Euwallacea sp

Euwallacea sp. IS/CA

(Sometimes known as Euwallacea nr. fornicatus Eichhoff and Xyleborus fronicatus Eichhoff).

Common name: Polyphagous shot hole borer.

Systematic position: Insecta, Holometabola, Coleoptera, Curculionidae.

Geographical distribution: California, Israel, and Vietnam.

Morphology: Body of female about 2.5 mm long, mostly black, thorax and elytra covered with small protuberances and stiff short hairs. Male smaller, with black thorax and brown elytra.

Host plants: About 20 and 200 species, in Israel and southern California, respectively.

Life history: The beetles live within galleries that they mine in host trees. They vector several fungi, of which Fusarium euwallaceae Freeman, Mendel, Aoki and O’Donnell, located in a cavity (mycacangia) in the female head, is the more important. The beetles arrive at the host trees, especially avocado, and mine galleries there. The fungus then infests and grows on the walls of borrows tunneled in the sapwood of the host trees. The larvae and adults feed on the fungus, raising a generation in about 60 days.

Economic importance: The damage caused by this beetle is due to its vectoring the fungus F. euwallaceae. The leaves of infested, and then infected, host trees (e.i. avocado) wilt, become discolored, the branches exude a typical gum and may break. Weakened young, and even mature, trees may subsequently die. The gum exudation becomes evident as it is colonized by whitish fungi (“sugaring”). The beetle-fungus complex may endanger avocado plantations.

Management

Monitoring: The chemical quercivorol can be used for monitoring the pest, especially in the spring.

Horticultural methods: Both chipping and solarisation of infested logs reduced pest emergence and its boring activities.

Mass trapping: Quercivorol can be used for mass trapping the pest, especially in the spring.

Chemical control: A pyrethroid and imidacloprid controlled the pest in California.

References

Byers, J.A., Maoz, Y. and Levi-Zada, A. 2017. Attraction of the Euwallacea sp. near fornicatus (Coleoptera: Curculionidae) to quercivorol and to infestations in avocado. Journal of Economic Entomology 110: 1512-1517.

Carrillo, D., Narvaez, T., Cossé, A.A., Stouthamer, R. and Cooperband, M. 2015. Attraction of Euwallacea nr. fornicatus (Coleoptera: Curculionidae: Scolytinae) to lures containing quercivorol. Florida Entomologist 98:780-782.

Jones, M.E. and Paine, T.D. 2015. Effect of chipping and solarization on emergence and boring activity of a recently introduced ambrosia beetle (Euwallacea sp., Coleoptera: Curculionidae: Scolytinae) in Southern California. Journal of Economic Entomology 108: 1852-1859.

Jones, M.E. and Paine, T.D. 2017. Potential pesticides for control of a recently introduced ambrosia beetle (Euwallacea sp.) in southern California. Journal of Pest Science 106: 1–10.

Mendel, Z. (and 8 co-authors) 2012. An Asian ambrosia beetle Euwallacea fornicates and its novel symbiotic fungus Fusarium sp. pose a serious threat to the Israeli avocado industry Phytoparasitica 40: 235–238.

Freeman, S. (and 7 co-authors). 2012. Obligate feed requirement of Fusarium sp. nov., an avocado wilting agent, by the ambrosia beetle Euwallacea aff. fornicata. Symbiosis 58: 245-251.

Freeman, S. (and 7 co-authors). 2013. Fusarium euwallaceae sp. nov. – a symbiotic fungus of Euwallacea sp., an invasive ambrosia beetle in Israel and California. Mycologia 105: 1595-1606.

Freeman, S. (and 8 co-authors) 2016. Symbiotic association of three fungal species throughout the life cycle of the ambrosia beetle Euwallacea nr. fornicatus. Symbiosis 68: 115-128.

Website https://www.google.co.il/search?q=euwallacea+aff.+fornicata+images&oq=Euwallacea+aff.+fornicata+image&gs_l=psy-ab.1.0.33i160k1.16123.19058.0.20760.6.6.0.0.0.0.178.824.0j5.5.0....0...1.1.64.psy-ab..1.4.659...33i21k1.iuEhMHZiev4

https://cisr.ucr.edu/pdf/polyphagous_shot_hole_borer.pdf

RESERVED REFS

Byers, J.A., Maoz, Y. and Levi-Zada, A. 2017. Attraction of the Euwallacea sp. near fornicatus (Coleoptera: Curculionidae) to quercivorol and to infestations in avocado. Journal of Economic Entomology 110: 1512-1517.

Abstract: mass trapping with quercivorol could be effective if begun in spring before Euwallacea sp. 1 establishes competing sources of attraction.

Carrillo, D., Narvaez, T., Cossé, A.A., Stouthamer, R. and Cooperband, M. 2015. Attraction of Euwallacea nr. fornicatus (Coleoptera: Curculionidae: Scolytinae) to lures containing quercivorol. Florida Entomologist 98:780-782.

Abstract: Euwallacea nr. fornicatus (Eichhoff) (Coleoptera: Curculionidae: Scolytinae) is an exotic ambrosia beetle that vectors fungal Fusarium spp. to avocados. Two field trials testing potential attractants to trap Euwallacea spp. were conducted in south Florida. Quercivorol + Ultra High Release Ethanol (URH) was the most powerful attractant for E. nr. fornicatus in the 2 field trials. In Florida, the populations of E. nr. Fornicates are small. The attractiveness of quercivorol lures to other Euwallacea spp. should be tested in conditions where population levels are greater as in California and Israel.

