Bioecological notes on Xylosandrus compactus (Eichhoff) (Coleoptera Curculionidae Scolytinae), a species recently recorded into Italy

Abstract

Intense trade flows favour the accidental diffusion of alien plant and animal species harmful to agricultural crops and forest ecosystems in many parts of the world. Particularly prone to such introductions are lignicolous species of woodboring beetles that attack living plants and can develop in lumber or crating wood, such as many species belonging to the subfamilies Scolytinae and Platypodinae (Coleoptera: Curculionidae). Investigations of marked witherings of laurel twigs (Laurus nobilis L.) carried out from autumn 2010 in an area of the Versilia coast (Lucca) revealed that the Black twig borer, Xylosandrus compactus (Eichhoff), was involved in this pathological expression. This species was recently recorded for the first time in Italy on ornamental plants in some localities in the Naples's province. Here we report its essential external morphological features, with useful characters for its distinction from X. germanus (Blandford), a morphologically similar species, as well as its essential bioecological features, with special reference to what has been observed in the abovementioned area of Tuscany. This should facilitate the rapid identification and verification of new outbreaks and, where possible, the timely implementation of control strategies.

Full text

REDIA, XCV, 2012: 67-77
(*) Consiglio per la ricerca e la sperimentazione in agricoltura, Research Centre for Agrobiology and Pedology, Via Lanciola n. 12/A,
50125 Firenze, Italy; e-mail: fabrizio.pennacchio@entecra.it.
(**) Via M. Buonarroti, 54 - Lido di Camaiore (Lucca), Italy.
Pennacchio F., Santini L., Francardi V. – Bioecological notes on Xylosandrus compactus (Eichhoff) (Coleoptera
Curculionidae Scolytinae), a species recently recorded into Italy.
Intense trade flows favour the accidental diffusion of alien plant and animal species harmful to agricultural crops
and forest ecosystems in many parts of the world. Particularly prone to such introductions are lignicolous species of wood-
boring beetles that attack living plants and can develop in lumber or crating wood, such as many species belonging to the
subfamilies Scolytinae and Platypodinae (Coleoptera: Curculionidae). Investigations of marked witherings of laurel twigs
(Laurus nobilis L.) carried out from autumn 2010 in an area of the Versilia coast (Lucca) revealed that the Black twig borer,
Xylosandrus compactus (Eichhoff), was involved in this pathological expression. This species was recently recorded for the
first time in Italy on ornamental plants in some localities in the Naples’s province. Here we report its essential external
morphological features, with useful characters for its distinction from X. germanus (Blandford), a morphologically similar
species, as well as its essential bioecological features, with special reference to what has been observed in the above-
mentioned area of Tuscany. This should facilitate the rapid identification and verification of new outbreaks and, where
possible, the timely implementation of control strategies.
KEY WORDS: Black twig borer, insect pest introduction, Laurus nobilis.
FABRIZIO PENNACCHIO (*) - LUCIANO SANTINI (**) - VALERIA FRANCARDI (*)
BIOECOLOGICAL NOTES ON XYLOSANDRUS COMPACTUS (EICHHOFF)
(COLEOPTERA CURCULIONIDAE SCOLYTINAE), A SPECIES RECENTLY
RECORDED INTO ITALY (1)
INTRODUCTION
The intense flow of goods affecting today’s global
market, in particular the intense trade in products from the
Far East, has led to an increase in accidental introductions
of plant and animal species harmful to crops and forest
ecosystems in various parts of the world (PELLIZZARI and
DALLA MONTÀ, 1997; HAACK, 2003, 2006). Particularly
prone to such introductions are wood-boring beetles that
complete their development in the inner parts of trunks,
branches and twigs of living plants and in lumber or
crating wood. These include lignicolous or xylomy -
cetophagous species belonging to the subfamilies
Scolytinae and Platypodinae (Coleoptera Curculionidae)
more than corticicolous or phloeophagous species which
are generally more easy to control through simple
debarking of the material. Moreover, during phytosanitary
inspections of imported lumber in ports, airports, freight
terminals, etc., it is more difficult to identify material
infested by lignicolous or xylomy cetophagous beetles than
that colonized by corticicolous beetles (HAACK, 2003;
RABAGLIA et al., 2006; KIRKENDALL and FACCOLI, 2010). In
North America, 22 of the 45 wood-boring species present
were introduced from different parts of the world
(RABAGLIA et al., 2006, 2009, 2010; OKINS and THOMAS,
2009). In Europe, 12 of the 19 species of bark beetles of
more or less recent introduction, including the two
– Received 31 October 2012 Accepted 10 November 2012 Published 4 December 2012
1 This study was carried out as part of the Project “Strateco-
Phitosanitary Emergences: Containment Strategies” D.M
30290/7303/09.
spermophagous species Coccotrypes dactyliperda (Fabricius)
and Dactylotrypes longicollis (Wollaston), are
xylomycetophagous (KIRKENDALL and FACCOLI, 2010). In
recent years, several species of exotic bark beetles (largely
lignicolous ones) have been identified in Italy, such as
Gnathotrichus materiarius (Fitch) (FACCOLI, 1998), Xylo -
sandrus germanus (Blandford) (ZANDIGIACOMO et al., 1998;
STERGULC et al., 1999), X. crassiusculus (Motschul sky)
(PENNACCHIO et al., 2003), Monarthrum mali (Fitch)
(KIRKENDALL et al., 2008), Ambrosiophilus atratus
(Eichhoff) (FACCOLI, 2008), Ambrosiodmus rubricollis
(Eichhoff) (FACCOLI et al., 2009) and Megaplatypus mutatus
(Chapuis) (TREMBLAY et al., 2000). To these we must add
two phloeophagous species: Phloeosinus armatus Raitter
(COVASSI, 1991) and Phloeotribus liminaris (Harris)
(PENNACCHIO et al., 2004).
