Angélica María Corona-López

Is branch damage by xylophages related to the presence of epiphytes

Host identity influences the guilds (epiphytes and xylophages) that interact within canopies. Host species can be categorized as either limiting or preferred hosts based on epiphyte load. It is possible that, depending on the host category (limiting or preferred), galleries bored by xylophages would affect the quality and availability of space for epiphytes. The objective of this study was to determine, among and within limiting and preferred hosts, the relationship between the damage inflicted by insects to branches and epiphytic bromeliads. We collected two branches each (with and without epiphytes, respectively) from limiting hosts (Bursera fagaroides, Ipomoea murucoides and I. pauciflora) and preferred hosts (Bursera copallifera and B. glabrifolia). The variables measured were: number and species of epiphytes, number of holes, number and taxonomical group of insects, percentage of epiphyte cover and percentage of area damaged by insects. These variables were compared among and within hosts and the significant correlations, where present, determined. We identified five bromeliad species and six taxonomical groups of insects. I.murucoides showed a higher proportion of damage and a larger number of insects. For the three limiting hosts, there was a negative relationship between (1) epiphyte cover and damaged area, (2) number of epiphyte individuals and number of xylophages and (3) number of epiphyte individuals and damaged area. Within species, B. copallifera, B. glabrifolia and I. pauciflora had more holes in branches that supported epiphytes than in branches without. We hypothesized that, inter-specifically, xylophages would interfere with the establishment of epiphytes by facilitating the release of allelopathics, but this possibility needs to be examined in more detail. Intra-specifically, it is possible that holes made by xylophages do not cause sufficient damage in hosts and, consequently, a possible repercussion on epiphytes is not reflected.

Is Allelopathic Activity of Ipomoea murucoides Induced by Xylophage Damage

Herbivory activates the synthesis of allelochemicals that can mediate plant-plant interactions. There is an inverse relationship between the activity of xylophages and the abundance of epiphytes on Ipomoea murucoides. Xylophagy may modify the branch chemical constitution, which also affects the liberation of allelochemicals with defense and allelopathic properties. We evaluated the bark chemical content and the effect of extracts from branches subjected to treatments of exclusion, mechanical damage and the presence/absence of epiphytes, on the seed germination of the epiphyte Tillandsia recurvata. Principal component analysis showed that branches without any treatment separate from branches subjected to treatments; damaged and excluded branches had similar chemical content but we found no evidence to relate intentional damage with allelopathy; however 1-hexadecanol, a defense volatile compound correlated positively with principal component (PC) 1. The chemical constitution of branches subject to exclusion plus damage or plus epiphytes was similar among them. PC2 indicated that palmitic acid (allelopathic compound) and squalene, a triterpene that attracts herbivore enemies, correlated positively with the inhibition of seed germination of T. recurvata. Inhibition of seed germination of T. recurvata was mainly correlated with the increment of palmitic acid and this compound reached higher concentrations in excluded branches treatments. Then, it is likely that the allelopathic response of I. murucoides would increase to the damage (shade, load) that may be caused by a high load of epiphytes than to damage caused by the xylophages.

Checklist of leaf beetles (Coleoptera: Chrysomelidae) from the state of Morelos, Mexico

We record 116 genera and 366 species of Chrysomelidae from the state of Morelos, Mexico. This represents an increase of 9.3% in the species richness of these beetles for the state. Also, Morelos is currently the third most diverse state in leaf beetles within Mexico, with 16.78% of total species recorded for the country. The most diverse genera were Calligrapha, Disonycha, Blepharida, Leptinotarsa, Cryptocephalus, Systena, Alagoasa, Diabrotica and Pachybrachis, each with more than eight species. Most of these genera contain large, showy beetles. When the chrysomelid fauna is more fully understood, some of the genera of tiny beetles will likely prove to be more diverse.

