Everton Ricardi Lozano

Combined physical and chemical methods to control lesser mealworm beetles under laboratory conditions

The lesser mealworm beetle, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), is an important insect pest. The insect acts as a disease vector and reservoir, negatively affecting the health of birds and humans, and harming poultry husbandry. Controlling the lesser mealworm is generally based on using synthetic chemical insecticides, which are sometimes ineffective, and is limited due to market concerns regarding the toxicity of chemical residues in food products. In this context, the present study aimed to evaluate the potential for the combination of physical and chemical methods to control A. diaperinus. Bioassays were conducted using poultry bedding and known populations of beetle adults and larvae. The treatments consisted of the isolated application of 400 g/m2 hydrated lime; 20% added moisture (distilled water); temperature increase to 45°C; an insecticide composed of cypermethrin, chlorpyrifos, and citronellal; and a combination of these factors. Beetle mortality was measured at 7 and 10 d of treatment. The hydrated lime and moisture treatments alone did not control A. diaperinus. Raising the temperature of the poultry bedding to 45°C effectively controlled both larvae (90±6%) and adults (90±4%). The use of insecticide provided adequate control of A. diaperinus in the conditions of the bioassay (93±2% and 68±5% for adults and larvae, respectively). The combination of the studied factors led to the total control of larvae and adults after 7 d of treatment.

Eficiência de Beauveria bassiana Vuill. e Isaria sp. para o controle de Thaumastocoris peregrinus Carpintero & Dellapé (Hemiptera: Thaumastocoridae).

The search for information to control Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) in Eucalyptus , focus on the use of biological control techniques, including the use of entomopathogenic fungi. The objective of this study was evaluated the pathogenicity of Beauveria bassiana and Isaria sp. on Thaumastocoris peregrinus, under laboratory conditions. To do so, we tested four isolates of Beauveria bassiana and one isolate of Isaria sp. concentration of 1.0 × 10 8 conidia mL -1 . The solution was applied on leaves of Eucalyptus camaldulensis , provided as food for the insect substrates, and maintained in glass bottles sealed with plastic film in a climatic chamber (26 ± 2 ° C, 14 h photoperiod and U.R. 70 ± 10%). Four replicates were performed (bottles) for isolated with 13 adult insects per bottle. Each bottle received 13 adult insects. Evaluations were performed until the fifth day after application. The dead insects were placed in humid chamber for confirmation of death by pathogen. All isolates were pathogenic to Thaumastocoris peregrinus . The confirmed mortality ranged between 37% and 80.1% for Beauveria bassiana , and was 87% for Isaria sp. after 10 days of application. The highest mean percentage of daily mortality (39.9%) occurred on the fourth day after contact with the substrate insect spray. The isolates of Beauveria bassiana and Isaria sp. evaluated presented potential to control Thaumastocoris peregrinus under laboratory conditions.

Bacillus thuringiensis Berliner e Anticarsia gemmatalis Hübner (Lepidoptera: Erebidae) sob ação de extratos vegetais

O objetivo deste trabalho foi avaliar o efeito de extratos vegetais aquosos de jambolao, Syzygium cumini (L.) Skeels (Myrtaceae), mamona, Ricinus communis (L.) (Euphorbiaceae), uva-do-japao, Hovenia dulcis (Thumberg) (Rhamnaceae) e urucum (Bixa orellana (L.) (Bixaceae), na concentracao de 10%, sobre Bacillus thuringiensis subesp. kurstaki(Btk) e sobre Anticarsia gemmatalis (Lepidoptera: Erebidae) e a associacao destes sobre A. gemmatalis, em condicoes de laboratorio. Os tratamentos constaram dos extratos aquosos e Btk isoladamente e a mistura de cada extrato com Btk. Estes foram incubados em agitador horizontal (30 ± 2°C, 150 rpm por 2 h) e, em seguida, aplicados sobre cubos de dieta artificial para A. gemmatalis, em placas de Petri. Como testemunha utilizou-se agua destilada esterilizada. Cada tratamento constou de 4 placas de Petri (repeticao), com 25 lagartas de segundo instar cada. Estas foram acondicionadas em câmara climatizada (27 ± 2°C umidade relativa 70 ± 10% e fotofase 14 h), avaliando-se a mortalidade apos 24, 48 e 72 h. Tambem foram avaliados o percentual de empupamento e o peso das pupas dos insetos sobreviventes. Nenhum dos extratos apresentou efeito inseticida para A. gemmatalis e efeito negativo para os cristais de Btk. A mortalidade acumulada causada pelos extratos de uva-do-japao, jambolao, urucum e mamona foram, respectivamente, de 54,73; 46,09; 47,19 e 65,73%; diferindo significativamente da testemunha (95,74%). O peso medio das pupas nao diferiu significativamente entre os tratamentos. A associacao dos extratos de uva-do-japao, colorau e mamona com Btk provocou mortalidade acumulada de 100% em A. gemmatalis.

Oviposition Behaviour of Cleruchoides noackae (Hymenoptera: Mymaridae) in the Laboratory

Thaumastocoris peregrinus has become a major pest in eucalyptus. The most promising control method is the use of the parasitoid, Cleruchoides noackae, but little is known about its biology. Thus, the aim of this study was to investigate the oviposition behaviour of C. noackae in T. peregrinus eggs laid on strips of paper towel in the laboratory. 12 copulated females were placed in a plastic petri dish containing five T. peregrinus eggs and their behaviour was observed for 30 min/female. Several behavioural events were performed: searching for the host, host evaluation, insertion of the ovipositor, internal recognition and oviposition. Time elapsed between the insertion of the ovipositor and its removal varied from two to ten minutes. Learning more about C. noackae biology is very important to understand the dynamics between the parasitoid and its host, aiming at its biological control.