Still in progress investigation of the causes of marked
and widespread witherings of the more or less thin
branches of laurel (Laurus nobilis L.) carried out from
autumn 2010 in a relatively small area of the Versilia coast
included in the municipalities of Lido di Camaiore,
Pietrasanta, Forte dei Marmi (Province of Lucca) and, only
for few isolated locations, in those of Montignoso and
Massa (Province of Massa-Carrara) revealed that the black
twig borer X. compactus (Eichhoff) was involved to some
extent in the aforementioned unusual phytopathology. This
species was recently recorded for the first time in Italy, by
the Phytopathological Laboratory of the Phytosanitary
Service of the Campania Region, on ornamental plants in
some localities of the province of Naples, such as Gussone
Park in Portici and the park of Capodimonte (FITOLAB,
2011a, 2011b). Shortly thereafter, it was recorded by us for
the province of Lucca (FRANCARDI et al., 2012).

In the present note, we report the essential features of
the external morphology and biology of X. compactus on
the basis of previous literature data and our investigations
carried out in the above-mentioned area of Tuscany in
2010-2012. This should facilitate the rapid identification
and verification of new outbreaks and, where possible,
allow for the adequate planning and timely implemen -
tation of control measures.
SPECIMENS EXAMINED
Many females and a male were found within the maternal
galleries in different localities in the municipalities of Lido
di Camaiore, Marina di Pietrasanta and Forte dei Marmi
(Lucca) between October 2010 and October 2012.
DISTRIBUTION
The native distribution area of X. compactus is probably
tropical and subtropical Southeast Asia (India, Sri Lanka,
Indochina, China, Indonesian Archipelago, Micronesia,
Philippines, Japan), from where it has been introduced
into many parts of the world. To date, its presence is
established for much of Africa, where it is widespread,
probably introduced several centuries ago during the first
trading missions. The species is recorded from Mauritania,
Sierra Leone, Liberia, Ivory Coast, Ghana, Nigeria, Came -
roon, Equatorial Guinea, Gabon, Republic of Congo,
Democratic Republic of Congo, Uganda, Kenya, Tanzania,
South Africa, as well as from the Indian Ocean islands
(Madagascar, Seychelles, Mauritius, Comoros, Reunion).
In North America, to which it was probably introduced in
the first half of the 20th century, it is now widespread in the
south-eastern states of the USA (Florida, Georgia,
Louisiana, Mississippi, Texas, North and South Carolina).
In Latin America, it is present in Brazil, Peru and the
Caribbean islands (Cuba and the Antilles). It is also
recorded from New Caledonia, New Zealand, Hawaii,
Samoa and Fiji (SCHEDL, 1962; BEAVER, 1976; WOOD
1977, 1980, 1982; SAMUELSON, 1981; CHAPIN and OLIVER,
1986; DEYRUP and ATKINSON, 1987; WOOD and BRIGHT,
1992; DELGADO and COUTURIER, 2010, 2012).
ADULT MORPHOLOGY
FEMALE – Body stout, cylindrical, dark brown or black,
shiny, with a length between 1.4 and 1.9 mm, length/width
ratio 2.1. Antennae with funicle consisting of 5 articles and
club obliquely truncated. Pronotum with length/width
ratio 0.94-0.95. Anterior margin armed with 6-10, most
commonly 6-8, rather coarse denticles. Elytra 1.2 times as
long as wide. Elytral slope with regularly arcuate profile,
striae with short but distinct rows of setolae, interstriae
with clearly longer rows of setolae (Fig. I, 1 and 2; Fig. II, 1
and 2).
MALE – very rare, apterous and haploid, much smaller
than the female (0.8-1.1 mm), twice as long as wide.
Pronotum narrowly rounded, flattened or slightly concave
in the median part, anteriorly lacking projecting denticles.
Spicules barely appreciable, almost obsolete. Elytral striae
and interstriae with irregular spotting.
Morphologically, X. compactus presents marked simila -
rities to X. germanus (Blandford). Nevertheless, it can be
distinguished from the latter by its smaller size (the
females of X. germanus measure 2.0-2.3 mm); by the
presence of rows of setolae on both the striae and the
interstriae of the elytral slope (in X. germanus the setolae
along the striae are obsolete or completely absent) and by
the flat interstriae (in X. germanus they are weakly convex)
(Fig. I, 3).
BIOLOGICAL NOTES
Like all representatives of the tribe Xyleborini, X.
compac tus is a xylomycetophagous bark beetle (WOOD,
1982). Its preimaginal development occurs in the pith
tissue of thin twigs of 1-2 years and of the current year
with a diameter between 2.5 and 12 mm; its feeding is
almost exclusively on an ambrosia-type fungus.
The adult female digs the maternal galleries, normally on
the side of the twig facing the ground or in any case on the
less exposed side, starting from an entrance hole of ca. 0.8
mm diameter around which, as also observed by DIXON et
al. (2003), there may be a small amount of loose frass that
tends to disperse in a short time. During the early
excavation phases, the female proceeds orthogonally to the
major axis of the twig, crossing the cortical tissue, the
phloem and xylem, until she reaches the pith. Within the
pith, she digs and later expands (proceeding in the
direction of the twig’s major axis) the true maternal gallery,
the one reserved for larval development, whose diameter
generally corresponds to that of the pith (Fig. III, 1 and 2).
