No description available.

No description available.

The carrot weevil, Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae), is an insect pest in carrot production in Ontario. The aim of this study was to survey the egg parasitoids attacking the carrot weevil in carrot fields in Ontario, and elucidate the seasonal and chemical ecology of these natural enemies. / Field surveys were conducted during three years in commercial carrot fields in the Holland Marsh and district marshes to detect the presence of carrot weevil egg parasitoids, to determine their geographical distribution and to evaluate the effect of insecticides on the rate of emergence and the activity of parasitoid adults. Two egg parasitoids, Anaphes listronoti Huber and A. victus Huber were found. The dominant species Anaphes listronoti is gregarious, was recovered from most of the sampled fields and was distributed in all sampled marshes whereas the solitary parasitoid A. victus was only sporadically found in the Holland Marsh. These Anaphes species occurred in carrot fields from the end of April to the beginning of September and seasonal parasitism averaged 33% in commercial carrot fields and up to 79% in an untreated plot. The insecticides phosmet, diazinon and cypermethrin used in carrot production, did not affect emergence rate of parasitoid adults indicating that immature stages are protected against insecticide penetration in the host egg. However, insecticide applications decreased parasitism rates and suggest a lethal effect on parasitoid adults by direct contact and insecticide residues, although no difference was observed between treatments. / Laboratory studies were performed to determine the existence of a sexual pheromone produced by female A. listronoti using a four-arm olfactometer. An automated system of insect tracking was developed to quantify male behavior in the olfactometer. The response of males to odor emitted by virgin females less than two days of age was measured. Virgin females less than one-day-old released a long-range pheromone from 4 hours until 16 hours after the onset of the photophase. Females of one and two days of age started to emit the sexual pheromone earlier than younger females.

No description available.

No description available.

In order that the citrus industry in South Africa may be commercially developed to the greatest possible extent it is of importance that certain basic ecological problems should be investigated. Until the complex relationships between the host plant, the insect pests and their parasites and predators are known, the results of applications of either chemical or biological control must be largely a matter of chance. A certain amount of rather generalised work in this connection has already been done in South Africa, principally by Carnegie (1955), Smithers (1953) and Whitehead (1948) in the Eastern Cape Province and by Steyn (1954) in the Transvaal. The first three of these workers were content to determine which species of insects occurred in citrus orchards and made some attempts to study the biology of certain predators. Steyn went a little further when he correlated ant activity with scale insect infestations. Without doubt the most economically important insect pests of citrus are the scale insects (Homoptera: Coccoidea). Introduction, p. 1.