Jones, M.E. and Paine, T.D. 2015. Effect of chipping and solarization on emergence and boring activity of a recently introduced ambrosia beetle (Euwallacea sp., Coleoptera: Curculionidae: Scolytinae) in Southern California. Journal of Economic Entomology 108: 1852-1859.

Abstract: We tested two sanitation methods to reduce beetle populations, chipping with a commercial chipper (wood from a single infested tree was fed through a commercial chipper, chipped, and sorted into three size classes using wire mesh screens (60 by 60 cm 2 ) with a mesh size of either 2.5 or 5 cm. Sorted chip size classes were coarse (>5 cm), medium (2.5–5 cm), and fine (<2.5 cm).

and solarization by covering logs with clear or black plastic in full sun. Both chipping and solarization decreased beetle emergence and boring activity compared to untreated control logs. Chipping was most effective for chip sizes <5 cm. Solarization was most effective using clear polyethylene sheeting during hot summer months, particularly August, when daily maximum temperatures were ≥35°C. Beetles persisted for 2 mo or more when solarization was applied during the spring or fall.

Jones, M.E. and Paine, T.D. 2017. Potential pesticides for control of a recently introduced ambrosia beetle (Euwallacea sp.) in southern California. Journal of Pest Science 106: 1–10.

Abstract: bifenthrin and imidacloprid were best in California.

Mendel, Z. (and 8 co-authors) 2012. An Asian ambrosia beetle Euwallacea fornicates and its novel symbiotic fungus Fusarium sp. pose a serious threat to the Israeli avocado industry Phytoparasitica 40: 235–238.

The ambrosia beetle, Euwallacea fornicates Eichhoff, was first recorded in Israel in 2009. The symbiotic fungus Fusarium sp., carried in mycacangia located in the anterior region of the female head, is responsible for the typical wilt symptoms inflicted on avocado (Persea americana Miller) trees. The beetle–fungus complex has become a serious threat to the avocado industry in Israel. Damage inflicted on avocado (Persea americana Miller) trees is caused by a novel, yet unnamed, symbiotic species within Clade 3 of the Fusarium solani species complex (FSSC; O’Donnell et al. 2008) which is vectored by the beetle. The adult and larva beetles feed on the fungal mycelium which is inoculated into the xylem and develops on the walls of the galleries tunneled in the sapwood by the beetle. This species appears to be a generalist and has been recorded from over 100 plant species comprising 36 families in Asia, where it is a major insect pest of tea (Camellia sinensis) in Sri Lanka.

Freeman, S. (and 7 co-authors). 2012. Obligate feed requirement of Fusarium sp. nov., an avocado wilting agent, by the ambrosia beetle Euwallacea aff. fornicata. Symbiosis 58: 245-251.

Abstract: The ambrosia beetle, Euwallacea aff. fornicata Eichhoff was first recorded in Israel in 2009. The symbiotic fungus Fusarium sp. nov., carried in the mandibular mycangia of the beetle, is responsible for typical wilt and dieback symptoms inflicted on avocado (Persea americana Miller) trees. The beetle-fungus complex has become a serious threat to the future of the avocado industry in Israel and elsewhere. When reared on Petri dishes, inoculated with 7-day-old cultures of the symbiotic Fusarium sp. nov., the beetle successfully completed its lifecycle and developed from egg to fertile adults in approximately 60 days. Galleries that were produced in the PDA medium by the adults, resembled those excavated in host plant xylem under natural host colonization conditions. Euwallacea aff. fornicata from avocado in Israel was not able to survive when fed with F. ambrosium but resulted in approximately 25% mortality when fed on F. solani; both isolates originated from infected tea. Likewise, the larvae of E. fornicatus from tea in Sri Lanka, were not able to survive or complete their lifecycle when supplied with a feed of the Fusarium sp. nov. isolated from avocado in Israel. Isolates of two other Fusaria, F. mangiferae from mango and F. oxysporum f. sp. melonis from melon, were not able to support development or survival of the beetle larvae from avocado from Israel, using the same Petri dish rearing method. This indicates that the Fusarium sp. nov. isolate from avocado is obligately required for the survival and development of Euwallacea aff. fornicata currently occurring in Israel, affecting this crop and additional hosts. The usefulness of the Petri dish assay to study the interactions between ambrosia beetles and their fungal symbionts is discussed.

Freeman, S. (and 7 co-authors). 2013. Fusarium euwallaceae sp. nov. – a symbiotic fungus of Euwallacea sp., an invasive ambrosia beetle in Israel and California. Mycologia 105: 1595-1606.

Abstract: The invasive Asian ambrosia beetle Euwallacea sp. (Coleoptera, Scolytinae, Xyleborini) and a novel Fusarium sp. that it farms in its galleries as a source of nutrition causes serious damage to more than 20 species of live trees and pose a serious threat to avocado production ( Persea americana) in Israel and California. Adult female beetles are equipped with mandibular mycangia in which its fungal symbiont is transported within and from the natal galleries. Damage caused to the xylem is associated with disease symptoms that include sugar or gum exudates, dieback, wilt and ultimately host tree mortality. In 2012 the beetle was recorded on more than 200 and 20 different urban landscape species in southern California and Israel respectively. Euwalla- cea sp. and its symbiont are closely related to the tea shot-hole borer (E. fornicatus) and its obligate symbiont, F. ambrosium occurring in Sri Lanka and India. To distinguish these beetles, hereafter the unnamed xyleborine in Israel and California will be referred to as Euwallacea sp. IS/CA . Studies proved that the Fusarium sp., which is cultivated in galleries by adult female Euwallacea sp. IS/CA for nutrition of the larvae and adults (Fig. ID), was responsible for the wilt and dieback on avocado in Israel and California. Results of rearing experiments also gest that the beetle-fungus mutualism is obligate.