This gallery extends partly beneath but mainly above the
entrance tunnel (see Figs. IV and V). In this micro-envi -
ronment, the female releases the spores of the symbiotic
ambrosia fungus carried by her in a special structure of the
pronotum called the mycangium (LHOSTE and ROCHE,
1959). After the fungal mycelium has began to develop,
the female will release a more or less large group of eggs.
According to ENTWISTLE (1964), unfertilized females and
those that have exhausted the sperm reserve lay eggs that
only produce haploid males by means of facultative
arrhenotokous parthenogenesis.
Egg hatching, occurring 4-6 days after deposition, is
followed by three larval stages and the pupal stage. The
entire cycle lasts from 27 to 40 days depen ding on the
physical and chemical conditions of the host tree and the
climatic conditions (BRADER, 1964; HARA and BRADSLEY,
1979). Throughout this developmental period, the mother
remains with her brood.
The newly emerged adults, whose sex ratio is strongly
biased in favour of females, are initially light brown. With
progressive consolidation of the integumental structures
and maturation of the gonads, the colour turns into a
definitive intense dark brown in 4-5 days (see Fig. III, 3).
Mating can occur from this moment on, taking place
inside the maternal gallery before the young females leave
the twig and disperse. In view of the above-mentioned
values, taken from the literature and based on regular
surveys carried out in Versilia on laurel plants in the period
2010-2012, it is reasonable to assume that, in this area of
recent introduction, the species can complete at least two
generations and the more or less protracted beginning of a
third between the end of April and late November.
Moreover, in this area, the species normally overwinters as
adults, sheltered and inactive inside the maternal galleries
in more or less numerous groups. When young females
leave the maternal gallery and disperse, their active flight is
certainly supported by the wind. Nevertheless, it seems
likely that when they develop on a particularly receptive
68 F. PENNACCHIO ET AL. REDIA, Vol. XCV, 2012

BIOECOLOGICAL NOTES ON XYLOSANDRUS COMPACTUS (EICHHOFF)… 69
host plant (which we found to be laurel in our study area)
they largely tend not to disperse in the air but rather to
remain on the original or nearby host plants and to dig
their own egg galleries in them. This could explain the
massive attacks during a single season which progressively
affect the same plant or the same laurel hedge, as well as
the relative slowness with which outbreaks expand, even
in areas such as Versilia where laurel is very widespread.
X. compactus is a primary phytophaguos which, like
many other xylomycetophagous bark beetles, is largely
poly phagous. Hence, it can cause severe phytosanitary
problems in areas of recent introduction. At present, more
than 220 host plants, belonging to 62 families, are known.
In the presumed native tropical regions and in those of
new introduction, the development of X. compactus occurs
at the expense of economically important plants such as
coffee, tea, mango, avocado, cacao and lychee. Several
other species of economic, ecological and ornamental
importance can be attacked, including those belonging to
the genera Acacia, Acer, Azalea, Celtis, Cornus, Eucalyptus,
Ficus, Hibiscus, Khaya, Liquidambar, Magnolia, Malus,
Ostrya, Platanus, Swietenia and Vitis (NGOAN et al., 1976;
WOOD, 1982; DIXON and WOODRUFF, 1982; MESHRAM et
al., 1993; INTACHAT and KIRTON, 1997; DAEHLER and
DUDLEY, 2002; MATSUMOTO, 2002). Other recorded host
plants in the same environments include perennial
herbaceous species belonging to the families
Orchideaceae, Araceae and Zingiberaceae (HARA and
BRADSLEY, 1979; HARA and SEWAKE, 1990). Additional
lists of host plants for this bark beetle are reported in
Fig. I – Scanning electron microscope (SEM) photos. 1. Xylosandrus compactus (Eichhoff) adult female:
overall appearance. 2. X. compactus: detail of elitral declivity. 3. Xylosandrus germanus (Blandford): detail of
elitral declivity (photo C. Benvenuti).

SCHEDL (1962), BRADER (1964), SAMUELSON (1981), and
WOOD and BRIGHT (1992).
In Italy, X. compactus attacks have been recorded on
laurel, holm oak and viburnum in Campania (cf.
FITOLAB, 2011a). To this can be added the host plants we
recently recorded in Versilia where, in addition to the
greatly preferred laurel, X. compactus also attacks and
develops on many other trees and shrubs such as cherry
laurel, pitto sporum, spindle, strawberry tree, hazelnut,
holm oak, English oak, maple, alder, beech, elm, lime,
sweetgum, tulip tree, magnolia, common dogwood,
pomegranate, azalea, rhododendron, camellia, gardenia,
lemon and olive.
However, despite such a large number of potential
hosts, it seems that only a few of them have the particular
physical and chemical characteristics to support the
development of large X. compactus populations. According
to BRADER (1964), we can state on the basis of our findings
that the different hosts of this bark beetle share the
following characters: small diameter of the woody twigs in
which the maternal gallery is dug, absence of pubescence
of the outer surface of the twigs and no emission of gum,
latex or other liquids from the wound produced by the
bark beetle when digging the gallery.