Este trabalho teve por objetivo verificar a seletividade de inseticidas alternativos ao parasitóide Telenomus podisi (Ashmead) (Hymenoptera: Scelionidae). Para isto foram utilizados os inseticidas alternativos Compostonat, Natuneem, Natualho, Óleo de Gerânio, Pironat e Rotenat. Foram pulverizados 0,2 mL de cada produto, na concentração recomendada pelo fabricante, sobre cartelas (1,0 × 5,0 cm) contendo ovos de Euschistus heros (Fabricius) (Hemiptera: Pentatomidae). A testemunha constou da pulverização de água destilada. Realizou-se teste com chance de escolha, confinando uma fêmea de T. podisi com duas cartelas, uma pulverizada com o inseticida alternativo e a outra com a testemunha, sendo avaliada a taxa de parasitismo, analisando a repelência provocada pelo inseticida alternativo em relação a sua respectiva testemunha. O teste sem chance de escolha consistiu em duas estratégias de pulverização, pulverização pré-parasitismo e pulverização pós-parasitismo. A pulverização pré-parasitismo consistiu em confinar uma fêmea com uma cartela pulverizada com o inseticida alternativo, ou confinada com uma cartela da testemunha, enquanto a pulverização pós-parasitismo consistiu em confinar uma fêmea com uma cartela não pulverizada, após 24 h retirou-se a fêmea e foi realizada a pulverização com o inseticida alternativo ou com água destilada, sendo esta a testemunha. Neste teste, avaliou-se o taxa de parasitismo, porcentagem de emergência, longevidade dos adultos, período ovo-adulto e razão sexual dos parasitóides emergidos. Verificou-se que no teste com chance de escolha os inseticidas alternativos Compostonat, Natualho e Óleo de Gerânio afetaram a taxa de parasitismo. No teste sem chance de escolha a taxa de parasitismo foi afetada pelos inseticidas alternativos Rotenat no pós-parasitismo, Natualho e Óleo de Gerânio no pré-parasitismo, enquanto a emergência foi reduzida por Compostonat e Óleo de Gerânio no pré-parasitismo. O parâmetro período ovo-adulto foi afetado pelos produtos Natualho no pré-parasitismo para fêmeas e Óleo de Gerânio no pós-parasitismo para macho, a razão sexual foi reduzida por Natualho e Óleo de Gerânio nos pós-parasitismo. A longevidade foi diminuída pelos inseticidas alternativos Rotenat e Óleo de Gerânio no pré-parasitismo, e aumentada pelo Óleo de Gerânio no pós-parasitismo. Assim, Natuneem foi o único produto a apresentar seletividade a T. podisi em todos os parâmetros avaliados, porém, os demais inseticidas alternativos não são seletivos, tomando por base os testes aqui realizados, pois afetaram a maioria dos parâmetros avaliados, comprometendo o controle do inseto-praga. / The aim of this study was to verify the selectivity of alternative insecticides to the egg parasitoid, Telenomus podisi (Ashmead) (Hymenoptera: Scelionidae). The following products were evaluated: Compostonat, Natuneem, Natualho, Geranium Oil, Pironat and Rotenat. A quantity of 0.2 ml of each product, at the manufacturer’s recommended concentration, was sprayed onto cards (1.0 × 5.0 cm) supporting the eggs of Euschistus heros (Fabricius) (Hemiptera: Pentatomidae). The control was sprayed with distilled water. In this test, it was available the parasitism rate, emergency of percentage, adults longevity, period of adult-egg, sexual ration of the emerged parasitoids. It was verified that in the test with chance of choice, the alternative insecticides Compostonat, Natualho and Geranium oil affect the rate of parasitism. In the test with no-chance of parasitism choice the rate of parasitism was affected by the alternative insecticides Rotenat in the post-parasitism, Natualho and Geranium oil in the pre-parasitism, while the emergency was reduced by Compostonat and Geranium oil in the pre-parasitism. The parameter period adult-egg was affected by the products Natualho in pre-parasitism for females and Geranium oil in the post-parasitism for male, the sexual ration was reduced by Natualho and Geranium oil in the post-parasitism. The longevity was reduced by alternative insecticides Rotenat and Geranium oil in the pre-parasitism, and elevated by Geranium oil in the post-parasitism. Thus, Natuneem was the unique product to present selectivity to T. podisi in all the available parameters, although the other alternative insecticides are no selective, basing in the tests hear realized, because they affected the majority of the available parameters, compromising the control of prague- insect.

