Neocurtilla hexadactyla (Perty) 1832

Frank, J. H. & McCoy, Earl D., 2014, Zoogeography of mole crickets (Orthoptera: Gryllotalpidae) in the West Indies, Insecta Mundi 2014 (331), pp. 1-14 : 2-3

Neocurtilla hexadactyla (Perty) 1832 [= Gryllotalpa hexadactyla Perty 1832 , = Gryllotalpa borealis

Burmeister 1838 (an old-established synonymy)]

This is the only mole cricket in the West Indies having four fixed tibial dactyls ( Fig. 5 ) in the West Indies to the present. West Indian adults have long flight wings ( Fig. 9 ). Many Florida adults have short flight wings and cannot fly ( Fig. 10 ). This species seems to be a very minor pest in the West Indies and Florida, perhaps because of its diet and habitat, neither of which is fully understood. The species’ distribution in the West Indies:

Trinidad and Tobago: Trinidad – 1906 ( Bruner 1906).

Grenada – 1893 ( Brunner von Wattenwyl 1893), see also Woodruff et al. (1998) and Frank et al. (2002).

St. Vincent – 1892 ( Brunner von Wattenwyl and Redtenbacher 1892).

Barbados – 1953 ( Tucker 1953).

St. Lucia – 1888 (specimen in NHM labeled Fort Castries St. Lucia W.I. Feb. 88, examined by J.H. Frank in September 2011 and identified as N. hexadactyla ).

Martinique – 2009 (Anon. 2009) a clear photograph, taken in October 2009 of a living adult of this species, undoubtedly many years after the arrival of the species in that island.

Dominica – 1899 (specimen in NHM labeled Dominica 99-119 examined by J.H. Frank in September 2011 and identified as N. hexadactyla ).

Guadeloupe – 1839 * ( Audinet Serville 1839), repeated by Saussure (1894).

Montserrat – 1904 ( Rehn 1905 as N. hexadactyla , based on a specimen collected there in 1904 by H. A. Ballou, now in ANSP, photographed there by J.A. Weintraub in 2010 and from the photograph confirmed as N. hexadactyla by J.H. Frank).

Antigua and Barbuda: Antigua – 1918 ( Caudell 1922); Barbuda – 1899 (specimen in NHM labeled Barbuda Gregory 99.164 examined by J.H. Frank in September 2011)

Puerto Rico – 1925-1926 (specimen in NHM labeled Porto Rico 1925-1926 H.E. Box, Pres. by Imp. Inst. Ent. Brit. Mus. 1930-336, examined by J.H. Frank in 2011, comments below).

Cuba – 1857 * ( Guérin-Méneville 1857) (also, Saussure 1874 reported that he had specimens of G. borealis from Cuba), see also Zayas 1974 for indication of its continued presence.

* Note that the records from Guadeloupe and Cuba stand out as being earlier than the others, thanks to

studies by European taxonomists.

Frank et al. (2007) found no evidence for the existence of Neocurtilla hexadactyla in Puerto Rico. Now we see (above) that a specimen exists. Its collector, Harold E. Box, was a British entomologist who moved to the New World tropics after spending years in East Africa. In 1925-1927 he was employed by Central Aguirre, a sugarcane plantation in southern Puerto Rico. Because of his employment history, it was natural that he would send unusual specimens to the Imperial Institute of Entomology in London. How was it possible that he would find a specimen of N. hexadactyla in Puerto Rico when thousands of other mole crickets examined in that island failed to produce one? Discounting the possibility of erroneous labeling, one possible explanation is an extraordinary weather event. Because adults are long-winged in most parts of the species’ range and can fly readily ( Frank et al. 2007), they are candidates for wind dispersal. The intense hurricane “San Liborio” entered the Caribbean at Martinique and then hit southern Puerto Rico on 23-24 July, 1926, killing 25 persons. The mole cricket found by Box may have arrived in Puerto Rico by wind-assisted flight from Martinique or nearby island. It seems that the species did not establish a population in Puerto Rico as a consequence (evidence in Frank et al. 2007). Extreme longdistance wind-assisted flight of Orthoptera is evidenced by desert locusts ( Schistocerca gregaria [Forskål]) found in Antigua, Barbados, Dominica, Martinique, St. Kitts, St. Lucia, St. Vincent, Trinidad and Suriname in October 1988 ( Kevan 1989, Ritchie and Pedgley 1989). After crossing the Atlantic, desert locusts also failed to establish a West Indian population.

Figures

Figures 5-8. Gryllotalpid dactyls. 5) Neocurtilla hexadactyla. Four fixed tibial dactyls. 6) Scapteriscus didactylus. Two fixed tibial dactyls separated at the base. 7) Scapteriscus abbreviatus. Two fixed and widely separated dactyls (the trochantal blade is broken off). 8) Scapteriscus imitatus. Two fixed tibial dactyls separated at the base.

Figures 9-14. Gryllotalpid habitus. 9) Neocurtilla hexadactyla. Habitus of an adult (from Grenada) with long flight wings. The cerci are prominent. 10) Neocurtilla hexadactyla. Habitus of an adult (from Florida) with short flight wings, barely protruding behind the tegmina. 11) Scapteriscus didactylus. Habitus of an adult (from Puerto Rico). 12) Scapteriscus didactylus. Habitus of a large nymph (from Trinidad) with short flight wings, darkly colored at the base, and dorsal to the tegmina before wing reversal. 13) Scapteriscus abbreviatus. Habitus of an adult (from Florida) with truncate apices of the tegmina. 14) Scapteriscus imitatus. Habitus of an adult (from Puerto Rico).