DAMAGES
In many areas of new introduction, X. compactus has
shown marked aggressiveness towards plants in apparently
good vegetative conditions, often leading to significant
economic losses (LAVABRE, 1958, 1959; SAMUELSON, 1981;
RAMESH 1987; EGONYU et al., 2009). Among the many
described cases, it should be noted that very intense attacks
on even young plants of Castanea sp. were observed in
China (Yan et al., 2001), while in Hawaii (ZIEGLER, 2001,
2002) there have been X. compactus attacks against rare
native species threatened with extinction (Colubrina
oppositifolia and Caesalpinia kavaien sis); hence, this beetle
is now a serious threat to the survival and biodiversity of
the natural ecosystems of these islands.
The attacks cause the desiccation of a more or less con -
spi cuous part of the thinner branches of the canopy, with
consequent physiological damage for the entire plant. As a
70 F. PENNACCHIO ET AL. REDIA, Vol. XCV, 2012
Fig. II – Xylosandrus compactus (Eichhoff). 1. Overall appearance of an adult female. 2.
Group of adults in a maternal gallery (photo P. Giannotti).

result production losses may occur in both agricul tural
and forest ecosystems, as well as significant aesthetic
damage of many ornamental plants (Fig. VI, 1 and 2)
(NELSON and DAVIS, 1972; RAMESH, 1987; WATERHOUSE,
1997; DELGADO and COUTURIER, 2010, 2012).
In laurel (in which the symptoms of the attack are always
particularly evident) and in all other host plants examined
by us, the damage appeared within 7-10 days, according to
the following successive stages. A blackish colouration
appeared rapidly on the outer surface of the twig in the
area closely adjacent to the entrance tunnel. Within a few
days, the blackening of the external tissues involved not
only a short inferior tract but also the entire part of the twig
superior to the entrance hole with contemporary rapid
necrosis and desiccation of the same sprig (Fig. VI, 1).
Most Authors attribute the damage caused by X.
compactus to the mechanical action of digging the maternal
galleries by the females in the tissues of living twigs and
shortly thereafter to the presumed pathogenicity of the
symbiotic ambrosia fungi brought in by the bark beetle.
There is no complete agreement on the identity of these
fungi: some Authors argue that it is Fusarium solani
(Mart.) Sacc (NGOAN et al., 1976; HARA and BEARDSLEY,
1979; DAEHLER and DUDLEY, 2002; BAMBARA, 2003;
DIXON et al., 2003), while others report it to be
Ambrosiella xylebori Brader (BRADER, 1964; BHAT and
SREEDHARAN, 1988) or Ambrosiella macrospora (Fr.-
Grossman) Batra (MUTHAPPA and VENKATASUBBAIAH,
1981). Other Authors considered this last fungus
fundamental for the larval feeding but not pathogenic for
the plant (FRANCKE-GROSSMAN, 1952). In any case, it
cannot be excluded that the pathogenicity of the ambrosia
fungus is supported by that of other parasitic fungi (agents
of anthracnose) that penetrate into the tissues through the
wound produced by the bark beetle (BRADER, 1964).
With regard to this issue, preliminary results have been
recently obtained at the Micology lab of the Department
of Agriculture, Food and Environment of the University of
Pisa. Tissues of Laurus nobilis, Acer pseudoplatanus and
Magnolia grandiflora with gellery systems, preovipositional
females and mature larvae of X. compactus, plated on
Potato Dextrose Agar gave rise to colonies of at least six
different sporulating fungi and two mycelia sterilia.
Among the sporulating fungi, Verticillium and Pestalo -
tiopsis have been recorded, and these two genera include
pathogenic species able to induce symptoms (tracheo -
mycoses and twig blight)similar to those observed in field
samples (VANNACCI, 2012, pers. comm.).
BIOECOLOGICAL NOTES ON XYLOSANDRUS COMPACTUS (EICHHOFF)… 71
Fig. III – Xylosandrus compactus (Eichhoff). 1. Group of larvae and pupae in the maternal
gallery. 2. Pupa. 3. Newly emerged adult (photo P. Giannotti).

CONTROL STRATEGIES
Since X. compactus spends much of its life cycle well
protected inside the maternal galleries dug in the most
internal tissues of the host twigs, the application of control
strategies based on synthetic chemical insecticides
normally encounters considerable difficulties, beyond the
limitations due to environmental, ecological and regulatory
concerns. Indeed, results of previous trials from which to
draw useful information to plan rapid, effective control
interventions are scarce and often contradictory (MAN -
GOLD et al., 1977; MIZELL et al., 1998).
Anyway rational approach to the use of insecticides is to
use molecules able to ensure a good contact action and
with good residual power to kill newly emerged females
when they move in the crown of the host plant in search of
suitable points in which to dig their galleries (see:
MANGOLD et al., 1977; YAN et al., 2001; BAMBARA, 2003).
However, to make this type of intervention more effective,
it seems essential to conduct careful monitoring, which can
be carried out with multifunnel traps baited with ethanol
(BURBANO et al., 2012). This can be very useful not only
for rapid assessment of the spread of the insect into new
settlement areas but also to precisely identify the periods
of flight of the females in order to plan the place and
timing of interventions to contain the species (ABREU et al.,
1997, 2012; OLIVER and MANNION, 2001). Although the
use of systemic insecticides might appear to be an effective
technique against such well protected insects, there are
still many doubts about their true usefulness (PEÑA et al.,
2011). This is primarily because the location of the
preimaginal stages and adults means that they are sepa -
rated from the surrounding tissues of the host plant by a
more or less substantial layer of mycelium of the symbiotic
fungus on which they feed, and there is no certainty that it
can incorporate lethal doses of the administered active
principle. Moreover, these forms of the bark beetle are
located, from the beginning of their development, inside
tissues whose normal function might be compromised and
have begun to wither. This withering adversely affects the
72 F. PENNACCHIO ET AL. REDIA, Vol. XCV, 2012
Fig. IV – Xylosandrus compactus (Eichhoff). 1. Laurel twigs (Laurus sp.) with the entrance
hole leading to a maternal gallery. 2. Section showing the development of the same gallery
(photo P. Giannotti).

