Revisiting the male-produced aggregation pheromone of the lesser mealworm, Alphitobius diaperinus (Coleoptera, Tenebrionidae): identification of a six-component pheromone from a Brazilian population

The lesser mealworm, Alphitobius diaperinus Panzer 1797 (Coleoptera: Tenebrionidae), is a cosmopolitan insect pest affecting poultry production. Due to its cryptic behavior, insecticide control is usually not efficient. Thus, sustainable and effective methods would have an enormous and positive impact in poultry production. The aim of this study was to confirm the identity of the male-produced aggregation pheromone for a Brazilian population of A. diaperinus and to evaluate its biological activity in behavioral assays. Six male-specific compounds were identified: (R)-limonene (1), (E)-ocimene (2), 2-nonanone (3), (S)-linalool (4), (R)-daucene (5), all described before in an American population, and a sixth component, (E,E)-α-farnesene (6), which is apparently exclusive to a Brazilian population. Y-Tube bioassays confirmed the presence of a male-produced aggregation pheromone and showed that all components need to be present in a similar ratio and concentration as emitted by male A. diaperinus to produce a positive chemotactic response

Development of pull and push–pull systems for management of lesser mealworm, Alphitobius diaperinus, in poultry houses using alarm and aggregation pheromones

BACKGROUND: The lesser mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae), is the most important insect pest affecting poultry production around the world, with all life stages being susceptible to infection by bacteria, viruses and fungi. Control of A. diaperinus in poultry houses using intensive insecticide application is not effective due to the cryp-tic behaviour of this pest. Here, we evaluated the potential of recently identified A. diaperinus alarm (1,4-benzoquinone, 2-methyl-1,4-benzoquinone and 2-ethyl-1,4-benzoquinone) and aggregation [(R)- limonene, 2-nonanone, (E)-ocimene, (S)-linalool, (R)-daucene and (E,E)- -farnesene] pheromones as tools for the management of this pest in poultry houses in Brazil. RESULTS: Laboratory arena assays with synthetic alarm pheromone confirmed A. diaperinus repellency. In an initial field assay, traps baited with synthetic aggregation pheromone captured significantly more insects than control traps. In further field assays that compared a pull (aggregation pheromone) and a push–pull (simultaneous alarm/aggregation pheromone deployment) system, a higher number of A. diaperinus were captured in aggregation pheromone-baited traps in the push–pull system. CONCLUSION: Our results suggest that alarm and aggregation pheromones can be deployed in poultry houses to trap significant numbers of adult A. diaperinus. Studies are underway to determine the potential for using these components as part of an integrated A. diaperinus management strategy

Variability in herbivore-induced defence signalling across different maize genotypes impacts significantly on natural enemy foraging behaviour

‘Smart’ plants that release volatile defence compounds in response to pest damage, and which recruit beneficial natural enemies, offer an opportunity for exploiting biological control in future crop protection strategies. Using six maize genotypes, Zapalote Chico (‘landrace’), Mirt2A, Sintético Spodoptera (SS), L3, and two commercial hybrids BRS 4103 and BRS 1040, the aim of this work was to evaluate maize responses to larval damage from the fall armyworm Spodoptera frugiperda, a major maize pest in Brazil, and the ability of the egg parasitoid Telenomus remus to respond to HIPVs induced by S. frugiperda damage. Y-tube olfactometer bioassays with T. remus showed preferential responses to the S. frugiperda-induced volatiles of SS and BRS 4103 compared to constitutive volatiles of the same genotypes, but to none of the other genotypes tested. Chemical analysis of maize volatile extracts showed that SS produced more volatile compounds in response to S. frugiperda damage, followed by BRS 4103. In addition, higher levels of mono, homo-, or sesquiterpenes, together with green leaf volatiles (GLVs) were the most attractive blend for T. remus; however, there was no attraction when only GLVs were produced in higher levels. In summary, these results show that volatile defence signalling produced by maize plants due to S. frugiperda damage varies significantly depending on maize genotype and this variability influences T. remus foraging behaviour

Development of an attract-and-infect device for biological control of lesser mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae) in poultry houses

