The aim of this study was to assess the biological aspects and food preferences of Helicoverpa armigera fed different sunflower genotypes and an artificial diet. Tests were performed under multiple-choice and no-choice conditions to evaluate the biological characteristics of H. armigera. In addition, the biological data obtained were used to determine parameters of fertility life tables. The results showed that H. armigera does not have a feeding preference among the sunflower genotypes tested. The larval period on sunflower ranged from 15.0 to 16.2 days. The maximum fecundity on sunflower was 542.6 eggs/female and that on the artificial diet was 794.5 eggs/female. In general, insects feeding on Helio 250 consumed greater quantities of leaves, had higher survival until the end of the pupal stage, displayed high population growth rates, and had low population doubling times, suggesting that in the field populations will achieve greater population densities when fed on Helio 250. Insects that fed on CF101 consumed smaller leaf areas, had lower survival until the end of the pupal stage, lower fertility rates, and lower population growth rates, and may also have displayed lower population densities and smaller reductions in field productivity. This insect developed best on an artificial diet in comparison to sunflower genotypes studied.

Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a polyphagous pest with a wide geographic distribution. This pest first arrived in Brazil in 2013, and since then studies on possible control methods for it have been necessary. A possible method for the control of H. armigera is using the egg parasitoid Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae). Therefore, the objective of this study was to evaluate the performance of T. pretiosum on H. armigera eggs, which are known to represent suitable hosts for the development of this parasitoid species in the laboratory. Parasitism and emergence rates and the duration of the egg-to-adult period of T. pretiosum were investigated following 24- and 48-h exposures of this parasitoid to H. armigera and Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) eggs. The longevity of offspring after the 24-h exposure was studied, as well as the frequency of parasitism and emergence, host preference, and the emergence of offspring from eggs of different ages or oviposited by lepidopterans on different days. Parasitism was 14.4 and 34.9% more frequent on C. cephalonica than on H. armigera after 24 and 48 h of exposure, respectively. In C. cephalonica, parasitism was 27.2% higher after 48 h. Parasitism was more frequent on C. cephalonica eggs collected on the second day of oviposition (76.2%), and on H. armigera on the third day of oviposition (71.1%). Parasitism frequency was lower on 2-day-old C. cephalonica eggs (63.3%) and on 3-day-old H. armigera eggs (41.3%). When tested with a chance of choice between hosts, T. pretiosum preferred H. armigera, while in the test with no chance of choice there was no difference in preference. Thus, T. pretiosum may be considered a tool for the Integrated Pest Management (IPM) of H. armigera.

The diamondback moth (DBM), Plutella xylostella (L.), is a major pest of brassica crops worldwide. Control of this pest is difficult because it rapidly develops resistance to synthetic and biological insecticides and because of the effects of insecticides on its natural enemies. Podisus nigrispinus (Dallas) is a predator that feeds on its prey, as well as on the host plants of its prey, and is an important biological control agent of DBMs. The aim of this study was to determine the susceptibility of P. xylostella larvae to two bioinsecticides: the HD1 strain of Bacillus thuringiensis (B. thuringiensis var. kurstaki) and the commercial product Agree â (B. thuringiensis var. aizawai CG 91). In addition, the impact of these bioinsecticides on the P. nigrispinus consumption of DBM larvae and phytophagy was evaluated. Both the HD1 strain and Agree â caused 100% mortality in P. xylostella larvae.P. nigrispinus nymphs fed only with kale leaves (Brassica oleracea var. acephala) sprayed with water, the HD1 strain, or Agree â did not complete their nymphal development. When prey was also available, P. nigiripinus fed on kale leaves to obtain water. Both nymphs and adults of P. nigrispinus consumed greater numbers of DBM larvae, and fed less on kale leaves, when sprayed with the HD1 strain or Agree â . These results suggest a positive interaction of B. thuringiensis-based products and the predator P. nigrispinus in the control of P. xylostella larvae.

ResumoO objetivo do trabalho foi avaliar diferentes dietas para lagartas de Diatraea saccharalis, com o intuito de obter informações sobre as características biológicas da praga e consequentemente avaliar a qualidade do parasitoide Cotesia flavipes, visando melhorar tecnicamente sua produção massal. Lagartas de 24 horas de idade foram transferidas para tubos (25 lagartas/ tubo) contendo dieta artificial com levedura de cerveja e germe de trigo e outra somente com germe de trigo como fonte de proteína. Depois de aproximadamente 15 dias, as lagartas foram retiradas dos tubos e acondicionadas em placas com dieta, sendo observadas lagartas de D. saccharalis não parasitadas e parasitadas para avaliação das características biológicas de D. saccharalis e C. flavipes nas diferentes dietas. Além da observação das características biológicas de D. saccharalis, foram realizadas medições nas lagartas de 15 dias de idade. Também, massas de pupas de C. flavipes produzidas em biofábrica foram classificadas em três diferentes tamanhos, sendo pequenas (1,3 a 2,5 cm de comprimento), médias (2,5 a 3,5 cm de comprimento) e grandes (3,5 a 4,0 cm de comprimento). Após a emergência dos adultos foi realizado o parasitismo em lagartas de D. saccharalis, sendo observados o número de machos e fêmeas, tamanho da massa, razão sexual e número de pupas inviáveis. A dieta artificial que contém somente germe de trigo é a mais indicada para criação massal do hospedeiro D. saccharalis para produção em larga escala de C. flavipes. Massas de pupas classificadas como grandes possuem melhor qualidade em criações massais de C. flavipes. Palavras-chave:Crambidae, broca-da-cana, controle biológico, cana-de-açúcar. Protein source in Diatraea saccharalis diet and its impact on production and quality control of Cotesia flavipes AbstractThe aim of this work was to evaluate different diets for Diatraea saccharalis larvae, obtaining information about the biological characteristics of the pest, and to evaluate the quality of Cotesia flavipes parasitoid, to improve mass rearing method. For the accomplishment of the experiment, 24 hour-old larvae were transferred to tubes (25 larvae/tube) containing artificial diets with yeast and wheat germ or just wheat germ as protein source. After approximately 15 days, the larvae were removed from tubes and placed in Petri dishes, being observed D. saccharalis larvae not parasitized and parasitized for evaluation of D. saccharalis and C. flavipes biological characteristics. Biological characteristics of D. saccharalis were also evaluated in 15 day-old larvae. Pupae mass of C. flavipes from mass rearing were classified in three different sizes separated in small (1.3 to 2.5 cm of length), moderate (2.5 to 3.5 cm of length) and large (3.5 to 4.0 cm of length) classes. After the adult emergency, the parasitism was evaluated in D. saccharalis larvae, being observed the number of males and females, size of pupae mass, sex ratio and number of unviable pupae. The artificial diet that contains wheat germ is the most suitable for D. ...

