and pupating insects are especially vulnerable to natural enemies and one possible component of their defensive strategy is the selection of suitable microhabitats. We hypothesized that larvae of the lady beetle Coleomegilla maculata lengi Timberlake select molting and pupation sites that effectively reduce their susceptibility to intraguild predation. We characterized microsites on potato plants and evaluated their associated risk of predation by the lacewing Chrysoperla rufilabris Burmeister (Neuroptera: Chrysopidae), a common intraguild predator. The majority of molts (>60%) occurred on potato plants in sites similar to those used by mobile coccinellid larvae. In contrast, 90% of the larvae left the plant to pupate. Second, third, and fourth instars selected artificial shelters for both molting and pupation when these were available. Vulnerability of pupae and newly molted larvae to lacewing larvae depended on plant microsite, with leaves supporting an aphid colony as the most risky sites. Molting and pupating microhabitat selection by coccinellid larvae appears to be a trade-off between the advantages of remaining close to the aphid resource, and the costs of being exposed to intraguild predators.

Ceraeochrysa placita (Neuroptera: Chrysopidae): Generic Characteristics of Larvae, Larval Descriptions, and Life Cycle

The 3 instars of Ceraeochrysa placita (Banks) express all the traits that typify trashcarrying lacewing larvae in the tribe Chrysopini: short, broad bodies; thorax with elongate, setaceous tubercles; abdomen humped, bearing hooked setae dorsally. Based on our comparison of C. placita larvae with descriptions of larvae in other trash-carrying chrysopine genera, we propose a tentative definition of Ceraeochrysa larvae. In addition, to aid in identifying C. placita larvae, we list a series of traits that distinguishes C. placita from previously described New World trash-carrying chrysopines. One of these traits appears unique to C. placita: in addition to the 2 or 3 long setae that typically occur at the apex of the dorsolateral thoracic tubercles of all chrysopine 1st instars, on C. placita each tubercle also bears a short, stout seta apically. Whether this trait is apomorphic for Ceraeochrysa , or for C. placita , is an open question. Finally, we present a series of biological traits that distinguishes C. placita . Eggs are laid on the trunks of medium- to large-sized trees, which are also feeding sites for prediapause larvae. It has a univoltine life cycle, and the 2nd instar is the overwintering stage. Photoperiod strongly influences the life cycle; short daylengths retard development in 1st instars, induce diapause in 2nd instars, and may have a role in postdiapause development. Compared with other chrysopids, C. placita's incubation and preoviposition periods are long.

Effect of early season insecticide use on predators and outbreaks of spider mites (Acari: Tetranychidae) in cotton

AbstractThe Australian cotton industry relies almost exclusively on synthetic insecticides for control of early season pests. These insecticides often disrupt predatory insect activity in the field. Potential predators of the twospotted spider mite, Tetranychus urticae Koch, in cotton, identified in field and confirmed in laboratory experiments, included a theridiid spider, a phytoseiid mite, a lacewing larva, predatory thrips, several Coccinellidae and several Hemiptera. These predators were mostly generalists, having previously been reported as predators of aphids or caterpillars of Helicoverpa spp. The effect of insecticides on T. urticae and its predators was evaluated in three field experiments. Cotton was artificially infested with T. urticae then sprayed five times at seven to ten day intervals with either dimethoate (140 g ai/ha), thiodicarb (750 g ai/ha and 187.5 g ai/ha), endosulfan (735 g ai/ha and 367.5 g ai/ha), methomyl (169 g ai/ha) or amitraz (400 g ai/ha). Tetranychus urticae populations reached higher densities in dimethoate, thiodicarb and methomyl treated cotton than in untreated cotton. Population densities of T. urticae in cotton treated with low rates of endosulfan or thiodicarb were similar to controls, while those in cotton treated with amitraz were lower. All insecticides caused significant reductions in at least one predator group. Significant negative relationships were found between early season abundance of predators and the mid-season abundance of T. urticae and positive relationships between predators and the lag-period for T. urticae outbreaks to develop. Predation is implicated as a key factor influencing the early season survival of T. urticae. The implications for developing integrated pest management strategies in cotton are discussed.

