Occurrence of Tegolophus brunneus and Phyllocoptruta oleivora (Acari: Eriophyidae) on the main citrus belt of Brazil and the differential toxicity of the acaricides to these species.

Many mites of the family Eriophyidae are important pests worldwide. In citrus crops, the eriophyid Phyllocoptruta oleivora stands out for the economic losses caused. The pest's injuries cause the darkening of leaves, twigs, and fruits, making them unfit for the fresh fruit market and affecting plant productivity. Another species that causes similar symptoms was described in Brazil recently, the brown citrus rust mite, Tegolophus brunneus. Although studies have not been performed with this species, growers and technicians have attributed the rise in rust damages in Brazil to T. brunneus, affirming that this mite is more aggressive and resistant to acaricides than P. oleivora. In this study, the distribution of T. brunneus in the main Brazilian citrus belt and the differential toxicity of the acaricides sulfur and abamectin were evaluated for both species. Infested fruits were collected from different orchards in many municipalities, covering the main citrus species and cultivars grown, aiming to show the main T. brunneus hosts. It was observed that only plants of Tahiti acid lime (Citrus latifolia) were infested by T. brunneus, whereas P. oleivora infested all citrus cultivars and species evaluated (Citrus spp.). In our study, T. brunneus and P. oleivora were never observed coinfesting the same fruit/leaf or plant. The acute toxicity test of sulfur and abamectin as acaricides showed that T. brunneus has greater tolerance to abamectin than P. oleivora. However, the acute toxicity of sulfur was similar for both species. These results showed T. brunneus specificity to infest Tahiti acid lime, causing important damage to this crop, and suggest that attention should be paid to managing this mite using abamectin.

Lethal and sublethal effects of insecticides on the survival and reproduction of Brevipalpus yothersi (Acari: Tenuipalpidae).

The overuse of insecticides to control vector insects such as Diaphorina citri Kuwayama in citrus groves has altered the population dynamics of pest mites. Among phytophagous mites, population outbreaks of citrus leprosis mite, Brevipalpus yothersi Baker, have been increasingly intense and frequent in Brazilian citrus groves. Despite the great importance of the B. yothersi mite for citrus production, the lethal and sublethal effects of insecticides on this mite have not yet been studied. Therefore, in this study, the effects of insecticides commonly used for D. citri control on B. yothersi mortality, reproduction, and instantaneous growth rate were assessed. For this, two experiments were carried out, one under controlled conditions and another in a greenhouse. The insecticides tested were beta-cyfluthrin, bifenthrin, buprofezin, chlorpyrifos, dimethoate, pyriproxyfen, and thiamethoxam at 0 (control), 0.0625, 0.125, 0.25, 0.5, 1, and twofold the recommended insecticide concentration for D. citri control. The pyriproxyfen insecticide provided high mortality of B. yothersi even at low concentrations. Furthermore, this insecticide negatively interfered with the reproduction of this mite. Beta-cyfluthrin, bifenthrin, buprofezin, chlorpyrifos, dimethoate, and thiamethoxam, in the tested concentrations, showed low impact on citrus leprosis mite. Regarding the reproduction of the mite, no significant increase in fecundity was observed on B. yothersi females exposed to insecticide residues, regardless of the concentration tested. Therefore, the application of these insecticides in the management of pest insects is unlikely to promote an increase in the citrus leprosis mite population.

Bioactivity of an oxymatrine-based commercial formulation against Brevipalpus yothersi Baker and its effects on predatory mites in citrus groves.