translocation of the active principle from the sites of
application and absorption.
Furthermore it can not be excluded that the damage can
be determined by the combined presence of exceptional
or abnormal climatic and/or edaphic conditions resonsable
to induce latent suffering in plants. For this reason all
cultivation practices that promote vigor of plants (above all,
land ploughing, balanced fertilization startegies and
emergency irrigation) can be still useful integrative
interventions, not only in order to mitigate the attacks of
this species, but also to promote a good vegetative recovery
of heavely attacked plants (DIXON e WOODRUFF, 1982;
BAMBARA, 2003).
Literature reports suggest a generally low importance
of natural enemies in limiting X. compactus populations,
especially in areas of new introduction. Studies con duc -
ted in Indonesia by LEPELLEY (1968) on the activity of
some parasitoids showed an inconstant efficacy. Howe ver,
some positive results were reported by KEUCHENIUS (1931)
for the island of Sumatra regarding the effects of a
eulophid wasp (Tetrastichus sp.) and a bethylid wasp. With
regard to our Tuscan study area, a larva of X. compactus
with a closely associated larva of a parasitoid was isolated
from a laurel twig from Marina di Pietrasanta in
September 2011. After 12 days, the parasitoid larva
produced a female of the braconid wasp Heterospilus
leptostoma Fischer. This species, not previously recorded
for Italy, belongs to the subfamily Doryctinae, whose
members are known as idiobiotic ectoparasitoids of
endophytic larvae of Lepidoptera, Hymenoptera Ten -
tredinidae and Coleoptera, especially bark beetles (SHAW,
1997; WHARTON et al., 1997) (Fig. VII, 1 and 2). Despite
the faunistic importance of this parasitoids, our exiguous
finding not allow us to make any conclusion of an applied
nature.
CONCLUSIONS
The results of our investigation indicate that wherever
X. compactus has been accidentally introduced it has
become a serious phytosanitary problem in a relatively
BIOECOLOGICAL NOTES ON XYLOSANDRUS COMPACTUS (EICHHOFF)… 73
Fig. V – Xylosandrus compactus (Eichhoff). 1. Olive twigs (Olea sp.) with the entrance hole
leading to a maternal gallery. 2. Development of these galleries (photo P. Giannotti).

short time because of the variety of plants it can attack. The
effects can be negative and economically disastrous for
agricultural and forestry production, especially in the
nursery sector and in the international and inland plant
trade. This is even more worrying on account of the
objective difficulty in adequately controlling the species
with the currently available materials and techniques and
the almost complete absence of previous studies to help
plan truly effective and environmentally friendly contain -
ment measures. Therefore, it is necessary to conduct
further, more extensive studies on the bioecology of this
species and the development of effective techniques to
monitor its infestations.
ACKNOWLEDGEMENTS
The Authors would like to thank Prof. Giovanni Vannac -
ci of the Section Patologia Vegetale of the Department of
Scienze Agrarie, Ambientali e Agroalimentari of the
University of Pisa, well as Dr. Augusto Loni and Mr. Paolo
Giannotti of the Section Entomologia Agraria of the same
Department, respectively for the identification of the
complex of fungi associated in dieback of twigs attacked by
bark beetle, for identification of the parasitoid Heterospilus
leptostoma Fischer and for the realization of most of the
photographs. The Authors are also grateful to the Technical
Assistant Claudia Benvenuti of the CRA ABP of Florence
for the realization of the SEM images and Dr. Alberto
Inghilesi of the Department of di Biologia evoluzionistica
“Leo Pardi” of the University of Florence, for providing
some specimens of X. germanus for comparative
morphological observa tions. We wish to thank the Plant
Protection Service of Tuscany, seat of Pisa, for reporting
some sites infested by X. compactus and provided some
samples for its determination, and Mr. Mario Pardini of the
“Agraria Pardini Giuseppe s.r.l.” of Lido di Camaiore for
the continued cooperation provided during the data
collection in the field.
74 F. PENNACCHIO ET AL. REDIA, Vol. XCV, 2012
Fig. VI – Xylosandrus compactus (Eichhoff). Evident signs of an attack. 1. On a laurel hedge.
2. On the crown of a lime tree (photo L. Santini).

REFERENCES
ABREU, R.L.S., DE ARAÚJO RIBEIRO G., VIANEZ B.F., SALES-
CAMPOS C., 2012 – Insects of the Subfamily Scolytinae
(Insecta: Coleoptera, Curculionidae) Collected with Pitfall
and Ethanol Traps in Primary Forest of Central
Amazonia. - Psyche, 8 pp.
ABREU, R.L.S., FONSECA C.R.V., MARQUES E.N., 1997 –
Analise das principais especies de Scolytidae coletadas em
floresta primaria no Estado do Amazonas. - An. Soc.
Entomol. Brasil, 26: 527-535.
