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Henoticus Thomson, C.G., 1868







POLYPHAGA Emery, 1886

CUCUJOIDEA Latreille, 1802




H. californicus (Mannerheim, 1843)

H. serratus (Gyllenhal, 1808)

Henoticus serratus (Gyllenhal, 1808)

This species is Holarctic in distribution; it occurs from Europe to the far east of Russia, it is widespread in North America and has been recorded from Hawaii. In Europe it is locally common from lowlands to about 1600 m from the Pyrenees to Northern Italy and the Balkans and north to the UK, Belgium and the far north of Fennoscandia. The UK distribution includes most of England and Wales north to the Humber but it tends to be sporadic and very local; it is generally absent from the West Country but more frequent in south eastern England, East Anglia and Merseyside, and there are a few records further north to Southern Scotland and from Ireland. Adults are present year-round, overwinter among decaying vegetation or under bark and are active from April until August or September, peaking in abundance during June and July. They visit a wide range of flowers in the spring, often hawthorn and other blossom, and they are sometimes common on willow catkins. More generally they occur in a wide range of habitats among compost and decaying leaf-litter, under loose and mouldy bark in both deciduous and coniferous woodland and wooded parkland, and among decaying fungi. Adults fly well and in Northern Europe they are early colonizers of recently burned woodland, they often occur under the bark of fire damaged or killed trees and are known to actively spread both arboreal and terrestrial fungal spores via paired prosternal and mesosternal mycangia. Little is known of the biology but the species is likely to be mycophagous and univoltine, with breeding occurring in the summer and winter spent in the adult stage. Adults may be sampled at any time by sieving or taking likely samples for extraction, they may be beaten from blossom etc. in spring and early summer and they sometimes appear in flight-interception traps placed in trees.

Henoticus serratus 1

Henoticus serratus 1

© U.Schmidt

Henoticus californicus

Henoticus californicus

@ Georges Pelletier, Canadian Forestry Service, Quebec City, Canada

Henoticus serratus 2

Henoticus serratus 2

© Lech Borowiec

1.8-2.3 mm. Elongate and discontinuous in outline with the head narrower than the pronotum and the pronotum narrower than the rounded elytra. Dorsal surface finely and randomly punctured and with fine pale and overlapping pubescence throughout. Body shiny, dark grey to black, sometimes with anterior and/or lateral pronotal margins narrowly paler, appendages pale brown, often with the femora, tibial apices and antennal clubs darker. Head transverse, broadest across prominent and coarsely-faceted eyes and narrowed and produced anteriorly to a rounded apical margin, vertex, frons and clypeus continuous and almost flat. Antennae inserted laterally in front of the eyes, 11-segmented with a loose 3-segmented club. Pronotum transverse, broadest behind the middle and with sharp, backward-facing teeth (which may become worn in older specimens) along the entire lateral margins, anterior margin rounded and basal margin more-or-less straight between obtuse angles. Surface evenly convex across the disc, with a variously developed but often indistinct sub-lateral line, and with a distinct fovea either side near the basal margin. Elytra evenly curved from rounded shoulders to a continuous apical margin, surface not striate but with a (sometimes very fine) sutural stria which tends to be deepened towards the apex. Legs long and slender, femora unmodified, tibiae only weakly broadened from the base and without obvious apical spurs. Tarsi 5-5-5 in females, 5-5-4 in males, all segments simple. Claws only very weakly toothed at the base.

Henoticus californicus (Mannerheim, 1843)

Probably indigenous to the Western United States and Mexico, this species has been spread to various parts of the world with the international trade in foodstuffs and is now widely established although in temperate regions it is synanthropic and generally unable to survive through the winter. The species has been recorded sporadically throughout the Holarctic and Oriental regions and there have been occasional records from Australia, New Zealand and South America but again always with imported foods and never becoming established in the wild. Most European records have been from western and northern countries, from France to Sweden and Finland, and most are from stored foods although very occasionally it appears outside among decaying vegetation. In the UK it is exclusively synanthropic, occurring among or near to stored foods, but it is very infrequent and most records are from commercial premises where monitoring is more likely to occur. Adults might occur at any time of year and in any appropriate situation, the majority of records are from vegetable foodstuffs with a low moisture content and they may appear in sealed bulk containers where the food has been insufficiently dried and so can develop fungal spores. Little is known of the biology but both adults and larvae are thought to feed exclusively on fungal hyphae and spores and females have been observed laying batches of eggs directly into mouldy host material. Although infestations tend to be rare in temperate regions, adults usually occur in numbers and may form large swarms when they disperse by flight.

2.0-2.4mm. Elongate-oval and discontinuous in outline, body pale to dark brown, appendages a little paler, dorsal surface finely and moderately densely punctured and with fine creamy pubescence throughout. Head widest across asymmetrically convex eyes and rather strongly narrowed to a rounded anterior margin, vertex and frons flat or slightly concave and without sculpture or distinct impressions. Antennae inserted laterally in front of the eyes; 2 basal segments expanded, 3-8 elongate and 9-11 form a loose and gradual club. Pronotum transverse, widest towards more-or-less rounded posterior angles and narrowed to a curved apical margin, lateral margin with sharp, backwardly developed teeth (which may be worn in older specimens) throughout. Pronotal disc rather flat, laterally depressed and with a fine line parallel to the margin (sometimes effaced anteriorly), surface usually uneven towards the base and with a variously-developed depression either side joined by a narrow impressed line. Scutellum widely-transverse and almost continuously curved. Elytra evenly curved from rounded shoulders to a continuous apical margin, surface usually less densely and a little more finely punctured than the pronotum, without striae but with a fine sutural impression that is often effaced towards the apex. In fresh specimens the dorsal pubescence is even and recumbent but this may become very uneven during life, especially on the elytra. Legs long and slender with unmodified femora and tibiae only slightly broadened from the base. Tarsi 5-segmented in females, 5-5-4 in males, all segments simple. Claws smooth and only weakly toothed at the base.

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