A new species of Apanteles from Mexico is described and illustrated. Apanteles montezumae Sánchez, Figueroa and Whitfield, new species, attacks Argyrotaenia montezumae Walsingham and Amorbia cuneana (Walsingham) (Lepidoptera: Tortricidae) on Rubus sp. in Michoacan state, Mexico.
To determine the natural parasitism in fruit fly populations in disturbed areas adjacent to commercial mango orchards in the states of Chiapas and Veracruz, Mexico, we recorded over one year the fruit fly–host associations, fly infestation, and parasitism rates in backyard orchards and patches of native vegetation. We also investigated the relationship between fruit size, level of larval infestation, and percent of parasitism, and attempted to determine the presence of superparasitism. The most recurrent species in trap catches was Anastrepha obliqua (Macquart), followed by Anastrepha ludens (Loew), in both study zones. The fruit infestation rates were higher in Chiapas than in Veracruz, with A. obliqua again being the most conspicuous species emerging from collected fruits. The diversity of parasitoids species attacking fruit fly larvae was greater in Chiapas, with a predominance of Doryctobracon areolatus (Szépligeti) in both sites, although the exotic Diachasmimorpha longicaudata (Ashmead) was well established in Chiapas. Fruit size was positively correlated with the number of larvae per fruit, but this relationship was not observed in the level of parasitism. The number of oviposition scars was not related to the number of immature parasitoids inside the pupa of D. areolatus emerging from plum fruits. Mass releases of Di. longicaudata seem not to affect the presence or prevalence of the native species. Our findings open new research scenarios on the role and impact of native parasitoid species attacking Anastrepha flies that can contribute to the development of sound strategies for using these species in projects for augmentative biological control.
This study describes four multiple nucleocapsid nucleopolyhedrovirus isolates recovered from infected larvae of beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), on crops in two different geographical regions of Mexico. Molecular and biological characterization was compared with characterized S. exigua multiple nucleopolyhedrovirus (SeMNPV) isolates from the United States (SeUS1 and SeUS2) and Spain (SeSP2). Restriction endonuclease analysis of viral DNA confirmed that all Mexican isolates were SeMNPV isolates, but molecular differences between the Mexican and the reference isolates were detected using PCR combined with restriction fragment length polymorphism (RFLP). Amplification of the variable region V01 combined with RFLP distinguished the two Mexican isolates, SeSLP6 and SeSIN6. BglII digestions showed that the majority of the isolates contained submolar bands, indicating the presence of genetic heterogeneity. Amplification of the variable regions V04 and V05 distinguished between American and the Spanish isolates. Biological characterization was performed against two laboratory colonies of S. exigua, one from Mexico, and another from Switzerland. Insects from the Mexican colony were less susceptible to infection than insects from Se-Swiss colony. In the Se-Mex colony, SeSP2 was the most pathogenic isolate followed by SeSIN6, although their virulence was similar to most of the isolates tested. In Se-Swiss colony, similar LD50 values were observed for the five isolates, although the virulence was higher for the SeSLP6 isolate, which also had the highest OB (occlusion body) yield. We conclude that the Mexican isolates SeSIN6 and SeSLP6 possess insecticidal traits of value for the development of biopesticides for the control of populations of S. exigua.
This study assessed several bioecological aspects of the black fig fly, Silba adipata McAlpine (Diptera: Lonchaeidae), the main pest of fig (Ficus carica L.). Figs were collected from eight sites in the Mexican states of Michoacán (Plan de Ayala, Los Tejones, Antúnez, Tangancícuaro, Indaparapeo, El Carrizal, and Charapendo) and Morelos (Telixtac). No infestation was recorded in figs collected in Charapendo, but, in the remaining sites, it was variable (2–33%). Figs from Plan de Ayala and El Carrizal were longer and contained more larvae than those from Telixtac and Los Tejones. Some figs (≤12) collected in Telixtac and Los Tejones contained few pupae or adults. The survival of larval and pupal stages (≤86%) and the proportion of females (40–53%) were determined at the sites where the infestation of figs was >6% (Telixtac, El Carrizal, Plan de Ayala, and Los Tejones). In the second part of this study, the development of individuals collected in Los Tejones was analyzed under constant conditions. The estimated larval duration time was between 13 and 15 d, whereas pupae lasted 11 d. The survival rate and longevity of females and males were very similar. Our results could help design a program for integrated pest management against S. adipata.
The Neotropical cornstalk borer, Diatraea lineolata (Walker), is a pest of economic importance in maize, Zea mays L., in Mexico. The objective was to evaluate natural parasitism by Apanteles diatraeae Muesebeck on D. lineolata larvae during four ‘Mejen’ maize-growing seasons at Tabasco, Mexico. Parasitism by the braconid A. diatraeae on D. lineolata larvae was relatively low, from 0.29 to 2.8%. Of a total of 15 parasitized larvae, 46.6% were 3rd instar, 26.7% 4th instar, and 26.7% 5th-instar larvae. A. diatraeae is a gregarious endoparasitoid, with an average of 57.1 wasps emerging per parasitized larva and a sex ratio of 1:0.44 (female:male). The braconid should be studied in greater detail to know more about its interrelationship with its host during phenological stages of the crop, before physiological maturity of maize plants.