Testing the Effects of Prey Type on the Life History and Population-Level Parameters of Chrysoperla externa (Neuroptera: Chrysopidae).

Green lacewings are valuable predators, utilized in augmentative biological control against various agricultural pests. However, further studies are required to comprehend the performance of these predators when consuming natural prey. We investigated the capacity of Chrysoperla externa (Hagen) to utilize the following three distinct prey types: the pupae of the coffee leaf miner Leucoptera coffeella (Guérin-Mèneville & Perrottet), the eggs of the sugarcane borer Diatraea saccharalis (F.), and the eggs of the Mediterranean flour moth Ephestia kuehniella (Zeller). The first two of these species are naturally occurring prey found in field crops, while the last serves as a factitious prey species for the mass rearing of natural enemies. We hypothesized that the type of prey would differentially affect the life history and population-level parameters of C. externa. Laboratory experiments were conducted to compare the pre-imaginal survival and developmental times, adult longevity and reproduction, and population growth of C. externa when larvae were provided with each of the three prey items. Results indicated that C. externa utilized the two natural prey items, L. coffeella pupae and D. saccharalis eggs, for its development, reproduction, and population growth. However, larvae developed significantly faster and females exhibited higher reproductive parameters, including fecundity and daily oviposition, when consuming the factitious prey, E. kuehniella eggs. This resulted in a higher intrinsic rate of population increase, as well as shorter times for the population to double in size. Understanding the population dynamics of C. externa when consuming different prey items is crucial for optimizing their utilization in augmentative biological control programs.

Functional response of 3 green lacewing species (Neuroptera: Chrysopidae) to Leucoptera coffeella (Lepidoptera: Lyonetiidae).

Green lacewings (Neuroptera: Chrysopidae) are predators commonly found in coffee plantations in Brazil that can serve as important biological control agents against insect pests such as the coffee leaf miner, Leucoptera coffeella (Lepidoptera: Lyonetiidae). However, the efficacy of different lacewing species in controlling L. coffeella needs to be evaluated before they are used in augmentative biological control programs. Here, laboratory experiments were conducted to investigate the effects of the L. coffeella developmental stage on the functional response of 3 species of green lacewings: Chrysoperla externa, Ceraeochrysa cincta, and Ceraeochrysa cornuta. The attack rate, handling time, and the number of prey attacked during 24 h with different densities (1, 2, 4, 8, 16, 32, and 64 individuals) of either L. coffeella larvae or pupae were recorded for each of the 3 lacewing species. Based on logistic regression models, all 3 predators showed a Type II functional response when consuming both larvae and pupae of L. coffeella. All 3 species also had similar attack rates (0.0091 larva/h and 0.0095 pupa/h), handling times (3.5 and 3.7 h for larvae and pupae, respectively), and estimated number of prey attacked during the observation period (6.9 larvae and 6.6 pupae) for L. coffeella larvae and pupae. Therefore, our laboratory studies show that the 3 green lacewings Ch. externa, Ce. cincta, and Ce. cornuta have potential for the biological control of L. coffeella, although these results need to be confirmed under field conditions. These findings have implications for the selection of lacewings for augmentative L. coffeella biocontrol.

Morphology of the male and female reproductive tracts of virgin and mated Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae).

Predatory insects have reproductive organs rich in complex changes that may be responsible for the success of their population growth. The species Chrysoperla externa is a predator used in biological control programs in Latin America. However, there is no morphological data about the morphology of the reproductive tract in this insect. This study describes the morphology of the reproductive organs of virgin and mated C. externa male and female. The male has a pair of testes yellow in color and five pairs of accessory glands closely associated with the seminal vesicles. The testis follicles are twisted filled with cysts in different developmental stages. The pair of ovaries in the females shows asymmetry with 9-11 ovarioles per ovary with oocytes in different developmental stages and a spherical spermatheca. Virgin and mated males have no differences in the size of the testes, seminal vesicle, and accessory glands. C. externa females show morphological changes in the reproductive tract according to sexual maturation, which is triggered by mating. The ovary activation occurs after female mating. The ovaries are of merotistic polytrophic type. The spermathecal reservoir is lined by a flattened epithelium with a thin cuticular intima and associated with well-developed muscles. It is concluded that the reproductive tract of C. externa is similar in virgin and mated males and females. Egg production is activated only after mating and the development of reproductive tract structures is faster in mated females.

