[Reprinted from the Indian fownal of Entomology,Yol.32, No. 2,pp. 145-l5l ;1970.1
p BIONOMICS OF T,HIACIDAS POSTICA WALKER (LEPIDOPTERA: NOCTUIDAE), A PEST OF ZIZYPHUS MAURITIAII,4 LAMARCK B. P. MEHnA AND B. N. Snn Indian Lqc Research Institute, Namkum, Ranchi Zizyphus mauritiana Lamarck (Rhamnaceae), ber, is an economically important species and also one of the major lac-host trees for the cultivation of Rangeeni, and sometimes Kusmi, lac. Thiacidas postica Walker is the most fre- quently occurring defoliator on this plant. Only two species, namely, Thiacidas postica and T. villis Wlk. have been tecorded from India (Hampson, 1892). T. postica has so farbeen recorded onZizyphus spp. only, most common of which t (Hampson, 1905; Lefroy, 1909; is Z. mauritiana Fletcher. l9l7 and l92l; Ayyar, 1940; Sevastopulo, 1940; Gardner, l94l; and Basha, 1952), while Norris, Glover and Aldis (1934) and Glover (1937) recorded it onZ. xylopyra and Z. mauritiana and Wiltshire (1964) on Z. spinachristi. Sah (present co-author) observed it on Z. oencplia M.ill., Z. mauritiana and Z. xylopyra at Mirzapur in 1966. The first and second instar larvae feed in groups on the soft tissue of tbe leaf, leaving the papery epidermal tissue. The later instar larvae feed singly starting from the margin and eating the whole lamina including the veins. During serious infestation they defoliate whole trees and retard their growth; young plants suffer most (Figs. I and 2).
Systematic position Hampson (1892), Dudgeon (1901), Lefroy (1909) and Swinhoe (1903) placed T. postica in Later, Hampson (1905) included it in Lascio- campidae bu it in Lymantriidae. Collenette (1935) was the first to p idas Walker 1855, Type I. postica Walker 1855, was a noctuid and that it was wrongly included in Lymantriidae. This rvas not taken note of by Sevastopulo (1940) and Gardner (1941), who continued to include it in Lymantriidae. Gardner (1946), however, accepted Collenette's inclusion of Thiacidas in the Acronyctinae on the basis of the larval structure. Gardner (1948) again examined the Genera Acronicta Treitschke, Diphthera Treitschke, Simyra Othsenheimer and Thiacidas Walker and included them in the subfamily Acronic- tinae. (cf. spelling in Gardner, 1946) of the family Noctuidae with the staternent that the larvae of this subfamily have a considerable resemblance to Lymantriidae but lack the mediodorsal glands on 46 and A, of that family. Wiltshire (1964) included this species in the Noctuidae.
Life History and Description of Stages The pest was collected in the larval stages fram Z.mauritianq trees and reared on their leaves in giass dishes 10.0 cm in diameter and 5.0 cm deep, I covered with wire-netting. A pair of adult male and female moths was introduced in a battery jar, l0 cm. in diameter and 30 cm deep, containing green twigs of the food plant and paper strips for egg laying.
1. Pre-oviposition and oviposition periods and fecundity : The pre-oviposition period was observed to be 2.0 days and oviposition period 4-5 days. Copulation continued for l0-12 hours at any time during the day 146 B. P. MnHnA AND B. N. S.rn or night. -126, glued together, were deposited d.uring the supplied for the purpose and some_ times on the field were generaily found on the ventral sur twigs. The numbei of eggs laid varied from 318-7 October and minimum dir:ing November to June.
2. Descriptiori of various stages and their period of development : with pole raised the upper tudina n white, raised,_ longi- circle, Pole and end in a baskei ?sures 0.68 mm ,""f9ff:,til.'"*t'f,TnT: genera the day. The incubation period wai found
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t'n' t (b) Mature larva of r. postica. (c) Female [1,0".%? F.[;!,?i,,,."".
