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Orius insidiosus is economically important for biological control of pests of vegetable and ornamental crops. To improve pest control with this predator, its densities in the crops can be enhanced by the provision of alternative foods, especially when prey are scarce. We therefore compared the performance of O. insidiosus on three alternative foods (Ricinus sp. pollen, bee pollen and the mixed stages of the astigmatid prey Tyrophagus putrescentiae) that are cheaper than frozen eggs of Ephestia kuehniella. Juvenile development was significantly shorter on E. kuehniella and T. putrescentiae than on Ricinus sp. pollen and on bee pollen and lowest without food. Female bugs had a higher oviposition rate when fed either E. kuehniella or T. putrescentiae, but produced fewer eggs when feeding on bee pollen and Ricinus sp. pollen. This shows that T. putrescentiae can possibly be used as cheap alternative food to boost predator populations in periods of low prey densities.

Aromatic plants can affect arthropod community composition and reduce herbivore populations by attracting beneficial insects such as generalist predators. To investigate the possible mechanisms underlying the attraction of aromatic plant species to natural enemies in the field, we assessed the attractiveness of Ocimum basilicum L. (basil), Mentha piperita L. (peppermint), Melissa officinalis L. (lemon balm) (Lamiaceae) and Cordia verbenacea DC (black sage) (Boraginaceae) to adults of the green lacewing Ceraeochrysa cubana Hagen (Neuroptera: Chrysopidae), a generalist predator widely distributed across the Americas. Additionally, we tested whether access to leaves and flowers of these plant species would affect larval survival, development or oviposition by C. cubana . The green lacewing was attracted to basil but not to the other aromatic plants. Larvae and adults did not benefit from the presence of any plant leaves, but basil flowers enhanced C. cubana larval and adult survival. Basil can be recommended as a companion crop in conservation biological control programs, not only for its well-known negative effects on pests, but also for its attractiveness to generalist predatory insects such as C. cubana . Besides attracting adults, basil flowers benefit both larvae and adults, which is desirable for conservation biological control.

Intercropping tomato plants with coriander is known to attract natural enemies of aphids, mostly coccinellids, but the cues involved in such attraction are not yet known. We investigated why coriander plants attract Cycloneda sanguinea, a generalist aphid predator. We performed a series of controlled experiments with coriander plants in vegetative and reproductive stages to examine the cues attracting C. sanguinea adults and larvae. In a Y-tube olfactometer, C. sanguinea adults were attracted by coriander volatiles produced during the vegetative plant stage suggesting an innate attraction to coriander. Attraction increased when aphid-infested tomato plants were offered together with coriander plants. Moreover, C. sanguinea females used coriander plants as oviposition sites, regardless of plant stage, which could partially explain the attraction to coriander volatiles during vegetative stage. Larvae hatching on coriander plants without prey were able to find nearby aphid-infested tomato plants within about three days after hatching. Additionally, a diet of coriander flowers increased female survivorship, but oviposition only occurred when females had aphids in their diet. Our results indicate that C. sanguinea adults orient to coriander nearing bloom and then use coriander pollen and/or nectar as a supplementary food before aphids become available. The implications of these findings for conservation biological control are discussed.

Plant diversity may increase natural enemy populations because some plants can provide alternative food to natural enemies. Extrafloral nectar is such an alternative food and plants producing extrafloral nectar are known to suffer less from herbivory. Little is known about the effect of plants with extrafloral nectaries on herbivory of neighbouring plants. Here, we investigated whether extrafloral nectaries of an associated tree (Inga subnuda subsp. luschnathiana) can enhance natural pest control in coffee agroforestry systems. We assessed the effect of nectar availability from Inga trees on parasitism of coffee leaf miners (Leucoptera coffeella) and on damage caused by coffee leaf miners and coffee berry borers (Hypothenemus hampei). Most of the nectary visitors were either parasitoids or predators, with most predators being natural enemies of coffee pests. Coffee plants were sampled every metre along a transect of 10–15 m extending from each Inga tree. The distance of the coffee plants from the Inga trees did not significantly correlate with coffee leaf miner parasitism, proportion of mined leaves or with the proportion of bored coffee berries. We subsequently used abundance and species richness of those nectary visitors without known association with leaf miners and borers as indirect measures of nectar availability. Whereas species richness had no significant effect on natural pest control, leaf miner parasitism increased significantly with the abundance of nectary visitors (excluding natural enemies of the coffee pests), and the proportion of mined leaves decreased significantly with this abundance. The proportion of bored fruits decreased with increasing abundance of visitors, but this trend was not significant. Together, these results suggest that Inga trees provide alternative food to natural enemies of coffee pests, resulting in increased natural control. Thus, extrafloral nectaries of associated trees can enhance natural pest control in agroforestry systems.