Intraguild predation between erigonid spiders, lacewing larvae and carabids

Abstract: Petri dish experiments were conducted to study intraguild predation (IGP) between erigonid spiders (Erigone atra (Blackwall), Oedothorax apicatus (Blackwall), a carabid beetle (Pterostichus melanarius (Ill.) and lacewing, Chrysoperla carnea (Stephens) larvae. Erigonid spiders increased the mortality rates of lacewing larvae to different degrees, depending on the species and sex of spider concerned. The effect of spiders on lacewing larvae was highest (up to nearly 100% mortality) in the absence of alternative prey. In the presence of three or 20 aphids (Sitobion avenae Fab.) female erigonids increased the mortality rates of lacewing larvae compared to controls, but predation on lacewing larvae decreased in the presence of increasing numbers of aphids. Males of O. apicatus caused no significant increase in mortality rate of lacewing larvae in the presence of aphids. Lacewing larvae (L2‐larvae and L3‐larvae) did not kill erigonid spiders. IGP between the female erigonids E. atra and O. apicatus was not found. P. melanarius fed on lacewing larvae and on erigonid spiders, and E. atra was preferred over O. apicatus. The sex‐specific and species‐specific IGP rates of spiders on lacewing larvae and the great influence of alternative prey on IGP rate reveal a general problem when data resulting from one sexual stage or one species or one feeding regime are generalized to a whole arthropod group. Moreover, the results suggest that an increase of top predators, such as carabid beetles, which prey only to a limited extent on the pest species itself, may affect natural insect pest control by IGP.

Laboratory study of Chrysoperla carnea (Stephens) (Neuropt., Chrysopidae) predation on Trialeurodes vaporariorum (Westwood) (Hom., Aleyrodidae)

Abstract: Larvae of the green lacewing, Chrysoperla carnea (Stephens), were raised on immature stages of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood). Whitefly of all stages were consumed, but none of the lacewings survived to pupation. First instar lacewings fed on whitefly eggs survived longest. Eggs and first larval instar whitefly were eaten in the greatest quantities. In a second experiment, lacewing first instar larvae were fed on whitefly eggs plus a food supplement. They did not survive longer than those fed on whitefly eggs alone. It is concluded that although they would not survive to produce a stable population in the greenhouse, inundative releases of lacewing larvae might be effective as a supplementary control method.

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.

Ontogenetic change of prey preference in the generalist predator Zelus renardii and its influence on predator–predator interactions

1. Two field experiments were conducted to test the hypothesis that the intensity of predation by a generalist predator on two species of prey changes with the developmental stage of the predator. The generalist predator studied was Zelus renardii Kolenati (Hemiptera: Reduviidae) and the prey were the lacewing larva, Chrysoperla carnea Stephens, and the cotton aphid, Aphis gossypii Glover.2. Zelus renardii and lacewings feed on aphids, thereby acting as potential competitors. In addition, Z. renardii feeds on lacewings. Thus, Z. renardii is an intraguild predator of lacewings.3. Zelus renardii exhibited changes in prey preferences across developmental stages. The older stages of Z. renardii exerted greater mortality on lacewings and fed on larger lacewing larvae than did the younger stages.4. Lacewings suppressed aphid population growth strongly. In contrast, none of the stages of Z. renardii was an effective control agent of the cotton aphid.5. The addition of Z. renardii frequently disrupted the effective control of aphids generated by lacewings. In one of the two replicates of the experiment, the disruption increased with the developmental stage of Z. renardii, paralleling the increase in lacewing mortality.6. Although the developmental stage of Z. renardii can influence the prevalence of intraguild predation and the intensity of the disruption of the aphid biological control, these experiments have demonstrated that even the youngest instars of Z. renardii can cause substantial lacewing mortality and release aphid populations from regulation.

