Phylogeography of the bark beetle Dendroctonus mexicanus Hopkins ( Coleoptera: Curculionidae: Scolytinae). Anducho-Reyes MA(1). ABSTRACT: The Mexican pine beetle (XPB) Dendroctonus mexicanus, is recorded here for the first time as a new introduction for the United States (US). Semiochemicals of Dendroctonus mexicanus, the Mexican pine beetle. Phylum: Arthropoda. Subphylum: Uniramia. Class: Insecta. Order: Coleoptera. Family.
Dendroctonue either case felling the tree before treatment of the bark is of advantage, and where burning is used, peeling the bark from the log is desirable. The large group outbreak in near San Rafael is believed to have occurred in this manner when the emerging beetles in the infested forest near Amecameca no longer found enough living host trees nearby.
It was in a number of these stands that the writer was able to follow in considerable detail the progress and development of the insect. However, some information on both natural and artificial control of the beetle is available and will therefore he included here. The nature of the rearings did not definitely establish dendrkctonus hymenopterous insects as parasites of D.
Allele frequencies, average mexifanus, heterozygosity by locus, deviations from Hardy—Weinberg equilibrium HWEF-statistics among populations, and average genetic flow were calculated. Frass is packed around each egg in its niche but the egg-galleries and nuptial chamber are kept open at all times. Table 2 indicates the length of time required for the most important color changes: Mirov shows that the oleoresin from P. Very few attacks have been found in Dendrcotonus.
Adults of the above species were observed feeding on the adults of D.
This species only invades the tree after the attacks of D. He also included many observations on the general features of the infestation and suggested various control measures.
Unasylva – Vol. 5, No. 4 – Pine bark beetles of Central Mexico
Male Dendroctonus mexicanus working the pitch flow in order to keep tunnel and entrance open. From many observations it appears, therefore, that the initial attack by D. These results indicate that eradication work on D.
A nuptial chamber is excavated in the phloem and from this chamber three or four winding egg-galleries dendrovtonus constructed. A very small number of the adult chalcids were reared, however, and their relative scarcity indicates that they are not an important factor in the biological control of the beetle.
The Ips infestation extended down the stem to a diameter of 6 in. Sylvio Bonansea refers to large infestations of D. The male working approximately two in. The adult insect as described by Hopkins averages 3.
Thank you for submitting a comment on this article. Hopkins of the Bureau of Entomology, U. Mexicanus Control experiments were not attempted in these studies as time was available only for collecting biological and ecological data.
EPPO Global Database
The declivity of the elytra is excavated and each side is armed with four short acute teeth. However, it was noted that infestations occurred during the coldest months of the denrdoctonus which suggests the absence of a dormancy period in the life cycle.
A high proportion of loci were out of HWE by homozygous excess, which may be explained by multiple factors. Martinez as Pinus montezumae and P.
This difference in dendoctonus character of the pitch tubes is due to differences between the chemical components of the oleoresins produced by the two species of pines. The habits of this species have not been fully described in previous publications, so are covered in some detail. Differences in brood potentials of D. In all the literature that is available there is very little information about the life history and habits of the insects, mecicanus host relationships or the causes of the aggressive outbreaks that are characteristic of the infestations.
A publication by Donald De Leon lists, with descriptions and host references, a number of the bark beetle species that attack pines in Mexico. For commercial re-use, please rendroctonus journals. Please check for further notifications by email. At higher elevations the two latter pines become more evident and fir Abies religiosa begins to appear and dendroctonuus in numbers with the increase in elevation. A comparison of jexicanus number of entrance holes, each of which represents the attack of a pair of parent beetles, and of the exit holes which represent the emergence of their progeny, will illustrate this difference.
Several large infestation centers were treated in this way. Sequence of attack on bark areas of Pinus Leiophylla Significance of the sequence of attack in individual trees There is thus a sequence of invasions of the living tree by these three species of scolytids. Acknowledgements The writer wishes to express his gratitude to the many people who aided in the preparation of this study; to John M.
As they increase in size, they gradually feed toward the outer, dry bark, attaining their maximum size as they reach the outer bark. You must accept the terms and conditions. This may very denxroctonus be due to the great scarcity of the birds, which through lack of protection seem to be approaching extermination in these areas.
It is interesting to note, however, that there is apparently a minimum diameter limit under which it does not attack P. Control through forest management Regulated cutting and management of pine stands may offer the best solution for prevention of outbreaks of D.
Table 3 is based on counts of the entrance and exit holes in bark areas, selected at random upon two killed trees representing both species of pine. Close-up of inner bark showing detail of egg galleries and early larval burrows of Dendroctonus mexicanus.
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