Paecilomyces niveus Stolk & Samson, 1971 (Ascomycota: Thermoascaceae) as a pathogen of Nasonovia ribisnigri (Mosley, 1841) (Hemiptera, Aphididae) in Brazil / Registro de Paecilomyces niveus Stolk & Samson, 1971 (Ascomycota: Thermoascaceae) como patógeno de Nasonovia ribisnigri (Mosley, 1841) (Hemiptera, Aphididae) no Brasil

Abstract Nasonovia ribisnigri is a key pest of lettuce (Lactuca sativa L.) in Brazil that requires alternative control methods to synthetic pesticides. We report, for the first time, the occurrence of Paecilomyces niveus as an entomopathogen of the aphid Nasonovia ribisnigri in Pinhais, Paraná, Brazil. Samples of mummified aphids were collected from lettuce crops. The fungus P. niveus (PaePR) was isolated from the insect bodies and identified by macro and micromorphology. The species was confirmed by sequencing Internal Transcribed Spacer (ITS) rDNA. We obtained a sequence of 528 bp (accession number HQ441751), which aligned with Byssochlamys nivea strains (100% identities). In a bioassay, 120 h after inoculation of N. ribisnigri with pathogenic P. niveus had an average mortality of 74%. The presence of P. niveus as a natural pathogen of N. ribisnigri in Brazil suggests that it may be possible to employ P. niveus to minimize the use of chemical insecticides.

Resumo Nasonovia ribisnigri é uma praga-chave do cultivo de alface (Lactuca sativa L.), exigindo métodos alternativos ao controle químico. Este trabalho registrou pela primeira vez, a ocorrência de Paecilomyces niveus como agente entomopatogenico do afídeo N. ribisnigri em Pinhais, Paraná, Brasil. Amostras de afídeos mumificados foram coletadas em plantas de alface. O fungo P. niveus (PaePR) foi isolado do corpo dos insetos e identificado por macro e micromorfologia e, confirmado por sequenciamento da região ITS do DNA ribossomal. A sequencia parcial de 528 bp (número de acesso HQ441751) apresentou alinhamento com 100% de identidade com sequencias de raças de Byssochlamys nivea. No bioensaio de patogenicidade P. niveus apresentou uma mortalidade média de N. ribisnigri de 74% até 120 horas da inoculação. O registro da presença de P. niveus como um patógeno natural de N. ribisnigri no Brasil sugere o potencial de utilização para minimizar o uso de inseticidas.

Differential susceptibility of adults and nymphs of Blattella germanica (L.) (Blattodea: Blattellidae) to infection by Metarhizium anisopliae and assessment of delivery strategies

Microbial insecticides for cockroach control, such as those containing entomopathogenic fungi, may be an alternative to reduce contamination by chemicals in housing and food storage environments. Virulence of isolate ESALQ1037 belonging to the Metarhizium anisopliae complex against nymphs and adults of Blattella germanica (L.), and its infectivity following exposure of insects to a contaminated surface or to M. anisopliae-bait were determined under laboratory conditions. Estimated LD50 15 d following topical inoculation was 2.69 x 10(5) conidia per adult, whereas for nymphs the maximum mortality was lower than 50 percent. Baits amended with M. anisopliae conidia had no repellent effect on targets; adult mortality was inferior to 25 percent, and nymphs were not susceptible. All conidia found in the digestive tract of M. anisopliae-bait fed cockroaches were unviable, and bait-treated insects that succumbed to fungal infection showed a typical mycelial growth on mouthparts and front legs, but not on the hind body parts. As opposed to baits, the use of a M. anisopliae powdery formulation for surface treatment was effective in attaining high mortality rates of B. germanica. Both nymphs and adults were infected when this delivery strategy was used, and mycelia growth occurred all over the body surface. Our results suggest that the development of powders or similar formulations of M. anisopliae to control B. germanica may provide faster and better results than some of the strategies based on baits currently available.

Survey of ticks (Acarina: Ixodidae) for Crimean haemorrhagic fever virus activity in Jammu & Kashmir state, India.

A survey of ixodid ticks was carried on in 1977 to determine the crimean haemorrhagic fever (CHF) virus activity in Jammu & Kashmir state, India. In all, 412 immatures and 3258 adults belonging to 7 genera and 16 species of ticks were collected as ectoparasites of small and large mammals. These included one species each of the genera Boophilus, Dermacentor and Nosomma, 2 species of Rhipicephalus, 3 species of Ixodes and 4 species each of Haemaphysalis and Hyalomma. Haem. bispinosa was the predominant species followed by B. microplus, Haem. montgomeryi, R. haemaphysaloides and Hyal. m. isaaci. The four Hyalomma species viz., Hyal. a. anatolicum (incriminated as the vector of CHF virus), Hyal. detritum, Hyal. dromedarii and Hyal. m. isaaci were found parasitizing goat, sheep, camel and cattle and were collected in the districts of Jammu, Rajouri, Poonch and Udhampur. Four species viz., Haem. intermedia, Hyal. detritum, Hyal. dromedarii and Hyal. m. isaaci are new records for the state. A total of 138 pools comprising eight species under six genera of ticks were processed for isolating the virus. CHF virus was not isolated. The role of ixodid ticks, particularly those of the genus Hyalomma in the dissemination of CHF virus is highlighted.