Selectivity of Entomopathogenic Fungi to Chrysoperla externa (Neuroptera: Chrysopidae).

We aimed to evaluate the selectivity of entomopathogenic fungi to larvae of Chrysoperla externa (Neuroptera: Chrysopidae). For this purpose, Beauveria bassiana (strain ESALQ PL63), Metarhizium anisopliae (strain ESALQ E9) and Metarhizium rileyi (strain UFMS 03) were assessed at different concentrations (1 × 107, 1 × 108 and 1 × 109 conidia mL-1). The control treatment consisted of distilled water and Tween80 0.01. The treatments were applied with a Potter spray tower using two different methodologies: direct application (DA) and dry film (DF). Up to 96 h after application, no treatment provided a larval mortality above 3%. After 120 h, only B. bassiana induced significant mortality in all instars, with rates of 26%, 17% and 10% for first, second and third instar larval periods, respectively. There was no difference regarding to the application method or concentration of conidia. The percentage of individuals that revealed changes in the length of the larval and pupal periods varied among different treatments with entomopathogenic fungi and control treatments, application methodologies and concentrations. Despite B. bassiana revealing a higher mortality than M. anisopliae and M. rileyi on larvae of C. externa, these three entomopathogenic fungi may be used in association with C. externa for sustainable pest management.

Genetic Variability of Ceraeochrysa cincta, Ceraeochrysa claveri, and Ceraeochrysa cubana (Neuroptera: Chrysopidae) Populations in Agroecosystems of Southeast Brazil.

The species of the genus Ceraeochrysa, known as green lacewings or trash-carriers, are widely distributed along the Americas and its islands. In Brazil, 28 species are found, including Ceraeochrysa cincta (Schneider), Ceraeochrysa claveri (Navás), and Ceraeochrysa cubana (Hagen). These species are recorded on many crops, where they are often used for biological control. For this use, knowledge of the genetic features of the species is extremely important because they are associated to the species' ability to withstand different conditions in new environments, such as variations of temperature and presence of pathogens. However, little is known about the genetic features of Ceraeochrysa species. Here, we analyze and compare the distribution of the genetic variability of C. cincta, C. claveri, and C. cubana in agroecosystem populations of southeast Brazil. We found a high genetic diversity in each of the three species, and no strong genetic structure was detected, such that genetic diversity is broadly shared among the crops and localities analyzed. We can conclude that there was a high gene flow among the sampled Ceraeochrysa populations (natural or driven by anthropic action) since the exchange of seedlings among crops can lead to the distribution of the specimens.

Interactions between Fungal-Infected Helicoverpa armigera and the Predator Chrysoperla externa.

The aim of the present study was to evaluate the interactions between Chrysoperla externa (Hagen, 1861) and the eggs and first-instar larvae of Helicoverpa armigera (Hübner 1805) infected by entomopathogenic fungi. The H. armigera eggs and larvae were treated with sterile distilled water + 0.01% Tween 80 (T1, control), Beauveria bassiana (Bals.) Vuill (T2), Metarhizium anisopliae (Metsch.) Sorok (T3), or Metarhizium rileyi (Farlow) Samson. (T4) at different concentrations (1 × 107, 1 × 108, and 1 × 109 con. mL-1). For each treatment, a single third-instar C. externa was offered prey (a combination of 80 eggs and 50 first-instar H. armigera larvae) at 0, 24, and 48 h after inoculation. Ten trials were completed for each treatment, and the entire experiment was repeated three times. Neither the concentrations of fungi nor the application method affected consumption by C. externa. Because all the predator larvae reached the pupal phase, with 100% viability in adults, these results suggest that entomopathogenic fungi and C. externa are compatible and that the simultaneous use of these biological control agents is possible for managing H. armigera.

Selectivity of pesticides used in peach orchards to eggs and pupae of the predators Chrysoperla externa and Coleomegilla quadrifasciata / Seletividade de produtos fitossanitários utilizados na cultura do pessegueiro a ovos e pupas dos predadores Chrysoperla externa e Coleomegilla quadrifasciata