Effects of Mechanical Handling on Green Lacewing Larvae (Chrysoperla Rufilabris)

Lacewing larvae (Chrysoperla rufilabris), used for biological control of insect pests, are typically released by hand for treatment of small-scale ornamental and fruit crops. This study investigated the potential for mechanical release of larvae. Second instar larvae were mixed into vermiculite and rice hull carriers and subjected to vibrational and rotational motion. The number of live, mobile larvae reclaimed from the treated material was determined. While the mechanical treatments did not significantly reduce the number of mobile larvae recovered, rotation resulted in slightly greater larval damage than vibration.

Laboratory Activity of Spinosad on Non-Target Beneficial Arthropods, 1994

Abstract This report details the results of a number of laboratory tests on spinosad as spray-dried broth (NAF-144) and an extracted 480 gms/liter SC (NAF-85) against a variety of beneficial organisms. All beneficial insects were obtained from a commercial supplier, Nature’s Control, P.O. Box 35, Medford, OR 97501. For topical, honey bee tests, the bees were confined to a petri dish and then sprayed with a hand syringe. For contact exposure, the exposure units consisted of glass tubes, 7.5 cm. long × 4 cm. in diameter. The tubes were treated by applying a uniform film to the inside of the glass tube using a fine DeVilbis sprayer. Materials were field applied to ‘Courtland’ Apples during bloom. Branches were harvested at 0, 16, 24, and 40 hours post spray. Bees were caged in the laboratory with the treated blossoms. The experiment was held at 40-50% RH and 23°C. The exposure units for Encarsia were treated by applying a uniform film to the inside of the glass tube using a fine DeVilbis sprayer. Ten newly emerged adult Encarsia formosa were aspired from the emergence chamber into each of the treated vials which were then capped with fine muslin. For Orius and Hippodamia and Lacewing exposure units were created by first treating the glass sheet by applying an even film of pesticide using a DeVilbis nozzle. After the sheet was dry, the Plexiglas sheet was placed on top of the glass sheet. 5 cm. tall rings were coated with Fluon and placed in holes drilled in the Plexiglas sheet and seated firmly against the glass creating separate exposure units. Each exposure unit was capped with muslin held in place with rubber bands. For the treated prey ingestion studies in the ladybird beetle test, squash leaves heavily infested with aphids were sprayed to run off and the treated aphids were driven off into the cage to be consumed by the beetles. Second instar, green lacewing larvae were fed tobacco budworm eggs which had been killed by freezing and treated by swirling them in formulated pesticides. For predatory mites, an even film of pesticide was applied to each leaf using a hand held syringe. After the leaves were dry, they were trimmed to an approximate diameter of 4 cm. and placed abaxial side up on agar in a petri dish. Five adult female predator mites were transferred by hand to each leaf. Tests were held under ambient laboratory conditions of approximately 23°C and 50% RH for 72 hours at which time, they were graded for mortality. LC50’s were generated using the Trimmed Spearman Karber method.

Indirect Effect of Insecticides Used in Pecan Orchards to Larvae of Chrysoperla rufilabris (Neuroptera: Chrysopidae)

Eight insecticides at two concentrations (low and high) were tested for toxicity to first, second, and third instars of Chrysoperla rufilabris (Burmeister). Lindane (0.65 and 1.3 g actual insecticide AI/l), endosulfan (0.375 and 0.75 g AI/l), carbaryl (1.2 and 2.4 g AI/l), azinphos-methyl (1.0 and 2.0 g AI/l, malathion (0.9 and 1.8 g AI/l), methomyl (0.225 and 0.45 g AI/l), phosmet (0.375 and 0.75 g AI/l), and esfenvalerate (0.0.15 and 0.03 g AI/l) treated cowpea aphids (Aphis craccivora Koch) were fed to the lacewing larvae in the laboratory. Among tested insecticides, azinphos-methyl was the most toxic insecticide to larvae at the low and high rates and was classified as moderately harmful. Lindane and carbaryl were slightly harmful; endosulfan, malathion, methomyl, phosmet, and esfenvalerate were harmless. In most cases the first instar larvae were the most susceptible to the insecticides tested. Both rates caused similar mortality of C. rufilabris larvae after 48 h of feeding with the exception of azinphos-methyl and methomyl which caused higher mortality at the high rate.