The acaricidal bioactivity of an oxymatrine-based commercial formulation against Brevipalpus yothersi Baker (Acari: Tenuipalpidae), a vector mite of the Citrus leprosis virus (CiLV), and its impact on predatory mites were assessed. For this purpose, laboratory and field assays using bioacaricide concentrations ranging from 0.5 to 2.0 mg L-1 of oxymatrine were performed during the years from 2015 to 2016. Laboratory results showed that the oxymatrine-based commercial formulation does not cause deleterious effects on B. yothersi eggs; however, it causes high larval mortality. For adult females, the bioacaricide caused high acute toxicity and residual effect for at least 5 days after application. In the field, the bioacaricide exhibited high acaricidal activity against B. yothersi, with efficacy levels similar to that of synthetic acaricide spirodiclofen (48 mg L-1) until 49 days after the application. The application of the bioacaricide did not negatively affect the population levels of phytoseiid predatory mites. Therefore, our results suggest that the oxymatrine-based commercial formulation is an important tool for management of the citrus leprosis mite in citrus groves.

Biological and demographic parameters of Tegolophus brunneus (Acari: Eriophyidae) in citrus.

The brown citrus rust mite, Tegolophus brunneus Flechtmann (Acari: Eriophyidae), causes citrus rust, as does Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae). As the citrus rust damage has intensified in recent years and T. brunneus has been reported in high population levels in several regions of Brazil, this mite has caused concern to growers and technicians. Because T. brunneus has been little studied and its bioecological characteristics are unknown, this study investigated the biological and demographic parameters of T. brunneus on citrus fruits under laboratory conditions. Our results showed that the egg incubation period and viability were 3.0 and 94.5%, respectively. The larval and nymphal stage durations were 1.1 and 2.8 days, respectively. The development time of the immature stage was 6.9 days, with 92.3% survival. When females and males were maintained together, the sex ratio of offspring was 0.7; virgin females produced only males. The pre-oviposition (from adult emergence to the first egg) and total pre-oviposition (egg-to-egg) periods were 1.6 and 8.5 days, respectively. Fecundity was 8.5 eggs, and female and male longevities were 13.2 and 11.4 days, respectively. The estimate of demographic parameters indicated that the Ro and T of T. brunneus were 6.45 offspring and 13.0 days, and r and λ were 0.142 and 1.153 day-1, respectively. These results suggest that T. brunneus has high growth potential on citrus trees. Therefore, management strategies may be required to reduce the population levels and damage caused by T. brunneus in citrus groves.

Spraying pyrethroid and neonicotinoid insecticides can induce outbreaks of Panonychus citri (Trombidiformes: Tetranychidae) in citrus groves.

Panonychus citri (McGregor) (Trombidiformes: Tetranychidae) is one of the main defoliator mites in citrus groves. In Brazil, P. citri was formerly considered a secondary pest, but in recent years, the population levels of this mite have increased in many groves, requiring additional acaricide applications for its control. The population growth of P. citri is associated with the increase in the number of applications of pyrethroid and neonicotinoid insecticides to control insect citrus pests. This study assessed the effects of pyrethroid (deltamethrin, esfenvalerate, λ-cyhalothrin) and neonicotinoid (imidacloprid and thiamethoxam) insecticides on biological, behavioral and demographic parameters of P. citri. None of the insecticides tested affected larval hatching, but deltamethrin, esfenvalerate, and λ-cyhalothrin reduced the survival of larvae and protonymphs. Deltamethrin, esfenvalerate, and λ-cyhalothrin induced a significant increase in the fecundity of surviving females. Pyrethroids also caused repellency and changed feeding and oviposition preferences. In contrast, imidacloprid and thiamethoxam did not affect the survival of immature stages, but imidacloprid significantly increased fecundity. Imidacloprid and thiamethoxam did not cause any repellent effect or changes in the feeding and oviposition preferences. Based on the demographic parameters, deltamethrin, λ-cyhalothrin, and imidacloprid increased Ro, r, and λ, whereas esfenvalerate and thiamethoxam were similar to the control. Therefore, the use of these insecticides (especially deltamethrin, λ-cyhalothrin, and imidacloprid) requires caution, such as avoiding repeated use of these compounds during the periods of P. citri incidence in citrus groves.

Susceptibility of Euseius concordis (Mesostigmata: Phytoseiidae) to pesticides used in citrus production systems.