This study aimed to assess, under laboratory conditions, the selectivity of nine pesticides used in peach to the egg and pupal stages of the predators Chrysoperla externa and Coleomegilla quadrifasciata. Tests consisted of the direct application of pesticides on eggs and pupae of predators and assessment of sublethal effects on fertility and fecundity of emerged adults. For eggs, the pesticides were classified according to the effects on the reduction of the percentage of larval hatching, while for pupae they were classified as a function of the total effect, according to the toxicity scale proposed by the International Organization for Biological and Integrated Control (IOBC). All the pesticides (used dose) were harmless (class 1) to eggs of C. externa, but abamectin (80) and copper + calcium (1%) were considered slightly harmful (class 2) to pupae. In bioassays with C. quadrifasciata, abamectin (80), deltamethrin (40), and malathion (150) were classified as slightly harmful (class 2), while fenitrothion (100) was moderately harmful (class 3) to predator eggs; in the pupal stage, abamectin (80), fenitrothion (100), and malathion (150) were considered harmful (class 4). Azadirachtin (1%), chlorantraniliprole (14), deltamethrin (40), copper + calcium (25% + 10%), and sulfur + calcium (3.5 Ba) were harmless (class 1) to eggs and pupae of C. externa and C. quadrifasciata and thus should be prioritized in sprayings for pest control in the IPM of peach.

Objetivou-se com este trabalho avaliar em laboratório a seletividade de nove produtos fitossanitários utilizados na cultura do pessegueiro sobre as fases de ovo e pupa dos predadores Chrysoperla externa e Coleomegilla quadrifasciata. Os ensaios consistiram da aplicação direta dos agrotóxicos sobre ovos e pupas dos predadores e avaliação de efeitos subletais na fertilidade e fecundidade dos adultos emergidos. Para ovos, os produtos fitossanitários foram classificados em função dos efeitos na redução da porcentagem de eclosão de larvas, e para pupas em função do efeito total, conforme a escala de toxicidade proposta pela International Organization for Biological and Integrated Control (IOBC). Todos os produtos fitossanitários (dosagem utilizada) foram inócuos (classe 1) aos ovos de C. externa, entretanto, abamectina (80) e cobre + cálcio (1%) foram considerados levemente nocivos (classe 2) às pupas. Nos bioensaios com C. quadrifasciata, abamectina (80), deltametrina (40) e malationa (150) foram classificados como levemente nocivos (classe 2), enquanto fenitrotiona (100) apresentou-se como moderadamente nocivo (classe 3) aos ovos do predador; para a fase de pupa, abamectina (80), fenitrotiona (100) e malationa (150) foram nocivos (classe 4). Os produtos Azadiractina (1%), clorantraniliprole (14), deltametrina (40), cobre + cálcio (25% + 10%) e enxofre + cálcio (3,5 Ba) são inócuos (classe 1) aos ovos e pupas de C. externa e C. quadrifasciata, e assim devem ser priorizados em pulverizações visando ao controle de pragas no MIP pessegueiro.

Selectivity of pesticides used in peach orchards to eggs and pupae of the predators Chrysoperla externa and Coleomegilla quadrifasciata / Seletividade de produtos fitossanitários utilizados na cultura do pessegueiro a ovos e pupas dos predadores Chrysoperla externa e Coleomegilla quadrifasciata

This study aimed to assess, under laboratory conditions, the selectivity of nine pesticides used in peach to the egg and pupal stages of the predators Chrysoperla externa and Coleomegilla quadrifasciata. Tests consisted of the direct application of pesticides on eggs and pupae of predators and assessment of sublethal effects on fertility and fecundity of emerged adults. For eggs, the pesticides were classified according to the effects on the reduction of the percentage of larval hatching, while for pupae they were classified as a function of the total effect, according to the toxicity scale proposed by the International Organization for Biological and Integrated Control (IOBC). All the pesticides (used dose) were harmless (class 1) to eggs of C. externa, but abamectin (80) and copper + calcium (1%) were considered slightly harmful (class 2) to pupae. In bioassays with C. quadrifasciata, abamectin (80), deltamethrin (40), and malathion (150) were classified as slightly harmful (class 2), while fenitrothion (100) was moderately harmful (class 3) to predator eggs; in the pupal stage, abamectin (80), fenitrothion (100), and malathion (150) were considered harmful (class 4). Azadirachtin (1%), chlorantraniliprole (14), deltamethrin (40), copper + calcium (25% + 10%), and sulfur + calcium (3.5 Ba) were harmless (class 1) to eggs and pupae of C. externa and C. quadrifasciata and thus should be prioritized in sprayings for pest control in the IPM of peach.(AU)