BAMBARA S., 2003 – Black twig borer. North Carolina State
Cooperative Extension Service, Department of
Entomology. Insect Note. http://www.ces.ncsu.edu/
depts/ent/notes/O&T/trees/note106/note106.html.
BEAVER R.A., 1976 – The biology of Samoan bark and
ambrosia beetles (Coleoptera, Scolytidae and
Platypodidae). - Bulletin of Entomological Research,
65(4):531-548
BHAT S.S., SREEDHARAN K., 1988 – Association of
Ambrosiella xylebori Brader, with the shoot hole borer
Xylosandrus compactus Eichhoff, a pest of robusta coffee.
- J. Coffee Res., 18 (1): 54-57.
BRADER L., 1964 – Etude de la relation entre le scolyte des
rameaux du caféier, Xylosandrus compactus Eichh. (X.
morstatti Hag.) et sa plante-hôte. Mededlingen
Landdbouwhogeschool, Wageningen, 64-7, 109 pp.
BURBANO E.G., WRIGHT M.G., GILLETTE N.E., MORI S.,
DUDLEY N., JONES T., KAUFMANN M. 2012 – Efficacy of
Traps, Lures, and Repellents for Xylosandrus compactus
(Coleoptera: Curculionidae) and Other Ambrosia Beetles
on Coffea arabica Plantations and Acacia koa Nurseries
in Hawaii. - Environ. Entomol. 41 (1): 133-140.
CHAPIN, J.B., OLIVER A.D., 1986 – New records for
Xylosandrus and Xyleborus species (Coleoptera:
Scolytidae). - Proc. Ent. Soc. Wash. 88: 680-683.
COVASSI M., 1991 – Il Phloeosinus armatus Reitter,
Coleottero Scolitide del Cipresso, nuovo per l’Italia, “Il
BIOECOLOGICAL NOTES ON XYLOSANDRUS COMPACTUS (EICHHOFF)… 75
Fig. VII – Heterospilus leptostoma Fischer (Braconidae Doryctinae), idiobiontic ectoparasite of
Xylosandrus compactus (Eichhoff). 1. Overall view of an adult female. 2. Larva (right) in close
contact with the host larva (left) (photo P. Giannotti).

Cipresso” – Proposte di valorizzazione ambientale e
produttiva nei paesi mediterranei della Comunità
Economica Europea, C.N.R. – C.E.E., Firenze, 12-13
dicembre 1991: 190-196.
DAEHLER C.C., DUDLEY N., 2002 – Impact of the black
twig borer, an introduced insect pest, on Acacia koa in the
Hawaiian Islands. - Micronesica, suppl. 6: 35-53.
DELGADO C., COUTURIER G., 2010 – Xylosandrus compac -
tus (Coleoptera: Curculionidae: Scolytinae), a new pest of
Swietenia macrophylla in the Peruvian Amazonia. -
Boletín de la Sociedad Entomológica Aragonesa
(S.E.A.), 47: 441 443.
DELGADO C., COUTURIER G., 2012 – Aspectos bioecológicos
y de control de Xylosandrus compactus (Eichhoff)
(Coleoptera: Curculionidae: Scolytinae), plaga de
Myrciaria dubia Mc Vaugh en la Amazonía peruana. -
Rev. per. entomol 47: 7-10.
DEYRUP M.A., ATKINSON T.H., 1987 – New distribution
records of Scolytidae from Indiana and Florida. Great
Lakes Ent. 20: 67-68.
DIXON W.N., WOODRUFF R.E., 1982 – The black twig
borer, Xylosandrus compactus (Eichhoff) (Coleoptera:
Scolytidae). Entomology Circular, Division of Plant
Industry, Florida Department of Agriculture and
Consumer Services, No. 250:2 pp.
DIXON W.N., WOODRUFF R.E., FOLTZ J.L., 2003 – Black
Twig Borer, Xylosandrus compactus (Eichhoff) (Insecta:
Coleoptera: Curculionidae: Scolytinae). Florida
Cooperative Extension Service, IFAS, University of
Florida, EENY-311, 5 pp.
EGONYU J.P., KUCEL P., KANGIRE A., SEWAYA F., NKUGWA
C., 2009 – Impact of the black twig borer on Robusta
coffee in Mukono and Kayunga districts, central Uganda. -
Journal of Animal & Plant Sciences, 3 (1): 163 - 169.
ENTWHISTLE P. F., 1964 – Inbreeding and arrhenotoky in
the ambrosia beetle Xyleborus compactus (Eichh.)
(Coleoptera: Scolytidae). - Proc. Roy. Ent. Soc. London,
Ser. A 39: 83-88.
FACCOLI M., 1998 – The North American Gnathotrichus
materiarius (Fitch) (Coleoptera Scolytidae): an ambrosia
beetle new to Italy. - Redia, 81:151-154.
FACCOLI M., 2008 – First record of Xyleborus atratus
Eichhoff from Europe, with an illustrated key to the
European XYLEBORINI (COLEOPTERA: CURCULIONIDAE:
SCOLYTINAE). - ZOOTAXA 1772:55-62.
FACCOLI M., FRIGIMELICA G., MORI N., PETRUCCO
TOFFOLO E., VETTORAZZO M., SIMONATO M., 2009 –
First record of Ambrosiodmus (Hopkins, 1915)
(Coleoptera: Curculionidae, Scolytinae) in Europe. -
Zootaxa 2303:57-60.
FITOLAB, 2011a – Monitore fitosanitario. www.agricoltura.
regione.campania.it/difesa/monitore_2011.html.
