Gryllus bimaculatus De Geer

Weissman, David B., Gray, David A., Pham, Hanh Thi & Tijssen, Peter, 2012, Billions and billions sold: Pet-feeder crickets (Orthoptera: Gryllidae), commercial cricket farms, an epizootic densovirus, and government regulations make for a potential disaster, Zootaxa 3504, pp. 67-88 : 72

Gryllus bimaculatus De Geer

( Fig. 3 a, b)

Commonly called the two spotted cricket or, by European breeders, the black cricket, G. b i m a c u l a t u s apparently is the most widely distributed Gryllus species and is found from the tip of South Africa north into Europe and east as far as Thailand ( Otte & Cade 1984). This is a medium-large sized, short hind femur, usually pure black, short or long hind winged cricket with a shiny pronotum. Most males have a pale area ( Fig. 3 a) at the base of each tegmen where they attach to the pronotum. Adult females may be without or have a slight indication of pale tegminal areas ( Fig. 3 a). Brown males are known (see Fig. 3 b, and Otte and Cade 1984). Song with 2–6 pulses/chirp, usually 3–5 chirps/second, pulse rate 21–28 at 25°C. Table 1 presents morphological and song parameters measurements from examined localities.

G. bimaculatus is readily available in European pet food stores, and we recently discovered them for sale in San Diego, California (DBW personal observations). Because of an apparently broad ecological tolerance as indicated by its widespread distribution, we feel this taxon is more likely than G. locorojo n. sp., to become an established agricultural pest in the USA. Supporting our concern, Smit (1964:79) notes that G. bimaculatus “….feeds on many kinds of vegetables” and can “eat the bark off young fruit trees.” As Meissner & Ahern (2011) state: “This species [ G. bimaculatus ] is a quarantine pest in the United States and its introduction into the United States is unacceptable.” Yet the USDA has known that this San Diego, California, pet food store has been selling this cricket since late May/ early June, 2012, but has taken no action to date (as of mid-August, 2012). Since the larger, commercial supplier of this cricket is also unknown, it is likely that many more USA pet food stores are selling G. bimaculatus since most commercial dealers sell to many retail stores.

SPECIES teeth in file file length teeth/mm tegmina length tegmina width

G. locorojo (n=40) 150–189 3.0–4.0 44.7–52.9 13.4–16.4 3.9–5.0

G. bimaculatus (n=12) 115–162 3.5–5.2 31.0–34.7 14.7–19.1 5.0–6.5

G. bimaculatus 140–160

G. argentinus 159–205 4.16–5.1 36.5–45.6 13.6–16.6 5.05–6.35

continued.

SONG

SPECIES hind femur length cercus length pulses/chirp chirps/second pulse rate G. locorojo (n=40) 10.77–12.92 9.25–10.82 1–3 0.5–1.5 25.0–41.7 G. bimaculatus (n=12) 9.41–11.18 (2) 3–5 (6) 2.5–4.5 20.8–27.8 G. bimaculatus 3–5 3 26 –30 G. argentinus 11.1–13.05 2 (3) 1–2.5 17.5–22.7

continued.

FEMALES

SPECIES hind femur length cercus length ovipositor length SOURCE G. locorojo (n=40) 9.32–13.74 8.96–11.37 10.34–13.84 this report G. bimaculatus (n=12) 9.49–10.82 11.32–12.67 this report G. bimaculatus Otte & Cade (1984) G. argentinus Pinho Martins & Zefa (2011)

Figures

FIGURE 3. Gryllus bimaculatus. a. Adult male (left) and adult female (right) both from pet store, San Diego Co., California. Note shiny pronotums and prominence of “ bimacula ” areas (red arrow pointing to left macula) at base of tegmina, although typically less so in the female. b. Adult male, more unusual light colored phase with cream colored eyes, from pet store in France. DNA profiles of both these “ populations ” are shown in Fig. 6.