Objetivou-se com este trabalho avaliar em laboratório a seletividade de nove produtos fitossanitários utilizados na cultura do pessegueiro sobre as fases de ovo e pupa dos predadores Chrysoperla externa e Coleomegilla quadrifasciata. Os ensaios consistiram da aplicação direta dos agrotóxicos sobre ovos e pupas dos predadores e avaliação de efeitos subletais na fertilidade e fecundidade dos adultos emergidos. Para ovos, os produtos fitossanitários foram classificados em função dos efeitos na redução da porcentagem de eclosão de larvas, e para pupas em função do efeito total, conforme a escala de toxicidade proposta pela International Organization for Biological and Integrated Control (IOBC). Todos os produtos fitossanitários (dosagem utilizada) foram inócuos (classe 1) aos ovos de C. externa, entretanto, abamectina (80) e cobre + cálcio (1%) foram considerados levemente nocivos (classe 2) às pupas. Nos bioensaios com C. quadrifasciata, abamectina (80), deltametrina (40) e malationa (150) foram classificados como levemente nocivos (classe 2), enquanto fenitrotiona (100) apresentou-se como moderadamente nocivo (classe 3) aos ovos do predador; para a fase de pupa, abamectina (80), fenitrotiona (100) e malationa (150) foram nocivos (classe 4). Os produtos Azadiractina (1%), clorantraniliprole (14), deltametrina (40), cobre + cálcio (25% + 10%) e enxofre + cálcio (3,5 Ba) são inócuos (classe 1) aos ovos e pupas de C. externa e C. quadrifasciata, e assim devem ser priorizados em pulverizações visando ao controle de pragas no MIP pessegueiro.(AU)

Pest Management Systems and Insecticide Tolerance of Lacewings (Neuroptera: Chrysopidae).

Lacewings (Neuroptera: Chrysopidae) are part of the beneficial fauna found in citrus orchards under both organic and conventional pest management. Due to their importance, knowledge about susceptibility of these predators to insecticides is a key element for their use as biological control agents. We studied the inter- and intraspecific susceptibility of the following lacewing species to bifenthrin, chlorpyrifos, and imidacloprid: Ceraeochrysa cincta (Schneider) (Neuroptera: Chrysopidae), Ceraeochrysa cubana (Hagen), Ceraeochrysa paraguaria (Navás), and Chrysoperla externa (Hagen). Different concentrations of these insecticides were sprayed on first instar larvae of these lacewing species from six orchards (three organic and three conventional), and LC50s were estimated. Development and reproduction of the most common lacewing, C. cincta, from both organic and conventional management systems were also studied. Lacewings from conventional management areas do not always have greater tolerance to insecticides. Chrysoperla externa was the most susceptible species to insecticides. Ceraeochrysa cincta displayed the highest LC50 and its populations from the conventional system showed lower egg hatching but shorter egg and larval developmental time. Adults collected from orchards managed conventionally lived longer, exhibited a higher population growth rate and a reduced doubling time. Ceraeochrysa cincta was the more tolerant species to insecticides better coping with systems that rely on chemical control as the main pest management tactic used.

Sublethal and transgenerational effects of thiamethoxam applied to cotton seed on Chrysoperla externa and Harmonia axyridis.

BACKGROUND: Thiamethoxam, when applied as a seed treatment, can contaminate plant products, such as extrafloral nectar, and have non-target effects on beneficial arthropods. This study assessed the non-target effects of thiamethoxam applied to cotton seed on the life history parameters of the predators Chrysoperla externa (Neuroptera: Chrysopidae) and Harmonia axyridis (Coleoptera: Coccinellidae). RESULTS: Exposure of C. externa larvae to plants grown from thiamethoxam-treated seeds caused sublethal and transgenerational effects. Thiamethoxam treatment doubled the proportion of pharate adults and reduced egg fertility in C. externa F0 and F1 generations. In addition, the insecticide prolonged pupal developmental time in the C. externa F1 generation. Thiamethoxam treatment also had a transgenerational effect on exposed H. axyridis larvae, reducing pupal survival in the F1 generation. In the adult bioassay, thiamethoxam treatment reduced egg fertility of C. externa, prolonged the larval period, and reduced both fecundity and egg fertility of the F1 generation. Thiamethoxam also caused transgenerational effect on H. axyridis adults, reducing larval survival of the F1 generation. CONCLUSION: Thiamethoxam seed treatment was harmful for both predators, but C. externa was more affected by the insecticide than H. axyridis. © 2018 Society of Chemical Industry.

