Assessment and Models of Insect Damage to Cones and Seeds of Pinus strobiformis in the Sierra Madre Occidental, Mexico

Abstract

Insect damage to cones and seeds has a strong impact on the regeneration of conifer forest ecosystems, with broader implications for ecological and economic services. Lack of control of insect populations can lead to important economic and environmental losses. Pinus strobiformis is the most widespread of the white pines in Mexico and is widely distributed throughout the mountains of northern Mexico. Relatively few studies have examined insect damage to the cones and seeds of these pines, especially in Mexico. In this study, we therefore analyzed insect damage to cones and seeds of P. strobiformis in Mexico by using X-ray and stereomicroscopic analysis. The specific objectives of the study were (a) to characterize insect damage by measuring external and internal cone traits, (b) to assess the health of seeds and cones of P. strobiformis in the Sierra Madre Occidental, Mexico, and (c) to estimate the relative importance of the effects of different environmental variables on cone and seed damage caused by insects. We found that 80% of P. strobiformis seeds and 100% of the tree populations studied had damage caused by insects. Most seeds were affected by Leptoglossus occidentalis, Tetyra bipunctata, Megastigmus albifrons, and the Lepidoptera complex (which includes Apolychrosis synchysis, Cydia latisigna, Eucosma bobana, and Dioryctria abietivorella). The cones of all tree populations were affected by some type of insect damage, with Lepidoptera causing most of the damage (72%), followed by Conophthorus ponderosae (15%), the hemipteran L. occidentalis (7%), and the wasp M. albifrons (6%). The proportion of incomplete seeds in P. strobiformis at the tree level, cone damage by M. albifrons and seed damage in L. occidentalis were associated with various climate and soil variables and with crown dieback. Thus, cone and seed insect damage can be severe and potentially impact seed production in P. strobiformis and the reforestation potential of the species. The study findings will enable managers to better identify insects that cause damage to cone and seeds. In addition, identification of factors associated with damage may be useful for predicting the levels of insect predation on seeds and cones.

The Determination of Harmful Hymenoptera and Lepidoptera Species in Forest Nurseries in the Western Black Sea Region of Türkiye

“…Dioryctria Zeller (Lepidoptera: Pyralidae) species cause a significant damage to cones and seeds (Aslan, 2018;Bracalini et al, 2013;Leal-Sáenz et al, 2021). Damage caused to tree cones by Dioryctria spp.…”

Propiedades fisicoquímicas, contenido de fenoles y melanoidinas en una vinaza de sotol de nombre de dios, Durango, México

“…En el caso específico del Cu (2.18 y 3.07 mg/L) es de importancia su determinación debido a su pertinencia en épocas de sequía; el principal problema del exceso de cobre es que actúa como insecticida sobre lombrices y hongos micorrícicos (Porcuna, 2013). El Mn es un microelemento esencial (1.62 y 1.12 mg/L), sin embargo, su efecto negativo es que, al alcanzar la acumulación excesiva en compañía de pH ácidos, lo vuelve tóxico y reduce la fotosíntesis en plantas (Leal-Sáenz et al, 2021). En el caso de los elementos Zn y Mn, la aplicación de vinazas en el suelo constituye un riesgo de salinización y toxicidad (Bautista-Zúniga et al, 2000).…”

Preliminary Analysis of Transcriptome Response of Dioryctria sylvestrella (Lepidoptera: Pyralidae) Larvae Infected with Beauveria bassiana under Short-Term Starvation

“…Dioryctria (Pyralididae, Lepidoptera) species are harmful to the cones, trunks, and branches of many Pinaceae plants. In recent years, there have been increasing reports on the damage caused by Dioryctria species in coniferous forests of the Northern Hemisphere, in North America [ 1 , 2 , 3 ], Europe [ 4 ], the Russian Far East [ 5 ], China [ 6 ], and Korea [ 7 ]. Among these species, D. sylvestrella is especially important.…”