Euseius concordis (Chant) is an important predatory mite found in citrus orchards. The toxicity of 19 pesticides used in citrus orchards on biological and population parameters of this mite was assessed. Our results indicated that formetanate hydrochloride, dimethoate and phosmet were highly harmful (100% mortality) to E. concordis. Carbosulfan, diflubenzuron, fenpropathrin, gamma-cyhalothrin, imidacloprid, lambda-cyhalothrin, lambda-cyhalothrin + thiamethoxam, mineral and vegetable oils, spinosad and thiamethoxam reduced the female's survival and/or fecundity, and were moderately harmful to E. concordis. Besides the acute toxicity, carbosulfan and formetanate hydrochloride were highly persistent [>30 days after spraying (DAS)]; dimethoate was moderately persistent (16-30 DAS); spinosad, gamma-cyhalothrin, lambda-cyhalothrin and lambda-cyhalothrin + thiamethoxam were slightly persistent (5-15 DAS); and the other pesticides were considered to be short-lived (<5 DAS). All compounds except lambda-cyhalothrin and thiamethoxam increased the pre-oviposition period in the female offspring. Carbosulfan, deltamethrin, diflubenzuron, etofenprox, fenpropathrin, gamma-cyhalothrin, mineral and vegetable oils, pyriproxyfen and tebufenozide reduced offspring fecundity, whereas thiamethoxam increased the fecundity. Mineral and vegetable oils reduced female longevity of the predator mite. Regarding population effects, imidacloprid, lambda-cyhalothrin, lambda-cyhalothrin + thiamethoxam and thiamethoxam led to an increase in net reproductive rate (R o ), intrinsic rate of increase (r), and finite rate of increase (λ) of E. concordis. Diflubenzuron, etofenprox, and mineral and vegetable oils reduced R o , r and λ. All pesticides except beta-cypermethrin, fenpropathrin and imidacloprid reduced the mean generation time (T) of the predator. Therefore, semi-field and field studies are needed to assess the compatibility of these compounds with E. concordis before adoption in IPM programs.

Impact of five insecticides used to control citrus pests on the parasitoid Ageniaspis citricola Longvinovskaya (Hymenoptera: Encyrtidae).

The parasitoid Ageniaspis citricola Longvnovskaya is a main biological control agent of the citrus leafminer Phyllocnistis citrella Stainton, an insect pest that causes considerable damage to citrus worldwide. However, the use of pesticides to control arthropod pests can reduce the effectiveness of parasitoids and disrupt integrated pest management in citrus groves. This study evaluated the impact on A. citricola of five insecticides that are used to control arthropod pests in citrus. Our results indicated that imidacloprid, chlorpyrifos, bifenthrin and ß-cyfluthrin were harmful (mortality >89 %) to A. citricola adults; whereas abamectin did not cause significant mortality and was considered harmless to the parasitoid. In addition to causing high mortality, imidacloprid and bifenthrin were considered moderately persistent, because they caused <25 % mortality to 17 and 24 days after spraying (DAS), respectively. Chlorpyrifos and ß-cyfluthrin were considered slightly persistent (mortality <25 %, 7 DAS). Although abamectin was considered harmless to A. citricola adults, had a short life (mortality <25 %, 3 DAS), and did not significantly affect the parasitism rate, the number and viability of pupae, or the longevity of A. citricola, this insecticide significantly reduced the proportion of females in the progeny compared to the control treatment. Therefore, semi-field and field studies that consider demographic parameters are needed to evaluate the impacts of these insecticides on the A. citricola parasitoid.

Impact of insect growth regulators on the predator Ceraeochrysa cincta (Schneider) (Neuroptera: Chrysopidae).

