Trombidiformes 257 



10. Novotrombicula Womersley and Kohls, 1947 



Type. Novotrombicula owiensis Womersley and Kohls, 1947 



11. Oenoschongastia Womersley and Kohls, 1947 



Type. Oenoschongastia cana Womersley and Kohls, 1947 



12. Riedlinia Oudemans, 1914 



Type. Riedlinia coeca Oudemans, 1914 



13. 5<7z/mci/5 Lawrence, 1949 



Type. Sauriscus ewingi Lawrence, 1949 



14. Schongastia Oudemans, 1910 



Type. Thrombidium vandersandei Oudemans, 1905 



15. Tecomatlana Hoffmann, 1941 



Type. Teconiatlana sandovali Hoffmann, 1947 



16. Trisetica Traub and Evans, 1950 



Type. Trisetica melvini Traub and Evans, 1950 



V nassigned genus: 



Speotrombicula Ewing, 1946 



Type. Trombicula trifurca Ewing, 1933 (based on an adult) 



Discussion: Trombiculids are very similar in their behavior to trom- 

 bidiids. As nymphs and adults they feed on eggs and early larval in- 

 stars of small arthropods. The stages in their life history are the same 

 as those of trombidiids, with the exception that no trombiculid is known 

 to undergo postimaginal molts. The big difference in their behavior is 

 the host preference of the larvae. Trombiculids, with few exceptions, 

 e.g. Acomatacarus paradoxa Andre, parasitize terrestrial vertebrates 

 including man and his domestic animals. 



Larvae (chiggers or red-bugs) belonging to the genera Trombicula 

 and Schongastia are insufferable human pests in many parts of the 

 world. In the United States, T. (E.) alfreddugesi (Oudemans), T. 

 (E.) splendens Ewing, and T. (E.) batatas (Linnaeus) are responsi- 

 ble for an irritating dermatitis. Some individuals are immune from the 

 effects of these chigger bites, while others will develop a blister meas- 

 uring several inches across at the site of a bite. 



In the Orient, species of Trombicula (Leptotrombidium) are the 

 vectors of a rickettsial disease known as scrub typhus or tsutsugamushi 

 disease. This disease caused a total of over 7,000 casualties in the 

 United States armed forces during World War II. No estimates are 

 available as to how prevalent the disease is in natives of many areas. 



Trombiculids are not only pests and vectors of disease from one 

 animal to another but are also damaging parasites of economically 



