Caulophilus oryzae ( Gyllenhal, 1838 )

Friedman, Ariel-Leib-Leonid, 2023, A review of the saproxylic weevil subfamily Cossoninae (Coleoptera: Curculionidae) in Israel, Israel Journal of Entomology (Oxford, England) 52 (6), pp. 75-96 : 84-86

Caulophilus oryzae ( Gyllenhal, 1838)

( Figs 4, 5, 15, 30, 31)

Rhyncolus oryzae Gyllenhal, 1838: 1075 .

Rhyncolus lauri Gyllenhal, 1838: 1076 .

Cossonus pinguis Horn, 1873: 442 .

Caulophilus sculpturatus Wollaston, 1854: 315 .

Pseudomimus avocadi Folwaczny, 1972: 91 , n. syn.

Holotype: sex unknown ( SGN, not examined): Israel: Tel Aviv, leg. Bytinski.

Material examined: Israel: Central Coastal Plain : Gan Shemu’el, avocado plantation, 14.i.2018, PPIS (1 ex.), ibidem, 22.i.2018 (3 exx.); Ra’anana, vi.1967, H. Bytinski-Salz, ex Avocado (9 exx.); Southern Coastal Plain: Gan Shelomo, avocado plantation, 23.ii.2018, L. Friedman, ex seed of Persea americana (16 exx. adults + some larvae in alcohol) .

Distribution: Nearctic Region, introduced in Europe (described from Sweden) ( Gyllenhal 1838; Kuschel 1962; Whitehead 1982; Anderson 2002; Peck 2005; HlavÁČ & Maughan 2013; Alonso-Zarazaga et al. 2023).Although Alonso-Zarazaga et al. (2023) record it only from Spain, UK, Canary Islands and Madeira, it is most probably more widely distributed, if not cosmopolitan ( Whitehead 1991). First recorded from Israel by Friedman (2009).

Biology: This species develops in the rotten seeds of avocado ( Persea americana Mill. ) (Lauraceace); recorded from a large variety of stored commodities: rice, corn, pulses, mammy apple, cola nuts, yam tubers, ginger roots, seeds of various plants

Figs 30–31. Caulophilus oryzae , paratype of Pseudomimus avocadi Folwaczny, 1972 ( SGN): (30) habitus, dorsal view; (31) labels (both photographs courtesy Laura Marrero Palma, SGN) .

etc., although it definitely prefers avocado seeds ( Cotton 1921, 1922; Kuschel 1962; Whitehead 1982, 1991; Salas-Araiza et al. 2001; Anderson 2002). Considered as a stored product pest of low importance, it does not attack well-dried and previously undamaged stored products ( Whitehead 1982, 1991). In Israel, avocado plantations occupy approximately 7,000 hectares and an expected yield of almost 100,000 tons of fruit per year; 70 % of the plantations in the coastal area, and the remaining in the Yizre’el Valley, the Hula Valley and the Jordan Valley ( Dor 2023). Caulophilus oryzae occurs in all avocado plantations, but is completely overlooked by the agriculturalists, hence both adults, eggs, larvae and pupae stay unnoticed in the rotten seeds in the ripening fruit on the ground causing no damage.

Comments: Caulophilus Wollaston is a mainly Neotropical genus, composed of four fossil in Dominican amber ( Davis & Engel 2007) and 16 extant ( Kuschel 1962) species, four of them occurring in the Caribbean, and extending also also into the Nearctic Region (Northern Mexico, Southern USA) ( Kuschel 1962; Whitehead 1982; Salas-Araiza et al. 2001; Anderson 2002; Peck 2005). One of them, C. oryzae , is known as a pest of stored products and in particular of the seeds of avocado (!) ( Cotton 1921, 1922; Kuschel 1962; Whitehead 1982, 1991; Salas-Araiza et al. 2001; Anderson 2002). Caulophilus oryzae , the broad-nosed grain weevil, was described by Gyllenhal (1838: 1075) from Stockholm, Sweden, found damaging rice of unknown origin in merchant shops, and immediately redescribed by the same Gyllenhal (1838: 1076) under the junior synonymous name of Rhyncholus lauri ( Gyllenhal, 1838) from avocado seeds (!) from Mexico. Thus, this American weevil, even before being described, was already an invasive pest in Europe before the middle of the nineteenth century.

Pseudomimus Hartmann, 1904 was originally erected for P. corpulentus Hartmann, 1904 from Tanzania. Since then, several species from the western, central and eastern tropical Africa have been assigned to it ( Alonso-Zarazaga & Lyal 1999). Pseudomimus avocadi Folwazcny, 1972 was described by Bronislaw Folwazcny (1972) from a series of ten individuals from Tel Aviv, reared by the eminent Israeli entomologist Hanan Bytinski-Salz from the seeds of avocado. The series of nine above cited specimens, mostly teneral, labeled “ex Avocado, Ra’anana, c.l. vi.1967, Bytinski-Salz” has probably been reared together with the type series of Pseudomimus avocadi . The difference between the recorded localities (Tel Aviv and Ra’anana respectively) can be easily explained: either the avocado orchard was in Ra’anana and the weevils were reared in Tel Aviv, or Tel Aviv was used as a common denominator for both places (Ra’anana is located 16 km NE of Tel Aviv, in 1960s it was a small place, hardly appearing on a map). According to the labels (Fig. 31), the type series was previously studied by the famous weevil expert Edward Voss and then by Folwacny. The author of this paper speculates that both specialists were influenced by Bytinski’s ideas on the presence of Afrotropical elements in the Israeli entomofauna ( Bytinski-Salz 1961), and this misled them to misidentify the American Caulophilus as an African Pseudomimus . Unfortunately, they did not take into account the low probability that an Afrotropical species would attack specifically a Persea , the plant native to the Neotropical Region. Pseudomimus avocadi was never collected since its original description before being discovered by the author in rotten avocado seeds in 2018. Most of the attempts to find this species were concentrated in the Jordan Valley, the ‘Arava Valley and the Negev Desert, areas in Israel in which insects with Afrotropical affinities predominantly occur ( Bytinski-Salz 1961; Freidberg 1988; Friedman 2009, 2019). The weevils from the type series in SGN, and those from 1967 and from 2018 in SMNHTAU, are identical and perfectly fit the description of P. avocadi ( Folwaczny 1972) , and lead to Caulophilus and not to “ Pseudomimus ” in the key to the Palaearctic Cossoninae ( Folwaczny 1973).

Therefore, Pseudomimus avocadi Folwaczny, 1972 is here proposed as a new junior subjective synonym of Caulophilus oryzae ( Gyllenhal, 1838) . Note that Caulophilus belongs to the tribe Dryotribini LeConte , whereas Pseudomimus to the tribe Rhyncolini Gistel. Thus , this is not an Israeli endemic with Afrotropical affinities, but an invasive species of Nearctic or Neotropical origin.