Pupal tongue

Look at larvae and pupae remains

When larvae and pupae killed by AFB dry out and turn to scale, their flat shape can make them difficult to identify. Remains of larvae can be especially hard to see, since the scale lies completely flat along the lower wall of the cell.

Remains of pupae are generally easier to identify, since a thin thread (which is the dried remains of the pupal tongue) can sometimes be seen pointing directly across the face of the cell, from the bottom angle to the top angle of the hexagon (Fig. 17 and 23).

 

 

Figure 17: Pupal scale with tongue
Figure 23: Infected pupa with tongue
stretched across the cell


Seeing a tongue, either in a moist, coffee-brown coloured sunken pupae (Fig. 23), or in pupal scale (Fig. 17), is a definitive diagnosis of AFB, since no other disease is likely to produce such a symptom.

The presence of a pupal tongue stretching across the cell can be used to reliably diagnose AFB.

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