The generalist predator Ceraeochrysa cincta (Schneider) (Neuroptera: Chrysopidae) is an important biological control agent of several arthropod pests in different agroecosystems. This study assessed the lethal and sublethal effects of six insect growth regulators sprayed on first-instar larvae of C. cincta. Lufenuron and diflubenzuron were highly harmful to first-instar larvae of C. cincta, causing 100 % of mortality before they reached the second instar. Buprofezin caused ~25 % mortality of the larvae and considerably reduced the fecundity and longevity of the insects, but substantially increased the proportion of females in the surviving population of C. cincta. Methoxyfenozide and tebufenozide did not affect the duration and survival of the immature stages, but methoxyfenozide significantly reduced the fecundity and longevity of the insects. Pyriproxyfen reduced the survival of the larval stage by 19.5 %, but did not affect the development, survival and reproduction of the surviving individuals. Based on reduction coefficient, the insecticides diflubenzuron and lufenuron were considered harmful to C. cincta, whereas buprofezin and methoxyfenozide were slightly harmful and tebufenozide and pyriproxyfen were harmless. The estimation of life-table parameters indicated that buprofezin and methoxyfenozide significantly reduced the R o , r and λ of C. cincta, whereas pyriproxyfen and tebufenozide caused no adverse effect on population parameters, indicating that these insecticides could be suitable for use in pest management programs towards the conservation and population increase of the predator in agroecosystems. However, more studies should be conducted to evaluate the compatibility of these insecticides with the predator C. cincta under semi-field and field conditions.

Are the Pupae and Eggs of the Lacewing Ceraeochrysa cubana (Neuroptera: Chrysopidae) Tolerant to Insecticides?

The tolerance of Ceraeochrysa cubana (Hagen) pupae and eggs to 11 insecticides was evaluated under laboratory conditions, based on lethal and sublethal effects. Eggs at three ages (≤24-h-old, 48- to 72-h-old, and 96- to 120-h-old) and pupae at ≤48-h-old were used. All the insecticides were considered harmless when applied at the pupal stage. Phosmet and pyriproxyfen insecticides were considered harmless to eggs irrespective of the age. Esfenvalerate was harmless to eggs at the ages of ≤24-h-old and 48- to 72-h-old. Imidacloprid SC and azadirachtin were harmless to eggs at ages of 48- to 72-h-old and 96- to 120-h-old, and thiamethoxam was only harmless to eggs at 96- to 120-h-old of age. In contrast, chlorpyrifos and malathion were harmful to eggs at the age of 96- to 120-h-old, and imidacloprid WG was slightly harmful to the three egg ages evaluated. Lambda-cyhalothrin + chlorantraniliprole and lambda-cyhalothrin + thiamethoxam were slightly and/or moderately harmful to all egg ages evaluated. Based on the life table parameters, the insecticides thiamethoxam, imidacloprid SC, phosmet, pyriproxyfen, and azadirachtin did not affect the net rate of reproduction (Ro) of C. cubana. Lambda-cyhalothrin + chlorantraniliprole decreased the Ro and increased the population doubling time (Td) independently of the egg ages evaluated. Therefore, the insecticides pyriproxyfen and phosmet are compatible with eggs of the predator C. cubana, but other insecticides should be evaluated under field conditions to verify their effects on the predator.

Development and reproduction of Panonychus citri (Prostigmata: Tetranychidae) on different species and varieties of citrus plants.

The species and varieties of citrus plants that are currently grown can favor the population growth of the citrus red mite Panonychus citri (McGregor) (Prostigmata: Tetranychidae) and alter the pest management programs in citrus groves. In this study we evaluated, in the laboratory, the development and reproduction of P. citri and estimated its life table parameters when reared on four varieties of Citrus sinensis (L.) Osbeck (Valencia, Pera, Natal, and Hamlin), one variety of Citrus reticulata Blanco (Ponkan) and one variety of Citrus limon (L.) Burm. (Sicilian). The incubation period and egg viability were not affected by the host plant. However, the development and survival of the immature stage were significantly lower on Hamlin orange than on Valencia, Pera and Natal oranges, Ponkan mandarin and Sicilian lemon. The fecundity and oviposition period of females were lower on Hamlin orange than on the other hosts. Mites reared on Valencia orange and Sicilian lemon had a higher net reproductive rate (R 0 ), intrinsic growth rate (r) and finite rate of increase (λ), and a shorter interval between generations (T) than on Pera, Natal and Hamlin oranges and Ponkan mandarin. On the other hand, mites reared on Hamlin orange had the lowest R 0 , r and λ and the highest T among the hosts. Based on the results obtained we recommend that for Valencia orange and Sicilian lemon, the mite monitoring programs should be more intense to detect the initial infestation of pest, avoiding the damage in plants and the increase in production costs.

