Álvaro Reyes-Olivas

Vivipary in coastal cacti: a potential reproductive strategy in halophytic environments.

Vivipary, the germination of seeds within the fruit prior to abscission from the maternal plant, is an important event in plants. Two main types of vivipary are known in vascular plants: true vivipary and pseudovivipary. In crop grasses, pseudovivipary is an undesirable character as it results in lower yields. To date, vivipary in the Cactaceae has been reported for less than 20 species, most of which are cultivated. Here, we report viviparous (cryptoviviparous-a subcategory of true vivipary) cacti in nature in members of the tribes Cacteae and Pachycereeae (subfamily Cactoideae). We present four species inhabiting coastal plains in areas subject to periodic flooding, namely, Ferocactus herrerae, Stenocereus alamosensis, S. thurberi, and Pachycereus schottii. These species from localities in northwestern Mexico had viviparous fruits and offspring in different stages of development. A potential trend in the data indicates that the overall proportion of viviparous plants is higher in coastal flooding areas relative to halophytic, nonflooding areas. In our view, vivipary is a reproductive strategy that has evolved to provide a more efficient mechanism favoring germination and new avenues for survival by contributing to population maintenance and short-distance dispersal on halophytic substrates.

Coleoptera Scarabaeoidea Collected with Light Trap in Deciduous Tropical Forest of Northern Sinaloa, Mexico

Abstract. Species richness, abundance, and seasonal distribution of Coleoptera Scarabaeoidea were evaluated in a deciduous tropical forest at Choix and El Fuerte, Sinaloa, Mexico, from July to October 2009 by means of nocturnal collections at three locations. More than 36,000 specimens were obtained, representing 45 species and 21 genera of Melolonthinae, Rutelinae, Dynastinae, Scarabaeinae, Hybosoridae, Ochodaeidae, Geotrupidae, Trogidae, and Passalidae. The genus with the highest richness index was Phyllophaga with 12 species, Phyllophaga opaca being the dominant species. The best represented species were Oxygrylius ruginasus (96.97%), Digitonthophagus gazella (1.18%), Cyclocephala freudei (0.34%), Pelidnota virescens (0.13%), and Phyllophaga opaca (0.04%). Adult activities were strictly seasonal, because the greatest abundance occurred during August (89.91%), where high rains were recorded, while during October no scarab beetle was collected.

Vivipary in Ferocactus herrerae (Cactaceae) in northern Sinaloa, México

Summary: Vivipary implies an active embryonic development with seed germination in the mother plant. The viviparous species are concentrated mainly in tropical and coastal areas with temporary flooding; thus, salinity and moisture are the main factors related to vivipary. This reproductive strategy is a rare event in the Cactaceae; however, vivipary in this family has been reported for 53 species (3.7% of the family). Ferocactus herrerae is a viviparous cactus native of northwestern Mexico, for which it has been suggested that the overall proportion of viviparous plants is higher in coastal flooding areas relative to halophytic, nonflooding areas. Thus, in this research we determine the correlation of the salinity/moisture with the vivipary incidence in Ferocactus herrerae. We performed Independence Tests between the reproductive types (viviparous/non-viviparous) and three salinity/ moisture conditions in experimental sites in northern Sinaloa, México. We had irrigation (Pueblito site), irrigation-salinity (UAS site), and control (San José site) sites. The Pueblito and UAS sites had 82% and 100% of viviparous plants compared with 56% recorded in the control. The UAS site produced 7 fruits per plant on average, with 43% viviparous, whereas the San José and Pueblito sites produced 18 fruits per plant with viviparous averages of 7.6% and 16.7% respectively. These results confirm that humid tropical and coastal environments are important in the development of vivipary in F. herrerae.

Identification of Leaf Miner1 and Its Parasitoids in Tomato Crops in Northern Sinaloa, Mexico

Abstract. During recent cropping seasons, leaf miners (family Agromyzidae), which usually are abundant and defoliate plants, have become major pests of tomato (Solanum lycopersicum L.) crops in northern Sinaloa, Mexico. The aim of this study was to identify the species of leaf miner in tomato crops and the parasitoids that naturally regulate them in northern Sinaloa. Tomato crops were sampled every 2 weeks from October 2013 to February 2014. Leaf blades with evidence of leaf miner were collected and confined in disposable plastic cups until adult leaf miners or parasitoids emerged. The species of leaf miner was Liriomyza sativae Blanchard. Associated parasitoid species were Neochrysocharis sp., Closterocerus sp. Ashmead, Opius sp. Muesebeck, and a species not yet identified in the family Figitidae. Parasitism of leaf miners per sample date ranged from 10 to 80%, and total parasitism per sample area was 21 to 28%.