FITOLAB, 2011b – Xylosandrus compactus.
www.agricoltura.regione.campania.it/difesa/xylosandrus
_2011.html.
FRANCARDI V., PENNACCHIO F., SANTINI. L., RUMINE P. ,
PAOLI A., NAVARRA A., MUSETTI N., 2012 – Prima
segnalazione di Xylosandrus compactus su Laurus
nobilis in Toscana. Atti delle Giornate Fitopatologiche,
13-16 marzo 2012, Milano Marittima (RA), pp. 443-446
FRANCKE-GROSMANN H., 1952 – Über die ambrosiazucht
der kiefernborkenkäfer myelophilus minor Htg. und Ips
acuminatus Gyll. - Meddelanden Statens
Skogsforskning-institut, Stockholm, 41: 1-52.
HAACK R.A., 2003 – Intercepted Scolytidae (Coleoptera) at
U.S. port of entry: 1985-2000. - Integr. Pest Manage. 6:
253-282.
HAACK R.A., 2006 – Exotic bark- and wood-boring
Coleoptera in the United States: recent establishments and
interceptions. - Can. J. For. Res. 36: 269–288
HARA A.H., BEARDSLEY J.W. JR., 1979 – Biology of the
black twig Borer, Xylosandrus compactus (Eichhoff), in
Hawaii. - Proceedings ofthe Hawaiian Entomological
Society, 13 (1): 55-70.
HARA A.H. SEWAKE K.T., 1990 – Black twig borer on
anthurium. HITAHR Brief No. 089. - CTAHR
Publication, University of Hawaii at Manoa, 2 pp.
INTACHAT J., KIRTON L.G., 1997 – Observations on insects
associated with Acacia mangium in Peninsular Malaysia.
- Journal of Tropical Forest Science, 9(4):561-564; 11
ref.
KEUCHENIUS, A.A.M.N., 1931 – Overzicht der ziekten en
plagen op koffie op ondememingen in Zuid-en West-
Sumatra over het jaar 1930. - Bergcultures 5: 203-204.
KIRKENDALL L.R., DAL CORTIVO M., GATTI E., 2008 –
First record of the ambrosia beetle, Monarthrum mali
(Curculionidae, Scolytinae) in Europe. - Journal of Pest
Science 81:175-178.
KIRKENDALL L.R., FACCOLI M., 2010 – Bark beetles and
pinhole borers (Curculionidae, Scolytinae, Platypodinae)
alien to Europe. In: Cognato A.I., Knížek M. (Eds) Sixty
years of discovering scolytine and platypodine diversity: A
tribute to Stephen L. Wood. - ZooKeys 56: 227– 251. doi:
10.3897/zookeys.56.529.
LAVAB R E E.W., 1958 – Le scolyte des branchettes du caféier
robusta Xyleborus morstatti Haged. - Café, Cacao, Thé,
2: 119-130.
LAVAB R E E.W., 1959 – Le scolyte des branchettes du caféier
robusta Xyleborus morstatti Haged. - Café, Cacao, Thé,
3: 21-33.
LEPELLEY R.H., 1968 – Pests of Coffee. London and
Harlow, UK: Longmans, Green and Co Ltd., 590 pp.
LHOSTE J., ROCHE A., 1959 – Contribution à la connais -
sance de l’anatomie interne de Xyleborus morstatti
Haged.. - Cafè, Cacao, Thè, 3: 76-86.
MANGOLD, J.R., WILKINSON R.C., SHORT D.E., 1977 –
Chlorpyrifos sprays for control of Xylosandrus compactus
in flowering dogwood. - J. Econ. Ent. 70: 789-790.
MATSUMOTO K., 2002 – Insect pests of Mahogany in
Indonesia and Malaysia. - Tropical Forestry, 55: 29-36.
MESHRAM P.B., HUSEN M., JOSHI K.C., 1993 – A new
report of ambrosia beetle, Xylosandrus compactus
Eichhoff. (Coleoptera: Scolytidae) as a pest of African
mahogany, Khaya sp. - Indian Forester, 119 (1): 75-77.
MIZELL, R.F., BOLQUES A., CRAMPTON P., 1998 –
Evaluation of insecticides to control the Asian ambrosia
beetle, Xylosandrus crassiusculus. - Proc. So. Nurs.
Grow. Assoc. 43: 162-165
MUTHAPPA B.N., VENKATASUBBAIAH P., 1981 – Association
of Ambrosia macrospora with Xylosandrus compactus,
the shot-hole borer of robusta Coffee in India. - J. Coffee
Res. 11: 54.
NELSON, R.E., DAVIS C.J., 1972 – Black twig borer, a tree
killer in Hawaii. USDA Forest Service Research Note
PSW 274. U. S. Dept of Ag.: Berkeley, CA, 2 pp.
NGOAN N.D., WILKINSON R.C., SHORT D.E., MOSES C.S.,
MANGOLD J.R., 1976 – Biology of an introduced ambrosia
beetle, Xylosandrus compactus, in Florida. - Annals of
the Entomological Society of America 69: 872-876.
OKINS K.E., THOMAS M.C., 2009 – Another Asian
Ambrosia Bettle Established in Florida (Coleoptera:
Curculionidae: Scolytinae: Xyleborini). - Pest Alerts,
Florida Department of Agriculture and Consumer
Services, 2 pp.
76 F. PENNACCHIO ET AL. REDIA, Vol. XCV, 2012

OLIVER B.J., MANNION C.M., 2001 – Ambrosia Beetle
(Coleoptera: Scolytidae) Species Attacking Chestnut and
Captured in Ethanol-Baited Traps in Middle Tennessee. -
Environ. Entomol. 30 (5): 909-918.