Can exposure to neem oil affect the spermatogenesis of predator Ceraeochrysa claveri?

Novel biological control methods and integrated pest management strategies are basic requirements for the development of sustainable agriculture. As a result, there is a growing demand for research on the use of plant extracts and natural enemies such as the green lacewing, Ceraeochrysa claveri, as natural pest control methods. Studies have shown that although natural compounds such as neem oil (Azadirachta indica) are effective as pest control strategies, they also cause sublethal effects on nontarget insects, such as C. claveri. The aim of this study was to examine the effects of neem oil on C. claveri testes. C. claveri larvae were fed Diatraea saccharalis eggs, which were pretreated with 0.5%, 1%, and 2% neem oil. Testes were collected from larvae, pupae, and adults and analyzed using light and electron (transmission and scanning) microscopy. Changes in cellular stress and possible cell death were also determined by TUNEL assay and the marker HSP-70. The results showed that neem oil affects the organization and distribution of cysts in the testes and the normal sequence of cyst development, causing a delay in spermatogenesis in the testes of treated insects. Tests for cellular stress and DNA fragmentation indicated there was no cellular alteration in the treated groups. Although neem oil does not induce cell death or changes in HSP-70 expression, this biopesticide negatively impacts the process of spermatogenesis and could decrease the perpetuation of this species in the agroecosystem, indicating that the use of neem oil in association with green lacewings as a biological control should be carefully evaluated.

Lethal and Sublethal Toxicity of Insecticides to the Lacewing Ceraeochrysa Cubana.

The lethal and sublethal effects of 11 insecticides on the predator Ceraeochrysa cubana (Hagen) were assessed under laboratory conditions. First-instar larvae and adults ≤ 48 h old were sprayed with the highest insecticides doses allowed to control Diaphorina citri Kuwayama in the citrus crop. The survival and duration rates of the different development stages, sex ratio, pre-oviposition period, fecundity, and fertility of the insects were evaluated. In the larval bioassay, chlorpyrifos and malathion had lethal effect which none larvae survived. Azadirachtin, lambda-cyhalothrin + chlorantraniliprole, lambda-cyhalothrin + thiamethoxam, and thiamethoxam had lethal and sublethal effects that did not allow to estimate the life table parameters because the low number of couples formed. Esfenvalerate, imidacloprid WG and SC, phosmet, and pyriproxyfen had sublethal effects which were reflected in the net reproductive rate and in the intrinsic rate of natural increase. In bioassay using adults, none of the individuals survived in the chlorpyrifos, lambda-cyhalothrin + chlorantraniliprole, lambda-cyhalothrin + thiamethoxam, malathion, or thiamethoxam treatments, and the azadirachtin, esfenvalerate, imidacloprid WG and SC, phosmet, and pyriproxyfen treatments were significantly lower compared to the control. None of the insecticides was harmless to first-instar larvae and adults of C. cubana under laboratory conditions showing their potential to reduce the efficiency of this predator.

Persistence of insecticides used in peach orchards to larvae and adults of the predator Chrysoperla externa (Neuroptera: Chrysopidae) / Persistência de inseticidas utilizados em pessegueiro sobre larvas e adultos do predador Chrysoperla externa (Neuroptera: Chrysopidae)

This work aimed to evaluate the persistence (duration of harmful activity) of five insecticides used for pest control in peach orchards, on larvae and adults of the predator Chrysoperla externa. The insecticides were sprayed on cv. Bordô vine plants using the maximum dosage recommended for peach orchards. Weekly, at 3, 10, 17, 24 and 31 days after spraying, larvae and adults of the predator were exposed to treated leaves in order to assess the residual effect of insecticides on mortality and possible effects on reproduction. Given the toxicity observed along the weekly bioassays, the insecticides were classified into persistence categories established by the International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC). High persistence was obtained for the organophosphorus insecticides (% of active ingredient) phosmet (0.100) and malathion (0.200), and both were considered persistent (> 30 days of harmful activity) to larvae and adults of C. externa. Similarly, the benzoylurea insecticide lufenuron (0.005), which acts exclusively on immature stages of insects, was persistent to larvae. Differences concerning the persistence for both development stages evaluated were observed for the pyrethroid insecticide deltamethrin (0.001), that was persistent to larvae but moderately persistent (16 ­ 30 days of harmful activity) to adults; and for the organophosphate fenthion (0.050) which was considered moderately persistent to larvae and short-lived (< 5 days of harmful activity) to adults of C. externa.(AU)