A cultura da melancia Citrullus lunatus (Thunberg, Matsumura & Nakai) abriga uma grande diversidade de artropodes, cada um desempenhando um papel especifico. Apesar de alguns desses artropodes serem considerados pragas, outros sao responsaveis pela aeracao do solo, liberacao de nutrientes e predacao das especies-praga, sendo, dessa forma, considerados beneficos as culturas. A agricultura intensiva praticada no Brasil para o cultivo da melancia e baseada no uso dos inseticidas como tiamethoxam e deltametrina, que pode nao so matar as pragas, mas tambem organismos nao-alvo. Pesquisas relacionadas a influencia de inseticidas sobre artropodes beneficos na cultura da melancia sao escassas. Este estudo foi realizado com o objetivo de avaliar o efeito dos inseticidas deltametrina e thiamethoxam na comunidade de artropodes existentes na superficie do solo, bem como naqueles artropopodes que habitam o dossel das plantas na cultura da melancia. Este estudo foi realizado no Estado do Tocantins, Brasil. Embora as aplicacoes de thiamethoxam e deltametrina foram eficientes no controle de populacoes de Aphis gossypii , como era esperado, os inseticidas afetaram negativamente artropodes nao-alvo como insetos detritivoros, insetos de dossel e da superficie do solo. Implicacoes ecologicas do impacto dos pesticidas sobre as especies de artropodes beneficos sao discutidos.

The attack of phytophagous mites may induce plants to produce volatiles, which in turn may attract predators. The occurrence of multiple phytophagous infestations on plants may influence predator response. In this paper, we investigated whether the attraction of the predatory mite Phytoseiulus macropilis (Banks) to phytophagous-infested plants would change with the simultaneous presence of two tetranichid mites Oligonychus ilicis (McGregor) and Tetranychus urticae Koch. While the former species is rarely found on strawberry plants and is only occasionally found in association with P. macropilis, the latter is commonly found on strawberry plants and is frequently found in association with P. macropilis. Y-tube olfactometer test assays demonstrated that the predator preferred plants infested with T. urticae, avoided plants infested with O. ilicis, and had no preference for plants infested with both phytophagous mite species. These results indicated that the presence of a non-prey species (O. ilicis) on a given plant can alter the response of the predator to one of its prey (T. urticae). The consequences of the predatory behavior determined in this study on the predator ability to control T. urticae population on strawberry plants are discussed.

The predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) has been used as a natural enemy to control herbivorous insects in eucalyptus plantations. However, because of the short co-evolutionary history of the predator with this imported plant species, the defensive compounds of eucalyptus may have a negative effect on the predator. Therefore, the survival and development of P. nigrispinus were studied on eucalyptus (Eucalyptus urophylla; exotic host plant) and guava (Psidium guajava; native host plant). P. nigrispinus performance was indeed superior on guava plants than on eucalyptus. The number of fertile eggs and nymphal survival were 52.6% and 12.0% on guava compared with 20.0% and 1.3% on eucalyptus, respectively. Longevity of P. nigrispinus was 115 days on guava and 98 days on eucalyptus. This shows that the predator is not yet fully adapted to the exotic host plant. One possible reason is that the plant toxic compounds in eucalyptus act on this predator by antibiosis.

