Allantoin and allantoic acid titre in the faeces and tissues of the developing larva of the moth, Orthaga exvinacea Hampson.

Allantoin and allantoic acid are investigated in the faeces and tissues of the developing sixth instar larva of the moth, Orthaga exvinacea. The nitrogen excreted as allantoin and allantoic acid is compared with nitrogen excreted as uric acid and ammonia. The larva excretes 2.35-5.14 mumol/g allantoin and 0.74-1.34 mumol/g allantoic acid which account for 0.83 to 2.39% and 0.23 to 0.53%, respectively, of the excreted total nitrogen. Allantoin and allantoic acid are found to be minor nitrogenous end-products of the larva. Allantoin and allantoic acid are also present in the haemolymph and fat body of the larva in varying concentrations. The level of allantoin in the haemolymph shows a negative correlation with the allantoin concentration of faeces and fat body. The allantoin is found to be stored in the fat body at a low level. The results of the present study also indicate the coexistence of uric acid storage and uricolysis.

Invertase activity in the gut of 6th instar larvae of Spodoptera mauritia Boisd. (Noctuidae, Lepidoptera).

Invertase activity has been studied in the fore-, mid- and hindgut of the 6th instar larva of Spodoptera mauritia. The highest activity was in the midgut except during the early hours of the larva period when the foregut showed comparatively increased activity. The hindgut invertase activity may be from the voiding of enzyme along with the undigested food.

The excretion of urea by the larvae of Spodoptera mauritia Boisd. (Noctuidae: Lepidoptera) during development.

The concentration of urea in the excreta of the 6th instar larvae of Spodoptera mauritia varies from 4.017 +/- 0.541 to 31.052 +/- 1.193 mumoles/g dry excreta (mean +/- SE). The observation confirms that urea excreted is of metabolic origin.