Comparative toxicity of an acetogenin-based extract and commercial pesticides against citrus red mite.

Acetogenins, a class of natural compounds produced by some Annonaceae species, are potent inhibitors of mitochondrial electron transport systems. Although the cellular respiration processes are an important biochemical site for the acaricidal action of compounds, few studies have been performed to assess the bioactivity of acetogenin-based biopesticides on spider mites, mainly against species that occur in orchards. Using residual contact bioassays, this study aimed to evaluate the bioactivity of an ethanolic extract from Annona mucosa seeds (ESAM) (Annonaceae) against the citrus red mite Panonychus citri (McGregor) (Acari: Tetranychidae), an important pest of the Brazilian citriculture. ESAM is a homemade biopesticide which was previously characterized by its high concentration of acetogenins. It caused both high mortality of P. citri females (LC50 = 7,295, 4,662, 3,463, and 2,608 mg l(-1), after 48, 72, 96, and 120 h of exposure, respectively) and significant oviposition deterrence (EC50 = 3.194,80 mg l(-1)). However, there was no effect on P. citri female fertility (hatching rate). In addition, the ESAM efficacy (in terms of its LC90) was compared with commercial acaricides/insecticides (at its recommended rate) of both natural [Anosom(®) 1 EC (annonin), Derisom(®) 2 EC (karanjin), and Azamax(®) 1.2 EC (azadirachtin + 3-tigloylazadirachtol)] and synthetic origin [Envidor(®) 24 SC (spirodiclofen)]. Based on all of the analyzed variables, the ESAM exhibited levels of activity superior to other botanical commercial acaricides and similar to spirodiclofen. Thus, our results indicate that ESAM may constitute a biorational acaricide for citrus red mite integrated pest management in Brazilian citrus orchards, particularly for local use.

Density and Dispersal Radius of Tamarixia radiata for Control of Diaphorina citri in Citrus Groves.

Tamarixia radiata (Waterston) is the main parasitoid wasp released in abandoned, organic, and non-commercial citrus groves and in orange jasmine areas  for biological control of Diaphorina citri Kuwayama (a vector of bacteria associated with huanglongbing), as a control tactic in a strategy termed External Management. The effectiveness of parasitism is influenced by the release density and radius of action of this parasitoid. This study determined the optimal release density and radius of action of T. radiata in a commercial citrus grove. Parasitoids were released at five densities (200, 400, 800, 1,600, and 3,200 wasps/ha) at the center of circular areas with four different radii (7.5, 15, 22.5, and 30 m). The parasitism rate was assessed using 'Valencia' sweet orange seedlings, each bearing 35 D. citri fourth-instar nymphs, attached to 26-year-old 'Valencia' sweet orange trees along the perimeter of each radius. For the 7.5-m radius, the highest parasitism rate (74.1%) was observed at the density of 3,200 wasps/ha. However, for the 15-m radius, the density of 3,200 wasps/ha resulted in lower parasitism (30.7%) of D. citri nymphs. No parasitism was observed for densities lower than 800 wasps/ha and release radii above 15 m. The highest parasitoid dispersal radius and area were 18.04 m and 114.02 m2, respectively, when 3,200 wasps were released. Therefore, 3,200 wasps/ha arranged at 56 equidistant release points (approximately 57 wasps/release point) is the recommended protocol for biological control of D. citri in citrus groves.