Variações nas características morfológicas das plantas podem ter efeito imediato sobre a preferência alimentar, escolha de sítios de oviposição e vulnerabilidade de herbívoros a inimigos naturais. A longo prazo, podem ter consequências sobre a dinâmica populacional desses organismos, já que atuam sobre seu desenvolvimento, sobrevivência e reprodução. Neste trabalho, avaliou-se o desenvolvimento de Polyphagotarsonemus latus (Banks) em cinco espécies de Capsicum com diferentes densidades de tricomas. Testou-se a hipótese de que o crescimento populacional de P. latus nessas plantas apresenta relação negativa com o aumento da densidade de tricomas nas folhas. Observou-se um padrão decrescente na taxa intrínseca de crescimento (r m) de P. latus com o aumento da densidade de tricomas nas folhas. O menor r m foi obtido em folhas de C. praetermissum (r m = 0,46), que apresenta a maior densidade de tricomas entre as espécies de Capsicum avaliadas. Os maiores valores de r m foram observados em espécies de Capsicum com densidade intermediária de tricomas nas folhas, Capsicum frutescens (r m = 0,77) e Capsicum chinense (r m = 0,76). Os tricomas de Capsicum spp. atuaram como fator limitante ao desenvolvimento de P. latus à medida que se apresentaram em maiores densidades e mais bem distribuídos na superfície foliar. Foi discutido ainda o papel da defesa morfológica e química de plantas de Capsicum sobre o desenvolvimento de P. latus. Plant morphology traits can affect the feeding preference, oviposition choice and the vulnerability of herbivores to natural enemies. At long term, these plant variations may influence herbivore population dynamics due to the interference on their development, survival and reproduction. In this paper, the development of the broad mite Polyphagotarsonemus latus (Banks) was evaluated on five species of Capsicum with different density of trichomes. We tested the hypothesis that P. latus population growth has a negative relationship with the increase trichome density on leaves. It was assessed a decrease in the intrinsic growth rate (r m) of P. latus with the increase of trichome density on the leaves tested. The lower r m was measured in leaves of C. praetermissum (r m = 0.46), which has the highest trichome density among the assessed Capsicum species. The highest values of r m were observed on Capsicum species with intermediate densities of trichomes on leaves such as Capsicum frutescens (r m = 0.77) and Capsicum chinense (r m = 0.76). Capsicum spp. trichomes acted as a limiting plant trait for the development of P. latus when they were in higher densities and better distributed on the leaf surface. We also discuss the role of morphologic and chemical plant defenses on P. latus development.

The broad mite, Polyphagotarsonemus latus, is one of the most serious pests attacking chilli pepper in Brazil. Aiming to offer an additional tool to be used for its control, we tested the acaricidal effect of neem, Azadirachta indica, on P. latus. Chilli pepper seedlings were sprayed with neem seed extract (NeemAzal T/S, 1% of azadiractin) at concentrations of 0.05, 0.10, 0.15 and 0.20 g a.i./l, with abamectin 1.8% (Vertimec 18 CE) and with water. Adult females of P. latus were transferred to each treated plant and after 6 d, the instantaneous rate of increase (ri) was calculated. All mites on plants treated with abamectin died without ovipositing before the end of the experiment. The ri for P. latus decreased linearly with increasing neem concentration, with the population growth rate becoming negative when mites were exposed to plants treated with neem at concentrations higher than 0.13 g a.i/l.