Este trabalho teve como objetivo avaliar a persistência (duração da atividade nociva) de cinco inseticidas utilizados no controle de pragas em pessegueiro, em larvas e adultos do predador Chrysoperla externa. Os inseticidas foram pulverizados em plantas de videira cv. Bordô utilizando-se a máxima dosagem recomendada para o pessegueiro. Semanalmente, aos 3, 10, 17, 24 e 31 dias após a pulverização, larvas e adultos do predador foram expostos a folhas pulverizadas para determinação do efeito residual dos inseticidas na mortalidade e possíveis efeitos na reprodução. Em função da toxicidade observada ao longo dos bioensaios semanais, os inseticidas foram classificados conforme a escala de persistência da International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC). Alta persistência foi obtida para os inseticidas (% de ingrediente ativo) fosmete (0,100) e malationa (0,200), sendo ambos considerados persistentes (> 30 dias de ação nociva) para larvas e adultos de C. externa. De forma semelhante, o inseticida do grupo das benzoilureias, lufenurom (0,005), que age exclusivamente sobre estágios imaturos de insetos, foi persistente para larvas. Diferenças quanto a persistência para ambos os estágios avaliados foi observada para o inseticida piretroide deltametrina (0,001), que se mostrou persistente para larvas, porém moderadamente persistente (16 ­ 30 dias de ação nociva) para adultos; e para o organofosforado fentiona (0,050), que foi considerado moderadamente persistente para larvas e de vida curta (< 5 dias de ação nociva) para adultos de C. externa.(AU)

Persistence of insecticides used in peach orchards to larvae and adults of the predator Chrysoperla externa (Neuroptera: Chrysopidae) / Persistência de inseticidas utilizados em pessegueiro sobre larvas e adultos do predador Chrysoperla externa (Neuroptera: Chrysopidae)

This work aimed to evaluate the persistence (duration of harmful activity) of five insecticides used for pest control in peach orchards, on larvae and adults of the predator Chrysoperla externa. The insecticides were sprayed on cv. Bordô vine plants using the maximum dosage recommended for peach orchards. Weekly, at 3, 10, 17, 24 and 31 days after spraying, larvae and adults of the predator were exposed to treated leaves in order to assess the residual effect of insecticides on mortality and possible effects on reproduction. Given the toxicity observed along the weekly bioassays, the insecticides were classified into persistence categories established by the International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC). High persistence was obtained for the organophosphorus insecticides (% of active ingredient) phosmet (0.100) and malathion (0.200), and both were considered persistent (> 30 days of harmful activity) to larvae and adults of C. externa. Similarly, the benzoylurea insecticide lufenuron (0.005), which acts exclusively on immature stages of insects, was persistent to larvae. Differences concerning the persistence for both development stages evaluated were observed for the pyrethroid insecticide deltamethrin (0.001), that was persistent to larvae but moderately persistent (16 ­ 30 days of harmful activity) to adults; and for the organophosphate fenthion (0.050) which was considered moderately persistent to larvae and short-lived (< 5 days of harmful activity) to adults of C. externa.(AU)

Este trabalho teve como objetivo avaliar a persistência (duração da atividade nociva) de cinco inseticidas utilizados no controle de pragas em pessegueiro, em larvas e adultos do predador Chrysoperla externa. Os inseticidas foram pulverizados em plantas de videira cv. Bordô utilizando-se a máxima dosagem recomendada para o pessegueiro. Semanalmente, aos 3, 10, 17, 24 e 31 dias após a pulverização, larvas e adultos do predador foram expostos a folhas pulverizadas para determinação do efeito residual dos inseticidas na mortalidade e possíveis efeitos na reprodução. Em função da toxicidade observada ao longo dos bioensaios semanais, os inseticidas foram classificados conforme a escala de persistência da International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC). Alta persistência foi obtida para os inseticidas (% de ingrediente ativo) fosmete (0,100) e malationa (0,200), sendo ambos considerados persistentes (> 30 dias de ação nociva) para larvas e adultos de C. externa. De forma semelhante, o inseticida do grupo das benzoilureias, lufenurom (0,005), que age exclusivamente sobre estágios imaturos de insetos, foi persistente para larvas. Diferenças quanto a persistência para ambos os estágios avaliados foi observada para o inseticida piretroide deltametrina (0,001), que se mostrou persistente para larvas, porém moderadamente persistente (16 ­ 30 dias de ação nociva) para adultos; e para o organofosforado fentiona (0,050), que foi considerado moderadamente persistente para larvas e de vida curta (< 5 dias de ação nociva) para adultos de C. externa.(AU)

Pollen Ingestion by Chrysoperla externa (Hagen) Adults in a Diversified Organic Agroecosystem.

