Mariano Flores-Dávila

Insecticidal Effect of Plant Extracts on Bactericera cockerelli (Hemiptera: Psyllidae) Nymphs

Abstract. Potato psyllid, Bactericera cockerelli (Sulcen), nymphs were treated with extracts of Annona muricata L., Carica papaya L., Euphorbia dentate Michx, Thuja occidentalis L., Sapindus saponaria L., and Azadirachta indica A. Juss. (neem) as a commercial check in the laboratory. At 72 hours, most potato psyllid nymphs died (98 and 100% mortalities) from A. muricata extract from seeds, at concentrations of 2,500 and 5,000 ppm, respectively, followed by A. indica oil that caused 91 and 100% mortality at concentrations of 2,000 and 2,500 ppm, respectively. A. muricata seed extract was the most effective insecticide in the study.

First Records of Lespesia postica and Vibrissina mexicana (Tachinidae) as Parasitoids of Monoctenus sanchezi (Diprionidae)

Abstract. Parasitoid flies of white cedar sawfly, Monoctenus sanchezi Smith, were identified molecularly and morphologically. Third and fourth instars of sawfly larvae were collected in white cedar trees, Juniperus flaccida Schltdl, at Sierra de Alvarez, San Luis Potosi, in 2011, 2012, and 2013. The material collected was taken to Universidad Autonoma Agraria Antonio Narro and identified to family. Molecular characterization was done at CINVESTAV Campus Irapuato, and DNA sequences were compared with GenBank Blast. Parasitoids obtained were Vibrissina mexicana (Aldrich) and Lespesia postica (Walker) (Diptera: Tachinidae) with 99 and 97% similarity, respectively. Parasitism of white cedar sawfly was 2.6, 4.25, and 5.5% in 2011, 2012, and 2013, respectively.

Plant Oils to Control Sitophilus zeamais Motschulsky1

Abstract. The maize weevil, Sitophilus zeamais Motschulsky, is the most important pest of stored maize, Zea mays L. The pest causes estimated losses of 5–10% worldwide. Oil extracts from plants show promise to control maize weevil with important advantages over conventional insecticide, such as non-toxicity to humans, biodegradability, and ecosystem safety. The objective of this research on maize weevils in laboratory conditions was to determine the insecticidal effect of 10 plant oils: garlic, Allium sativum L.; cinnamon, Cinnamomum verum J.; hot pepper, Capsicum annuum L.; clove, Syzygium aromaticum L.; mint, Mentha piperita L.; black pepper, Piper nigrum L.; rosemary, Rosmarinus officinalis L.; rue, Ruta graveolens L.; thyme, Thymus vulgaris L. and allyl (commercial product). Residual film was used to test plant oils at five concentrations: 9,000, 7,000, 5,000, 3,000, and 1,000 ppm. The number of weevils killed was counted at 72 hours, and treatment means were compared using a Tukey multiple separation test. PC-Probit analysis determined LC50 and LC95. Most weevils, 52.47 and 60.38%, were killed by garlic and black pepper oils, respectively; at 9,000 ppm; fewer than 50% were killed with the other plant oils. Use of garlic and black pepper oil might be an alternative method to manage this insect pest in stored maize.

Thrips (Thysanoptera) Species and their Fluctuation in Abundance in Mango at Campeche, Mexico

Abstract. The objectives of this study in late 2008 to 2010 at San Antonio Cayal, Campeche, Mexico, were to determine the thrips species associated with inflorescences and leaves and the fluctuation of thrips in abundance on mango, Mangifera spp. Four species of thrips were found in inflorescences and two species in foliage. The phytophagous species of thrips Heliothrips haemorrhoidalis Bouché, Frankliniella Invasor Sakimura, Frankliniella occidentalis Pergande, and Frankliniella sp. (undescribed), and the predator mites Leptothrips macconeli (DL Crawford), and Leptothrips macro-cellatos Wakson were observed. Abundance of nymph and adult thrips per leaf ranged from 0.0 to 0.33 on several sampling dates, with 0.14 adults per leaf during the month of May. In 2010 zero adult and nymph thrips were recorded as in 2009 on several sampling dates, with most nymph and adult thrips per leaf (0.05 each) found in the month of April.