O morangueiro, Fragaria x ananassa, pode ser atacado por diferentes espécies de ácaros fitófagos, dentre elas o ácaro-vermelho, Oligonychus ilicis McGregor, e o ácaro-rajado, Tetranychus urticae Kock. Essas espécies são encontradas juntas, alimentando-se, com maior freqüência, sobre a epiderme adaxial e abaxial das folhas, respectivamente. Neste trabalho estudou-se o padrão de escolha de O. ilicis e T. urticae por sítio de alimentação em plantas de morangueiro. Duas hipóteses foram formuladas: a primeira, que a escolha por sítios de alimentação estaria relacionada à aptidão das espécies; a segunda, que esta escolha seria determinada pela presença do heteroespecífico. Com o objetivo de testar tais hipóteses, avaliou-se a preferência, biologia e sucesso reprodutivo de O. ilicis e T. urticae sobre a face abaxial e adaxial de folhas de morangueiro infestadas ou não pelo heteroespecífico. O. ilicis preferiu permanecer sobre a face adaxial enquanto T. urticae preferiu permanecer sobre a face abaxial de folhas de morangueiro. A preferência pelas faces foliares correlacionou-se com o sucesso reprodutivo das espécies, avaliado pela taxa intrínseca de crescimento populacional (r m). O padrão de escolha não se alterou quando as espécies foram submetidas ao teste de escolha entre as faces foliares previamente infestadas pelo heteroespecífico. É discutida a possibilidade de T. urticae induzir defesas da planta capazes de reduzir a aptidão de O. ilicis e vice-versa. A possibilidade dessas espécies permanecerem juntas sobre plantas de morangueiro aumenta a capacidade de dano à cultura. Many phytophagous mites can attack strawberry plants, Fragaria x ananassa, among them the southern red mite, Oligonychus ilicis McGregor, and the two-spotted spider mite, Tetranychus urticae Koch. They are found together feeding on the same plant on the upper and underside of the leaves, respectively. Here we studied the choice for feeding sites of O. ilicis and T. urticae on strawberry plants. The first hypothesis tested whether the feeding site choice would be related to the fitness of the species. The second hypothesis dealt whether the feeding site would be determined by the presence of a heterospecific mite. We evaluated the preference, biology and reproductive success of O. ilicis and T. urticae on the under and upper side surface of strawberry leaves infested or not by the heterospecific. O. ilicis preferred to stay on the upper side surface while T. urticae preferred the underside. The preference for the leaf surface correlated with the reproductive success of the species (measured by the intrinsic growth rate). The choice pattern of feeding sites did not alter when the choice test was applied using sites previously infested by heterospecific. Although O. ilicis and T. urticae, apparently, do not interact directly for feeding sites, there is a chance that the first species induces defenses in strawberry plant enabling to reduce the fitness of the second species. The possibility of those species stay together on strawberry plant increases the damage capacity to the culture.

A survey of the seasonal occurrence of stink bug egg parasitoids was carried out in soy bean fields in the Triangulo Mineiro region, Minas gerias state Brazil A survey of the seasonal occurrence of stink bug egg parasitoids was carried out in soy bean fields in the Triangulo Mineiro region, Minas gerias state Brazil

A ação letal e subletal de defensivos alternativos sobre o ácaro-branco Polyphagotarsonemus latus (Banks) foi avaliada em laboratório. Plantas de pimenta "Malagueta" (6 cm de altura) foram pulverizadas, nas dosagens recomendadas para hortaliças, com os seguintes produtos: biofertilizante "Supermagro", "Calda Viçosa", calda sulfocálcica, acaricida abamectina e água. Após a pulverização, foram transferidas dez fêmeas de P. latus para cada planta. Seis dias após, avaliou-se o número de ácaros por planta e calculou-se a taxa instantânea de crescimento populacional (r i). A população final de P. latus em plantas tratadas com a calda sulfocálcica, com a "Calda Viçosa" e com o acaricida abamectina foi significativamente menor do que em plantas tratadas com água e com "Supermagro". Foram obtidos valores negativos para a r i de P. latus em plantas tratadas com a calda sulfocálcica (r i = -0,2922) e com a "Calda Viçosa" (r i = -0,0301). Valores positivos para a r i foram obtidos para ácaros em plantas tratadas com "Supermagro" (r i = 0,2373) e com água (r i = 0,1971), indicando aumento da população de P. latus nessas plantas. Não foi possível o cálculo do r i para ácaros em plantas tratadas com abamectina devido a morte de todas as fêmeas no inicio do experimento. A "Calda Viçosa" e a calda sulfocálcica apresentaram potencial de controle para o ácaro branco P. latus em pimenta. Lethal and sublethal effects of alternative pesticides on the broad mite Polyphagotarsonemus latus were evaluated. Chilli pepper plants (6 cm high) were sprayed with one of the following treatments: biofertilizer "Supermagro", "Viçosa mixture" (a nutrient amended Bordeaux mixture), lime sulfur, abamectin and water. After spraying, 10 females of P. latus were transferred to each plant. Six days after, the number of mites per plant was counted and the instantaneous rate of increase (r i) was evaluated for each treatment. The population of P. latus on plants treated with lime sulfur, "Viçosa mixture" and abamectin was significantly lower than on plants treated with biofertilizer and water. Negative values of the instantaneous rate of increase (r i), were obtained for P. latus on plants treated with lime sulfur (r i = -0.2922) and with "Viçosa mixture" (r i = -0.0301). Positive values were obtained for mites on plants treated with biofertilizer (r i = 0.2373) and water (r i = 0.1971), which indicate increase of P. latus population on these plants. It was not possible to calculate r i for mites on abamectin treated plants, because all females died at the beginning of the experiment. Lime sulfur and "Viçosa mixture" showed potential for controlling broad mite P. latus on chilli pepper "Malagueta".