The lesser mealworm, Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae), is the most important pest in poultry production systems worldwide. Adults and larvae serve as alternative low-quality food for chickens and as a vehicle for animal pathogens resulting in significant economic losses for farmers. Control of this pest is usually performed through insecticide application during the interval between chicken flocks. However, due to the cryptic behaviour of this pest, chemical control is usually not effective. With the aim of developing a sustainable approach to control A. diaperinus, we evaluated integration of the A. diaperinus aggregation pheromone with a highly virulent strain (Unioeste 04) of the fungus Beauveria bassiana (Bals.) Vuill. (Ascomycota: Cordycipitaceae) using an attract-and-infect device. Significant levels of A. diaperinus mortality and lower numbers of offspring (larvae) were observed in laboratory experiments using Unioeste 04. Horizontal transmission of the Unioeste 04 strain through contaminated living A. diaperinus and cadavers was also observed. In field experiments in commercial poultry houses, a significant level of A. diaperinus mortality was observed in Unioeste 04-treated arenas. The results show that the A. diaperinus aggregation pheromone can be used as an attractant in a device impregnated with infective fungal propagules, increasing adult infection and enhancing disease spread. In addition, the use of the microbial control agent inside the device allows the fungus to remain effective for longer periods in the adverse conditions of the poultry house environment

Revisiting the Male-Produced Aggregation Pheromone of the Lesser Mealworm, Alphitobius diaperinus (Coleoptera, Tenebrionidae): Identification of a Six-Component Pheromone from a Brazilian Population

The lesser mealworm, Alphitobius diaperinus Panzer 1797 (Coleoptera: Tenebrionidae), is a cosmopolitan insect pest affecting poultry production. Due to its cryptic behavior, insecticide control is usually not efficient. Thus, sustainable and effective methods would have an enormous and positive impact in poultry production. The aim of this study was to confirm the identity of the male-produced aggregation pheromone for a Brazilian population of A. diaperinus and to evaluate its biological activity in behavioral assays. Six male-specific compounds were identified: (<i>R</i>)-limonene (<b>1</b>), (<i>E</i>)-ocimene (<b>2</b>), 2-nonanone (<b>3</b>), (<i>S</i>)-linalool (<b>4</b>), (<i>R</i>)-daucene (<b>5</b>), all described before in an American population, and a sixth component, (<i>E</i>,<i>E</i>)-α-farnesene (<b>6</b>), which is apparently exclusive to a Brazilian population. Y-Tube bioassays confirmed the presence of a male-produced aggregation pheromone and showed that all components need to be present in a similar ratio and concentration as emitted by male A. diaperinus to produce a positive chemotactic response

Desempenho de diferentes substratos na decomposição de carcaça de frango de corte Performance of different substrates in the decomposition of broiler carcass

Objetivou-se com este trabalho avaliar o desempenho de diferentes substratos na decomposição de carcaça de frango de corte. Utilizaram-se seis câmaras de uma composteira, medindo 0,80 m de largura, 1,20 m de profundidade e 1,50 m de altura cada uma. Os substratos utilizados foram: acícula de pinus, bagaço de cana, palha de milho, casca de amendoim, capim e maravalha. A compostagem foi acompanhada de 4 períodos. A pilha de cada câmara foi montada em 5 camadas, de cujo total foram depositadas, em duas camadas, 5 carcaças de aves, distribuídas uniformemente. A cada 10 dias se realizou o tombamento das pilhas com o objetivo de aerar o substrato e se lhe adicionou água. Após 30 dias realizou-se o tombamento final. Na montagem das pilhas e nos tombamentos pesaram-se, separadamente, as carcaças e os substratos. Durante o processo os parâmetros monitorados foram matéria seca, cinzas, fósforo, potássio, nitrogênio, pH, carbono orgânico e razão C/N. Todos os substratos foram eficientes na decomposição das carcaças de aves e os valores da composição físico-química final dos substratos estão de acordo com os valores da IN-25/Mapa, ou seja, todos os substratos podem ser utilizados como fertilizantes orgânicos simples.<br>The aim of this study was to evaluate the performance of different substrates in the decomposition of broiler carcasses. Six containers of a compost maker were used each one measuring 0.80 m width, 1.20 m depth and 1.50 m height. The substrates were: pine aciculae, sugarcane bagasse, corn straw, peanut shells, grass and sawdust. The composting was accompanied by four periods. The pile of each container was made up of five layers, in which, five poultry carcasses were uniformly deposited in two layers. The tumbling of the piles was done every 10 days, with the purpose to provide aeration for the substrate and water was added to the same. After 30 days, the final tumbling was done. In the assembly piles and in the tumbling process the carcasses and the substrate were weighed separately. During the process, the monitored parameters were dry matter, ashes, phosphorus, potassium, nitrogen, pH, organic carbon and C/N ratio. All substrates were efficient in the decomposition of the broiler carcasses and final physiochemical composition values are in agreement with values in IN-25/Mapa, in other words, all of the substrates can be used as simple organic fertilizers