Florida Landscaping Blog
The southern and tawny mole cricket are quite similar in appearance and biology.
The shortwinged mole cricket differs in appearance because of the short wings, but also in behavior because it has no calling song and the short wings render it incapable of flight. Typically, the eggs of these three species are deposited in April-May, and nymphs predominate through August. In southern Florida, however, the shortwinged mole cricket can produce eggs throughout the year.
Beginning in August or September some adults are found, but overwintering occurs in both the nymphal and adult stages. Maturity is attained by the overwintering nymphs in April, and eggs are produced at about this time. A single generation per year is normal, though in southern Florida there are two generations in southern mole crickets and an extra peak of adult flight in the summer, resulting in spring, summer, and autumn flights from the two generations.
In both southern and tawny mole crickets, adult emergence occurs earlier in southern Florida than in northern Florida.
Eggs: The eggs are deposited in a chamber in the soil adjacent to one of the tunnels. The chamber is constructed at a depth of 5 to 30 cm below the soil surface. It typically measures 3 to 4 cm in length, width, and height. The eggs are oval to bean-shaped, and initially measure about 3 mm in length and 1.7 mm in width.
The eggs increase in size as they absorb water, eventually attaining a length of about 3.9 mm and a width of 2.8 mm. The color varies from grey to brownish. The eggs are deposited in a loose cluster, often numbering 25 to 60 eggs. Duration of the egg stage is 10 to 40 days. Total fecundity is not certain, but more than 100 eggs have been obtained from a single female, and the mean number of egg clutches produced per female is 4.8
Three species of mole crickets were inadvertently introduced to the southeastern United States about 1900, and have caused serious plant damage.
The introduced species are: the shortwinged mole cricket, Scapteriscus abbreviatus Scudder; the southern mole cricket, Scapteriscus borellii Giglio-Tos (known until recently as S. acletus Rehn and Hebard); and the tawny mole cricket, Scapteriscus vicinus Scudder.
These are not the only mole crickets found in North America, but they are the most damaging. For example, a native species, the northern mole cricket, Neocurtilla hexadactyla (Perty), is widely distributed in the eastern states west to about South Dakota and Texas, and including southern Ontario, but is not a pest.
The European mole cricket, Gyllotalpa gryllotalpa (Linnaeus), has been introduced from Europe into the northeastern states, but is of minor significance. Changa, Scapteriscus didactylus (Latreille), invaded Puerto Rico from South America prior to 1800, and has caused considerable damage to crops on this island, but does not occur elsewhere in the United States.
In the years since introduction to the United States, the Scapteriscus spp. have expanded their ranges, but they differ considerably in their current distribution.
The shortwinged mole cricket, which is flightless, remains fairly confined to the southern Florida and southern Georgianortheast Florida introduction sites, though it also occurs in Puerto Rico and the Virgin Islands. It has been redistributed in southern Florida, but is largely found in coastal areas.
In contrast, the southern mole cricket is now found from North Carolina to eastern Texas, including the northern regions of Georgia and Alabama and the entire peninsula of Florida, and recently was detected in Yuma, Arizona. The tawny mole cricket is somewhat intermediate in its spread; it occurs from North Carolina to Louisiana, and throughout Florida, but thus far remains restricted to the southern coastal plain.