Amblyseius herbicolus (Banks) is found associated with broad mites Polyphagotarsonemus latus in crops such as chili pepper in Brazil. The species has a potential for controlling P. latus, but little is known about its development and reproduction on this pest as well as on other food sources. We studied biological, reproductive and life table parameters of A. herbicolus on three different diets: broad mites, castor bean pollen (Ricinus communis) and sunnhemp pollen (Crotalaria juncea). The predator was able to develop and reproduce on all diets. However, its intrinsic growth rate was higher on the diet of broad mites or on castor bean pollen than on sunnhemp pollen. Differences among pollen species may be due to their nutritional content. Feeding on alternative food such as pollen can facilitate the predator’s mass rearing and maintain its population on crops when prey is absent or scarce. Other strategies of using pollen to sustain predator population and reduce pest damage are discussed.

O objetivo deste trabalho foi avaliar o efeito da teia produzida por Tetranychus evansi (Acari: Tetranychidae) na eficiência de predação por coccinelídeos Cycloneda sanguinea e Eriopis connexa e pelo crisopídeo Chrysoperla externa. A eficiência em predar as fêmeas de T. evansi na presença e na ausência de sua teia em discos de folhas de tomateiro com ácaros foi avaliada para cada instar das diferentes espécies de predadores. Foi observado efeito negativo da teia produzida por T. evansi na eficiência de predação do segundo e do terceiro instar de C. externa. Quanto à E. connexa, somente a predação pelo último instar foi influenciada negativamente pela presença da teia. A predação pelas larvas de primeiro e terceiro instar de C. sanguinea foi significativamente menor na presença da teia; no entanto, o resultado foi contrário para o quarto instar. O efeito da teia de T. evansi como mecanismo de defesa varia conforme a espécie e o estágio de desenvolvimento do predador. The aim of this work was to evaluate the effect of the webbing produced by Tetranychus evansi (Acari: Tetranychidae) on the predation efficiency of Cycloneda sanguinea and Eriopis connexa coccinellids and of the Chrysoperla externa chrysopid. The predation efficiency on T. evansi females with and without webbing on tomato leaf discs was evaluated for each juvenile stage of the different predator species tested. There was a negative effect of T. evansi webbing on the predation efficiency of the second and third C. externa juvenile stages. Regarding E. connexa, only the predation by the oldest juvenile stage was negatively affected by the webbing. The predation efficiency of the first and the third juvenile stages of C. sanguinea was lower in the presence of webbing, but the opposite was observed for the fourth stage. The defensive role of T. evansi webbing varies according to the predator species and their developmental stage.

The predatory mite Phytoseiulus macropilis is a potential biological control agent of the two-spotted spider mite (TSSM) Tetranychus urticae on strawberry plants. Its ability to control TSSM was recently assessed under laboratory conditions, but its ability to locate and control TSSM under greenhouse conditions has not been tested so far. We evaluated whether P. macropilis is able to control TSSM on strawberry plants and to locate strawberry plants infested with TSSM under greenhouse conditions. Additionally, we tested, in an olfactometer, whether odours play a role in prey-finding by P. macropilis. The predatory mite P. macropilis required about 20 days to achieve reduction of the TSSM population on strawberry plants initially infested with 100 TSSM females per plant. TSSM-infested plants attract an average of 27.5 +/- 1.0% of the predators recaptured per plant and uninfested plants attracted only 5.8 +/- 1.0% per plant. The predatory mites were able to suppress TSSM populations on a single strawberry plant and were able to use odours from TSSM-infested strawberry plants to locate prey in both olfactometer and arena experiments. Hence, it is concluded that P. macropilis can locate and reduce TSSM population on strawberry plants under greenhouse conditions.