Selection of Bacillus thuringiensis strains in citrus and their pathogenicity to Diaphorina citri (Hemiptera: Liviidae) nymphs.

Bacillus thuringiensis (Bt) toxins are effective in controlling insect pests either through the spraying of products or when expressed in transgenic crops. The discovery of endophytic Bt strains opened new perspectives for studies aimed at the control of sap-sucking insects, such as the Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae), a vector of "Candidatus Liberibacter spp.," associated with citrus huanglongbing (HLB). In this study, translocation of endophytic Bt strains in citrus seedlings inoculated with Bt suspension delivered by soil-drench, and their systemic pathogenicity to D. citri nymphs were investigated. The pathogenicity of three wild-type Bt strains against D. citri third-instar nymphs was demonstrated. Among the 10 recombinant strains tested (each of them harboring a single cry or cyt gene), 3 can be highlighted, causing 42%-77% and 66%-90% nymphal mortality at 2 and 5 d after inoculation, respectively. The isolation of Bt cells from young citrus shoots and dead nymphs, and PCR performed with specific primers, confirmed the involvement of the Bt strains in the psyllid mortality. This is the first report showing the translocation of Bt strains from citrus seedling roots to shoots and their potential to control D. citri nymphs that fed on these soil-drench inoculated seedlings. The Bt strains that caused the highest mortality rates have the potential to be used as bioinsecticides to control D. citri and the identified genes can be used for the production of transgenic Bt citrus.

Behavioral responses of Diaphorina citri to host plant volatiles in multiple-choice olfactometers are affected in interpretable ways by effects of background colors and airflows.

In several phytophagous hemipterans, behavior appears to be mediated by both visual and chemical cues. For the Asian citrus psyllid (ACP) Diaphorina citri (Hemiptera: Liviidae), olfactometric assays are generally difficult to interpret owing to the low proportion of individuals responding to odors (~30-40%), which compromises the efficiency and reliability of the results of behavioral tests. In the present study, the ACP behavioral response to emitted odors from sweet orange (Citrus sinensis L. Osbeck) flushes in a 4-arm olfactometer using different colors (four white-, two white- and two yellow- on opposite sides, or four yellow-colored fields), and the role of the airflow in the concentration of volatile organic compounds (VOCs) were assessed at two airflows [0.4 and 0.1 L/min (LPM)]. Exposure to 'Pera' sweet orange or clean air in treatments with four yellow-colored-fields increased the response rate of ACP females to the odor sources compared with exposure to 'Pera' sweet orange or clean air in treatments with four white-colored-fields, independently of the odor source and airflow tested. For the assays using two white- and two yellow-colored fields on opposite sides and 0.4 or 0.1 LPM airflow, the residence time of ACP females to odors ('Pera' sweet orange or clean air) was similar or higher in treatments using yellow- than those using white-colored fields. For both assays (VOCs and olfactometric behavioral parameters), the reduction in airflow from 0.4 to 0.1 LPM greatly changed the airborne concentration and ACP behavior. Quantitative chemical analyses revelead that the concentration of most compounds emitted by 'Pera' sweet orange flushes for the headspace using 0.1 LPM airflow were greater than the concentrations measured using 0.4 LPM airflow. Therefore, this treatment design provides an useful tool to assess the ACP behavioral response to the odors from citrus plants, and it can also help in the discrimination of dose-response screenings for VOCs or conspecific insects.

The impact of four widely used neonicotinoid insecticides on Tetragonisca angustula (Latreille) (Hymenoptera: Apidae).

