No abstract

The red palm mite, Raoiella indica Hirst, has been primarily found associated with coconut and musaceous plants in the New World. However, it has also been recorded on several other palms, heliconiaceous and zingiberaceous species. This study was conducted to evaluate the suitability of different botanical families on which R. indica has been collected in the field and of arecaceous plants of the natural vegetation of the neotropics. In total, ten species of Arecaceae as well as Heliconia psittacorum [Heliconiaceae] and Alpinia purpurata [Zingiberacae] were evaluated, using coconut as a control. The study was carried out under controlled conditions (29 ± 0.5 °C, 60 ± 10% RH and photoperiod 12 h of light). Raoiella indica was able to complete immature development only on coconut, Adonidia merrillii, Ptychosperma macarthurii, H. psittacorum and A. purpurata. Duration of the immature phase (egg-adult) ranged between 21.5 days on coconut to 34.1 days on A. purpurata. Longevity was at least 50% greater and oviposition at least 38% higher on coconut than on other plants. Intrinsic rate of increase (rm) was higher on coconut (0.166) and A. merrillii (0.042), but negative on the other two plant species. Raoiella indica could not reach adulthood on any of the other ten arecaceous species considered in the study. The results suggested R. indica to be a threat to A. merrillii in addition to coconut, but not to other evaluated plants. However, complementary studies should be conducted to investigate whether the experimental procedures adopted in this study could not have prevented the mite from a better performance than it could have been under field conditions, especially in relation to Mauritia flexuosa, one of the dominant arecaceous plants in South America.

This paper refers to the first report of mites of the family Phytoseiidae from Senegal. It is based mostly on a survey conducted in the Fatick (Sine Saloum) Region, in the interior, and the Dakar Region, at the coast, in search of predators associated with the tomato red spider mite, Tetranychus evansi Baker & Pritchard. The latter has been recently introduced to Senegal, where it is causing considerable damage to solanaceous plants. Phytoseiids have been widely studied in other countries for the biological control of phytophagous mites. Seven species were found in this survey. Measurements of the species collected are provided. Neoseiulus californicus (McGregor) was only found in 2010. This could represent a new introduction into the country; it is reported for the second time in northern sub-Saharan Africa. This species and Amblyseius swirskii Athias-Henriot were often associated with T. evansi and Tetranychus urticae Koch, but their possible impact on those pests was not evaluated.

No abstract

The mealybug Phenacoccus herreni Cox & Williams causes considerable damage to cassava Manihot esculenta Crantz. Field surveys conducted between 1988 and 1994 indicated the mealybug was present in 57 municipalities in six States in north-eastern Brazil, in some places reaching high levels of infestation. Several native natural enemy species were found associated with the pest in Brazil. Exotic encyrtid parasitoids were imported and released in fields in the States of Bahia and Pernambuco. Apoanagyrus diversicornis (Howard) was introduced from Colombia, and Acerophagus coccois Smith, and Aenasius vexans (Kerrich) were introduced from Venezuela. By the end of 1996, a total of 35,930 parasitoids had been released. In Bahia, Apoanagyrus diversicornis was recovered 130, 234, 304 and 550 km from its release site after 6, 14, 21 and 33 months, respectively. Acerophagus coccois was recovered at 180 km from its release site nine months after release. Aenasius vexans, however, did not disperse at all despite being consistently recovered at its release site. In Pernambuco, 9010 parasitoids were released from October, 1995 onwards. Acerophagus coccois and Aenasius vexans were recovered up to 40 km from the release sites after three and five months of their initial releases, respectively. The establishment and dispersal of these parasitoids are discussed.