Chrysoperla externa (Hagen) larvae prey on pest insects and mites in agroecosystems, and adults mainly feed on pollen, nectar, and honeydew. Therefore, preserving this lacewing in crop systems depends on having plants that provide these resources. The objectives of this research were to identify pollen grains ingested by Ch. externa adults collected in a diversified organic agroecosystem and to evaluate whether there is a difference in the amount of ingested pollen grains between males and females. The adults of Ch. externa were collected in four different crops during 13 months in Seropédica, state of Rio de Janeiro, Brazil, using a collecting net. The adults were killed and underwent acetolysis, in order to recover the pollen in the gut. A total of 37,441 pollen grains from 19 Angiospermae families were found, besides 16 Pteridophyte spores. Among the recognized pollen grains, those of Poaceae were the majority, both in frequency of occurrence (87.5%) and in quantity (33496), and were found and recovered in every month of collection. Females and males ingested, respectively, 71.9 and 28.1% of the total number of Angiospermae pollen grains consumed by both sexes. The highest number of Poaceae pollens was obtained from the females (72.1% of the total number of Poaceae pollen, recovered from females + males). Taken as a whole, this study showed that adults of Ch. externa find possibilities to maintain throughout the year, in different crops, but the main source of pollen to males and females was Poaceae plants.

Reproductive potential of Chrysoperla externa maintained in different cage sizes in laboratory conditions / Potencial reprodutivo de Chrysoperla externa mantidos em diferentes tamanhos de gaiolas, em condições de laboratório

This study investigated the influence of cage sizes on the survival and reproductive potential of Chrysoperla externa (Hagen). Size of breeding cages significantly affected the reproductive potential of C. externa . Our results indicated that in cages smaller (7.5cm of diameter) than those usually recommended for the rearing of this insect (10cm diameter), females showed higher rates of oviposition. Reduction of space for rearing natural enemies in the laboratory is very important for developing biological control programs. (AU)

Investigou-se a interferência do tamanho das gaiolas de criação de adultos de Chrysoperla externa (Hagen) sobre o seu potencial reprodutivo e sua sobrevivência. O tamanho das gaiolas de criação afetou significativamente o potencial reprodutivo deste crisopídeo. Os resultados indicaram que em gaiolas menores (7,5cm de diâmetro) do que as habitualmente usadas para a criação de adultos desse predador (10cm de diâmetro) ocorreram maiores taxas de oviposição. A redução de espaço para a criação de inimigos naturais para atender aos programas de controle biológico em laboratório é muito importante. (AU)

Reproductive potential of Chrysoperla externa maintained in different cage sizes in laboratory conditions / Potencial reprodutivo de Chrysoperla externa mantidos em diferentes tamanhos de gaiolas, em condições de laboratório

This study investigated the influence of cage sizes on the survival and reproductive potential of Chrysoperla externa (Hagen). Size of breeding cages significantly affected the reproductive potential of C. externa . Our results indicated that in cages smaller (7.5cm of diameter) than those usually recommended for the rearing of this insect (10cm diameter), females showed higher rates of oviposition. Reduction of space for rearing natural enemies in the laboratory is very important for developing biological control programs.

Investigou-se a interferência do tamanho das gaiolas de criação de adultos de Chrysoperla externa (Hagen) sobre o seu potencial reprodutivo e sua sobrevivência. O tamanho das gaiolas de criação afetou significativamente o potencial reprodutivo deste crisopídeo. Os resultados indicaram que em gaiolas menores (7,5cm de diâmetro) do que as habitualmente usadas para a criação de adultos desse predador (10cm de diâmetro) ocorreram maiores taxas de oviposição. A redução de espaço para a criação de inimigos naturais para atender aos programas de controle biológico em laboratório é muito importante.

Rearing Chrysoperla externa Larvae on Artificial Diets.

