PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 359 



When termites attack the new shoots of sugarcane the first visible 

 external symptom is the " dead heart." The termites begin to gnaw 

 in just at the base of the shoot and gradually eat into the centre, thus 

 destroying the growing point. Therefore the heart leaf dries quickly. 

 They may continue to eat and consume the entire base, detaching the 

 shoot entirely from the sett. Then the entire shoot dries and comes 

 out of the ground at the slightest pull. Cases are frequent when only 

 the shoots are attacked, leaving untouched the setts from which they 

 arise ; but more often the setts as well as the shoots are corroded. Older 

 canes with well-developed stems or even ripe canes are not immune, 

 as has been observed at Dacca and other places. Damage to grown or 

 ripe canes has so far been sHght at Pusa even in the Brickfield plots where 

 damage to new .shoots and setts has been severe. In this field the termites 

 were active from about March to July and what led to the stoppage of 

 their activity afterwards cannot be explained. We. propose to continue 

 our observations by growing sugarcane in the same field. 



Mole-crickets. 



The mole-crickets (Gnjllotalpa africana) are common underground 

 insects which usually frequent moist soils. They are very conmion 

 in the moist or rather wet sandy beds of the River Gandak where their 

 eggs can easily be collected. Eggs collected from this place have been 

 reared in the Insectary. The nymphs were fed wholly on live fly maggots 

 and they took about five-and-a-half months to come to the adult stage. 

 The life-history is illustrated in- Plate 22. Up to about fifty eggs are 

 deposited loosely in a cluster in a chamber specially formed at the bottom 

 of the hole. There does not seem to be any regularity of broods as all 

 stages of the insect are observable throughout the year. 



Gryllotalpa africana has been observed to cause rather serious damage 

 to new shoots of sugarcane at Pusa on two occasions, once about March- 

 April in-the JhiJIi field in 1913 and again about the same time of the year 

 in the Brickfield in 1918. In cultivated fields, the insect fives in under- 

 ground holes about two feet or more deep. It comes up and attacks the 

 new shoots of sugarcane much in the way somewhat diagrammatically 

 shown in Plate 23. The shoots are gnawed from the side at a point 

 above their junction with the sett, the gnawing being like a scooped-out 

 round hole with chewed-up fibrous margins and extending up to the core 

 of the stem. The tender base of the heart leaf is eaten. Therefore 

 the heart leaf dries and a " dead heart," characteristic of borers, is the 

 result. 



It is not easy to observe the mole-crickets in the act of gnawing the 

 shoots. Therefore the following corroborative experiment was carried 