Jatropha curcas has a high biofuel oil content, which could replace polluting fuels, and has great potential for large scale monoculture cultivation in the conventional system. We explored the occurrence, spatial distribution and the functional response of the main phytophagous species of this plant and their natural enemies to explore the potential for conservative biological control. We began sampling phytophagous species and predators when J. curcas plants were six months old. The most common species of phytophagous insects were nymphs and adults of Empoasca kraemeri, followed by Frankliniella schultzei and Myzus persicae. Among the predators, Ricoseius loxocheles, Iphiseioides zuluagai, Araneidae, larvae and adults of Psyllobora vigintimaculata and Anthicus sp. were the most frequently encountered. The most common parasitoids were the families Encyrtidae and Braconidae. The highest densities of E. kraemeri and F. schultzei on the edges of the J. curcas crop follow spatial patterns similar to those of their natural enemies I. zuluagai and Anthicus sp. These arthropods can be considered efficient predators of immature stages of E. kraemeri and F. schultzei on J. curcas.

Plantas de morangueiro Fragaria x ananassa podem apresentar mecanismos de defesa direta e indireta contra herbívoros. Tais defesas podem alterar o comportamento e o desenvolvimento dos ácaros fitófagos e seus inimigos naturais, reduzindo a taxa de herbivoria. Testou-se o efeito da pré-infestação de plantas de morangueiro por Tetranychus urticae Koch sobre o seu desenvolvimento e reprodução. Plantas de morangueiro cultivar IAC Campinas foram divididas em dois grupos: plantas limpas e plantas pré-infestadas por T. urticae. A infestação prévia de plantas de morangueiro por T. urticae não alterou a duração das fases imaturas, a fecundidade e a sobrevivência das fêmeas do ácaro. Tais resultados podem estar associados à inexistência ou baixo nível de resistência induzida da cultivar IAC Campinas, ou ainda, ao fato de a pré-infestação ter sido insuficiente para induzir defesa. Assim, a resistência relatada na cultivar IAC Campinas a T. urticae pode estar relacionada às defesas indiretas. Plants of strawberry Fragaria x ananassa may present mechanisms of direct and indirect defenses against herbivores. Such defenses may influence behaviour and development of phythophagous mites and their natural enemies, thereby reducing herbivory rate. We tested the effect of pre-infestation of strawberry plants by Tetranychus urticae Koch on the development and reproduction of the mite species. Strawberry plants (cultivar IAC Campinas) were divided into two groups: plants without and plants with pre-infestation of T. urticae. The length of immature phases, the number of eggs per female and the survival of mites were not altered by the pre-infestation. These results may be associated to either the absence or low level of induced resistance of the cultivar IAC Campinas or perhaps the pre-infestation was insufficient to induce defenses. The reported resistance of this cultivar to T. urticae could be related to indirect defenses.

Many omnivorous arthropods are important natural enemies because they can feed on plant-provided pollen and several prey species, and thus persist in crops even in the absence of the target pest. Hence, populations of these predators can be established in a crop by providing alternative food, thus increasing biological control. We investigated how alternative food affects broad mite (Polyphagotarsonemus latus) control on chilli pepper plants by predatory mites. The predatory mite Amblyseius herbicolus had high oviposition and population growth rates when fed with cattail pollen, chilli pepper pollen and bee-collected pollen, and a low rate on the alternative prey Tetranychus urticae. Supplementing pepper plants with pollen resulted in better control of broad mite populations. Release of A. herbicolus on young plants with weekly addition of honeybee pollen until plants produce flowers seems a viable strategy to sustain populations of this predator, thus protecting young, vulnerable plants from broad mite infestations.