Application of neonicotinoid insecticides on crops can reduce the pollination services and population levels of the stingless bee Tetragonisca angustula (Latreille) (Hymenoptera: Apidae) in Neotropical agroecosystems. However, the impact of these insecticides on this bee has not been fully investigated. This study assessed the susceptibility levels of T. angustula to four neonicotinoid insecticides (acetamiprid, imidacloprid, thiacloprid and thiamethoxam), widely used to manage pests on different crops, and their effects on locomotion of the bee. Neonicotinoids with the cyano radical caused lower bee mortality (assessed by mean lethal concentration, LC50), while those compounds with the nitro radical were highly harmful to T. angustula. Locomotion activity was strongly impaired in bees treated with thiacloprid and imidacloprid, while acetamiprid did not affect the locomotion activity, which was similar to the control. Application of thiamethoxam caused hyperactivity, as observed by increases of ∼4.5 and 5.0-fold in mean speed and distance traveled, respectively. These results suggest that applications of neonicotinoid insecticides can negatively affect the pollination activity of T. angustula. These results can also help to develop strategies to conserve these pollinators in agroecosystems.

Susceptibility of Ceraeochrysa cubana larvae and adults to six insect growth-regulator insecticides.

The impacts of six insect growth-regulators were assessed on the predator Ceraeochrysa cubana (Hagen) larvae and adults. Our results showed that diflubenzuron, lufenuron and pyriproxyfen caused 100% larva mortality, whereas buprofezin, methoxyfenozide and tebufenozide were similar to control treatment. In comparison to the control, buprofezin prolonged the duration of larval stage, while methoxyfenozide and tebufenozide reduced the predator larva development time. Buprofezin, methoxyfenozide and tebufenozide did not affect the C. cubana duration and survival of pupal stage, fecundity and fertility. However, methoxyfenozide and tebufenozide reduced predator female and male longevities. Based on a reduction coefficient, diflubenzuron, lufenuron and pyriproxyfen were highly harmful to first instar larvae, while buprofezin, methoxyfenozide and tebufenozide were considered slightly harmful to the predator. Estimating the life table parameters, our results showed that buprofezin, methoxyfenozide and tebufenozide reduced the C. cubana Ro, r and λ. In comparison to the control, buprofezin prolonged the T and methoxyfenozide and tebufenozide shortened the predator T. In adults, our results showed that the insecticides did not cause significant mortality, but diflubenzuron, lufenuron and pyriproxyfen reduced the C. cubana fecundity and longevity. Diflubenzuron and lufenuron also reduced the C. cubana fertility. Based on a reduction coefficient, diflubenzuron and lufenuron were highly harmful to C. cubana adults, while pyriproxyfen was slightly harmful and buprofezin, methoxyfenozide and tebufenozide were considered harmless to the predator. Therefore, insect growth-regulators affect the C. cubana biological or populational parameters, and they can harm the integrated pest management programs that aim the predator conservation and/or augmentation in agroecosystems.

Controle químico da Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) e da Hypocala andremona (Stoll) (Lepidoptera: Noctuidae) em laboratório / Chemical control of Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) and Hypocala andremona (Stoll) (Lepidoptera: Noctuidae) in laboratory

A Hypocala andremona (Stoll) (Lepidoptera: Noctuidae) e a Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) são as principais pragas do caquizeiro na Serra Gaúcha contudo, há poucas informações sobre o controle químico dessas lagartas. Neste trabalho, avalia-se a eficácia dos inseticidas: acefato, benzoato de emamectina (+ óleo mineral), clorpirifós-etil, espinosade, etofemproxi, fenitrotiona, fosmete, metoxifenozida, tiacloprido e triclorfom no controle da A. sphaleropa e da H. andremona em laboratório. Os inseticidas (em gramas de ingrediente ativo por 100 litros de água - g i.a. 100L-1) acefato (37,5 e 75,0), benzoato de emamectina (0,375 e 0,5), clorpirifós-etil (45,0 e 67,5), espinosade (4,8 e 9,6), etofemproxi (10,0 e 15,0), fenitrotiona (75,0), metoxifenozida (14,4) e triclorfom (120,0 e 150,0) resultaram em mortalidade superior a 80,0 por cento entre as lagartas de A. sphaleropa. Em relação à H. andremona, observou-se que o acefato (37,5 e 75,0), o benzoato de emamectina (0,375 e 0,5), o clorpirifós-etil (45,0 e 67,5), o espinosade (4,8 e 9,6), o etofemproxi (10 e 15,0), a fenitrotiona (50 e 75,0), o fosmete (50,0 e 100,0), a metoxifenozida (9,6 e 14,4) e o triclorfom (120,0 e 150,0) causaram mortalidade superior a 80 por cento. Esses inseticidas apresentaram elevada eficiência em laboratório e características desejáveis para uso no manejo de lagartas do caquizeiro. No entanto, para validar o seu emprego em pomares comerciais é necessária avaliação de campo.