No abstract

A traça-das-crucíferas, Plutella xylostella (L.) (Lepidoptera: Plutellidae), é considerada uma das pragas mais importantes de brassicáceas (Brassicaceae) em todo o mundo. A praga ocorre todos os anos no Brasil, onde o seu manejo é feito principalmente com controle químico por causa de sua conveniência e rápida ação inicial. O uso indiscriminado de inseticidas afeta organismos não-alvo e tem sido associado com o aumento da resistência de populações de P. xylostella. Estas preocupações despertaram o interesse para o uso de outras estratégias de controle, que incluem o uso de microrganismos entomopatogênicos como Bacillus thuringiensis Berliner e do predador Orius insidiosus (Say) (Hemiptera: Anthocoridae). O objetivo foi avaliar o efeito de B. thuringiensis (B. thuringiensis aizawai GC 91, Agree®) nas características biológicas de O. insidiosus. Os predadores foram alimentados com ovos de P. xylostella tratados com água destilada (controle) ou com suspensão de B. thuringiensis (0,7 g/0,5 L). Os seguintes aspectos biológicos foram avaliados: duração, sobrevivência e consumo durante o período ninfal; e consumo, número de ovos por fêmea e viabilidade de ovos durante a fase adulta. Os parâmetros de tabela de vida de fertilidade também foram avaliados para os tratamentos com ovos tratados e não tratados com B. thuringiensis. Os resultados mostraram que dentre os parâmetros de O. insidiosus a duração de ninfas de segundo ínstar, consumo ninfal e longevidade de fêmeas foram afetados pela presença de B. thuringiensis nos ovos tratados. Fêmeas alimentadas com ovos tratados mostraram menor número da progênie, que consequentemente levou a uma menor taxa de crescimento populacional.

Although the parasitoid Cotesia flavipes (Cameron) has proven effective in controlling sugarcane borer Diatraea saccharalis (Fabricius) for many years, concern has arisen over the quality of individuals produced at large scales. The parasitoid has been reared in laboratories in Brazil for more than 40 years, with no new introductions of new populations during that period. Since the quality of the parasitoids was not verified at the time of the species' introduction in Brazil, we do not know if there has been any reduction in quality so far. However, it is possible to determine whether the parasitoid could reduce in quality in future generations. Thus, the objective of this research was to assess the quality of these insects over 10 generations and look for evidence of any loss in quality. We used two populations: one from a biofactory that has been maintained in the laboratory for over 40 years, and an inbred laboratory population. Both were bred, and compared for 10 generations. We wanted to determine what happened to the quality of the parasitoid after 10 generations in an extreme inbreeding situation. To assure inbreeding, newly emerged females were forced to mate with a sibling. Individual females were then allowed to parasitize larvae of D. saccharalis. We performed evaluations for each generation until the tenth generation, and recorded the sex ratio, percentage emergence, number of offspring/females, and longevity of both males and females. Results of the measurements of biological characteristics demonstrated random significant differences between populations; best results were obtained intermittently for both the biofactory population and the inbred population. No significant differences across generations for the same population were observed. Thus, rearing of a C. flavipes population subjected to inbreeding for 10 generations was not sufficient to reveal any deleterious effects of inbreeding.

A survey of Monomachus (Hymenoptera, Monomachidae) was carried out with five Malaise traps/area in five areas of Atlantic Rainforest in São Paulo State, Brazil. The sampling effort in all localities amounted to 9,900 traps-day. Data were obtained from a total of 304 exemplars of Monomachus: 66 females and 238 males. The highest occurrence of Monomachus was observed between June and September with a frequency peak in July, and they were most frequent in Parque Estadual Morro do Diabo (PEMD) (350 m above sea level), where the sampling effort to catch each exemplar was 65.1 traps-day. From the sample of females of Monomachus captured in the Parque Estadual Intervales, Parque Estadual da Serra do Mar/Núcleo Santa Virgínia (PESM/NSV), PEMD and Estação Ecológica Juréia Itatins, between December 2009 and December 2010, two species were recognized: M. fuscator (N = 58 / 87.9 %) and M. cubiceps (8 / 12.1 %). In additional samplings in 2011 at PESM/NSV two exemplars of M. klugii recorded only from Rio de Janeiro State, Brazil were obtained, showing that its distribution has extended to São Paulo State.