Fatores que afetam a eficiência da Terra de Diatomácea no controle de adultos de Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) / Factors affecting Diatomaceous Earth effectiveness in the control of Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) adults

A terra de diatomácea (TD) é uma alternativa potencial para o controle do cascudinho-dosaviários, Alphitobius diaperinus (Panzer). O objetivo do presente estudo foi conhecer a interferência de alguns fatores ambientais e comportamentais dessa espécie sobre a efi ciência da terra diatomácea no seu controle. Para isso, avaliou-se o efeito da temperatura do ambiente e do substrato (ração parafrangos e cama do aviário) na atividade da TD, assim como a atividade repelente do produto sobre adultos. A 32ºC a mortalidade de insetos foi signifi cativamente maior (53 e 84%, respectivamente para as concentrações de 86 e 172 g/m2) (P < 0,05). Além disso, o substrato infl uenciou, obtendo-se mortalidade de 95% na ração, contra apenas 4% na cama de aviário. Parte dos resultados pode ser atribuída à remoção das partículas de TD pela cama de aviário, conforme indicado pela análise em microscopia eletrônica de varredura (MEV) e também pela determinação da concentração de rodamina na superfície dos insetos. Quanto ao comportamento dos insetos, as armadilhas com TD capturaramcerca de 50% menos insetos que aquelas contendo apenas ração, mostrando, assim, a ação repelentedo produto. Assim, os fatores ambientais infl uenciam a efi ciência de TD e, portanto, devem ser levados em consideração para orientar as estratégias de utilização de TD em campo.

Diatomaceous earth (DE) is a potential alternative to control the lesser mealworm of poultry farms Alphitobius diaperinus (Panzer). Our study aimed to understand the role of some of theenvironmental and insect behavioral factors play on DE effectiveness, such as the substrate (chicken food and poultry house litter), temperature and DE repellent activity on lesser mealworm adults. Mortality was higher at the highest temperature (32ºC), and it increased with DE concentration (53and 84% respectively, for concentrations of 86 and 172 g/m2) (P < 0.05). The substrate also infl uencedDE effectiveness: 95% mortality was observed in the feed, against 4% in the poultry litter. Part of these results can be attributed to the removal of DE particles by the poultry bedding, as supported by scanning electron microscopy (SEM) observations and rhodamine concentration on the surface of the insects. As to insect behavior, DE had a repellent effect, since trap capture decreased nearly 50% in traps containing DE as opposed to those containing only food. Therefore, environmental factors do affect the DE effectiveness, and they must be taken into consideration when looking into developing control strategies in the field.

Reproducción y ultraestructura del huevo y larva de primer estadio de Gyriosomus kingi (Coleoptera: Tenebrionidae) del desierto de Atacama

Reproduction and ultrastructure of egg and first instar larvae of Gyriosomus kingi (Coleoptera: Tenebrionidae) from the desert of Atacama. Gyriosomus is an important Chilean genus of Tenebrionidae, inhabiting the coastal desert of this country. in this environment, the Gyriosomus-species are both eremic and endemic components of the epigean entomofauna. Despite the ecological importance of these species in the Chilean desert, there is a lack of knowledge on the preimaginal stages of them. in this paper we describe the egg and first instar larval morphology of G. kingi Reed, 1873, along with some bionomic aspects of the female. The eggs and larva were obtained from couples kept under laboratory conditions, after being captured during the spring of year 2002, in coastal sites of National Park Llanos de Challe, located in the southern border of the Atacama Desert (28°01’S, 71°03’W). The first third of the chorion presents subhexagonal cells lacking aeropyles. The larvae is oligopod and elongated. its cephalic capsule is strongly chitinized with the prothoracic legs longer and thicker than the rest. According laboratory observations, each egg-laying includes seven to ten eggs each time, with a maximum of six egg-laying per female. The eggs are buried into the soil, covered by a mucilaginous layer which creates a clay-sandy film attached to the chorion. Rev. Biol. Trop. 55 (2): 637-644. Epub 2007 June, 29.