ssed through six to eight instars; seven tember to November 1961, six instars 62, June to September 1967 in the generation during n all the instars are nearlv been described in detail e in the other instars are mentioned. I
Fig. 1. f nfestation ol Z. mouritiana lree by T. postica, Ir'=
Fig. 2- Z. mauritiano tree denuded by T. postica. Bionomics of Thiacidas postica t47
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r rr 6 oo .9P I \o€ o\ o\ 5 5 5{ \o \o@ d;ood: qN oi O\o d;++t b c.l r$r \o \o 5'j9_o i \\O\ o\ {o\ Bionomics of Thiacidas postica l4g .- T4. newly_hatched larva has a black head with short, thinly and evenly distributed setae. The prothorax is black, depressed in the centre, with anterior margin green posterior dirty and creamy. - Legs ar_e light brownish; abdomen creamy with ten segments and five pairs of prolegs on the abdominal segments 3 to 6 ani 10. Long white setae of over the thorax and abdomen. a pair of long pale brown s four on the abdominal segmeni g and a pair on segment k and upper half white. The larva measures 1.6 mm in length. This instar lasts 2-8 days. fr _ The p_rothorax of the second instar larva is creamy, with the middle portion e\ black. Two long.and black setae are present onthe abdominal segment l and three I on segment 8. The larva measures 2.6 mm in length. This instar-lasts 2-8 days. The abdomen of the third instar larva is yellowish with reddish tubercles bearingwhite_setaeofvarioussizes. Twolongandblacksetaeare present on the metathorax, four on the abdominal segment 8 and two on segrnenl 9. The larva measures 6.5 mm in length. This instar lasts 2-9 days. bec ; #i'fl"J;ffi:Jil ll:,lxj;, pro the abdominal segments l, 9 and 10."l?fl: Six tub )en on each somite. Nine pairs of elliptical spiracles with black margins are present on the prothorax and abdominal segments 1 to 8. The larva measures 11.0 mm in length. This instar lasts 2-8 days. The fifth instar larva measures 21.0 mm in length. This instar lasts2-13 days. Ground colour of the body of the sixth instar larva (Fig. 3b) is white above and pale yellow beneath. A variable dorsolateral band of dark colour is present on each side from the prothorax to the last abdominal segment and reddish tufts of hair on abdominal segments I to 8. The larva measures 24.8mm in length. This instar lasts 2-19 days. The seventh and eighth instar larvae have a white fleck on either side near the ocelli; setae of the head rather long and few. Prothorax is without lateral pencils and abdominal segments I to 4 without dense compact tufts. Body setae rather long, fine not conspicuously branched and mostly uhite but a few longer, thicker and black setae are present. Spiracles are large and eiliptical. with biack margins. Ground colour of skin is white above and pale yellow beneath, both with some mottling; a variable dorsolateral band along each side is usually darker with some blackish mottling. Legs are testaceous; prolegs pale green with some testaceous externally. Gardner (1941) has described a mature larva in greater details. The mature or final instar larva measures 30.0 mm in length soon after moulting 43.4 mm just pupation. -v3 and before The seventh instar lasted 4-13 days in 1962 and 3-7 days in 1968, while the eighth instar 4.0 days both 1n 1962 and 1968. fi Total larval period was found to be 16-55 days. (iiil Prepupa.' The mature larva passes throrlgh a prepupal stage, when it stops feeding and wanders restlessly in the breeding cage. The colour of the larva gradually changes to pale yellow, all the hairs are shed and the length is reduced. It then makes a tough cocoon of white silken threads reinforced with bits of leaves and hairs shed by it, and rests inside it. Finally jt rnoults into a pupa. In the field, pupation takes place in the folds of the leaves fallen on the ground. The prepupal stage usually lasts 3-26 days, but a somervhat longer period Iasting3T-56dayswasobservedinall examples of the two generations of 1967. 150 B. p. MrsnA AND B. N. Sns