We tested three artificial diets for rearing larvae of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae), aiming at reducing the production costs of this predator. Two of the diets come from studies with other species of lacewings, and the third is a modification described in this paper. All diets were based on animal protein and were supplied to 2nd and 3rd instar larvae, whereas 1st instar larvae received eggs of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae). We evaluated the preimaginal duration and survival, adult size, longevity and fecundity, egg hatchability, and predatory capacity of larvae produced. The performance of the diets was followed for seven generations. The diet we describe showed to be the best among the artificial diets tested. Our results show that C. externa can be successfully reared on artificial diets during second and third instars, reducing in 90% the dependency on eggs of A. kuehniella.

Reproductive potential of Chrysoperla externa maintained in different cage sizes in laboratory conditions

ABSTRACT: This study investigated the influence of cage sizes on the survival and reproductive potential of Chrysoperla externa (Hagen). Size of breeding cages significantly affected the reproductive potential of C. externa . Our results indicated that in cages smaller (7.5cm of diameter) than those usually recommended for the rearing of this insect (10cm diameter), females showed higher rates of oviposition. Reduction of space for rearing natural enemies in the laboratory is very important for developing biological control programs.

RESUMO: Investigou-se a interferência do tamanho das gaiolas de criação de adultos de Chrysoperla externa (Hagen) sobre o seu potencial reprodutivo e sua sobrevivência. O tamanho das gaiolas de criação afetou significativamente o potencial reprodutivo deste crisopídeo. Os resultados indicaram que em gaiolas menores (7,5cm de diâmetro) do que as habitualmente usadas para a criação de adultos desse predador (10cm de diâmetro) ocorreram maiores taxas de oviposição. A redução de espaço para a criação de inimigos naturais para atender aos programas de controle biológico em laboratório é muito importante.

Seletividade de agrotóxicos utilizados no pessegueiro sobre o estágio larval do predador Chrysoperla externa (Hagen) / Selectivity of pesticides used in peach orchards on the larval stage of the predator Chrysoperla externa (Hagen)

Foi avaliada neste trabalho a seletividade de dezesseis agrotóxicos utilizados na cultura do pessegueiro sobre o estágio larval de Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) em bioensaios conduzidos em laboratório (temperatura de 25±1ºC, umidade relativa 70±10% e fotofase 14 horas). Os bioensaios consistiram na exposição de larvas do predador a resíduos secos dos agrotóxicos pulverizados sobre placas de vidro. Foram avaliadas a duração dos estágios de desenvolvimento, a mortalidade, a fecundidade e fertilidade dos adultos remanescentes, sendo os agrotóxicos classificados em função do efeito total como inócuos ( 30%), levemente nocivos (30-79%), moderadamente nocivos (80-99%) e nocivos (>99%), conforme recomendação da International Organization for Biological and Integrated Control of Noxious Animals and Plants. Somente abamectina e deltametrina prolongaram significativamente o período pós-embrionário. A fecundidade e fertilidade dos adultos sobreviventes não foram afetadas por nenhum agrotóxico testado. O acaricida/inseticida abamectina, os dois inseticidas a base de óleo mineral, os fungicidas azoxystrobina, captana, dodina, folpete, mancozebe e mancozebe + oxicloreto de cobre e o herbicida glifosato são inócuos; o fungicida tebuconazole é levemente nocivo; o inseticida deltametrina é moderadamente nocivo e os inseticidas dimetoato, fosmete e malationa, e o

The selectivity of sixteen pesticides used in peach orchards in Brazil was evaluated on larvae of Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) in laboratory (25±1ºC, 70±10% RH and 14 hours photophase). The bioassays consisted on the exposure of larvae to fresh dry pesticide film applied on glass plates. Lenght of each development stage, the mortality, the fecundity and fertility of survival adults were evaluated. Pesticides were classified according to the total toxic effect in harmless ( 30%), slightly harmful (30-79%), moderately harmful (80-99%) and harmful (>99%), in conformity to International Organization for Biological Control of Noxious Animals and Plants (IOBC) recommendation. Only abamectin and deltamethrin caused significant prolongation in the post embryonic period. Fecundity and fertility of survival adults were not affected by any pesticide tested. The acaricide/insecticide abamectin, the two mineral oils, the fungicides mancozeb, dodine, azoxystrobin, captan, mancozeb + cooper oxichloride and pholpet, and the herbicide ghlyphosate were harmless; the fungicide tebuconazole was slightly harmful; the insecticide deltamethrin was moderately harmful; and the insecticides malathion, dimethoate and phosmet, and the herbicide paraquat dichloride were harmful to C. externa larvae.