PELLIZZARI G., DALLA MONTÀ L., 1997 – 1945-1995 –
Fifty years of incidental insect pest introduction to Italy. -
Acta Phytopathologica et Entomologica Hungarica, 32
(1-22): 171-183.
PEÑA J.E., CRANE J.H., CAPINERA J.L., DUNCAN R.E.,
KENDRA P.E., PLOETZ R.C., MCLEAN S., BRAR G:,
THOMAS M.C., CAVE R.D., 2011 – Chemical Control of
the Redbay Ambrosia Beetle, Xyleborus glabratus, and
Other Scolytinae (Coleoptera: Curculionidae). - Florida
Entomologist, 94 (4): 882-896.
PENNACCHIO F., ROVERSI P.F., FRANCARDI V., GATTI E.,
2003 – Xylosandrus crassiusculus (Motschulsky) a bark
beetle new to Europe. - Redia 86: 77-80.
PENNACCHIO F., FAGGI M., GATTI E., CARONNI F.,
COLOMBO M., ROVERSI P.F., 2004 – First record of
Phloeotribus liminaris (Harris) in Europe (Coleoptera
Scolytidae). - Redia 87: 85-89.
RABAGLIA R.J., DOLE S.A., COGNATO A.I., 2006 – Review
of American Xyleborina (Coleoptera: Curculionidae:
Scolytinae) occurring North of Mexico, with an illustrated
key. - Annals of the Entomological Society of America
99: 1034-1056.
RABAGLIA R.J., VANDENBERG N.J., ACCIAVATTI R.E., 2009 –
First records of Anisandrus maiche Stark (Coleoptera:
Curculionidae: Scolytinae) from North America. -
Zootaxa, 2137: 23-28.
RABAGLIA R.J., KNÍŽEK M., JOHNSON W., 2010 – First
records of Xyleborinus octiesdentatus (Murayama)
(Coleoptera, Curculionidae, Scolytinae) from North
America. - ZooKeys, 56: 219-226.
RAMESH P.K., 1987 – Observations on crop loss in robusta
coffee due to mealybug and shot-hole borer. - Journal of
Coffee Research, 17(1): 94-95
SAMUELSON, G.A., 1981 – A synopsis of Hawaiian
Xyleborini (Coleoptera: Scolytidae). - Pacific Insects, 23:
50-92.
SCHEDL K.E., 1962 – Scolytidae und Platypodidae Afrikas.
Band II. Familie Scolytidae. - Rev. Ent. Mozambique 5:
1-594.
SHAW M.R., 1997 – The genus Heterospilus Haliday in
Britain, with description of a new species and remarks on
related taxa (Hymenoptera: Braconidae: Doryctinae). -
Zool. Med. Leiden, 71: 33-41.
STERGULC F., FRIGIMELICA G., ZANDIGIACOMO P., BATTISTI
A., 1999 – Gravi deperimenti del noce comune in giovani
impianti da legno in Friuli-Venezia Giulia. - Sherwood
44: 27-30.
TREMBLAY E., ESPINOSA B., MANCINI D., CAPRIO G., 2000
– Un coleottero proveniente dal Sudamerica minaccia i
pioppi. - L’informatore Agrario 48: 89-90.
YAN S.P., HUANG H.Y., WANG J.B., 2001 – The occurrence
of chestnut beetle and its control. South China Fruits, 30
(1): 48.
WATERHOUSE D.F., 1997 – The Major Invertebrate Pests
and Weeds of Agriculture and Plantation Forestry in the
Southern and Western Pacific. ACIAR Monograph No.
44. Canberra, Australia: ACIAR, VI+93 pp.
WHARTON R.A., MARSH P.M., SHARKEY M.J. (eds.), 1997 –
Manual of the new world genera of the family Braconidae
(Hymenoptera). Spec. pub. of international society of
Hymenopterist, Washington D.C., 439 pp.
WOOD S.L., 1977 – Introduced and exported american
Scolytidae (Coleoptera). - Great Basin Naturalist, 37 (1):
67-74.
WOOD S.L., 1980 – New american bark beetle (Coleoptera:
Scolytidae) with two recently introduced species. - Great
Basin Naturalist, 40 (4): 353-358.
WOOD S.L., 1982 – The bark and ambrosia beetles of North
and Central America (Coleoptera: Scolytidae), a
taxonomic monograph. - Great Basin Naturalist,
Memoirs, N.6, 1359 pp.
WOOD S.L., BRIGHT D.E. JR., 1992 – A catalog of
Scolytydae and Platypodidae (Coleoptera), part 2:
Taxonomic index. - Great Basin Naturalist, Memoirs,
N.13, 1553 pp.
ZANDIGIACOMO P., STERGULC F., FRIGIMELICA G., BATTISTI
A., 1998 – Casi di improvviso e grave deperimento del
noce comune in Friuli-Venezia Giulia (in seguito ad
attacco di Xylosandrus germanus). - Notiziario ERSA,
XI (6): 11-13.
ZIEGLER M, 2001 – Kauila. - Environment Hawai’i, 12 (1):
1-2.
ZIEGLER M, 2002 – Uhiuhi. - Environment Hawai’i, 12
(11): 1-2.
BIOECOLOGICAL NOTES ON XYLOSANDRUS COMPACTUS (EICHHOFF)… 77