Influence of larval food consumption on the fecundity of the lacewing Chrysoperla carnea

AbstractThe effects of food consumption on larval growth and development and adult fecundity of the common green lacewing, Chrysoperla carnea (Stephens), were studied on two populations of larvae derived from either a laboratory colony or from field‐collected adults. The number of eggs of the Mediterranean flour moth, Anagasta kuehniella (Zeller), provided to individual lacewing larvae was varied to produce three food‐supply treatments: low, intermediate, and high. Food‐supply was found to influence larval growth and development and adult fecundity. Lacewing larvae provided with an overabundance of moth eggs developed faster than larvae provided with fewer moth eggs than they could have consumed. Adult females that developed from the high feeding treatment had a substantially shorter preoviposition period, a later decline in egg deposition, and a significantly higher fecundity than adults arising from the other feeding classes. Unrestricted feeding by adult lacewings on an artificial diet did not compensate for prior low feeding regimes. The overall performance of the lacewings derived from the laboratory colony was substantially poorer than that of the lacewings derived from field‐collected adults. This effect was accentuated when the larvae were given a low food‐supply. This overall decrease in vigor is attributed to inbreeding of the laboratory culture over a one year period. These finds are relevant to mass rearing programs for this biological control agent.

Pyrethroid Esterase(s) May Contribute to Natural Pyrethroid Tolerance of Larvae of the Common Green Lacewing 1

Larvae of the common green lacewing, Chrysopa carnea Stephens1, have a remarkable natural tolerance to pyrethroids, providing important selectivity in integrated control programs. A portion of this tolerance is attributable to detoxification by pyrethroid esterase(s). This larval enzyme(s) has unusually high activity and a unique specificity for hydrolyzing cis -permethrin and -cypermethrin two- to three-fold faster than the corresponding trans -isomers. Deltamethrin is also hydrolyzed rapidly. Certain properties of the larval pyrethroid esterase(s) parallel the sensitivity of the larvae to pyrethroid poisoning. Larval pyrethroid esterase(s) increases in activity for hydrolyzing trans -permethrin on larval growth in agreement with the increased tolerance to trans -permethrin poisoning. The relative rates of hydrolysis of deltamethrin and the cis - and trans -isomers of permethrin and cypermethrin by the larval pyrethroid esterase(s) generally coincide with the tolerance of the larvae to these pyrethroids. Phenyl saligenin cyclic phosphonate, a potent inhibitor for larval pyrethroid esterase, synergizes trans -permethrin toxicity by 68-fold from an LD50 of 17,000 μg/g to one of 250 μg/g. Although the involvement of penetration rates, nerve sensitivity, and oxidative detoxification has not been evaluated, it is clear that pyrethroid esterase(s) is a major factor contributing to the natural pyrethroid tolerance of lacewing larvae.

PREDATION ON ADULTS OF THE FLEA BEETLE PHYLLOTRETA CRUCIFERAE BY LACEWING LARVAE (NEUROPTERA: CHRYSOPIDAE)