Conhecer os efeitos dos produtos fitossanitários naturais (PFN) sobre insetos praga e organismos não alvo é fundamental no contexto do Manejo Integrado de Pragas. Esse trabalho objetivou avaliar a atividade de PFN sobre Anticarsia gemmatalis (Lepidoptera: Noctuidae), esporos e cristais de Bacillus thuringiensis subesp. kurstaki (Btk) e a seletividade sobre Apis mellifera L. (Hymenoptera: Apidae). Foram utilizados os extratos de pitanga (Eugenia uniflora), pimenta (Capsicum baccatum var. pendulum), trombeta (Brugmansia suaveolens) e uva-do-japão (Hovenia dulcis), à 5%, Natuneem®, Natualho®, Pironat®, Rotenat® e Calda Bordalesa (CB), na concentração recomendada pelo fabricante. Para esporos, os tratamentos Btk + PFN e Btk, isoladamente, foram incubados em agitador horizontal (150 rpm, 30 ± 2 ºC, 2 h) e, inoculados em meio de cultura ágar nutriente (AN), em placas de Petri. Foram preparadas quatro placas (repetições), acondicionadas em câmara climatizada (30 ± 2 ºC, 18 h), quantificando-se as unidades formadoras de colônias (UFC)/mL. Para cristais, os PFN e Btk, isoladamente, água destilada esterilizada (testemunha) e Btk + PFN, após incubação, nas condições descritas acima, foram aplicados sobre cubos de dieta artificial para A. gemmatalis, em placas de Petri, que receberam 20 lagartas de segundo ínstar, cada. Foram preparadas quatro placas (repetições), acondicionadas em câmara climatizada (26 ± 2 ºC, UR: 70%±10 % fotofase 14 h). Avaliou-se a mortalidade após, 24, 48, 72, 96 e 120 h, o percentual de empupamento e emergência e o período ovo-adulto. A seletividade sobre A. mellifera foi avaliada pulverizando-se os tratamentos sobre operárias e adicionando-os a pasta Cândi. Como testemunha utilizou-se respectivamente água destilada esterilizada e pasta Cândi pura. Em ambos os experimentos utilizou-se 30 operárias por tratamento (repetição), individualizadas em tubos de vidro (10 cm × 2,5 cm), acondicionados em câmara climatizada (25 ± 2 °C, U.R. 70% ± 10%, fotofase de 12 h) e a mortalidade, avaliada a uma; duas; três; quatro; cinco; seis; nove; 12; 15; 18; 21; 24; 30; 36; 42; 48; 60; 72 e 96 h. Verificou-se que os extratos de pitanga, pimenta e uva-do-japão reduziram significativamente as UFC/mL. O extrato de pitanga foi o único que afetou negativamente a toxicidade dos cristais de Btk. Nenhum extrato vegetal afetou a mortalidade, não havendo diferença entre os tempos de avaliação, nem o empupamento, emergência e período ovo-adulto. Na mistura com Btk o extrato de pitanga retardou a mortalidade e o extrato de pimenta acelerou a mortalidade. Nos experimentos com A. mellifera, houve redução significativa, apenas para o extrato de uva-do-japão, quando pulverizado. Os produtos Natuneem® e Rotenat® aumentaram significativamente as UFC/mL. Somente a CB afetou negativamente a toxicidade dos cristais de Btk. Nos demais parâmetros, observou-se redução significativa do percentual de empupamento para CB e Natualho®e percentual de emergência para CB e Natuneem®. Entre os tempos de avaliação, não houve influência dos produtos isolados, na mistura com Btk Natualho®, Pironat®, Rotenat® aceleraram a mortalidade e a CB influenciou negativamente. Não se verificou atividade dos produtos sobre o período ovo-adulto. Para A. mellifera, em ambos os experimentos, os produtos não afetaram significativamente a longevidade. / Knowing the effects of natural products phytosanitary (NPP) on pests and organisms target is not essential in the context of Integrated Pest Management. This study aimed to evaluate the activity of PFN on Anticarsia gemmatalis Hubner (Lepidoptera: Noctuidae), spores and crystals of Bacillus thuringiensis subsp. kurstaki (Btk) and selectivity of Apis mellifera L. (Hymenoptera: Apidae). We used extracts of cherry (Eugenia uniflora), pepper (Capsicum baccatum var. pendulum), trumpet (Brugmansia suaveolens) and Blueberry japan (Hovenia dulcis), to 5%, Natuneem®, Natualho®, Pironat®, Rotenat® Bordeaux and Syrup (SB), the concentration recommended by the manufacturer. For spores, the treatments Btk + NFP and Btk alone were incubated on horizontal shaker (150 rpm, 30 ± 2 ° C, 2 h) and inoculated onto nutrient agar plates (NA), in petri dishes. We prepared four plates (repetitions), placed in a climatic chamber (30 ± 2 º C, 18 h), quantifying the colony forming units (CFU) / mL. To crystals, the PFN and Btk alone sterilized distilled water (control) and Btk + NFP after incubation under the conditions described above were applied on artificial diet cubes for A. gemmatalis, in Petri dishes, which received 20 second instar larvae of each. We prepared four plates (repetitions), placed in a climatic chamber (26 ± 2 º C, RH 70% ± 10% photophase 14 h), evaluating mortality after 24, 48, 72, 96 and 120 h, the percentage empupament and the emergence and egg-adult period. The selectivity of A. mellifera was evaluated by spraying treatments on workers and adding them to pasta Candi. As a control we used respectively sterile distilled water and paste Candi pure. In both experiments, we used 30 workers per treatment (repeat), individually in glass tubes (10 cm × 2.5 cm), packed in a climatic chamber (25 ± 2 ° C, RH 70% ± 10%, photophase 12 h) mortality, assessed by one, two, three, four, five, six, nine, 12, 15, 18, 21, 24, 30, 36, 42, 48, 60, 72 and 96 h. It was found that the extracts of cherry, pepper and Blueberry japan significantly reduced CFU / mL. The cherry extract was the only negatively affecting toxicity of Btk crystals. No plant extract affected the mortality, there was no difference between the time of evaluation, nor empupament, emergence and egg-adult period. In mixture with Btk cherry extract delayed the mortality and pepper extract accelerated mortality. In experiments with A. mellifera, was significantly reduced only to extract Blueberry japan, when sprayed. Natuneem® products and Rotenat® were the only ones who have significantly increased CFU / mL. Only the SB negatively affected the toxicity of Btk crystals. Ns other parameters, there was significant reduction in the percentage of empupament for SB and Natualho® and percentage of emergency and SB Natuneem®. Between the time of evaluation, no influence of individual products, the mix with Btk Natualho®, Pironat®, Rotenat® accelerated mortality and SB negatively influenced. There was no activity of the products on the egg-adult period. To A. mellifera, in both experiments, the products did not significantly affect longevity.

