484 MEDICAL ENTOMOLOGY 



Before describing the blood-sucking species short reference will be 

 made to those bugs which are of interest to the parasitologist. 



FAMILY PENTATOMIDAE. 



This family, which is the largest of the Heteroptera, is usually 

 divided into fourteen subfamilies, each of which contains many genera 

 and species. Most pentatomids are remarkable for their beautiful 

 colouration, especially the species which belong to the subfamily 

 Scutelleraria ; those of the subfamily Tessaratominae, although usually 

 of more sombre colours, are often of considerable size. T, javanica, 

 the bug found on the soap-nut tree, is a large insect common in many 

 parts of India. It possesses large stink glands, secreting a strong 

 smelling fluid, which it can eject to a distance of several inches. 

 The subfamily Pentatominiae contains among others two species, 

 Erthesina fullo and Halys dentatus, which are naturally infected 

 with flagellates, the former with a species of herpetomonas and the 

 latter with a crithidia. The flagellate of Halys dentatus is another good 

 example of a typical crithidia which is parasitic in an insect which does 

 not suck blood. 



FAMILY LYGAEIDAE 



The bugs belonging to this family are of great economic importance, 

 as many of the species are very destructive to food plants. Lygaeids 

 are chiefly distinguished from coreids, to which they are closely allied, by 

 their antennae, which are inserted on the side of the head, and also 

 by the presence of ocelli. Most of the species are small, but they are as 

 a rule very active, and readily take to flight if an attempt is made 

 to catch them. 



Several of the species belonging to this family are infected with 

 flagellates. Oxycarenus laetus, which is common on the cotton plant in 

 Madras, is nearly always infected with a species of Herpetomonas. This 

 bug lays its eggs near the cotton seeds and all the stages may be found 

 collected together in the boll, feeding on the juice of the seeds. Lygaeus 

 pandarus (militaris), another lygaeid which is common on the milk plant, 

 Calotropis gigantea, is nearly always infected with Herpetomonas lygaei, a 

 flagellate which very closely resembles the parasite of Kala Azar. Lygaeus 

 hospes is infected with the same parasite. Nysius minor, a small bug 

 which lives on the latex juice of the common weed Euphorbia pihilifera 

 in India, is of peculiar interest, for it is in all probability the invertebrate 



