Anisandrus maiche

Stark, 1936

Anisandrus maiche is an to East Asia that has established in North America and Europe. It is a significant pest of stressed trees in orchards, forests, and ornamental settings, boring into wood and cultivating symbiotic in galleries. The has been recorded in the United States since 2005, in Italy and Switzerland since 2021-2022, and was previously detected in Ukraine and European Russia. Its spread is facilitated by international transport of wood products and an inbreeding mating system that allows single females to establish new populations.

Anisandrus maiche by (c) Emily Franzen, some rights reserved (CC BY), uploaded by Emily Franzen. Used under a CC-BY license.

Anisandrus (10.3897-zookeys.768.24697) Figure 5 by Gomez DF, Rabaglia RJ, Fairbanks KEO, Hulcr J (2018) North American Xyleborini north of Mexico: a review and key to genera and species (Coleoptera, Curculionidae, Scolytinae). ZooKeys 768: 19-68. https://doi.org/10.3897/zookeys.768.24697. Used under a CC BY 4.0 license.

Xyleborini (10.3897-zookeys.983.52630) Figure 22 by Smith SM, Beaver RA, Cognato AI (2020) A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China. ZooKeys 983: 1-442.. Used under a CC BY 4.0 license.

Pronunciation

How to pronounce Anisandrus maiche: /ˈænɪsændrəs ˈmaɪkɛ/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Anisandrus maiche can be distinguished from the similar-looking Xylosandrus germanus by morphological examination; molecular identification using COI, 28S, and CAD markers confirms identity. All trapped specimens in European studies have been female, consistent with the haplodiploid system typical of Xyleborini . The species is smaller than many other ambrosia beetles and requires careful examination for reliable identification.

Images

Habitat

Found in managed and natural forests, apple orchards, and urban areas including school grounds. In orchard systems, captures are higher at orchard edges and near woodlots than in interior areas. Occupies forest interiors, forest edges, and orchard edges simultaneously. Attacks stressed and weakened trees across multiple .

Distribution

to East Asia; in United States (first recorded 2005 in Pennsylvania, established in Indiana, Michigan, New York), Canada, western Russia, Ukraine, Italy (first recorded 2021), and Switzerland (canton Ticino, 2022). In Europe, currently known from northern Italy and southern Switzerland with potential for further spread.

Seasonality

activity occurs primarily from June to mid-August in Switzerland, with trapping records from late May to mid-September in New York. In Michigan apple orchards, peak activity occurs between 961.2 and 1,102.9 above 10°C, later than Xylosandrus germanus. Can potentially infest stressed trees throughout the growing season.

Diet

Cultivates and feeds on , primarily Ambrosiella cleistominuta, in galleries bored into wood. The mutualistic fungus serves as the sole nutritional source for and .

Life Cycle

Development requires temperatures above 14°C; no development occurs at 10°C, with females surviving up to 8 weeks. At 14°C, only occasional production occurs. Complete development from egg to observed at 18°C, with eggs appearing at 2 weeks and all present by 8 weeks. is haplodiploid and inbreeding, with females producing offspring from stored sperm.

Behavior

Exhibits haplodiploid inbreeding system where single females can establish . Bores into trees to create galleries for fungal . activity is influenced by ethanol and fungal volatiles; attraction to ethanol-baited traps is reduced by benzyl alcohol, isobutyl alcohol, hexanol, methyl phenylacetate, phenethyl alcohol, and piperitone. Isoamyl alcohol repels during early flight period. Shows high fidelity to its mutualistic Ambrosiella cleistominuta.

Ecological Role

Acts as a for its nutritional Ambrosiella cleistominuta and potentially other including Fusarium lateritium, which may serve as a vector. Contributes to tree stress and dieback in invaded . Interspecific transfer of fungal symbionts has been observed with Xylosandrus crassiusculus in Switzerland, an unusual association given typical -fungus specificity.

Human Relevance

Listed as an EU associated with plants for planting and wood material . Causes in apple orchards through tree boring and fungal introduction, leading to continued stress, potential yield loss, and dieback. Subject to citizen science programs for early . Management relies on ethanol-baited bottle traps, which capture more specimens than sticky v-traps or delta traps with lower non-target bycatch.

Similar Taxa

Xylosandrus germanusCo-occurs in orchards and forests; similar but differs in (peaks earlier in season), distribution within regions (X. germanus more abundant near Lake Ontario, A. maiche more abundant in Finger Lakes), and slightly smaller size.
Cnestus mutilatusAnother Asian detected in same citizen science surveys in Italy; both are EU with similar invasion via wood products.
Xylosandrus crassiusculusOverlaps in distribution in Europe; unusual association documented in Switzerland where A. cleistominuta was found in X. crassiusculus galleries, suggesting potential for exchange between these .