Hypocala andremona (Stoll) (Lepidoptera: Noctuidae) and Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) are the main insect-pests of the persimmon in the Serra Gaúcha region, State of Rio Grande do Sul (RS). No informations are available about chemical control of these caterpillars. The effect of acephate, emmamectin benzoate (+ mineral oil), clorpyriphos-ethyl, spinosad, etofenprox, fenitrothion, fosmet, methoxyfenozide, tiacloprid and trichlorphon on H. andremona and A. sphaleropa were evaluated in laboratory. Acephate (g.a.i.100 L-1) (37.5 and 75.0), emmamectin benzoate (0.375 and 0.5), clorpyriphos-ethyl (45.0 and 67.5), spinosad (4.8 and 9.6), etofenprox (10.0 and 15.0), fenitrothion (75.0), methoxyfenozide (14.4) and trichlorphon (120,0 and 150,0) resulted in a mortality of A. sphaleropa higher than 80.0 percent. For H. andremona, this effect was observed to acephate (37.5 and 75.0), emmamectin benzoate (0.375 and 0.5), clorpyriphos-ethyl (45.0 and 67.5), spinosad (4.8 and 9.6), etofenprox (10.0 and 15.0), fenitrothion (50.0 and 75.0), fosmet (50.0 and 100.0), methoxyfenozide (9.6 and 14.4) and trichlorphon (120.0 and 150.0). These insecticides showed potential to control caterpillars in the persimmon culture, being necessary field evaluations to use the compounds in commercial orchards.

Controle químico da forma galícola da filoxera Daktulosphaira vitifoliae (Fitch, 1856) (Hemiptera: Phylloxeridae) na cultura da videira / Chemical control of grape phylloxera Daktulosphaira vitifoliae (Fitch, 1856) leaf form (Hemiptera: Phylloxeridae) on vineyards

A filoxera Daktulosphaira vitifoliae (Fitch, 1856) (Hemiptera: Phylloxeridae) é considerada a principal praga da videira. O inseto se alimenta da parte aérea e raízes sendo que os maiores prejuízos são observados em raízes de Vitis vinifera cultivada como pé-franco. O dano nas folhas é importante em viveiros, quando o ataque ocorre nos ramos utilizados como porta-enxertos, resistentes à forma radícola. Este trabalho foi realizado com o objetivo de selecionar inseticidas que possam ser empregados como substitutos aos fosforados e piretróides no manejo da forma galícola da filoxera. Os inseticidas imidacloprid, thiamethoxam, acephate, abamectin, deltamethrin e fenitrothion, foram avaliados em condições de campo, sob infestação natural, em plantas matrizes do porta-enxerto Paulsen 1103. Imidacloprid (Provado 200 SC, 40mL 100L-1) e thiamethoxam (Actara 250 WG, 30g 100L-1) reduziram as injúrias causadas pela forma galícola da filoxera nos ponteiros em nível superior a 90 por cento, proporcionando controle superior aos inseticidas deltamethrin (Decis 25 CE, 40mL 100L-1) e fenitrothion (Sumithion 500 CE, 150 mL/100L) considerados referência no controle do inseto. Os inseticidas acephate (Orthene 750 BR, 100g 100L-1) e abamectin (Vertimec 18 CE, 80mL 100L-1) não foram eficientes.