Gyriosomus es un importante género chileno de Tenebrionidae, habitante del desierto costero del país. En este ambiente, las especies de Gyriosomus son un componente erémico y endémico de la entomofauna epígea. A pesar de la importancia ecológica que estas especies tienen en el desierto chileno, poco se conoce respecto de la morfología de los estados preimaginales. En este trabajo se describe la morfología del huevo y de la larva de primer estadio de G. kingi Reed, 1873, y se entregan algunos antecedentes acerca de la bionomía de la hembra. Los huevos y las larvas fueron obtenidos a partir de parejas mantenidas en condiciones de laboratorio. Los adultos fueron capturados durante la primavera del año 2002, en sitios costeros del Parque Nacional Llanos de Challe, localizado en la frontera sur del Desierto de Atacama (28°01’S; 71°03’W). El primer tercio del corión del huevo presenta celdas subhexagonales sin aeropilas. La larva es oligópoda y elongada. Su cápsula cefálica está fuertemente quitinizada y sus patas protorácicas son más largas y más gruesas que las restantes. Según observaciones de laboratorio, cada ovipostura incluye de siete a diez huevos cada vez, con un máximo de seis oviposturas por hembra. Los huevos son enterrados en el suelo, recubiertos con un mucílago que genera una película de arena-arcilla adherida al corión.

Studies on the genus Stylocephalus ellis, 1912 [Apicomplexa: Eugregarinida: Stylocephalidae] in beetles [Coleoptera: tenebrionidae] from El Fayoum governorate, Egypt

Four species of the genus Stylocephalus Ellis, 1912 were recorded and described from beetles in El Fayoum Governorate; S. iongicollis, S. phalloides, S. variabilis and S. eastoni. Both S. phall-oides and S. variabilis were recorded in Zophosis sp. and Pimelia angulata, respectively for the first time in Egypt. Out of 105 Blaps polychresta, 18 [17.14%] were infected with S. longicollis and 57 [54.29%] with S. eastoni. Out of 30 Pimelia angulata, 17 [56.76%] were infected with 5. variabilis and all examined Zophosis sp. [n=67] were infected with S. phalloides. Scanning electron microscopy on S. longicollis revealed morphological features not reported before; three pairs of longitudinal ribs extending from the second fifth till the posterior extremity of old sporont and a minute pore on the anterior tip of epimerite. In S. eastoni, the epimerite-host epithelium relationship revealed that the parasite invades host's gut with the distal part of epimerite. Regarding the gross pathological symptoms, heavily infected hosts showed a sluggish motility, short antennae, swollen abdomen, lack of fat accumulation, and putrid smell in dead beetles

Olfaction in the Colorado potato beetle: ultrastructure of antennal sensilla in Leptinotarsa sp.

Sensillae on the antennae of the Colorado potato beetle, Leptinotarsa decemlineata are described using scanning (SEM) and transmission (TEM) electron microscopy and compared with SEM observations of antennal sensilla in L. haldemani and L. texana. In all the three species, 13 distinct sensillar types were identified with a higher density of sensilla in the more polyphagous species, L. decemlineata than in the moderately host specific L. haldemani and the highly host specific L. texana. Cuticular specializations and the predominance of olfactory sensilla are discussed in relation to host specificity in the three species.

Spermiogenesis in Palembus dermestoides (Coleptera: Tenebrionidae) with emphasis on the formation of mitochondrial derivatives

The testes of Palembus dermestoides are formed by six follicles coated and interconnected by a peritoneal sheath. Long, cylindrical and slightly twisted spermatophores were observed. Spermiogenesis followed the usual sequence for insects. During spermiogenesis, the nucleus was transferred to the cell periphery and the mitochondria were grouped at the posterior pole of the cell. Two mitochondrial derivatives and two paracrystalline electrondense bodies were present close to the axoneme. The mitochondrial derivatives were surrounded by a single row of microtubules in immature spermatozoa. The axoneme had the typical 9+9+2 microtubular pattern of insects.