Xylophagous Beetles (Coleoptera: Buprestidae and Cerambycidae) from Ficus carica L. (Moraceae) in Morelos, Mexico

Abstract Xylophagous buprestid (Coleoptera: Buprestidae) and cerambycid beetles (Coleoptera: Cerambycidae) associated with common fig or “higuera”, Ficus carica L. (Moraceae), were studied in small orchards from Morelos, Mexico. Three species of Buprestidae and 11 species of Cerambycidae were identified. The cerambycids Eutrichillus comus Bates and Neoptychodes trilineatus (L.) were the most prevalent and abundant species reared from the sampled orchards. Ficus carica is recorded for the first time as a host for the buprestids Acmaeodera rustica Fischer, Chrysobothris analis LeConte, and Chrysobothris distincta Gory and the cerambycids Anelaphus piceum (Chemsak), E. comus, Lagocheirus obsoletus obsoletus Thomson, Sphaenothecus trilineatus Dupont, and Stenosphenus rufipes Bates. The role of xylophagous insects in the phytosanitary conditions of this fruit crop is discussed.

New host records of Cerambycidae (Coleoptera) from central Mexico

Abstract. Longhorn beetles (Coleoptera: Cerambycidae) feed during their larval stage on wood from recently dead or diseased trees and may have a wide variety of hosts. However, reports of larval hosts for Cerambycidae could be misinterpreted from field observations. The use of freshly cut branches to attract longhorn beetles is a method that provides reliable information about which hosts they use. This study reports new records of larval hosts of longhorn beetles in the tropical dry forest of San Andres de la Cal, Morelos, Mexico. In the study area, species of woody plants were sampled, from each of which sections of branches were cut and left exposed to local field conditions for two months to attract beetles. Branches were later collected and placed in emergence chambers. A total of 26 species of Cerambycidae emerged from the branches of 51 species of woody plants of the families Apocynaceae, Araliaceae, Burseraceae, Celastraceae, Convolvulaceae, Euphorbiaceae, Fabaceae, Juglandaceae, Malpighiaceae, Malvaceae, Moraceae, Oleaceae and Rubiaceae. For all 26 cerambycid species, we found previously unreported hosts, and for nine species, the hosts we report are the first recorded in the literature. The nine species whose host relationships have not been previously reported are: Euderces basimaculatus Giesbert & Chemsak 1997; E. pulcher (Bates, 1874); Elytroleptus grandis Linsley 1935; Neocompsa puncticollis asperula (Bates, 1885); Acanthoderes (Pardalisia) lacrymans (Thomson, 1865); Olenosus serrimanus Bates, 1872; Oreodera brailovskyi Chemsak & Noguera, 1993; O. copei McCarty, 2001 and Spliaenothecus picticornis Bates, 1880.

Diversity of Buprestidae (Coleoptera) from El Limón de Cuauchichinola, Tepalcingo, Morelos, Mexico

Abstract. A systematic survey was conducted to assess the diversity of Buprestidae in the tropical deciduous forest at El Limón de Cuauchichinola, municipality of Tepalcingo, Morelos State, Mexico. Samples were collected five days each month for one year, and the UAEM (CIUM) insect collection was examined for Buprestidae specimens. Four subfamilies, 12 tribes, 19 genera and 73 species were recorded, with the genera Agrilus Curtis, 1825, Chrysobothris Eschscholtz, 1829, and Acmaeodera Eschscholtz, 1829 having the greatest number of species. Nonparametric estimator analysis estimates that only 68% of buprestid species occurring in the forest were recorded. The annual value of diversity calculated with the Shannon-Wiener index was 3.08. Maximum diversity and evenness values were recorded during the rainy season. Maximum richness and abundance values were recorded during July and August, the months with the highest amount of rainfall, and correlated with rainfall 78% and 72%, respectively.

Head shape variation in cerambycid saproxylic beetles as a function of host plant selection

Saproxylic insects depend on deadwood for larval development, and a certain degree of specialization may be involved in their choice of host plants and/or wood in a particular stage of degradation. The plant species chosen for oviposition in turn act as an environmental pressure on the head morphology of larvae and it is expected that head shape plasticity varies directly with the number of woody plant species used for larval development in each insect species. We analyzed head shape variation in saproxylic beetles with respect to host plant species, maximum time of larval emergence and season of the year when insects colonized branches. Generalist species in the use of host plants showed significant variation in head shape and size. Time of emergence and season did not appear to affect head shape, although season was a determinant factor of abundance and possibly head size variation.