Proceedings of a conference : training in the control of Sirex noctilio by the use of natural enemies : Colombo, Brazil November 4 to 9, 1996

Abstract

In South America, the rate of afforestation with exotic pines has dramatically increased during the last two decades. The countries of South America are dependent on plantations of fast-growing trees to help meet their national needs for lumber, pulpwood, fuelwood, and other wood products. Also, these plantations alleviate the pressure on some naturally occurring species in areas such as the Amazon Basin, Atlantic Forest, and Auraucaria Forest. There are presently 5.0 million hectares of forest plaiitations in Brazil, of which 2.0 million hectares consist of various species of pines. Pines in South America were relatively pest-free; however, in the early 1990s, several species of insects and fungi were accidentally introduced into the continent. These pests have caused wide¬ spread, serious damage. Several pest species now threaten the future viability of pine, as well as tree biodiversity as a component of South American forestry programs. Sirex noctilio F. (Hymenoptera: Siricidae), is native to southern Europe, the Near East, and north Africa, where it is a secondary invader in the boles of weakened and dying pines. It is not considered a pest in its native habitat. This horntail is associated with a fungus, Amylostereian areolatiim, which is toxic to certain pines. By the mid 1980s, S. noctilio was causing extensive mortality In New Zealand, Tasmania, and Australia. Sirex noctilio was first reported in South America (in Uruguay in 1980). In 1988 it was found in the southern part of Brazil. It has caused widespread losses, and, in some local cases, has resulted in over sixty-percent mortality in pine plantations in Brazil and neighboring countries. In Brazil, the insect presently occurs in the southern states of Rio Grande do Sul, Santa Catarina, and Paraná, and covers an area of approximately 200,000 hectares of pine plantations. This region contains approximately sixty percent of the country's pine plantations. Current annual losses attributed to S. noctilio in this region are estimated at US$ 5 million. There is a tremendous potential for further spread of this pest in South America, especially into Chile, which has in excess of 1.3 million hectares of Monterey pine (Finns radiata D. Don.) plantations. Additionally, countries such as the United States are potentially threatened by S. noctilio as interna¬ tional trade increases.

Population biology of the European woodwasp,Sirex noctilio, in Galicia, Spain

“…The overall sex ratio in Galicia was 1:2.9 (female: male), which is somewhat more male biased than reported by Spradbery & Kirk (1978) for Europe (1:1.8); but not nearly as biased as in some invasive populations (1:32 in Brazil: Iede et al ., 1998; 1:12 in South Africa: Hurley et al ., 2008). Even the relatively modest sex ratio bias in Galicia was enough to be the second strongest demographic factor of those we could parse (48% reduction in population growth potential compared to a 1: 1 sex ratio; table 1).…”

“…Parasitism by D. siricidicola in invaded areas, where it has been repeatedly introduced as a control agent, can be both higher and lower than we found in Galicia. In Australia infection can reach 100% of the population within inoculated trees (Bedding & Akhurst, 1974, but see Nahrung et al ., 2015); infection levels in Brazil are 70 to 80% (Iede et al ., 1998), and in South Africa infection ranges from 23 to 96% (Tribe & Cillié, 2004). However there have been less successful introductions in Brazil (Fenili et al ., 2000), Argentina (Eskiviski et al ., 2003) and South Africa (Hurley et al ., 2007).…”

Biotic and abiotic effects on density, body size, sex ratio, and survival in immature stages of the European woodwasp, Sirex noctilio

“…Photograph credit: Jeff Garnas are not uncommon for haplodiploid species, including wasps, though unfortunately, few studies have assessed variation in this ratio over space and/or time. In the introduced range, estimates range from approximately equivalent to those in its native range (x̄ = 1.75:1; range = [1.4,2.1]) up to 20:1 or even 32:1 in New Zealand and Brazil, respectively (Iede et al, 1998;Zondag & Nuttall, 1977), with estimates of 10:1 or greater being common ( Figure A1).…”

Detection and Identification of <I>Amylostereum areolatum</I> (Russulales: Amylostereaceae) in the Mycangia of <I>Sirex nigricornis</I> (Hymenoptera: Siricidae) in Central Louisiana

“…Although it is a minor and infrequent pest in its native range of Eurasia and North Africa, in some cases introduction and establishment of S. noctilio to the southern hemisphere has resulted in signiÞcant mortality (up to 80%) of the North American pines Pinus radiata D. Don and Pinus taeda L. (Haugen et al 1990, Iede et al 1998, Tribe and Cillié 2004, Ryan and Hurley 2012. Economic analyses predict potential losses over a 30-yr period of US$48 Ð 606 million in Georgia, US$7Ð76 million in Minnesota, and US$7Ð77 million in California (U.S. Department of Agriculture [USDA] 2000).…”