Scolytus multistriatus (Marsham) and Scolytus scolytus (F.).

AbstractPopulations of Scolytus multistriatus (Marsham) from two areas of California were sampled in 1979 to investigate various factors influencing mortality. English-elm bolts (Ulmus procera Salisb.) ranging between 2.0 and 12.9 cm in diameter yielded mean mortalities from 49.1 to 86.0%. Mortality was highly correlated with egg density for branch samples from 7.0 to 12.9 cm in diameter. The minimum acceptable elm-branch diameter (2.8 cm) was attacked only during the first sampling period (mid-May to mid-June). Branch diameter, and therefore bark thickness, demonstrated a strong positive relationship with the density of S. multistriatus eggs, attacks, gallery lengths, and emerged adults. Gallery length density was positively correlated with attack density. At low attack densities in small-diameter branches, mean gallery lengths were shorter.

Download Full-text

Some effects of freezing temperatures on overwintering larvae of the large elm bark beetle (Scolytus scolytus)

Annals of Applied Biology ◽

10.1111/j.1744-7348.1974.tb01501.x ◽

1974 ◽

Vol 78 (3) ◽

pp. 219-224 ◽

Cited By ~ 7

Author(s):

G. BARSON

Keyword(s):

Bark Beetle ◽

Scolytus Scolytus ◽

Elm Bark Beetle ◽

Freezing Temperatures

Download Full-text

Scolytus multistriatus. [Distribution map].

Distribution Maps of Plant Pests ◽

10.1079/dmpp/20056600347 ◽

1975 ◽

Author(s):

Keyword(s):

North America ◽

Geographical Distribution ◽

Bark Beetle ◽

Host Plants ◽

Dutch Elm Disease ◽

Scolytus Multistriatus ◽

Distribution Map ◽

Elm Bark Beetle ◽

New Distribution ◽

Distribution In Europe

Abstract A new distribution map is provided for Scolytus multistriatus (Marsham) (Col., Scolytidae) (Smaller Elm Bark-beetle) (A vector of Dutch elm disease). Host Plants: Ulmus spp. Information is given on the geographical distribution in EUROPE (excl. USSR), Austria, Belgium, Britain, Bulgaria, Corsica, Czechoslovakia, France, Germany, Greece, Hungary, Italy, Netherlands, Poland, Portugal, Rumania, Spain, Switzerland, Yugoslavia, ASIA (excl. USSR), Iran, USSR, AFRICA, Algeria, Egypt, NORTH AMERICA, Canada, U.S.A.

Download Full-text

Bursaphelenchus michalskii sp. n. (Nematoda: Aphelenchoididae), a nematode associate of the large elm bark beetle, Scolytus scolytus Fabr. (Coleoptera: Curculionidae), in Dutch elm disease-affected elm, Ulmus laevis Pall.

Nematology ◽

10.1163/15685411-00003215 ◽

2019 ◽

Vol 21 (3) ◽

pp. 301-318

Author(s):

Marek Tomalak ◽

Anna Filipiak

Keyword(s):

Body Length ◽

Bark Beetle ◽

Excretory Pore ◽

Dutch Elm Disease ◽

Molecular Profile ◽

Male Body ◽

Morphometric Characters ◽

Scolytus Scolytus ◽

Elm Bark Beetle ◽

Ulmus Laevis

Summary Bursaphelenchus michalskii sp. n. is described from the bark of the European white elm, Ulmus laevis. All propagative stages of the nematode were found in larval galleries of the large elm bark beetle, Scolytus scolytus, and in overlapping gallery systems of this species and the small European elm bark beetle, S. multistriatus. Dauer juveniles of the new nematode are transmitted to new breeding trees under elytra of adult S. scolytus. Bursaphelenchus michalskii sp. n. is characterised by the female body length of 953 (838-1108) μm and male body length of 893 (811-971) μm, very slender body (a = 53.9 (46.1-58.5) and 60.9 (52.2-72.0) in female and male, respectively), lateral fields with three incisures (two bands), excretory pore usually located anterior to the median bulb, lack of vulval flap, long post-uterine sac, relatively small spicules 12.3 (10.8-13.3) μm long with no cucullus and with distinct, somewhat thorn-like, dorsally bent or reflexed condylus and a conical or digitate rostrum, and the arrangement of the seven male caudal papillae (i.e., a single precloacal ventromedian papilla (P1), one pair of adcloacal ventrosublateral papillae (P2) at or just anterior to cloacal slit, one ventrosublateral, postcloacal pair (P3) located at ca 60% of the tail length, posterior to cloacal slit, and one pair (P4) of ventrosublateral papillae located near the base of the bursa). The newly described species shares most of the key morphological characters with members of the eremus-group (sensu Braasch et al., 2009). However, B. michalskii sp. n. is unique amongst Bursaphelenchus species by a combination of female tail and spicule shape, excretory pore position, and other morphometric characters. These findings were confirmed by DNA sequencing and phylogenetic analysis of the 18S and 28S rDNA regions and by the unique molecular profile of the ITS region (ITS-RFLP).

Download Full-text