Several instances of predation by lacewing larvae on adults of the flea beetle Phyllotreta cruciferae (Goeze) have been observed in Saskatchewan. Other reported insect predators of rapeseed-crop-infesting flea beetles in the Canadian prairie provinces are the beetle Collops vittatus Say (Gerber and Osgood 1975), and one of the big-eyed bugs, Geocoris bullatus (Say) (Burgess 1977).The first observation of an attack on an adult flea beetle by a lacewing larva was in August 1972, when some lacewing larvae, adult flea beetles, diamondback moth larvae (Plutella xylostella (L.)) and unidentified aphids and midges were swept from maturing rapeseed near Aberdeen, Saskatchewan. One of these lacewing larvae attacked an adult of P. cruczferae in a glass collecting-vial and carried the flea beetle around in its jaws. Other lacewing larvae attacked aphids, midges, and diamondback moth larvae. Further evidence for lacewing larvae feeding on adult flea beetles was obtained in August 1979, when a sizeable population of lacewing larvae in a rapeseed crop was encountered near St. Gregor, Saskatchewan. One of the larvae swept from this crop had an adult of P. cruciferae in its jaws when it was first seen in the sweep net. Later the same day, another lacewing larva, swept from a nearby rapeseed field, attacked an adult of P. cruciferae in a collecting vial. In the laboratory both lacewing larvae, still carrying their prey, were quick-frozen, preserved in 70% ethanol and later photographed.

Viability of the epizoic lichen flora carried and dispersed by green lacewing (Nodita pavida) larvae

Specimens of green lacewing (Nodita pavida) larvae were collected in oak–hickory stands in southern Ohio. Lacewing larvae construct and carry 'packets' of cryptogamic vegetation upon their backs, a habit which camouflages them from predators and prey. Light and scanning electron microscopy were used to elucidate the attachment and composition of the packets, which consist of lichen soredia and thallus fragments, pieces of bark, moss gametophyte fragments, angiosperm pollen grains, fungal spores, and other plant and insect debris. Rates of net photosynthesis and respiration of lichen diaspores removed from lacewing packets were found to be similar to those of independent lichen thalli growing on trees where the larvae were collected. Viability of lichen propagules on lacewing cocoons attached to the bark substrate was further demonstrated. A discussion is presented in which this unique dispersal mechanism for viable lichen propagules is considered together with the adaptive value of insect camouflage.

Accumulation and effects of methyl mercury hydroxide in a terrestrial food chain under laboratory conditions

Seedlings of tomato ( Lycopersicon esculentum Mill.), corn ( Zea mays L.) and bean ( Phaseolus vulgaris L.) were grown in complete nutrient solutions containing methyl mercury hydroxide (MMH). Aphids ( Macrosiphum gei Ashmead) and green lacewing larvae ( Chysopa carnea Stephens) were reared on the plants. Experiments were designed to examine the rate of accumulation and sensitivity to MMH. Tomatoes were killed within four to eight days at concentrations of MMH exceeding 0·05 ppm. Growth was inhibited by concentrations of 0·01 ppm for tomatoes and 0·05 ppm for corn and beans. Maximum mercury concentrations were found on the second day of treatment in tomato foliage, on the fourth day in aphids and on the sixth day in lacewings. Tomatoes, grown in 0·006 ppm MMH solutions for two days, concentrated mercury in foliage to 250 times while aphids and lacewings concentrated mercury to 1670 and 4178 times the concentration in treatment solutions, respectively. Significant decrease in fecundity and increase in development time occurred when aphids fed on tomatoes growing in 0·02 ppm MMH.

Lace wing Larvae Control Aphids on Greenhouse Snapdragons1

Abstract Eight lacewing (Chrysopa earned) larvae per greenhouse snapdragon (Antirrhinum majus), released 4 at a time twice during 8 weeks effectively controlled aphids (Myzus persicae). Two initial sprays of malathion and nicotine sulfate 1 week apart followed by release of 4 lacewing larvae per plant also were effective. Flowers produced under chemical or biological control systems were equal in quality. Lacewing larvae in a 21°C greenhouse required a week longer to effectively control aphids than those in a 24°C greenhouse.

Preferences of Golden-Eye Lacewing Larvae for Pea Aphids, Leafhopper and Plant Bug Nymphs, and Alfalfa Weevil Larvae

Preferences of Golden-Eye Lacewing Larvae for Pea Aphids, Leafhopper and Plant Bug Nymphs, and Alfalfa Weevil Larvae