Rebeca Álvarez-Zagoya

A critical evaluation of host ranges of parasitoids of the subtribe Diabroticina (Coleoptera: Chrysomelidae: Galerucinae: Luperini) using field and laboratory host records.

Abstract The subtribe Diabroticina is a large group of New World Chrysomelidae that includes corn rootworms, cucumber beetles and other pests. Recent introductions of Diabrotica virgifera virgifera LeConte into Europe, and the development of resistances to current management practices of rootworms in the USA have increased interest in new sustainable options for managing those pests. The only parasitoids that have been shown to consistently target and develop inside the beetle adults are Centistes gasseni Shaw, Centistes diabroticae Gahan (both Hym.: Braconidae), and Celatoria diabroticae Shimer, Celatoria compressa (Wulp), Celatoria bosqi Blanchard, and Celatoria setosa Coquillett (all Diptera: Tachinidae). This review improves our understanding of the realised and potential host range of these known parasitoids by rectifying erroneous references in light of new host records and from laboratory host range tests. Based on this critical review, all tachinid and braconid species studied are considered to be specific at least to the level of subtribe, i.e. Diabroticina. Celatoria setosa, Celatoria diabroticae and C. bosqi, have a narrow realized and potential host range; the former is restricted to the genus Acalymma and the last two to the fucata and virgifera groups of the genus Diabrotica. The braconids Centistes gasseni and C. diabroticae are also specific. The realized host range of C. gasseni includes species in the Diabrotica fucata and virgifera groups; while its potential host range also includes Acalymma species. The realized and potential host range of Centistes diabroticae includes Acalymma species as well as species in the fucata and virgifera groups of Diabrotica. Celatoria compressa has the broadest realised range compared to the other species studied, since it was obtained from species in several genera of Diabroticina; and its potential host range may also include Old World Aulacophora species.

First Record of Aedes (Stegomyia) aegypti (L.) 1 at Durango City, Mexico

Abstract. The yellow fever mosquito, Aedes (Stegomyia) aegypti (Linnaeus 1762), was recorded for the first time at Durango City and Mezquital, State of Durango, Mexico. This is a new high-altitude record at northern latitude.

Factors Affecting Seed Production of Pinus engelmannii Carr in Seed Stands in Durango State, Mexico

Abstract. Insects that affect the quality of seeds in three seed stands of Pinus engelmannii Carr in the state of Durango, Mexico, were identified and quantified. Ten trees at each of the three sites were randomly selected, and the seeds were collected from each of 10 fully developed cones. From the total seeds harvested, 400 were randomly selected and subjected to X-ray analysis to quantify whether seeds were filled, empty, or damaged by insects. The main factors that affected seed quality were poor pollination and pest attack, especially by Leptoglossus occidentalis Heidemann. Most seeds were damaged by pests at El Encinal (42.8%) and fewest at Las Cumbres (19.4%). Damage caused by the insect Cydia latisigna Miller occurred more frequently at El Encinal (5.0%) and less frequently at Las Cumbres (2.2%). Megastigmus albifrons Walker was found most frequently at La Florida (1.1%); at Las Cumbres, no damage was caused by this insect. The greatest damage caused by Leptoglossus was observed at El Encinal (1.3%), and minor damage occurred at Las Cumbres and La Florida (0.5). Most damaged seeds were at El Encinal (61.7%), while least were at Las Cumbres (22.8%). These results showed the seed bug (L. occidentalis) is the agent that causes major damage as seeds develop.

Registro de Lespesia archippivora1, Lespesia postica1, y Archytas marmoratus1 Parasitando Larvas de Spodoptera frugiperda2 en Durango, México

Resumen. Tres parasitoides: Lespesia archippivora Riley, Lespesia postica Walker, y Archytas marmoratus Townsend (Diptera: Tachinidae), son registrados por primera vez en Durango, México atacando al gusano cogollero, Spodoptera frugiperda (J. E. Smith).

DNA Isolation from Diabrotica Virgifera Zeae Krysan and Smith and Diabrotica Virgifera Virgifera LeConte (Coleoptera: Chrysomelidae) by a CTAB Simplified Procedure

Abstract. Microsatellite markers are used in genotypic studies of Diabrotica spp. Usually commercial kits are used for DNA extraction from preserved tissues. A simplified procedure, based on the CTAB, was used to obtain DNA from tissues preserved in 75% ethanol and from fresh samples of Diabrotica spp. from Durango and Jalisco, Mexico. Significantly more DNA was obtained from fresh than preserved tissues (926 and 827 ng/µL, respectively). However, the quality of DNA was similar (A260nm/A280nm mean value = 1.93) between the two kinds of tissue. The CTAB procedure was used to isolate similar quality and quantity of DNA as obtained by using commercial kits but was less time consuming and expensive. The DVV-D2 loci, a characteristic microsatellite of Diabrotica genus, was amplified.