4 1 o TachardiincE. 



upon its floor — from five to seven conical circular pits. At the fundus of 

 each pit is a single larger pore communicating with a short cylindrical duct 

 ^fig' 6). At the base of each process is a large trumpet-shaped spiracle ijig. 4), 

 the orifice of which is surrounded by an irregular chain of ceriferous pores. 

 The ventral spiracles are of similar form and structure, but much smaller. The 

 dorsal spine {fig. 7) is stout, broad at the base and tapering gradually to the 

 apex ; there are one or more small denticulations on each side of the 

 basal area ; the spine is placed on the summit of a longish, slender, fleshy 

 tubercle. The caudal process, in this species, remains soft and pliable, and 

 does not exhibit any definite segmentation ; its extremity, however, is densely 

 chitinous and is surrounded by a laciniate fringe which is incomplete on the 

 venter {fig. 3) ; the ten anal setse spring from clusters of ceriferous pores on a 

 broad chitinous ring. An interrupted series of small globular groups of pores 

 surrounds the base of the caudal process. Antennas minute and inconspicuous ; 

 each consisting of a small chitinous tubercle, with irregularly truncate apex 

 bearing a few stout bristles. Mouth parts small ; but the post-oral lobes are 

 comparatively large and well-defined. Length of mature insect (under com- 

 pression) averaging 5 mm. 



The nymphal insect can be distinguished from the early adult female by the 

 absence of the dorsal spine ; the body is more depressed and the stigmatic 

 processes are sessile ; otherwise the structural characters are similar to those 

 of the adult. The covering of lac is comparatively thin ; the individual tests 

 are small and of the symmetrical form described above {see fig. 11). 



The adult male may be either winged or apterous. In the winged form, the 

 thoracic segments are broad and strongly developed, to give attachment to the 

 muscles actuating the long hyaline wings which have an expanse (according to 

 Imms) averaging 4"5 mm. The thorax, in the apterous form, is little or no 

 broader than the base of the abdomen and remains soft and undeveloped. 

 Both forms are of a bright crimson colour, and are provided — at the posterior 

 extremity — with a long-pointed penial sheath and a pair of slender white 

 filaments which are twice or more the length of the actual body of the insect. 

 The antennae are normally ten-jointed ; but it has been observed by Dr. Imms 

 that — in the apterous form — the number is frequently reduced to nine. The 

 head bears four prominent black ocelli, of which one pair has a ventral and 

 the other a dorsal aspect. Length (including penis) 175 mm. 



Habitat. The list of plants upon which Tachardia lacca occurs naturally, or 

 upon which it has been cultivated in India, is a long one, including nine species 

 of Ficus, three of Dalbergia, three of Grewia, two each of Bufea, Zizyphus^ 

 Albizzia, Acacia and Shorea, and single species of the genera Sckleichera, 

 Ougenia^ Xylia, Prosopus, Cajanus, Kydia, Piihecolobtum, Cassia, Diptcro- 

 carpus, Peniacine, Tamarindus, Garuga, Strebliis and Ccesalpinia ; but by far 

 the more usual host plants appear to be (in the order named) Buteafrondosa^ 

 Zizyphus jujuba, Schleichera trijuga and Ficus religiosa. 



The species is not indigenous in Ceylon, but has been introduced and 

 successfully established within the last few years ; but has never produced such 

 profuse incrustations of lac as it does in India. 



My description and figures have been drawn up partly from Indian and 

 partly from Ceylonese examples. 



Tachardia lacca is the source of the commercial shellac that is used so 

 largely in the composition of varnishes, French polish, sealing wax, &c. A 