Este trabalho teve por objetivo verificar a seletividade de inseticidas alternativos ao parasitóide Telenomus podisi (Ashmead) (Hymenoptera: Scelionidae). Para isto foram utilizados os inseticidas alternativos Compostonat, Natuneem, Natualho, Óleo de Gerânio, Pironat e Rotenat. Foram pulverizados 0,2 mL de cada produto, na concentração recomendada pelo fabricante, sobre cartelas (1,0 × 5,0 cm) contendo ovos de Euschistus heros (Fabricius) (Hemiptera: Pentatomidae). A testemunha constou da pulverização de água destilada. Realizou-se teste com chance de escolha, confinando uma fêmea de T. podisi com duas cartelas, uma pulverizada com o inseticida alternativo e a outra com a testemunha, sendo avaliada a taxa de parasitismo, analisando a repelência provocada pelo inseticida alternativo em relação a sua respectiva testemunha. O teste sem chance de escolha consistiu em duas estratégias de pulverização, pulverização pré-parasitismo e pulverização pós-parasitismo. A pulverização pré-parasitismo consistiu em confinar uma fêmea com uma cartela pulverizada com o inseticida alternativo, ou confinada com uma cartela da testemunha, enquanto a pulverização pós-parasitismo consistiu em confinar uma fêmea com uma cartela não pulverizada, após 24 h retirou-se a fêmea e foi realizada a pulverização com o inseticida alternativo ou com água destilada, sendo esta a testemunha. Neste teste, avaliou-se o taxa de parasitismo, porcentagem de emergência, longevidade dos adultos, período ovo-adulto e razão sexual dos parasitóides emergidos. Verificou-se que no teste com chance de escolha os inseticidas alternativos Compostonat, Natualho e Óleo de Gerânio afetaram a taxa de parasitismo. No teste sem chance de escolha a taxa de parasitismo foi afetada pelos inseticidas alternativos Rotenat no pós-parasitismo, Natualho e Óleo de Gerânio no pré-parasitismo, enquanto a emergência foi reduzida por Compostonat e Óleo de Gerânio no pré-parasitismo. O parâmetro período ovo-adulto foi afetado pelos produtos Natualho no pré-parasitismo para fêmeas e Óleo de Gerânio no pós-parasitismo para macho, a razão sexual foi reduzida por Natualho e Óleo de Gerânio nos pós-parasitismo. A longevidade foi diminuída pelos inseticidas alternativos Rotenat e Óleo de Gerânio no pré-parasitismo, e aumentada pelo Óleo de Gerânio no pós-parasitismo. Assim, Natuneem foi o único produto a apresentar seletividade a T. podisi em todos os parâmetros avaliados, porém, os demais inseticidas alternativos não são seletivos, tomando por base os testes aqui realizados, pois afetaram a maioria dos parâmetros avaliados, comprometendo o controle do inseto-praga. / The aim of this study was to verify the selectivity of alternative insecticides to the egg parasitoid, Telenomus podisi (Ashmead) (Hymenoptera: Scelionidae). The following products were evaluated: Compostonat, Natuneem, Natualho, Geranium Oil, Pironat and Rotenat. A quantity of 0.2 ml of each product, at the manufacturer’s recommended concentration, was sprayed onto cards (1.0 × 5.0 cm) supporting the eggs of Euschistus heros (Fabricius) (Hemiptera: Pentatomidae). The control was sprayed with distilled water. In this test, it was available the parasitism rate, emergency of percentage, adults longevity, period of adult-egg, sexual ration of the emerged parasitoids. It was verified that in the test with chance of choice, the alternative insecticides Compostonat, Natualho and Geranium oil affect the rate of parasitism. In the test with no-chance of parasitism choice the rate of parasitism was affected by the alternative insecticides Rotenat in the post-parasitism, Natualho and Geranium oil in the pre-parasitism, while the emergency was reduced by Compostonat and Geranium oil in the pre-parasitism. The parameter period adult-egg was affected by the products Natualho in pre-parasitism for females and Geranium oil in the post-parasitism for male, the sexual ration was reduced by Natualho and Geranium oil in the post-parasitism. The longevity was reduced by alternative insecticides Rotenat and Geranium oil in the pre-parasitism, and elevated by Geranium oil in the post-parasitism. Thus, Natuneem was the unique product to present selectivity to T. podisi in all the available parameters, although the other alternative insecticides are no selective, basing in the tests hear realized, because they affected the majority of the available parameters, compromising the control of prague- insect.