An unusually long duration lasting 125 a of the generation reared from Novemb larvae collected on 4.11.1964 remained in 14.11.1964 ro 10.6.1965. This ohenom (1964), who found many of the autunrna calls, prepupal coma in the cocoons in Ba (iv) Pupa (Fig. 3 c) : The gene for the thoracic segments which are dark on tlre abdominal segments 2 to 7. cremasters. Apparently there is no d J pupae except the size ; male being smaller Iasts 7-39 days. .tr (v)_ Adult Head, thorax, . _ .' abdomen and fore-wing are greyish-brown with black double lines on fo-re- and hind-wings. It has beei des&iu.o i" a.tu;i uy HaTpson (1892). The longevity was found to be 2-9 days for male and z-s Jay's for females. 3. Seasonal history : _usually overlap. The active period h the larvae have also been reCorded tions could be reared in the laboratorv_ mid-May, second from end of June io o end of October and fourth from end tion resulting from the eggs laid in Some. ra-rvae of this generation went into o*on"'Jjii:'i"tiilot:;.lt:u"I, Yil:.n; only in June. Natural Enemies A^b-raconid, two ichneumonids and a chalcid were reared in the laboratory from the field-parasitised material. (t) Apanteles taprobanoe Cam. site of the third and fourth instar lar immediately on emerging from the host b 9qn_e-rq9-f1om the pupa. Field parasitism 1963 (107 larvae collected and 26 found 1964 ll45 larvae collected and 32 found p
(ii usus lus sp. (lchneumonidae) were found as of rh oeceinbei 1964. Tht6r;;iti; -l larvae, on the ho and hung themselves from the lur branch of e help J (iii) Brachvmeria. sp. (chalcididae). Five specimens energed from the mature larvae of the pest in December 1964 and four-specimens as f,yp.rparutlt.i from C. obtusus Moil. Sutvttll.cny . .Thiacidas postica Walker has been recorded as a defoliator of ber, Zizyphus mouritiana Lamarck. It is active during March to November, after *6icir' tfri activity is retarded due to cold. Tbe life-history and various ,tug." of c.;;ilry-;;i Bionomics of Thiacidas postica l5t have been described. There are fiv its life-cycle in 36-214 days. Some some 208 days in prepupal coma in the Cam.), two ichneumonids (Charops a clraicid (Brachymeria sp.) have been re The chalcid was also recorded as a hyper
AcrNowtnocEMENTS The authors are grateful to Dr. G. S. Misra, Director, for providing facilities, and to Dr. A. Bhattacharya, Entomologist, for his helpfut briticisml Thanks are also due to Mr. K. s. Pradhan and fur. G. S. Arori, Zoological Survey of India, for identifying the moth, to Messrs R. G. Fennah, G. J. Keirich }"d 9. E. J. Nixon, commonwealth Institute of Entomology, London, for identify- ing.the parasites and to IuIt.R.L. Singh, Artist and photographer, for the diagrams and photographs appearing in this paper. RrnenrNcns Ayyar, T. V. R. 1940. Hand Book of Economic Entomology for South India. Superintendent, Govenrment Press, Madras.321 pp. Basha, J. M. G. 1952. Experiments on the control of the fruit borers of jujube lZizyphus spP.), Carpomlavesuviana Costa and Meridarchis scyrodes Meyr. in- South lndia. Indian J . Ent. 14 :, 229-238- Collenette, C. L. 1915. Genera and rypes of the Lymantriidae (Heterocera). Stylops. 4 : 241-246. Dudgeon, G. C. 1901. A catalogue of the Heterocera of Sikkim and Bhutan. J. Bombav nat. Hist. Soc. 13 : 4O6-425. Fletcher, T. B. 1917. Rep. Proc. Second ent. Meet. Pusa.1917 :253. Flercher, T. B. 1921. Annotated list of lndian crop-pests. Bull. agric. Res. Inst. Pzsa. No, 100 : 46 pp. Gardner, J. C. M. 1941. Itnmature stages of Indian Lepidoptera (3,,. Indian Forest Rec. (New Series) Ent. 6 (9t :299-314. Gardner, J. C. M. 1946. On larvae of Noctuidae (Lepidoptera) .l. Trans. R. ent, Soc. Lond.96: 6I_72. Gardner, J: C._M_.^ 1918. On larvae of the Noctuidae (Lepidoptera). IV. Trans. R. ent. Soc. Lond. 99 : 291-3 I 8. Glover, P. M. 1937. Lac Cultivation in India. Indian Lac Research Institute. Namktrm, Rancbi. ll9 pp. Hampson, G. F. 1892, The fauna of British India, London. Moths. 1 :445-446. Hampson, G. F. 1905. The moths of India. Supplementary Daper to the volumes in "The Fauna of Brirish India" Series III. part lIl. l. noinb:ay nat. Hist. Soc. 16: r93-216. Lefroy, H. M. 1909. Indian Insect Life. Thacker Spink and Co., Calcutta and Simla. 459 pp. Mehra, B. P. 1956. Annotated list of some of the insect pests of host trees of lac and their control. Bull. Indian Lac Res.1nsr. No. 88 : 6. Norris, D., Glover, P. M. and Aldis, R. W. 1934. Lac and the Indian Lac Research Institute, Namkum: 53 PP. Sevastopulo, D. G. 1910. On the food-plants of Indian Bombyces (Heterocera). J. Bombay nat. Hist. Soc. 4l : 817-827. Swinhoe. C. C. 1903. A revision of the world Lymantriidae in the national collection. Trans. R. ent. Soc. Lond. 5l : 461. Wiltshire, E. P. 1964. The Lepidoptera of Bahrain. J. Bontbay nat. Hist. Soc.6l: ll9-141.
(Revised ms. receited : 5-12-1969)