No. 1.] H. W. Peal—Two pests of the Indigo Plant. 43 



6. A PRELIMINARY REPORT ON TWO SERIOUS PESTS 

 OF THE INDIGO PLANT. 1 



By H. W. Peal, F.E.S. 



Assistant Entomologist, Indian Museum. 



Thanks to the pains-taking work undertaken by the late Mr„ 

 de NiceVille in Behar in 1901 a large number of the Lepidopterous 

 pests of Indigo have been discovered and in some cases worked up. 

 There are, however, in addition to these pests several others which 

 undoubtedly do great damage, at any rate in some districts. 



To mention some of the more important : there are several 

 species of grasshoppers, including some of the green long horned 

 species (Family Locustidse), a membracid (order Hemiptera), an 

 aleurodid (order Hemiptera), an aphid (order Hemiptera). Two 

 species of chrysomelid beetles (order Coleoptera'* and a cricket 

 {Gryllas sp. order Orthoptera) and a species of thrips (order Phy- 

 sopada). 



So far as my present observations go, judging from the amount 

 of damage done in the fields, the Chrysomelid beetles do but little 

 injury. 



The membracid and the aleurodid, though occurring on both 

 native and Natal plants, are without doubt primarily pests on the 

 latter, and though not excessively numerous, might, with the in- 

 creased use of Natal plant (which is probable), become serious here- 

 after. I have but little doubt that taken all round the various species 

 of grasshoppers are among the most serious of the insect pests on 

 indigo. They are not confined to any particular districts, occur 

 in the indigo fields in amazing numbers and are apparently regardless 

 of weather conditions, as I have found them abundant both during 

 the dry hot months and also during the rains. 



A cricket {Gryllus sp.) is very abundant in some of the indigo 

 districts. It forms burrows all over the indigo fields, sometimes so 

 thickly that several burrows occur in a square foot. Not only are 

 they destructive owing to their numbers but also because of the 

 habit they have of biting off the young indigo plants from near the 

 ground in order to feed on the leaves. 



In some districts (the southern ones) where the rainfall is either 

 late or scanty, the most serious pests undoubtedly are the Aphid and 

 the Thrips. 



1 This Report is the outcome of a tour paid by the Assistant Entomologist 

 to the Indigo Districts in May 1902. — Ed. 