Several ant species may be associated with the same honeydew producing insect in citrus orchards. Recently antagonism and competition between two such ants were reported from Letaba. This report stimulated the present study, the purpose of which is to ascertain which ant species are most numerous in citrus orchards ln the Eastern Cape Province; the reasons for these ants being able to occupy orchards; and, finally, their relationships. A survey of the Sundays River Valley and the Fish River Valley revealed that three species - Anoplolepis custodiens Smith, Anoplolepis steingroeveri Forel, and Pheidole megacephala Fabricius - were commonly found in citrus orchards in association with Soft Brown Scale insects. The territorial relationships of these ants were determined by plotting their distribution at intervals for over a year. It was found that this distribution could be correlated with seasonal climatic conditions, the effects of farming practices, brood rearing requirements and behavioural differences between the three species. The ant, A.steingroeveri, had not been previously studied, and since foraging is an integral part of territorial behaviour, some aspects of its biology, and more especially its foraging activity, were investigated to compare it with the known biology of the other two species. Observations on the foraging activity of A. steingroeveri were made at monthly lntervals for almost a year, and correlated with climatic conditions prevailing at the time. Some seasonal and dally variations in foraging behaviour could not be readily explained in terms of the effects of temperature and humidity on the ants. Other factors, includ1ng trophallactic stimulation and overcast skies, were found to influence ant activity. Owing to the apparent lack of information in the literature and possibility of periodic honeydew production by Soft Brown Scale insects controlling ant activity was investigated in the laboratory. The results of this study showed that it was not likely that honeydew excretion restricted the activity of the ants. Several investigators have also found that many interrelated climatic factors correlated with ant foraging behaviour, but have expressed dissatisfaction at not being able to reach the crux of the matter. To clarify the issue a constant temperature chamber was constructed in which a colony of Crematogaster ants was housed and the ants were subjected to a series of temperatures at different humidities, all other factors were eliminated or kept constant. The effects of these two factors on the thermokinetics and foraging activity of the ants were registered. This thesis contains several sections and at the end of each the results are discussed in the light of the available literature and comparisons are drawn between the species under investigation. The main results are given in the summary. After the summary two appendices are included. One is an attempt to compare the effect on ant size of the honeydew diet of orchard colonies with the proteinaceoue diet of veld ants. The other appendix is an experiment to control citrus ants with an insecticide.