A simple, light clip-cage for experiments with aphids: A simple clip-cage for experiments with aphids

Clip‐cages are a useful experimental tool for confining small insects to leaves when aiming to study their behaviour and/or other biological parameters. Nonetheless, clip‐cages are usually heavy and may damage the leaves, which renders them less useful for numerous research studies. We propose a very simple clip‐cage, which is cheap, extremely light, and easy to make and handle, and which has less of the negative, damaging nature of traditional clip‐cages. Each clip‐cage was prepared using two discs of foam‐floating tubes: one for support and one for confining the insects. On the upper surface of the latter, a rectangle of microperforated plastic flower sleeve (8 cm2) was glued using a nontoxic glue stick. To bind the two parts to the leaf, four staples (23/13) were used. We tested the clip‐cages by confining Myzus persicae to Brassica oleracea and Brassica rapa leaves and then compared the results obtained with those acquired using classic clip‐cages. Each foam clip‐cage was assembled in less than 2 min. Our experiments confirmed the M. persicae escape rate of 6%, which compared favourably with the escape rate of 40% for the classic clip‐cage. Furthermore, the clip‐cages did not interfere with the growth rate of the aphids. The foam clip‐cages are up to 200% cheaper than the classic clip‐cages. They are light, durable, easily put together and transported, and have the potential to be easily used in field experiments.

OCORRÊNCIA ESPONTÂNEA DE Beauveria bassiana (Bals. Criv.) Vuill. 1912 (ASCOMYCETES: CLAVICIPITACEAE) SOBRE Thaumastocoris peregrinus (HEMIPTERA: THAUMASTOCORIDAE)

Exemplars of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae), insect pest of the genus Eucalyptus , were found dead in the Eucalyptus grandis plantation in the city of Realeza, the southwest region of the state of Parana, Brazil, with white mycelial growth on the surface of the body. Isolation procedures were performed (in Potato-Dextrose-Agar culture) and identification of the pathogen, whereas the ratio between the microorganism and the insect has been established by Kochs postulate. The fungus through standard procedures, was identified as Beauveria bassiana. In the laboratory testing pathogenicity were performed and caused mortality confirmed in 72.2% of the insects at the concentration of 1.0 x 10 8 conidia.mL -1 after six days inoculation. Studies on the selection of isolates should be performed and justified by the growing demand of the forest sector in search of control strategies for this insect pest. Thus, was verified that Beauveria bassiana naturally infects Thaumastocoris peregrinus, occurring spontaneously in the Parana state.

Produtos Alternativos para Controle de Thaumastocoris peregrinus e Indução de Resistência em Plantas

This study aimed to evaluate the effect of alternative insecticide on Thaumastocoris peregrinus, as well as the potential to act in the resistance induction process in plants. Leaves of Eucalyptus camaldulensis were immersed in the solution of Orobor®, Topneem®, Rotenat®, Rotenat CE®, Baicao®, Compostonat®, Pironat®, Assist®, garlic extract and bordeaux mixture. They were subsequently transferred to tubes containing 10 adults of T. peregrinus, assessing daily the number of dead insects. The products with insecticidal effect were tested for their potential to induce resistance, evaluating the synthesis of the phytoalexin glyceollin (pterocarpanoide) and phenylpropanoids route activation in soybean cotyledons by the enzyme phenylalanine ammonia-lyase. We used water as control and chitosan (1%) as an inductor of reference. Rotenat®, Compostonat®, Rotenat CE® and Topneem® showed insecticidal effect while Rotenat CE® and Topneem® showed potential as resistance inducers, expressing significant amounts of phytoalexins and activity of PAL (phenylalanine ammonia-lyase).

Getting ready for battle: do cabbage seeds treated with jasmonic acid and chitosan affect chewing and sap-feeding insects?

Induced defence allows plants to manage energy reserves more efficiently by synthesizing defence compounds only when needed. A risk of induced defence is that when plants are challenged by herbivores, they may suffer considerable damage before the defence is mounted. Priming can cause a state of readiness for the induction of the defence response, leading to a reduction in the damage received in an energy‐efficient and less costly manner. Our objective was to verify whether seed coating with jasmonic acid (JA) and chitosan (CH) could prime plants against chewing and sap‐feeding herbivores by affecting their herbivory of treated plants. We used Brassica oleracea L. var. capitata cv. Derby Day (Brassicaceae) seeds treated with JA and CH, second‐instar Plutella xylostella L. (Lepidoptera: Plutellidae), and newborn nymphs of Myzus persicae (Sulzer) (Hemiptera: Aphididae). We evaluated life‐history, performance, and fecundity traits of the insects. Neither JA nor CH affected B. oleracea leaf area. Both JA and CH affected P. xylostella. JA reduced the mean relative growth rate of P. xylostella and led to 84% pre‐imaginal mortality, whereas CH reduced oviposition. JA reduced significantly the intrinsic rate of increase in M. persicae, whereas CH did not differ from the control. Therefore, JA and CH seed coating lead to long‐term defence priming in B. oleracea against chewing and sap‐feeding insects.